--- /dev/null
+;========================================================\r
+; MODEX.ASM - A Complete Mode X Library\r
+;\r
+; Version 1.04 Release, 3 May 1993, By Matt Pritchard\r
+; With considerable input from Michael Abrash\r
+;\r
+; The following information is donated to the public domain in\r
+; the hopes that save other programmers much frustration.\r
+;\r
+; If you do use this code in a product, it would be nice if\r
+; you include a line like "Mode X routines by Matt Pritchard"\r
+; in the credits.\r
+;\r
+; =========================================================\r
+;\r
+; All of this code is designed to be assembled with MASM 5.10a\r
+; but TASM 3.0 could be used as well.\r
+;\r
+; The routines contained are designed for use in a MEDIUM model\r
+; program. All Routines are FAR, and is assumed that a DGROUP\r
+; data segment exists and that DS will point to it on entry.\r
+;\r
+; For all routines, the AX, BX, CX, DX, ES and FLAGS registers\r
+; will not be preserved, while the DS, BP, SI and DI registers\r
+; will be preserved.\r
+;\r
+; Unless specifically noted, All Parameters are assumed to be\r
+; "PASSED BY VALUE". That is, the actual value is placed on\r
+; the stack. When a reference is passed it is assumed to be\r
+; a near pointer to a variable in the DGROUP segment.\r
+;\r
+; Routines that return a single 16-Bit integer value will\r
+; return that value in the AX register.\r
+;\r
+; This code will *NOT* run on an 8086/8088 because 80286+\r
+; specific instructions are used. If you have an 8088/86\r
+; and VGA, you can buy an 80386-40 motherboard for about\r
+; $160 and move into the 90's.\r
+;\r
+; This code is reasonably optimized: Most drawing loops have\r
+; been unrolled once and memory references are minimized by\r
+; keeping stuff in registers when possible.\r
+;\r
+; Error Trapping varies by Routine. No Clipping is performed\r
+; so the caller should verify that all coordinates are valid.\r
+;\r
+; Several Macros are used to simplify common 2 or 3 instruction\r
+; sequences. Several Single letter Text Constants also\r
+; simplify common assembler expressions like "WORD PTR".\r
+;\r
+; ------------------ Mode X Variations ------------------\r
+;\r
+; Mode # Screen Size Max Pages Aspect Ratio (X:Y)\r
+;\r
+; 0 320 x 200 4 Pages 1.2:1\r
+; 1 320 x 400 2 Pages 2.4:1\r
+; 2 360 x 200 3 Pages 1.35:1\r
+; 3 360 x 400 1 Page 2.7:1\r
+; 4 320 x 240 3 Pages 1:1\r
+; 5 320 x 480 1 Page 2:1\r
+; 6 360 x 240 3 Pages 1.125:1\r
+; 7 360 x 480 1 Page 2.25:1\r
+;\r
+; -------------------- The Legal Stuff ------------------\r
+;\r
+; No warranty, either written or implied, is made as to\r
+; the accuracy and usability of this code product. Use\r
+; at your own risk. Batteries not included. Pepperoni\r
+; and extra cheese available for an additional charge.\r
+;\r
+; ----------------------- The Author --------------------\r
+;\r
+; Matt Pritchard is a paid programmer who'd rather be\r
+; writing games. He can be reached at: P.O. Box 140264,\r
+; Irving, TX 75014 USA. Michael Abrash is a living\r
+; god, who now works for Bill Gates (Microsoft).\r
+;\r
+; -------------------- Revision History -----------------\r
+; 4-12-93: v1.02 - SET_POINT & READ_POINT now saves DI\r
+; SET_MODEX now saves SI\r
+; 5-3-93: v1.04 - added LOAD_DAC_REGISTERS and\r
+; READ_DAC_REGISTERS. Expanded CLR Macro\r
+; to handle multiple registers\r
+;\r
+ \r
+ PAGE 255, 132\r
+ \r
+ .MODEL Medium\r
+ .286\r
+ \r
+ ; ===== MACROS =====\r
+ \r
+ ; Macro to OUT a 16 bit value to an I/O port\r
+ \r
+OUT_16 MACRO Register, Value\r
+ IFDIFI <Register>, <DX> ; If DX not setup\r
+ MOV DX, Register ; then Select Register\r
+ ENDIF\r
+ IFDIFI <Value>, <AX> ; If AX not setup\r
+ MOV AX, Value ; then Get Data Value\r
+ ENDIF\r
+ OUT DX, AX ; Set I/O Register(s)\r
+ENDM\r
+ \r
+ ; Macro to OUT a 8 bit value to an I/O Port\r
+ \r
+OUT_8 MACRO Register, Value\r
+ IFDIFI <Register>, <DX> ; If DX not setup\r
+ MOV DX, Register ; then Select Register\r
+ ENDIF\r
+ IFDIFI <Value>, <AL> ; If AL not Setup\r
+ MOV AL, Value ; then Get Data Value\r
+ ENDIF\r
+ OUT DX, AL ; Set I/O Register\r
+ENDM\r
+ \r
+ ; macros to PUSH and POP multiple registers\r
+ \r
+PUSHx MACRO R1, R2, R3, R4, R5, R6, R7, R8\r
+ IFNB <R1>\r
+ PUSH R1 ; Save R1\r
+ PUSHx R2, R3, R4, R5, R6, R7, R8\r
+ ENDIF\r
+ENDM\r
+ \r
+POPx MACRO R1, R2, R3, R4, R5, R6, R7, R8\r
+ IFNB <R1>\r
+ POP R1 ; Restore R1\r
+ POPx R2, R3, R4, R5, R6, R7, R8\r
+ ENDIF\r
+ENDM\r
+ \r
+ ; Macro to Clear Registers to 0\r
+ \r
+CLR MACRO Register, R2, R3, R4, R5, R6\r
+ IFNB <Register>\r
+ XOR Register, Register ; Set Register = 0\r
+ CLR R2, R3, R4, R5, R6\r
+ ENDIF\r
+ENDM\r
+ \r
+ ; Macros to Decrement Counter & Jump on Condition\r
+ \r
+LOOPx MACRO Register, Destination\r
+ DEC Register ; Counter--\r
+ JNZ Destination ; Jump if not 0\r
+ENDM\r
+ \r
+LOOPjz MACRO Register, Destination\r
+ DEC Register ; Counter--\r
+ JZ Destination ; Jump if 0\r
+ENDM\r
+ \r
+ \r
+ ; ===== General Constants =====\r
+ \r
+ False EQU 0\r
+ True EQU -1\r
+ nil EQU 0\r
+ \r
+ b EQU BYTE PTR\r
+ w EQU WORD PTR\r
+ d EQU DWORD PTR\r
+ o EQU OFFSET\r
+ f EQU FAR PTR\r
+ s EQU SHORT\r
+ ?x4 EQU <?,?,?,?>\r
+ ?x3 EQU <?,?,?>\r
+ \r
+ ; ===== VGA Register Values =====\r
+ \r
+ VGA_Segment EQU 0A000h ; Vga Memory Segment\r
+ \r
+ ATTRIB_Ctrl EQU 03C0h ; VGA Attribute Controller\r
+ GC_Index EQU 03CEh ; VGA Graphics Controller\r
+ SC_Index EQU 03C4h ; VGA Sequencer Controller\r
+ SC_Data EQU 03C5h ; VGA Sequencer Data Port\r
+ CRTC_Index EQU 03D4h ; VGA CRT Controller\r
+ CRTC_Data EQU 03D5h ; VGA CRT Controller Data\r
+ MISC_OUTPUT EQU 03C2h ; VGA Misc Register\r
+ INPUT_1 EQU 03DAh ; Input Status #1 Register\r
+ \r
+ DAC_WRITE_ADDR EQU 03C8h ; VGA DAC Write Addr Register\r
+ DAC_READ_ADDR EQU 03C7h ; VGA DAC Read Addr Register\r
+ PEL_DATA_REG EQU 03C9h ; VGA DAC/PEL data Register R/W\r
+ \r
+ PIXEL_PAN_REG EQU 033h ; Attrib Index: Pixel Pan Reg\r
+ MAP_MASK EQU 002h ; Sequ Index: Write Map Mask reg\r
+ READ_MAP EQU 004h ; GC Index: Read Map Register\r
+ START_DISP_HI EQU 00Ch ; CRTC Index: Display Start Hi\r
+ START_DISP_LO EQU 00Dh ; CRTC Index: Display Start Lo\r
+ \r
+ MAP_MASK_PLANE1 EQU 00102h ; Map Register + Plane 1\r
+ MAP_MASK_PLANE2 EQU 01102h ; Map Register + Plane 1\r
+ ALL_PLANES_ON EQU 00F02h ; Map Register + All Bit Planes\r
+ \r
+ CHAIN4_OFF EQU 00604h ; Chain 4 mode Off\r
+ ASYNC_RESET EQU 00100h ; (A)synchronous Reset\r
+ SEQU_RESTART EQU 00300h ; Sequencer Restart\r
+ \r
+ LATCHES_ON EQU 00008h ; Bit Mask + Data from Latches\r
+ LATCHES_OFF EQU 0FF08h ; Bit Mask + Data from CPU\r
+ \r
+ VERT_RETRACE EQU 08h ; INPUT_1: Vertical Retrace Bit\r
+ PLANE_BITS EQU 03h ; Bits 0-1 of Xpos = Plane #\r
+ ALL_PLANES EQU 0Fh ; All Bit Planes Selected\r
+ CHAR_BITS EQU 0Fh ; Bits 0-3 of Character Data\r
+ \r
+ GET_CHAR_PTR EQU 01130h ; VGA BIOS Func: Get Char Set\r
+ ROM_8x8_Lo EQU 03h ; ROM 8x8 Char Set Lo Pointer\r
+ ROM_8x8_Hi EQU 04h ; ROM 8x8 Char Set Hi Pointer\r
+ \r
+ ; Constants Specific for these routines\r
+ \r
+ NUM_MODES EQU 8 ; # of Mode X Variations\r
+ \r
+ ; Specific Mode Data Table format...\r
+ \r
+Mode_Data_Table STRUC\r
+ M_MiscR DB ? ; Value of MISC_OUTPUT register\r
+ M_Pages DB ? ; Maximum Possible # of pages\r
+ M_XSize DW ? ; X Size Displayed on screen\r
+ M_YSize DW ? ; Y Size Displayed on screen\r
+ M_XMax DW ? ; Maximum Possible X Size\r
+ M_YMax DW ? ; Maximum Possible Y Size\r
+ M_CRTC DW ? ; Table of CRTC register values\r
+Mode_Data_Table ENDS\r
+ \r
+ ; ===== DGROUP STORAGE NEEDED (42 BYTES) =====\r
+ \r
+ .DATA?\r
+ \r
+SCREEN_WIDTH DW 0 ; Width of a line in Bytes\r
+SCREEN_HEIGHT DW 0 ; Vertical Height in Pixels\r
+ \r
+LAST_PAGE DW 0 ; # of Display Pages\r
+PAGE_ADDR DW 4 DUP (0) ; Offsets to start of each page\r
+ \r
+PAGE_SIZE DW 0 ; Size of Page in Addr Bytes\r
+ \r
+DISPLAY_PAGE DW 0 ; Page # currently displayed\r
+ACTIVE_PAGE DW 0 ; Page # currently active\r
+ \r
+CURRENT_PAGE DW 0 ; Offset of current Page\r
+CURRENT_SEGMENT DW 0 ; Segment of VGA memory\r
+ \r
+CURRENT_XOFFSET DW 0 ; Current Display X Offset\r
+CURRENT_YOFFSET DW 0 ; Current Display Y Offset\r
+ \r
+CURRENT_MOFFSET DW 0 ; Current Start Offset\r
+ \r
+MAX_XOFFSET DW 0 ; Current Display X Offset\r
+MAX_YOFFSET DW 0 ; Current Display Y Offset\r
+ \r
+CHARSET_LOW DW 0, 0 ; Far Ptr to Char Set: 0-127\r
+CHARSET_HI DW 0, 0 ; Far Ptr to Char Set: 128-255\r
+ \r
+ .CODE\r
+ \r
+ ; ===== DATA TABLES =====\r
+ \r
+ ; Data Tables, Put in Code Segment for Easy Access\r
+ ; (Like when all the other Segment Registers are in\r
+ ; use!!) and reduced DGROUP requirements...\r
+ \r
+ ; Bit Mask Tables for Left/Right/Character Masks\r
+ \r
+Left_Clip_Mask DB 0FH, 0EH, 0CH, 08H\r
+ \r
+Right_Clip_Mask DB 01H, 03H, 07H, 0FH\r
+ \r
+ ; Bit Patterns for converting character fonts\r
+ \r
+Char_Plane_Data DB 00H,08H,04H,0CH,02H,0AH,06H,0EH\r
+ DB 01H,09H,05H,0DH,03H,0BH,07H,0FH\r
+ \r
+ ; CRTC Register Values for Various Configurations\r
+ \r
+MODE_Single_Line: ; CRTC Setup Data for 400/480 Line modes\r
+ DW 04009H ; Cell Height (1 Scan Line)\r
+ DW 00014H ; Dword Mode off\r
+ DW 0E317H ; turn on Byte Mode\r
+ DW nil ; End of CRTC Data for 400/480 Line Mode\r
+ \r
+MODE_Double_Line: ; CRTC Setup Data for 200/240 Line modes\r
+ DW 04109H ; Cell Height (2 Scan Lines)\r
+ DW 00014H ; Dword Mode off\r
+ DW 0E317H ; turn on Byte Mode\r
+ DW nil ; End of CRTC Data for 200/240 Line Mode\r
+ \r
+MODE_320_Wide: ; CRTC Setup Data for 320 Horz Pixels\r
+ DW 05F00H ; Horz total\r
+ DW 04F01H ; Horz Displayed\r
+ DW 05002H ; Start Horz Blanking\r
+ DW 08203H ; End Horz Blanking\r
+ DW 05404H ; Start H Sync\r
+ DW 08005H ; End H Sync\r
+ DW nil ; End of CRTC Data for 320 Horz pixels\r
+ \r
+MODE_360_Wide: ; CRTC Setup Data for 360 Horz Pixels\r
+ DW 06B00H ; Horz total\r
+ DW 05901H ; Horz Displayed\r
+ DW 05A02H ; Start Horz Blanking\r
+ DW 08E03H ; End Horz Blanking\r
+ DW 05E04H ; Start H Sync\r
+ DW 08A05H ; End H Sync\r
+ DW nil ; End of CRTC Data for 360 Horz pixels\r
+ \r
+MODE_200_Tall:\r
+MODE_400_Tall: ; CRTC Setup Data for 200/400 Line modes\r
+ DW 0BF06H ; Vertical Total\r
+ DW 01F07H ; Overflow\r
+ DW 09C10H ; V Sync Start\r
+ DW 08E11H ; V Sync End/Prot Cr0 Cr7\r
+ DW 08F12H ; Vertical Displayed\r
+ DW 09615H ; V Blank Start\r
+ DW 0B916H ; V Blank End\r
+ DW nil ; End of CRTC Data for 200/400 Lines\r
+ \r
+MODE_240_Tall:\r
+MODE_480_Tall: ; CRTC Setup Data for 240/480 Line modes\r
+ DW 00D06H ; Vertical Total\r
+ DW 03E07H ; Overflow\r
+ DW 0EA10H ; V Sync Start\r
+ DW 08C11H ; V Sync End/Prot Cr0 Cr7\r
+ DW 0DF12H ; Vertical Displayed\r
+ DW 0E715H ; V Blank Start\r
+ DW 00616H ; V Blank End\r
+ DW nil ; End of CRTC Data for 240/480 Lines\r
+ \r
+ ; Table of Display Mode Tables\r
+ \r
+MODE_TABLE:\r
+ DW o MODE_320x200, o MODE_320x400\r
+ DW o MODE_360x200, o MODE_360x400\r
+ DW o MODE_320x240, o MODE_320x480\r
+ DW o MODE_360x240, o MODE_360x480\r
+ \r
+ ; Table of Display Mode Components\r
+ \r
+MODE_320x200: ; Data for 320 by 200 Pixels\r
+ \r
+ DB 063h ; 400 scan Lines & 25 Mhz Clock\r
+ DB 4 ; Maximum of 4 Pages\r
+ DW 320, 200 ; Displayed Pixels (X,Y)\r
+ DW 1302, 816 ; Max Possible X and Y Sizes\r
+ \r
+ DW o MODE_320_Wide, o MODE_200_Tall\r
+ DW o MODE_Double_Line, nil\r
+ \r
+MODE_320x400: ; Data for 320 by 400 Pixels\r
+ \r
+ DB 063h ; 400 scan Lines & 25 Mhz Clock\r
+ DB 2 ; Maximum of 2 Pages\r
+ DW 320, 400 ; Displayed Pixels X,Y\r
+ DW 648, 816 ; Max Possible X and Y Sizes\r
+ \r
+ DW o MODE_320_Wide, o MODE_400_Tall\r
+ DW o MODE_Single_Line, nil\r
+ \r
+MODE_360x240: ; Data for 360 by 240 Pixels\r
+ \r
+ DB 0E7h ; 480 scan Lines & 28 Mhz Clock\r
+ DB 3 ; Maximum of 3 Pages\r
+ DW 360, 240 ; Displayed Pixels X,Y\r
+ DW 1092, 728 ; Max Possible X and Y Sizes\r
+ \r
+ DW o MODE_360_Wide, o MODE_240_Tall\r
+ DW o MODE_Double_Line , nil\r
+ \r
+MODE_360x480: ; Data for 360 by 480 Pixels\r
+ \r
+ DB 0E7h ; 480 scan Lines & 28 Mhz Clock\r
+ DB 1 ; Only 1 Page Possible\r
+ DW 360, 480 ; Displayed Pixels X,Y\r
+ DW 544, 728 ; Max Possible X and Y Sizes\r
+ \r
+ DW o MODE_360_Wide, o MODE_480_Tall\r
+ DW o MODE_Single_Line , nil\r
+ \r
+MODE_320x240: ; Data for 320 by 240 Pixels\r
+ \r
+ DB 0E3h ; 480 scan Lines & 25 Mhz Clock\r
+ DB 3 ; Maximum of 3 Pages\r
+ DW 320, 240 ; Displayed Pixels X,Y\r
+ DW 1088, 818 ; Max Possible X and Y Sizes\r
+ \r
+ DW o MODE_320_Wide, o MODE_240_Tall\r
+ DW o MODE_Double_Line, nil\r
+ \r
+MODE_320x480: ; Data for 320 by 480 Pixels\r
+ \r
+ DB 0E3h ; 480 scan Lines & 25 Mhz Clock\r
+ DB 1 ; Only 1 Page Possible\r
+ DW 320, 480 ; Displayed Pixels X,Y\r
+ DW 540, 818 ; Max Possible X and Y Sizes\r
+ \r
+ DW o MODE_320_WIDE, o MODE_480_Tall\r
+ DW o MODE_Single_Line, nil\r
+ \r
+MODE_360x200: ; Data for 360 by 200 Pixels\r
+ \r
+ DB 067h ; 400 scan Lines & 28 Mhz Clock\r
+ DB 3 ; Maximum of 3 Pages\r
+ DW 360, 200 ; Displayed Pixels (X,Y)\r
+ DW 1302, 728 ; Max Possible X and Y Sizes\r
+ \r
+ DW o MODE_360_Wide, MODE_200_Tall\r
+ DW o MODE_Double_Line, nil\r
+ \r
+MODE_360x400: ; Data for 360 by 400 Pixels\r
+ \r
+ DB 067h ; 400 scan Lines & 28 Mhz Clock\r
+ DB 1 ; Maximum of 1 Pages\r
+ DW 360, 400 ; Displayed Pixels X,Y\r
+ DW 648, 816 ; Max Possible X and Y Sizes\r
+ \r
+ DW o MODE_360_Wide, MODE_400_Tall\r
+ DW o MODE_Single_Line, nil\r
+ \r
+ \r
+ ; ===== MODE X SETUP ROUTINES =====\r
+ \r
+;======================================================\r
+;SET_VGA_MODEX% (ModeType%, MaxXPos%, MaxYpos%, Pages%)\r
+;======================================================\r
+;\r
+; Sets Up the specified version of Mode X. Allows for\r
+; the setup of multiple video pages, and a virtual\r
+; screen which can be larger than the displayed screen\r
+; (which can then be scrolled a pixel at a time)\r
+;\r
+; ENTRY: ModeType = Desired Screen Resolution (0-7)\r
+;\r
+; 0 = 320 x 200, 4 Pages max, 1.2:1 Aspect Ratio\r
+; 1 = 320 x 400, 2 Pages max, 2.4:1 Aspect Ratio\r
+; 2 = 360 x 200, 3 Pages max, 1.35:1 Aspect Ratio\r
+; 3 = 360 x 400, 1 Page max, 2.7:1 Aspect Ratio\r
+; 4 = 320 x 240, 3 Pages max, 1:1 Aspect Ratio\r
+; 5 = 320 x 480, 1 Page max, 2:1 Aspect Ratio\r
+; 6 = 360 x 240, 3 Pages max, 1.125:1 Aspect Ratio\r
+; 7 = 360 x 480, 1 Page max, 2.25:1 Aspect Ratio\r
+;\r
+; MaxXpos = The Desired Virtual Screen Width\r
+; MaxYpos = The Desired Virtual Screen Height\r
+; Pages = The Desired # of Video Pages\r
+;\r
+; EXIT: AX = Success Flag: 0 = Failure / -1= Success\r
+;\r
+ \r
+SVM_STACK STRUC\r
+ SVM_Table DW ? ; Offset of Mode Info Table\r
+ DW ?x4 ; DI, SI, DS, BP\r
+ DD ? ; Caller\r
+ SVM_Pages DW ? ; # of Screen Pages desired\r
+ SVM_Ysize DW ? ; Vertical Screen Size Desired\r
+ SVM_Xsize DW ? ; Horizontal Screen Size Desired\r
+ SVM_Mode DW ? ; Display Resolution Desired\r
+SVM_STACK ENDS\r
+ \r
+ PUBLIC SET_VGA_MODEX\r
+ \r
+SET_VGA_MODEX PROC FAR\r
+ \r
+ PUSHx BP, DS, SI, DI ; Preserve Important Registers\r
+ SUB SP, 2 ; Allocate workspace\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+ ; Check Legality of Mode Request....\r
+ \r
+ MOV BX, [BP].SVM_Mode ; Get Requested Mode #\r
+ CMP BX, NUM_MODES ; Is it 0..7?\r
+ JAE @SVM_BadModeSetup ; If Not, Error out\r
+ \r
+ SHL BX, 1 ; Scale BX\r
+ MOV SI, w MODE_TABLE[BX] ; CS:SI -> Mode Info\r
+ MOV [BP].SVM_Table, SI ; Save ptr for later use\r
+ \r
+ ; Check # of Requested Display Pages\r
+ \r
+ MOV CX, [BP].SVM_Pages ; Get # of Requested Pages\r
+ CLR CH ; Set Hi Word = 0!\r
+ CMP CL, CS:[SI].M_Pages ; Check # Pages for mode\r
+ JA @SVM_BadModeSetup ; Report Error if too Many Pages\r
+ JCXZ @SVM_BadModeSetup ; Report Error if 0 Pages\r
+ \r
+ ; Check Validity of X Size\r
+ \r
+ AND [BP].SVM_XSize, 0FFF8h ; X size Mod 8 Must = 0\r
+ \r
+ MOV AX, [BP].SVM_XSize ; Get Logical Screen Width\r
+ CMP AX, CS:[SI].M_XSize ; Check against Displayed X\r
+ JB @SVM_BadModeSetup ; Report Error if too small\r
+ CMP AX, CS:[SI].M_XMax ; Check against Max X\r
+ JA @SVM_BadModeSetup ; Report Error if too big\r
+ \r
+ ; Check Validity of Y Size\r
+ \r
+ MOV BX, [BP].SVM_YSize ; Get Logical Screen Height\r
+ CMP BX, CS:[SI].M_YSize ; Check against Displayed Y\r
+ JB @SVM_BadModeSetup ; Report Error if too small\r
+ CMP BX, CS:[SI].M_YMax ; Check against Max Y\r
+ JA @SVM_BadModeSetup ; Report Error if too big\r
+ \r
+ ; Enough memory to Fit it all?\r
+ \r
+ SHR AX, 2 ; # of Bytes:Line = XSize/4\r
+ MUL CX ; AX = Bytes/Line * Pages\r
+ MUL BX ; DX:AX = Total VGA mem needed\r
+ JNO @SVM_Continue ; Exit if Total Size > 256K\r
+ \r
+ DEC DX ; Was it Exactly 256K???\r
+ OR DX, AX ; (DX = 1, AX = 0000)\r
+ JZ @SVM_Continue ; if so, it's valid...\r
+ \r
+@SVM_BadModeSetup:\r
+ \r
+ CLR AX ; Return Value = False\r
+ JMP @SVM_Exit ; Normal Exit\r
+ \r
+@SVM_Continue:\r
+ \r
+ MOV AX, 13H ; Start with Mode 13H\r
+ INT 10H ; Let BIOS Set Mode\r
+ \r
+ OUT_16 SC_INDEX, CHAIN4_OFF ; Disable Chain 4 Mode\r
+ OUT_16 SC_INDEX, ASYNC_RESET ; (A)synchronous Reset\r
+ OUT_8 MISC_OUTPUT, CS:[SI].M_MiscR ; Set New Timing/Size\r
+ OUT_16 SC_INDEX, SEQU_RESTART ; Restart Sequencer ...\r
+ \r
+ OUT_8 CRTC_INDEX, 11H ; Select Vert Retrace End Register\r
+ INC DX ; Point to Data\r
+ IN AL, DX ; Get Value, Bit 7 = Protect\r
+ AND AL, 7FH ; Mask out Write Protect\r
+ OUT DX, AL ; And send it back\r
+ \r
+ MOV DX, CRTC_INDEX ; Vga Crtc Registers\r
+ ADD SI, M_CRTC ; SI -> CRTC Parameter Data\r
+ \r
+ ; Load Tables of CRTC Parameters from List of Tables\r
+ \r
+@SVM_Setup_Table:\r
+ \r
+ MOV DI, CS:[SI] ; Get Pointer to CRTC Data Tbl\r
+ ADD SI, 2 ; Point to next Ptr Entry\r
+ OR DI, DI ; A nil Ptr means that we have\r
+ JZ @SVM_Set_Data ; finished CRTC programming\r
+ \r
+@SVM_Setup_CRTC:\r
+ MOV AX, CS:[DI] ; Get CRTC Data from Table\r
+ ADD DI, 2 ; Advance Pointer\r
+ OR AX, AX ; At End of Data Table?\r
+ JZ @SVM_Setup_Table ; If so, Exit & get next Table\r
+ \r
+ OUT DX, AX ; Reprogram VGA CRTC reg\r
+ JMP s @SVM_Setup_CRTC ; Process Next Table Entry\r
+ \r
+ ; Initialize Page & Scroll info, DI = 0\r
+ \r
+@SVM_Set_Data:\r
+ MOV DISPLAY_PAGE, DI ; Display Page = 0\r
+ MOV ACTIVE_PAGE, DI ; Active Page = 0\r
+ MOV CURRENT_PAGE, DI ; Current Page (Offset) = 0\r
+ MOV CURRENT_XOFFSET, DI ; Horz Scroll Index = 0\r
+ MOV CURRENT_YOFFSET, DI ; Vert Scroll Index = 0\r
+ MOV CURRENT_MOFFSET, DI ; Memory Scroll Index = 0\r
+ \r
+ MOV AX, VGA_SEGMENT ; Segment for VGA memory\r
+ MOV CURRENT_SEGMENT, AX ; Save for Future LES's\r
+ \r
+ ; Set Logical Screen Width, X Scroll and Our Data\r
+ \r
+ MOV SI, [BP].SVM_Table ; Get Saved Ptr to Mode Info\r
+ MOV AX, [BP].SVM_Xsize ; Get Display Width\r
+ \r
+ MOV CX, AX ; CX = Logical Width\r
+ SUB CX, CS:[SI].M_XSize ; CX = Max X Scroll Value\r
+ MOV MAX_XOFFSET, CX ; Set Maximum X Scroll\r
+ \r
+ SHR AX, 2 ; Bytes = Pixels / 4\r
+ MOV SCREEN_WIDTH, AX ; Save Width in Pixels\r
+ \r
+ SHR AX, 1 ; Offset Value = Bytes / 2\r
+ MOV AH, 13h ; CRTC Offset Register Index\r
+ XCHG AL, AH ; Switch format for OUT\r
+ OUT DX, AX ; Set VGA CRTC Offset Reg\r
+ \r
+ ; Setup Data table, Y Scroll, Misc for Other Routines\r
+ \r
+ MOV AX, [BP].SVM_Ysize ; Get Logical Screen Height\r
+ \r
+ MOV CX, AX ; CX = Logical Height\r
+ SUB BX, CS:[SI].M_YSize ; CX = Max Y Scroll Value\r
+ MOV MAX_YOFFSET, CX ; Set Maximum Y Scroll\r
+ \r
+ MOV SCREEN_HEIGHT, AX ; Save Height in Pixels\r
+ MUL SCREEN_WIDTH ; AX = Page Size in Bytes,\r
+ MOV PAGE_SIZE, AX ; Save Page Size\r
+ \r
+ MOV CX, [BP].SVM_Pages ; Get # of Pages\r
+ MOV LAST_PAGE, CX ; Save # of Pages\r
+ \r
+ CLR BX ; Page # = 0\r
+ MOV DX, BX ; Page 0 Offset = 0\r
+ \r
+@SVM_Set_Pages:\r
+ \r
+ MOV PAGE_ADDR[BX], DX ; Set Page #(BX) Offset\r
+ ADD BX, 2 ; Page#++\r
+ ADD DX, AX ; Compute Addr of Next Page\r
+ LOOPx CX, @SVM_Set_Pages ; Loop until all Pages Set\r
+ \r
+ ; Clear VGA Memory\r
+ \r
+ OUT_16 SC_INDEX, ALL_PLANES_ON ; Select All Planes\r
+ LES DI, d CURRENT_PAGE ; -> Start of VGA memory\r
+ \r
+ CLR AX ; AX = 0\r
+ CLD ; Block Xfer Forwards\r
+ MOV CX, 8000H ; 32K * 4 * 2 = 256K\r
+ REP STOSW ; Clear dat memory!\r
+ \r
+ ; Setup Font Pointers\r
+ \r
+ MOV BH, ROM_8x8_Lo ; Ask for 8x8 Font, 0-127\r
+ MOV AX, GET_CHAR_PTR ; Service to Get Pointer\r
+ INT 10h ; Call VGA BIOS\r
+ \r
+ MOV CHARSET_LOW, BP ; Save Char Set Offset\r
+ MOV CHARSET_LOW+2, ES ; Save Char Set Segment\r
+ \r
+ MOV BH, ROM_8x8_Hi ; Ask for 8x8 Font, 128-255\r
+ MOV AX, GET_CHAR_PTR ; Service to Get Pointer\r
+ INT 10h ; Call VGA BIOS\r
+ \r
+ MOV CHARSET_HI, BP ; Save Char Set Offset\r
+ MOV CHARSET_HI+2, ES ; Save Char Set Segment\r
+ \r
+ MOV AX, True ; Return Success Code\r
+ \r
+@SVM_EXIT:\r
+ ADD SP, 2 ; Deallocate workspace\r
+ POPx DI, SI, DS, BP ; Restore Saved Registers\r
+ RET 8 ; Exit & Clean Up Stack\r
+ \r
+SET_VGA_MODEX ENDP\r
+ \r
+ \r
+;==================\r
+;SET_MODEX% (Mode%)\r
+;==================\r
+;\r
+; Quickie Mode Set - Sets Up Mode X to Default Configuration\r
+;\r
+; ENTRY: ModeType = Desired Screen Resolution (0-7)\r
+; (See SET_VGA_MODEX for list)\r
+;\r
+; EXIT: AX = Success Flag: 0 = Failure / -1= Success\r
+;\r
+ \r
+SM_STACK STRUC\r
+ DW ?,? ; BP, SI\r
+ DD ? ; Caller\r
+ SM_Mode DW ? ; Desired Screen Resolution\r
+SM_STACK ENDS\r
+ \r
+ PUBLIC SET_MODEX\r
+ \r
+SET_MODEX PROC FAR\r
+ \r
+ PUSHx BP, SI ; Preserve Important registers\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+ CLR AX ; Assume Failure\r
+ MOV BX, [BP].SM_Mode ; Get Desired Mode #\r
+ CMP BX, NUM_MODES ; Is it a Valid Mode #?\r
+ JAE @SMX_Exit ; If Not, don't Bother\r
+ \r
+ PUSH BX ; Push Mode Parameter\r
+ \r
+ SHL BX, 1 ; Scale BX to word Index\r
+ MOV SI, w MODE_TABLE[BX] ; CS:SI -> Mode Info\r
+ \r
+ PUSH CS:[SI].M_XSize ; Push Default X Size\r
+ PUSH CS:[SI].M_Ysize ; Push Default Y size\r
+ MOV AL, CS:[SI].M_Pages ; Get Default # of Pages\r
+ CLR AH ; Hi Byte = 0\r
+ PUSH AX ; Push # Pages\r
+ \r
+ CALL f SET_VGA_MODEX ; Set up Mode X!\r
+ \r
+@SMX_Exit:\r
+ POPx SI, BP ; Restore Registers\r
+ RET 2 ; Exit & Clean Up Stack\r
+ \r
+SET_MODEX ENDP\r
+ \r
+ \r
+ ; ===== BASIC GRAPHICS PRIMITIVES =====\r
+ \r
+;============================\r
+;CLEAR_VGA_SCREEN (ColorNum%)\r
+;============================\r
+;\r
+; Clears the active display page\r
+;\r
+; ENTRY: ColorNum = Color Value to fill the page with\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+ \r
+CVS_STACK STRUC\r
+ DW ?,? ; DI, BP\r
+ DD ? ; Caller\r
+ CVS_COLOR DB ?,? ; Color to Set Screen to\r
+CVS_STACK ENDS\r
+ \r
+ PUBLIC CLEAR_VGA_SCREEN\r
+ \r
+CLEAR_VGA_SCREEN PROC FAR\r
+ \r
+ PUSHx BP, DI ; Preserve Important Registers\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+ OUT_16 SC_INDEX, ALL_PLANES_ON ; Select All Planes\r
+ LES DI, d CURRENT_PAGE ; Point to Active VGA Page\r
+ \r
+ MOV AL, [BP].CVS_COLOR ; Get Color\r
+ MOV AH, AL ; Copy for Word Write\r
+ CLD ; Block fill Forwards\r
+ \r
+ MOV CX, PAGE_SIZE ; Get Size of Page\r
+ SHR CX, 1 ; Divide by 2 for Words\r
+ REP STOSW ; Block Fill VGA memory\r
+ \r
+ POPx DI, BP ; Restore Saved Registers\r
+ RET 2 ; Exit & Clean Up Stack\r
+ \r
+CLEAR_VGA_SCREEN ENDP\r
+ \r
+ \r
+;===================================\r
+;SET_POINT (Xpos%, Ypos%, ColorNum%)\r
+;===================================\r
+;\r
+; Plots a single Pixel on the active display page\r
+;\r
+; ENTRY: Xpos = X position to plot pixel at\r
+; Ypos = Y position to plot pixel at\r
+; ColorNum = Color to plot pixel with\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+ \r
+SP_STACK STRUC\r
+ DW ?,? ; BP, DI\r
+ DD ? ; Caller\r
+ SETP_Color DB ?,? ; Color of Point to Plot\r
+ SETP_Ypos DW ? ; Y pos of Point to Plot\r
+ SETP_Xpos DW ? ; X pos of Point to Plot\r
+SP_STACK ENDS\r
+ \r
+ PUBLIC SET_POINT\r
+ \r
+SET_POINT PROC FAR\r
+ \r
+ PUSHx BP, DI ; Preserve Registers\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+ LES DI, d CURRENT_PAGE ; Point to Active VGA Page\r
+ \r
+ MOV AX, [BP].SETP_Ypos ; Get Line # of Pixel\r
+ MUL SCREEN_WIDTH ; Get Offset to Start of Line\r
+ \r
+ MOV BX, [BP].SETP_Xpos ; Get Xpos\r
+ MOV CX, BX ; Copy to extract Plane # from\r
+ SHR BX, 2 ; X offset (Bytes) = Xpos/4\r
+ ADD BX, AX ; Offset = Width*Ypos + Xpos/4\r
+ \r
+ MOV AX, MAP_MASK_PLANE1 ; Map Mask & Plane Select Register\r
+ AND CL, PLANE_BITS ; Get Plane Bits\r
+ SHL AH, CL ; Get Plane Select Value\r
+ OUT_16 SC_Index, AX ; Select Plane\r
+ \r
+ MOV AL,[BP].SETP_Color ; Get Pixel Color\r
+ MOV ES:[DI+BX], AL ; Draw Pixel\r
+ \r
+ POPx DI, BP ; Restore Saved Registers\r
+ RET 6 ; Exit and Clean up Stack\r
+ \r
+SET_POINT ENDP\r
+ \r
+ \r
+;==========================\r
+;READ_POINT% (Xpos%, Ypos%)\r
+;==========================\r
+;\r
+; Read the color of a pixel from the Active Display Page\r
+;\r
+; ENTRY: Xpos = X position of pixel to read\r
+; Ypos = Y position of pixel to read\r
+;\r
+; EXIT: AX = Color of Pixel at (Xpos, Ypos)\r
+;\r
+ \r
+RP_STACK STRUC\r
+ DW ?,? ; BP, DI\r
+ DD ? ; Caller\r
+ RP_Ypos DW ? ; Y pos of Point to Read\r
+ RP_Xpos DW ? ; X pos of Point to Read\r
+RP_STACK ENDS\r
+ \r
+ PUBLIC READ_POINT\r
+ \r
+READ_POINT PROC FAR\r
+ \r
+ PUSHx BP, DI ; Preserve Registers\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+ LES DI, d CURRENT_PAGE ; Point to Active VGA Page\r
+ \r
+ MOV AX, [BP].RP_Ypos ; Get Line # of Pixel\r
+ MUL SCREEN_WIDTH ; Get Offset to Start of Line\r
+ \r
+ MOV BX, [BP].RP_Xpos ; Get Xpos\r
+ MOV CX, BX\r
+ SHR BX, 2 ; X offset (Bytes) = Xpos/4\r
+ ADD BX, AX ; Offset = Width*Ypos + Xpos/4\r
+ \r
+ MOV AL, READ_MAP ; GC Read Mask Register\r
+ MOV AH, CL ; Get Xpos\r
+ AND AH, PLANE_BITS ; & mask out Plane #\r
+ OUT_16 GC_INDEX, AX ; Select Plane to read in\r
+ \r
+ CLR AH ; Clear Return Value Hi byte\r
+ MOV AL, ES:[DI+BX] ; Get Color of Pixel\r
+ \r
+ POPx DI, BP ; Restore Saved Registers\r
+ RET 4 ; Exit and Clean up Stack\r
+ \r
+READ_POINT ENDP\r
+ \r
+ \r
+;======================================================\r
+;FILL_BLOCK (Xpos1%, Ypos1%, Xpos2%, Ypos2%, ColorNum%)\r
+;======================================================\r
+;\r
+; Fills a rectangular block on the active display Page\r
+;\r
+; ENTRY: Xpos1 = Left X position of area to fill\r
+; Ypos1 = Top Y position of area to fill\r
+; Xpos2 = Right X position of area to fill\r
+; Ypos2 = Bottom Y position of area to fill\r
+; ColorNum = Color to fill area with\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+ \r
+FB_STACK STRUC\r
+ DW ?x4 ; DS, DI, SI, BP\r
+ DD ? ; Caller\r
+ FB_Color DB ?,? ; Fill Color\r
+ FB_Ypos2 DW ? ; Y pos of Lower Right Pixel\r
+ FB_Xpos2 DW ? ; X pos of Lower Right Pixel\r
+ FB_Ypos1 DW ? ; Y pos of Upper Left Pixel\r
+ FB_Xpos1 DW ? ; X pos of Upper Left Pixel\r
+FB_STACK ENDS\r
+ \r
+ PUBLIC FILL_BLOCK\r
+ \r
+FILL_BLOCK PROC FAR\r
+ \r
+ PUSHx BP, DS, SI, DI ; Preserve Important Registers\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+ LES DI, d CURRENT_PAGE ; Point to Active VGA Page\r
+ CLD ; Direction Flag = Forward\r
+ \r
+ OUT_8 SC_INDEX, MAP_MASK ; Set up for Plane Select\r
+ \r
+ ; Validate Pixel Coordinates\r
+ ; If necessary, Swap so X1 <= X2, Y1 <= Y2\r
+ \r
+ MOV AX, [BP].FB_Ypos1 ; AX = Y1 is Y1< Y2?\r
+ MOV BX, [BP].FB_Ypos2 ; BX = Y2\r
+ CMP AX, BX\r
+ JLE @FB_NOSWAP1\r
+ \r
+ MOV [BP].FB_Ypos1, BX ; Swap Y1 and Y2 and save Y1\r
+ XCHG AX, BX ; on stack for future use\r
+ \r
+@FB_NOSWAP1:\r
+ SUB BX, AX ; Get Y width\r
+ INC BX ; Add 1 to avoid 0 value\r
+ MOV [BP].FB_Ypos2, BX ; Save in Ypos2\r
+ \r
+ MUL SCREEN_WIDTH ; Mul Y1 by Bytes per Line\r
+ ADD DI, AX ; DI = Start of Line Y1\r
+ \r
+ MOV AX, [BP].FB_Xpos1 ; Check X1 <= X2\r
+ MOV BX, [BP].FB_Xpos2 ;\r
+ CMP AX, BX\r
+ JLE @FB_NOSWAP2 ; Skip Ahead if Ok\r
+ \r
+ MOV [BP].FB_Xpos2, AX ; Swap X1 AND X2 and save X2\r
+ XCHG AX, BX ; on stack for future use\r
+ \r
+ ; All our Input Values are in order, Now determine\r
+ ; How many full "bands" 4 pixels wide (aligned) there\r
+ ; are, and if there are partial bands (<4 pixels) on\r
+ ; the left and right edges.\r
+ \r
+@FB_NOSWAP2:\r
+ MOV DX, AX ; DX = X1 (Pixel Position)\r
+ SHR DX, 2 ; DX/4 = Bytes into Line\r
+ ADD DI, DX ; DI = Addr of Upper-Left Corner\r
+ \r
+ MOV CX, BX ; CX = X2 (Pixel Position)\r
+ SHR CX, 2 ; CX/4 = Bytes into Line\r
+ \r
+ CMP DX, CX ; Start and end in same band?\r
+ JNE @FB_NORMAL ; if not, check for l & r edges\r
+ JMP @FB_ONE_BAND_ONLY ; if so, then special processing\r
+ \r
+@FB_NORMAL:\r
+ SUB CX, DX ; CX = # bands -1\r
+ MOV SI, AX ; SI = PLANE#(X1)\r
+ AND SI, PLANE_BITS ; if Left edge is aligned then\r
+ JZ @FB_L_PLANE_FLUSH ; no special processing..\r
+ \r
+ ; Draw "Left Edge" vertical strip of 1-3 pixels...\r
+ \r
+ OUT_8 SC_Data, Left_Clip_Mask[SI] ; Set Left Edge Plane Mask\r
+ \r
+ MOV SI, DI ; SI = Copy of Start Addr (UL)\r
+ \r
+ MOV DX, [BP].FB_Ypos2 ; Get # of Lines to draw\r
+ MOV AL, [BP].FB_Color ; Get Fill Color\r
+ MOV BX, SCREEN_WIDTH ; Get Vertical increment Value\r
+ \r
+@FB_LEFT_LOOP:\r
+ MOV ES:[SI], AL ; Fill in Left Edge Pixels\r
+ ADD SI, BX ; Point to Next Line (Below)\r
+ LOOPjz DX, @FB_LEFT_CONT ; Exit loop if all Lines Drawn\r
+ \r
+ MOV ES:[SI], AL ; Fill in Left Edge Pixels\r
+ ADD SI, BX ; Point to Next Line (Below)\r
+ LOOPx DX, @FB_LEFT_LOOP ; loop until left strip is drawn\r
+ \r
+@FB_LEFT_CONT:\r
+ \r
+ INC DI ; Point to Middle (or Right) Block\r
+ DEC CX ; Reset CX instead of JMP @FB_RIGHT\r
+ \r
+@FB_L_PLANE_FLUSH:\r
+ INC CX ; Add in Left band to middle block\r
+ \r
+ ; DI = Addr of 1st middle Pixel (band) to fill\r
+ ; CX = # of Bands to fill -1\r
+ \r
+@FB_RIGHT:\r
+ MOV SI, [BP].FB_Xpos2 ; Get Xpos2\r
+ AND SI, PLANE_BITS ; Get Plane values\r
+ CMP SI, 0003 ; Plane = 3?\r
+ JE @FB_R_EDGE_FLUSH ; Hey, add to middle\r
+ \r
+ ; Draw "Right Edge" vertical strip of 1-3 pixels...\r
+ \r
+ OUT_8 SC_Data, Right_Clip_Mask[SI] ; Right Edge Plane Mask\r
+ \r
+ MOV SI, DI ; Get Addr of Left Edge\r
+ ADD SI, CX ; Add Width-1 (Bands)\r
+ DEC SI ; To point to top of Right Edge\r
+ \r
+ MOV DX, [BP].FB_Ypos2 ; Get # of Lines to draw\r
+ MOV AL, [BP].FB_Color ; Get Fill Color\r
+ MOV BX, SCREEN_WIDTH ; Get Vertical increment Value\r
+ \r
+@FB_RIGHT_LOOP:\r
+ MOV ES:[SI], AL ; Fill in Right Edge Pixels\r
+ ADD SI, BX ; Point to Next Line (Below)\r
+ LOOPjz DX, @FB_RIGHT_CONT ; Exit loop if all Lines Drawn\r
+ \r
+ MOV ES:[SI], AL ; Fill in Right Edge Pixels\r
+ ADD SI, BX ; Point to Next Line (Below)\r
+ LOOPx DX, @FB_RIGHT_LOOP ; loop until left strip is drawn\r
+ \r
+@FB_RIGHT_CONT:\r
+ \r
+ DEC CX ; Minus 1 for Middle bands\r
+ JZ @FB_EXIT ; Uh.. no Middle bands...\r
+ \r
+@FB_R_EDGE_FLUSH:\r
+ \r
+ ; DI = Addr of Upper Left block to fill\r
+ ; CX = # of Bands to fill in (width)\r
+ \r
+ OUT_8 SC_Data, ALL_PLANES ; Write to All Planes\r
+ \r
+ MOV DX, SCREEN_WIDTH ; DX = DI Increment\r
+ SUB DX, CX ; = Screen_Width-# Planes Filled\r
+ \r
+ MOV BX, CX ; BX = Quick Refill for CX\r
+ MOV SI, [BP].FB_Ypos2 ; SI = # of Line to Fill\r
+ MOV AL, [BP].FB_Color ; Get Fill Color\r
+ \r
+@FB_MIDDLE_LOOP:\r
+ REP STOSB ; Fill in entire line\r
+ \r
+ MOV CX, BX ; Recharge CX (Line Width)\r
+ ADD DI, DX ; Point to start of Next Line\r
+ LOOPx SI, @FB_MIDDLE_LOOP ; Loop until all lines drawn\r
+ \r
+ JMP s @FB_EXIT ; Outa here\r
+ \r
+@FB_ONE_BAND_ONLY:\r
+ MOV SI, AX ; Get Left Clip Mask, Save X1\r
+ AND SI, PLANE_BITS ; Mask out Row #\r
+ MOV AL, Left_Clip_Mask[SI] ; Get Left Edge Mask\r
+ MOV SI, BX ; Get Right Clip Mask, Save X2\r
+ AND SI, PLANE_BITS ; Mask out Row #\r
+ AND AL, Right_Clip_Mask[SI] ; Get Right Edge Mask byte\r
+ \r
+ OUT_8 SC_Data, AL ; Clip For Left & Right Masks\r
+ \r
+ MOV CX, [BP].FB_Ypos2 ; Get # of Lines to draw\r
+ MOV AL, [BP].FB_Color ; Get Fill Color\r
+ MOV BX, SCREEN_WIDTH ; Get Vertical increment Value\r
+ \r
+@FB_ONE_LOOP:\r
+ MOV ES:[DI], AL ; Fill in Pixels\r
+ ADD DI, BX ; Point to Next Line (Below)\r
+ LOOPjz CX, @FB_EXIT ; Exit loop if all Lines Drawn\r
+ \r
+ MOV ES:[DI], AL ; Fill in Pixels\r
+ ADD DI, BX ; Point to Next Line (Below)\r
+ LOOPx CX, @FB_ONE_LOOP ; loop until left strip is drawn\r
+ \r
+@FB_EXIT:\r
+ POPx DI, SI, DS, BP ; Restore Saved Registers\r
+ RET 10 ; Exit and Clean up Stack\r
+ \r
+FILL_BLOCK ENDP\r
+ \r
+ \r
+;=====================================================\r
+;DRAW_LINE (Xpos1%, Ypos1%, Xpos2%, Ypos2%, ColorNum%)\r
+;=====================================================\r
+;\r
+; Draws a Line on the active display page\r
+;\r
+; ENTRY: Xpos1 = X position of first point on line\r
+; Ypos1 = Y position of first point on line\r
+; Xpos2 = X position of last point on line\r
+; Ypos2 = Y position of last point on line\r
+; ColorNum = Color to draw line with\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+ \r
+DL_STACK STRUC\r
+ DW ?x3 ; DI, SI, BP\r
+ DD ? ; Caller\r
+ DL_ColorF DB ?,? ; Line Draw Color\r
+ DL_Ypos2 DW ? ; Y pos of last point\r
+ DL_Xpos2 DW ? ; X pos of last point\r
+ DL_Ypos1 DW ? ; Y pos of first point\r
+ DL_Xpos1 DW ? ; X pos of first point\r
+DL_STACK ENDS\r
+ \r
+ PUBLIC DRAW_LINE\r
+ \r
+DRAW_LINE PROC FAR\r
+ \r
+ PUSHx BP, SI, DI ; Preserve Important Registers\r
+ MOV BP, SP ; Set up Stack Frame\r
+ CLD ; Direction Flag = Forward\r
+ \r
+ OUT_8 SC_INDEX, MAP_MASK ; Set up for Plane Select\r
+ MOV CH, [BP].DL_ColorF ; Save Line Color in CH\r
+ \r
+ ; Check Line Type\r
+ \r
+ MOV SI, [BP].DL_Xpos1 ; AX = X1 is X1< X2?\r
+ MOV DI, [BP].DL_Xpos2 ; DX = X2\r
+ CMP SI, DI ; Is X1 < X2\r
+ JE @DL_VLINE ; If X1=X2, Draw Vertical Line\r
+ JL @DL_NOSWAP1 ; If X1 < X2, don't swap\r
+ \r
+ XCHG SI, DI ; X2 IS > X1, SO SWAP THEM\r
+ \r
+@DL_NOSWAP1:\r
+ \r
+ ; SI = X1, DI = X2\r
+ \r
+ MOV AX, [BP].DL_Ypos1 ; AX = Y1 is Y1 <> Y2?\r
+ CMP AX, [BP].DL_Ypos2 ; Y1 = Y2?\r
+ JE @DL_HORZ ; If so, Draw a Horizontal Line\r
+ \r
+ JMP @DL_BREZHAM ; Diagonal line... go do it...\r
+ \r
+ ; This Code draws a Horizontal Line in Mode X where:\r
+ ; SI = X1, DI = X2, and AX = Y1/Y2\r
+ \r
+@DL_HORZ:\r
+ \r
+ MUL SCREEN_WIDTH ; Offset = Ypos * Screen_Width\r
+ MOV DX, AX ; CX = Line offset into Page\r
+ \r
+ MOV AX, SI ; Get Left edge, Save X1\r
+ AND SI, PLANE_BITS ; Mask out Row #\r
+ MOV BL, Left_Clip_Mask[SI] ; Get Left Edge Mask\r
+ MOV CX, DI ; Get Right edge, Save X2\r
+ AND DI, PLANE_BITS ; Mask out Row #\r
+ MOV BH, Right_Clip_Mask[DI] ; Get Right Edge Mask byte\r
+ \r
+ SHR AX, 2 ; Get X1 Byte # (=X1/4)\r
+ SHR CX, 2 ; Get X2 Byte # (=X2/4)\r
+ \r
+ LES DI, d CURRENT_PAGE ; Point to Active VGA Page\r
+ ADD DI, DX ; Point to Start of Line\r
+ ADD DI, AX ; Point to Pixel X1\r
+ \r
+ SUB CX, AX ; CX = # Of Bands (-1) to set\r
+ JNZ @DL_LONGLN ; jump if longer than one segment\r
+ \r
+ AND BL, BH ; otherwise, merge clip masks\r
+ \r
+@DL_LONGLN:\r
+ \r
+ OUT_8 SC_Data, BL ; Set the Left Clip Mask\r
+ \r
+ MOV AL, [BP].DL_ColorF ; Get Line Color\r
+ MOV BL, AL ; BL = Copy of Line Color\r
+ STOSB ; Set Left (1-4) Pixels\r
+ \r
+ JCXZ @DL_EXIT ; Done if only one Line Segment\r
+ \r
+ DEC CX ; CX = # of Middle Segments\r
+ JZ @DL_XRSEG ; If no middle segments....\r
+ \r
+ ; Draw Middle Segments\r
+ \r
+ OUT_8 DX, ALL_PLANES ; Write to ALL Planes\r
+ \r
+ MOV AL, BL ; Get Color from BL\r
+ REP STOSB ; Draw Middle (4 Pixel) Segments\r
+ \r
+@DL_XRSEG:\r
+ OUT_8 DX, BH ; Select Planes for Right Clip Mask\r
+ MOV AL, BL ; Get Color Value\r
+ STOSB ; Draw Right (1-4) Pixels\r
+ \r
+ JMP s @DL_EXIT ; We Are Done...\r
+ \r
+ \r
+ ; This Code Draws A Vertical Line. On entry:\r
+ ; CH = Line Color, SI & DI = X1\r
+ \r
+@DL_VLINE:\r
+ \r
+ MOV AX, [BP].DL_Ypos1 ; AX = Y1\r
+ MOV SI, [BP].DL_Ypos2 ; SI = Y2\r
+ CMP AX, SI ; Is Y1 < Y2?\r
+ JLE @DL_NOSWAP2 ; if so, Don't Swap them\r
+ \r
+ XCHG AX, SI ; Ok, NOW Y1 < Y2\r
+ \r
+@DL_NOSWAP2:\r
+ \r
+ SUB SI, AX ; SI = Line Height (Y2-Y1+1)\r
+ INC SI\r
+ \r
+ ; AX = Y1, DI = X1, Get offset into Page into AX\r
+ \r
+ MUL SCREEN_WIDTH ; Offset = Y1 (AX) * Screen Width\r
+ MOV DX, DI ; Copy Xpos into DX\r
+ SHR DI, 2 ; DI = Xpos/4\r
+ ADD AX, DI ; DI = Xpos/4 + ScreenWidth * Y1\r
+ \r
+ LES DI, d CURRENT_PAGE ; Point to Active VGA Page\r
+ ADD DI, AX ; Point to Pixel X1, Y1\r
+ \r
+ ;Select Plane\r
+ \r
+ MOV CL, DL ; CL = Save X1\r
+ AND CL, PLANE_BITS ; Get X1 MOD 4 (Plane #)\r
+ MOV AX, MAP_MASK_PLANE1 ; Code to set Plane #1\r
+ SHL AH, CL ; Change to Correct Plane #\r
+ OUT_16 SC_Index, AX ; Select Plane\r
+ \r
+ MOV AL, CH ; Get Saved Color\r
+ MOV BX, SCREEN_WIDTH ; Get Offset to Advance Line By\r
+ \r
+@DL_VLoop:\r
+ MOV ES:[DI], AL ; Draw Single Pixel\r
+ ADD DI, BX ; Point to Next Line\r
+ LOOPjz SI, @DL_EXIT ; Lines--, Exit if done\r
+ \r
+ MOV ES:[DI], AL ; Draw Single Pixel\r
+ ADD DI, BX ; Point to Next Line\r
+ LOOPx SI, @DL_VLoop ; Lines--, Loop until Done\r
+ \r
+@DL_EXIT:\r
+ \r
+ JMP @DL_EXIT2 ; Done!\r
+ \r
+ ; This code Draws a diagonal line in Mode X\r
+ \r
+@DL_BREZHAM:\r
+ LES DI, d CURRENT_PAGE ; Point to Active VGA Page\r
+ \r
+ MOV AX, [BP].DL_Ypos1 ; get Y1 value\r
+ MOV BX, [BP].DL_Ypos2 ; get Y2 value\r
+ MOV CX, [BP].DL_Xpos1 ; Get Starting Xpos\r
+ \r
+ CMP BX, AX ; Y2-Y1 is?\r
+ JNC @DL_DeltaYOK ; if Y2>=Y1 then goto...\r
+ \r
+ XCHG BX, AX ; Swap em...\r
+ MOV CX, [BP].DL_Xpos2 ; Get New Starting Xpos\r
+ \r
+@DL_DeltaYOK:\r
+ MUL SCREEN_WIDTH ; Offset = SCREEN_WIDTH * Y1\r
+ \r
+ ADD DI, AX ; DI -> Start of Line Y1 on Page\r
+ MOV AX, CX ; AX = Xpos (X1)\r
+ SHR AX, 2 ; /4 = Byte Offset into Line\r
+ ADD DI, AX ; DI = Starting pos (X1,Y1)\r
+ \r
+ MOV AL, 11h ; Staring Mask\r
+ AND CL, PLANE_BITS ; Get Plane #\r
+ SHL AL, CL ; and shift into place\r
+ MOV AH, [BP].DL_ColorF ; Color in Hi Bytes\r
+ \r
+ PUSH AX ; Save Mask,Color...\r
+ \r
+ MOV AH, AL ; Plane # in AH\r
+ MOV AL, MAP_MASK ; Select Plane Register\r
+ OUT_16 SC_Index, AX ; Select initial plane\r
+ \r
+ MOV AX, [BP].DL_Xpos1 ; get X1 value\r
+ MOV BX, [BP].DL_Ypos1 ; get Y1 value\r
+ MOV CX, [BP].DL_Xpos2 ; get X2 value\r
+ MOV DX, [BP].DL_Ypos2 ; get Y2 value\r
+ \r
+ MOV BP, SCREEN_WIDTH ; Use BP for Line width to\r
+ ; to avoid extra memory access\r
+ \r
+ SUB DX, BX ; figure Delta_Y\r
+ JNC @DL_DeltaYOK2 ; jump if Y2 >= Y1\r
+ \r
+ ADD BX, DX ; put Y2 into Y1\r
+ NEG DX ; abs(Delta_Y)\r
+ XCHG AX, CX ; and exchange X1 and X2\r
+ \r
+@DL_DeltaYOK2:\r
+ MOV BX, 08000H ; seed for fraction accumulator\r
+ \r
+ SUB CX, AX ; figure Delta_X\r
+ JC @DL_DrawLeft ; if negative, go left\r
+ \r
+ JMP @DL_DrawRight ; Draw Line that slopes right\r
+ \r
+@DL_DrawLeft:\r
+ \r
+ NEG CX ; abs(Delta_X)\r
+ \r
+ CMP CX, DX ; is Delta_X < Delta_Y?\r
+ JB @DL_SteepLeft ; yes, so go do steep line\r
+ ; (Delta_Y iterations)\r
+ \r
+ ; Draw a Shallow line to the left in Mode X\r
+ \r
+@DL_ShallowLeft:\r
+ CLR AX ; zero low word of Delta_Y * 10000h\r
+ SUB AX, DX ; DX:AX <- DX * 0FFFFh\r
+ SBB DX, 0 ; include carry\r
+ DIV CX ; divide by Delta_X\r
+ \r
+ MOV SI, BX ; SI = Accumulator\r
+ MOV BX, AX ; BX = Add fraction\r
+ POP AX ; Get Color, Bit mask\r
+ MOV DX, SC_Data ; Sequence controller data register\r
+ INC CX ; Inc Delta_X so we can unroll loop\r
+ \r
+ ; Loop (x2) to Draw Pixels, Move Left, and Maybe Down...\r
+ \r
+@DL_SLLLoop:\r
+ MOV ES:[DI], AH ; set first pixel, plane data set up\r
+ LOOPjz CX, @DL_SLLExit ; Delta_X--, Exit if done\r
+ \r
+ ADD SI, BX ; add numerator to accumulator\r
+ JNC @DL_SLLL2nc ; move down on carry\r
+ \r
+ ADD DI, BP ; Move Down one line...\r
+ \r
+@DL_SLLL2nc:\r
+ DEC DI ; Left one addr\r
+ ROR AL, 1 ; Move Left one plane, back on 0 1 2\r
+ CMP AL, 87h ; wrap?, if AL <88 then Carry set\r
+ ADC DI, 0 ; Adjust Address: DI = DI + Carry\r
+ OUT DX, AL ; Set up New Bit Plane mask\r
+ \r
+ MOV ES:[DI], AH ; set pixel\r
+ LOOPjz CX, @DL_SLLExit ; Delta_X--, Exit if done\r
+ \r
+ ADD SI, BX ; add numerator to accumulator,\r
+ JNC @DL_SLLL3nc ; move down on carry\r
+ \r
+ ADD DI, BP ; Move Down one line...\r
+ \r
+@DL_SLLL3nc: ; Now move left a pixel...\r
+ DEC DI ; Left one addr\r
+ ROR AL, 1 ; Move Left one plane, back on 0 1 2\r
+ CMP AL, 87h ; Wrap?, if AL <88 then Carry set\r
+ ADC DI, 0 ; Adjust Address: DI = DI + Carry\r
+ OUT DX, AL ; Set up New Bit Plane mask\r
+ JMP s @DL_SLLLoop ; loop until done\r
+ \r
+@DL_SLLExit:\r
+ JMP @DL_EXIT2 ; and exit\r
+ \r
+ ; Draw a steep line to the left in Mode X\r
+ \r
+@DL_SteepLeft:\r
+ CLR AX ; zero low word of Delta_Y * 10000h\r
+ XCHG DX, CX ; Delta_Y switched with Delta_X\r
+ DIV CX ; divide by Delta_Y\r
+ \r
+ MOV SI, BX ; SI = Accumulator\r
+ MOV BX, AX ; BX = Add Fraction\r
+ POP AX ; Get Color, Bit mask\r
+ MOV DX, SC_Data ; Sequence controller data register\r
+ INC CX ; Inc Delta_Y so we can unroll loop\r
+ \r
+ ; Loop (x2) to Draw Pixels, Move Down, and Maybe left\r
+ \r
+@DL_STLLoop:\r
+ \r
+ MOV ES:[DI], AH ; set first pixel\r
+ LOOPjz CX, @DL_STLExit ; Delta_Y--, Exit if done\r
+ \r
+ ADD SI, BX ; add numerator to accumulator\r
+ JNC @DL_STLnc2 ; No carry, just move down!\r
+ \r
+ DEC DI ; Move Left one addr\r
+ ROR AL, 1 ; Move Left one plane, back on 0 1 2\r
+ CMP AL, 87h ; Wrap?, if AL <88 then Carry set\r
+ ADC DI, 0 ; Adjust Address: DI = DI + Carry\r
+ OUT DX, AL ; Set up New Bit Plane mask\r
+ \r
+@DL_STLnc2:\r
+ ADD DI, BP ; advance to next line.\r
+ \r
+ MOV ES:[DI], AH ; set pixel\r
+ LOOPjz CX, @DL_STLExit ; Delta_Y--, Exit if done\r
+ \r
+ ADD SI, BX ; add numerator to accumulator\r
+ JNC @DL_STLnc3 ; No carry, just move down!\r
+ \r
+ DEC DI ; Move Left one addr\r
+ ROR AL, 1 ; Move Left one plane, back on 0 1 2\r
+ CMP AL, 87h ; Wrap?, if AL <88 then Carry set\r
+ ADC DI, 0 ; Adjust Address: DI = DI + Carry\r
+ OUT DX, AL ; Set up New Bit Plane mask\r
+ \r
+@DL_STLnc3:\r
+ ADD DI, BP ; advance to next line.\r
+ JMP s @DL_STLLoop ; Loop until done\r
+ \r
+@DL_STLExit:\r
+ JMP @DL_EXIT2 ; and exit\r
+ \r
+ ; Draw a line that goes to the Right...\r
+ \r
+@DL_DrawRight:\r
+ CMP CX, DX ; is Delta_X < Delta_Y?\r
+ JB @DL_SteepRight ; yes, so go do steep line\r
+ ; (Delta_Y iterations)\r
+ \r
+ ; Draw a Shallow line to the Right in Mode X\r
+ \r
+@DL_ShallowRight:\r
+ CLR AX ; zero low word of Delta_Y * 10000h\r
+ SUB AX, DX ; DX:AX <- DX * 0FFFFh\r
+ SBB DX, 0 ; include carry\r
+ DIV CX ; divide by Delta_X\r
+ \r
+ MOV SI, BX ; SI = Accumulator\r
+ MOV BX, AX ; BX = Add Fraction\r
+ POP AX ; Get Color, Bit mask\r
+ MOV DX, SC_Data ; Sequence controller data register\r
+ INC CX ; Inc Delta_X so we can unroll loop\r
+ \r
+ ; Loop (x2) to Draw Pixels, Move Right, and Maybe Down...\r
+ \r
+@DL_SLRLoop:\r
+ MOV ES:[DI], AH ; set first pixel, mask is set up\r
+ LOOPjz CX, @DL_SLRExit ; Delta_X--, Exit if done..\r
+ \r
+ ADD SI, BX ; add numerator to accumulator\r
+ JNC @DL_SLR2nc ; don't move down if carry not set\r
+ \r
+ ADD DI, BP ; Move Down one line...\r
+ \r
+@DL_SLR2nc: ; Now move right a pixel...\r
+ ROL AL, 1 ; Move Right one addr if Plane = 0\r
+ CMP AL, 12h ; Wrap? if AL >12 then Carry not set\r
+ ADC DI, 0 ; Adjust Address: DI = DI + Carry\r
+ OUT DX, AL ; Set up New Bit Plane mask\r
+ \r
+ MOV ES:[DI], AH ; set pixel\r
+ LOOPjz CX, @DL_SLRExit ; Delta_X--, Exit if done..\r
+ \r
+ ADD SI, BX ; add numerator to accumulator\r
+ JNC @DL_SLR3nc ; don't move down if carry not set\r
+ \r
+ ADD DI, BP ; Move Down one line...\r
+ \r
+@DL_SLR3nc:\r
+ ROL AL, 1 ; Move Right one addr if Plane = 0\r
+ CMP AL, 12h ; Wrap? if AL >12 then Carry not set\r
+ ADC DI, 0 ; Adjust Address: DI = DI + Carry\r
+ OUT DX, AL ; Set up New Bit Plane mask\r
+ JMP s @DL_SLRLoop ; loop till done\r
+ \r
+@DL_SLRExit:\r
+ JMP @DL_EXIT2 ; and exit\r
+ \r
+ ; Draw a Steep line to the Right in Mode X\r
+ \r
+@DL_SteepRight:\r
+ CLR AX ; zero low word of Delta_Y * 10000h\r
+ XCHG DX, CX ; Delta_Y switched with Delta_X\r
+ DIV CX ; divide by Delta_Y\r
+ \r
+ MOV SI, BX ; SI = Accumulator\r
+ MOV BX, AX ; BX = Add Fraction\r
+ POP AX ; Get Color, Bit mask\r
+ MOV DX, SC_Data ; Sequence controller data register\r
+ INC CX ; Inc Delta_Y so we can unroll loop\r
+ \r
+ ; Loop (x2) to Draw Pixels, Move Down, and Maybe Right\r
+ \r
+@STRLoop:\r
+ MOV ES:[DI], AH ; set first pixel, mask is set up\r
+ LOOPjz CX, @DL_EXIT2 ; Delta_Y--, Exit if Done\r
+ \r
+ ADD SI, BX ; add numerator to accumulator\r
+ JNC @STRnc2 ; if no carry then just go down...\r
+ \r
+ ROL AL, 1 ; Move Right one addr if Plane = 0\r
+ CMP AL, 12h ; Wrap? if AL >12 then Carry not set\r
+ ADC DI, 0 ; Adjust Address: DI = DI + Carry\r
+ OUT DX, AL ; Set up New Bit Plane mask\r
+ \r
+@STRnc2:\r
+ ADD DI, BP ; advance to next line.\r
+ \r
+ MOV ES:[DI], AH ; set pixel\r
+ LOOPjz CX, @DL_EXIT2 ; Delta_Y--, Exit if Done\r
+ \r
+ ADD SI, BX ; add numerator to accumulator\r
+ JNC @STRnc3 ; if no carry then just go down...\r
+ \r
+ ROL AL, 1 ; Move Right one addr if Plane = 0\r
+ CMP AL, 12h ; Wrap? if AL >12 then Carry not set\r
+ ADC DI, 0 ; Adjust Address: DI = DI + Carry\r
+ OUT DX, AL ; Set up New Bit Plane mask\r
+ \r
+@STRnc3:\r
+ ADD DI, BP ; advance to next line.\r
+ JMP s @STRLoop ; loop till done\r
+ \r
+@DL_EXIT2:\r
+ POPx DI, SI, BP ; Restore Saved Registers\r
+ RET 10 ; Exit and Clean up Stack\r
+ \r
+DRAW_LINE ENDP\r
+ \r
+ \r
+ ; ===== DAC COLOR REGISTER ROUTINES =====\r
+ \r
+;=================================================\r
+;SET_DAC_REGISTER (Register%, Red%, Green%, Blue%)\r
+;=================================================\r
+;\r
+; Sets a single (RGB) Vga Palette Register\r
+;\r
+; ENTRY: Register = The DAC # to modify (0-255)\r
+; Red = The new Red Intensity (0-63)\r
+; Green = The new Green Intensity (0-63)\r
+; Blue = The new Blue Intensity (0-63)\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+ \r
+SDR_STACK STRUC\r
+ DW ? ; BP\r
+ DD ? ; Caller\r
+ SDR_Blue DB ?,? ; Blue Data Value\r
+ SDR_Green DB ?,? ; Green Data Value\r
+ SDR_Red DB ?,? ; Red Data Value\r
+ SDR_Register DB ?,? ; Palette Register #\r
+SDR_STACK ENDS\r
+ \r
+ PUBLIC SET_DAC_REGISTER\r
+ \r
+SET_DAC_REGISTER PROC FAR\r
+ \r
+ PUSH BP ; Save BP\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+ ; Select which DAC Register to modify\r
+ \r
+ OUT_8 DAC_WRITE_ADDR, [BP].SDR_Register\r
+ \r
+ MOV DX, PEL_DATA_REG ; Dac Data Register\r
+ OUT_8 DX, [BP].SDR_Red ; Set Red Intensity\r
+ OUT_8 DX, [BP].SDR_Green ; Set Green Intensity\r
+ OUT_8 DX, [BP].SDR_Blue ; Set Blue Intensity\r
+ \r
+ POP BP ; Restore Registers\r
+ RET 8 ; Exit & Clean Up Stack\r
+ \r
+SET_DAC_REGISTER ENDP\r
+ \r
+;====================================================\r
+;GET_DAC_REGISTER (Register%, &Red%, &Green%, &Blue%)\r
+;====================================================\r
+;\r
+; Reads the RGB Values of a single Vga Palette Register\r
+;\r
+; ENTRY: Register = The DAC # to read (0-255)\r
+; Red = Offset to Red Variable in DS\r
+; Green = Offset to Green Variable in DS\r
+; Blue = Offset to Blue Variable in DS\r
+;\r
+; EXIT: The values of the integer variables Red,\r
+; Green, and Blue are set to the values\r
+; taken from the specified DAC register.\r
+;\r
+ \r
+GDR_STACK STRUC\r
+ DW ? ; BP\r
+ DD ? ; Caller\r
+ GDR_Blue DW ? ; Addr of Blue Data Value in DS\r
+ GDR_Green DW ? ; Addr of Green Data Value in DS\r
+ GDR_Red DW ? ; Addr of Red Data Value in DS\r
+ GDR_Register DB ?,? ; Palette Register #\r
+GDR_STACK ENDS\r
+ \r
+ PUBLIC GET_DAC_REGISTER\r
+ \r
+GET_DAC_REGISTER PROC FAR\r
+ \r
+ PUSH BP ; Save BP\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+ ; Select which DAC Register to read in\r
+ \r
+ OUT_8 DAC_READ_ADDR, [BP].GDR_Register\r
+ \r
+ MOV DX, PEL_DATA_REG ; Dac Data Register\r
+ CLR AX ; Clear AX\r
+ \r
+ IN AL, DX ; Read Red Value\r
+ MOV BX, [BP].GDR_Red ; Get Address of Red%\r
+ MOV [BX], AX ; *Red% = AX\r
+ \r
+ IN AL, DX ; Read Green Value\r
+ MOV BX, [BP].GDR_Green ; Get Address of Green%\r
+ MOV [BX], AX ; *Green% = AX\r
+ \r
+ IN AL, DX ; Read Blue Value\r
+ MOV BX, [BP].GDR_Blue ; Get Address of Blue%\r
+ MOV [BX], AX ; *Blue% = AX\r
+ \r
+ POP BP ; Restore Registers\r
+ RET 8 ; Exit & Clean Up Stack\r
+ \r
+GET_DAC_REGISTER ENDP\r
+ \r
+ \r
+;===========================================================\r
+;LOAD_DAC_REGISTERS (SEG PalData, StartReg%, EndReg%, Sync%)\r
+;===========================================================\r
+;\r
+; Sets a Block of Vga Palette Registers\r
+;\r
+; ENTRY: PalData = Far Pointer to Block of palette data\r
+; StartReg = First Register # in range to set (0-255)\r
+; EndReg = Last Register # in Range to set (0-255)\r
+; Sync = Wait for Vertical Retrace Flag (Boolean)\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+; NOTES: PalData is a linear array of 3 byte Palette values\r
+; in the order: Red (0-63), Green (0-63), Blue (0-63)\r
+;\r
+ \r
+LDR_STACK STRUC\r
+ DW ?x3 ; BP, DS, SI\r
+ DD ? ; Caller\r
+ LDR_Sync DW ? ; Vertical Sync Flag\r
+ LDR_EndReg DB ?,? ; Last Register #\r
+ LDR_StartReg DB ?,? ; First Register #\r
+ LDR_PalData DD ? ; Far Ptr to Palette Data\r
+LDR_STACK ENDS\r
+ \r
+ PUBLIC LOAD_DAC_REGISTERS\r
+ \r
+LOAD_DAC_REGISTERS PROC FAR\r
+ \r
+ PUSHx BP, DS, SI ; Save Registers\r
+ mov BP, SP ; Set up Stack Frame\r
+ \r
+ mov AX, [BP].LDR_Sync ; Get Vertical Sync Flag\r
+ or AX, AX ; is Sync Flag = 0?\r
+ jz @LDR_Load ; if so, skip call\r
+ \r
+ call f SYNC_DISPLAY ; wait for vsync\r
+ \r
+ ; Determine register #'s, size to copy, etc\r
+ \r
+@LDR_Load:\r
+ \r
+ lds SI, [BP].LDR_PalData ; DS:SI -> Palette Data\r
+ mov DX, DAC_WRITE_ADDR ; DAC register # selector\r
+ \r
+ CLR AX, BX ; Clear for byte loads\r
+ mov AL, [BP].LDR_StartReg ; Get Start Register\r
+ mov BL, [BP].LDR_EndReg ; Get End Register\r
+ \r
+ sub BX, AX ; BX = # of DAC registers -1\r
+ inc BX ; BX = # of DAC registers\r
+ mov CX, BX ; CX = # of DAC registers\r
+ add CX, BX ; CX = " " * 2\r
+ add CX, BX ; CX = " " * 3\r
+ cld ; Block OUTs forward\r
+ out DX, AL ; set up correct register #\r
+ \r
+ ; Load a block of DAC Registers\r
+ \r
+ mov DX, PEL_DATA_REG ; Dac Data Register\r
+ \r
+ rep outsb ; block set DAC registers\r
+ \r
+ POPx SI, DS, BP ; Restore Registers\r
+ ret 10 ; Exit & Clean Up Stack\r
+ \r
+LOAD_DAC_REGISTERS ENDP\r
+ \r
+ \r
+;====================================================\r
+;READ_DAC_REGISTERS (SEG PalData, StartReg%, EndReg%)\r
+;====================================================\r
+;\r
+; Reads a Block of Vga Palette Registers\r
+;\r
+; ENTRY: PalData = Far Pointer to block to store palette data\r
+; StartReg = First Register # in range to read (0-255)\r
+; EndReg = Last Register # in Range to read (0-255)\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+; NOTES: PalData is a linear array of 3 byte Palette values\r
+; in the order: Red (0-63), Green (0-63), Blue (0-63)\r
+;\r
+ \r
+RDR_STACK STRUC\r
+ DW ?x3 ; BP, ES, DI\r
+ DD ? ; Caller\r
+ RDR_EndReg DB ?,? ; Last Register #\r
+ RDR_StartReg DB ?,? ; First Register #\r
+ RDR_PalData DD ? ; Far Ptr to Palette Data\r
+RDR_STACK ENDS\r
+ \r
+ PUBLIC READ_DAC_REGISTERS\r
+ \r
+READ_DAC_REGISTERS PROC FAR\r
+ \r
+ PUSHx BP, ES, DI ; Save Registers\r
+ mov BP, SP ; Set up Stack Frame\r
+ \r
+ ; Determine register #'s, size to copy, etc\r
+ \r
+ les DI, [BP].RDR_PalData ; ES:DI -> Palette Buffer\r
+ mov DX, DAC_READ_ADDR ; DAC register # selector\r
+ \r
+ CLR AX, BX ; Clear for byte loads\r
+ mov AL, [BP].RDR_StartReg ; Get Start Register\r
+ mov BL, [BP].RDR_EndReg ; Get End Register\r
+ \r
+ sub BX, AX ; BX = # of DAC registers -1\r
+ inc BX ; BX = # of DAC registers\r
+ mov CX, BX ; CX = # of DAC registers\r
+ add CX, BX ; CX = " " * 2\r
+ add CX, BX ; CX = " " * 3\r
+ cld ; Block INs forward\r
+ \r
+ ; Read a block of DAC Registers\r
+ \r
+ out DX, AL ; set up correct register #\r
+ mov DX, PEL_DATA_REG ; Dac Data Register\r
+ \r
+ rep insb ; block read DAC registers\r
+ \r
+ POPx DI, ES, BP ; Restore Registers\r
+ ret 8 ; Exit & Clean Up Stack\r
+ \r
+READ_DAC_REGISTERS ENDP\r
+ \r
+ \r
+ ; ===== PAGE FLIPPING AND SCROLLING ROUTINES =====\r
+ \r
+;=========================\r
+;SET_ACTIVE_PAGE (PageNo%)\r
+;=========================\r
+;\r
+; Sets the active display Page to be used for future drawing\r
+;\r
+; ENTRY: PageNo = Display Page to make active\r
+; (values: 0 to Number of Pages - 1)\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+ \r
+SAP_STACK STRUC\r
+ DW ? ; BP\r
+ DD ? ; Caller\r
+ SAP_Page DW ? ; Page # for Drawing\r
+SAP_STACK ENDS\r
+ \r
+ PUBLIC SET_ACTIVE_PAGE\r
+ \r
+SET_ACTIVE_PAGE PROC FAR\r
+ \r
+ PUSH BP ; Preserve Registers\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+ MOV BX, [BP].SAP_Page ; Get Desired Page #\r
+ CMP BX, LAST_PAGE ; Is Page # Valid?\r
+ JAE @SAP_Exit ; IF Not, Do Nothing\r
+ \r
+ MOV ACTIVE_PAGE, BX ; Set Active Page #\r
+ \r
+ SHL BX, 1 ; Scale Page # to Word\r
+ MOV AX, PAGE_ADDR[BX] ; Get offset to Page\r
+ \r
+ MOV CURRENT_PAGE, AX ; And set for future LES's\r
+ \r
+@SAP_Exit:\r
+ POP BP ; Restore Registers\r
+ RET 2 ; Exit and Clean up Stack\r
+ \r
+SET_ACTIVE_PAGE ENDP\r
+ \r
+ \r
+;================\r
+;GET_ACTIVE_PAGE%\r
+;================\r
+;\r
+; Returns the Video Page # currently used for Drawing\r
+;\r
+; ENTRY: No Parameters are passed\r
+;\r
+; EXIT: AX = Current Video Page used for Drawing\r
+;\r
+ \r
+ PUBLIC GET_ACTIVE_PAGE\r
+ \r
+GET_ACTIVE_PAGE PROC FAR\r
+ \r
+ MOV AX, ACTIVE_PAGE ; Get Active Page #\r
+ RET ; Exit and Clean up Stack\r
+ \r
+GET_ACTIVE_PAGE ENDP\r
+ \r
+ \r
+;===============================\r
+;SET_DISPLAY_PAGE (DisplayPage%)\r
+;===============================\r
+;\r
+; Sets the currently visible display page.\r
+; When called this routine syncronizes the display\r
+; to the vertical blank.\r
+;\r
+; ENTRY: PageNo = Display Page to show on the screen\r
+; (values: 0 to Number of Pages - 1)\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+ \r
+SDP_STACK STRUC\r
+ DW ? ; BP\r
+ DD ? ; Caller\r
+ SDP_Page DW ? ; Page # to Display...\r
+SDP_STACK ENDS\r
+ \r
+ PUBLIC SET_DISPLAY_PAGE\r
+ \r
+SET_DISPLAY_PAGE PROC FAR\r
+ \r
+ PUSH BP ; Preserve Registers\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+ MOV BX, [BP].SDP_Page ; Get Desired Page #\r
+ CMP BX, LAST_PAGE ; Is Page # Valid?\r
+ JAE @SDP_Exit ; IF Not, Do Nothing\r
+ \r
+ MOV DISPLAY_PAGE, BX ; Set Display Page #\r
+ \r
+ SHL BX, 1 ; Scale Page # to Word\r
+ MOV CX, PAGE_ADDR[BX] ; Get offset in memory to Page\r
+ ADD CX, CURRENT_MOFFSET ; Adjust for any scrolling\r
+ \r
+ ; Wait if we are currently in a Vertical Retrace\r
+ \r
+ MOV DX, INPUT_1 ; Input Status #1 Register\r
+ \r
+@DP_WAIT0:\r
+ IN AL, DX ; Get VGA status\r
+ AND AL, VERT_RETRACE ; In Display mode yet?\r
+ JNZ @DP_WAIT0 ; If Not, wait for it\r
+ \r
+ ; Set the Start Display Address to the new page\r
+ \r
+ MOV DX, CRTC_Index ; We Change the VGA Sequencer\r
+ \r
+ MOV AL, START_DISP_LO ; Display Start Low Register\r
+ MOV AH, CL ; Low 8 Bits of Start Addr\r
+ OUT DX, AX ; Set Display Addr Low\r
+ \r
+ MOV AL, START_DISP_HI ; Display Start High Register\r
+ MOV AH, CH ; High 8 Bits of Start Addr\r
+ OUT DX, AX ; Set Display Addr High\r
+ \r
+ ; Wait for a Vertical Retrace to smooth out things\r
+ \r
+ MOV DX, INPUT_1 ; Input Status #1 Register\r
+ \r
+@DP_WAIT1:\r
+ IN AL, DX ; Get VGA status\r
+ AND AL, VERT_RETRACE ; Vertical Retrace Start?\r
+ JZ @DP_WAIT1 ; If Not, wait for it\r
+ \r
+ ; Now Set Display Starting Address\r
+ \r
+ \r
+@SDP_Exit:\r
+ POP BP ; Restore Registers\r
+ RET 2 ; Exit and Clean up Stack\r
+ \r
+SET_DISPLAY_PAGE ENDP\r
+ \r
+ \r
+;=================\r
+;GET_DISPLAY_PAGE%\r
+;=================\r
+;\r
+; Returns the Video Page # currently displayed\r
+;\r
+; ENTRY: No Parameters are passed\r
+;\r
+; EXIT: AX = Current Video Page being displayed\r
+;\r
+ \r
+ PUBLIC GET_DISPLAY_PAGE\r
+ \r
+GET_DISPLAY_PAGE PROC FAR\r
+ \r
+ MOV AX, DISPLAY_PAGE ; Get Display Page #\r
+ RET ; Exit & Clean Up Stack\r
+ \r
+GET_DISPLAY_PAGE ENDP\r
+ \r
+ \r
+;=======================================\r
+;SET_WINDOW (DisplayPage%, Xpos%, Ypos%)\r
+;=======================================\r
+;\r
+; Since a Logical Screen can be larger than the Physical\r
+; Screen, Scrolling is possible. This routine sets the\r
+; Upper Left Corner of the Screen to the specified Pixel.\r
+; Also Sets the Display page to simplify combined page\r
+; flipping and scrolling. When called this routine\r
+; syncronizes the display to the vertical blank.\r
+;\r
+; ENTRY: DisplayPage = Display Page to show on the screen\r
+; Xpos = # of pixels to shift screen right\r
+; Ypos = # of lines to shift screen down\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+ \r
+SW_STACK STRUC\r
+ DW ? ; BP\r
+ DD ? ; Caller\r
+ SW_Ypos DW ? ; Y pos of UL Screen Corner\r
+ SW_Xpos DW ? ; X pos of UL Screen Corner\r
+ SW_Page DW ? ; (new) Display Page\r
+SW_STACK ENDS\r
+ \r
+ PUBLIC SET_WINDOW\r
+ \r
+SET_WINDOW PROC FAR\r
+ \r
+ PUSH BP ; Preserve Registers\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+ ; Check if our Scroll Offsets are Valid\r
+ \r
+ MOV BX, [BP].SW_Page ; Get Desired Page #\r
+ CMP BX, LAST_PAGE ; Is Page # Valid?\r
+ JAE @SW_Exit ; IF Not, Do Nothing\r
+ \r
+ MOV AX, [BP].SW_Ypos ; Get Desired Y Offset\r
+ CMP AX, MAX_YOFFSET ; Is it Within Limits?\r
+ JA @SW_Exit ; if not, exit\r
+ \r
+ MOV CX, [BP].SW_Xpos ; Get Desired X Offset\r
+ CMP CX, MAX_XOFFSET ; Is it Within Limits?\r
+ JA @SW_Exit ; if not, exit\r
+ \r
+ ; Compute proper Display start address to use\r
+ \r
+ MUL SCREEN_WIDTH ; AX = YOffset * Line Width\r
+ SHR CX, 2 ; CX / 4 = Bytes into Line\r
+ ADD AX, CX ; AX = Offset of Upper Left Pixel\r
+ \r
+ MOV CURRENT_MOFFSET, AX ; Save Offset Info\r
+ \r
+ MOV DISPLAY_PAGE, BX ; Set Current Page #\r
+ SHL BX, 1 ; Scale Page # to Word\r
+ ADD AX, PAGE_ADDR[BX] ; Get offset in VGA to Page\r
+ MOV BX, AX ; BX = Desired Display Start\r
+ \r
+ MOV DX, INPUT_1 ; Input Status #1 Register\r
+ \r
+ ; Wait if we are currently in a Vertical Retrace\r
+ \r
+@SW_WAIT0:\r
+ IN AL, DX ; Get VGA status\r
+ AND AL, VERT_RETRACE ; In Display mode yet?\r
+ JNZ @SW_WAIT0 ; If Not, wait for it\r
+ \r
+ ; Set the Start Display Address to the new window\r
+ \r
+ MOV DX, CRTC_Index ; We Change the VGA Sequencer\r
+ MOV AL, START_DISP_LO ; Display Start Low Register\r
+ MOV AH, BL ; Low 8 Bits of Start Addr\r
+ OUT DX, AX ; Set Display Addr Low\r
+ \r
+ MOV AL, START_DISP_HI ; Display Start High Register\r
+ MOV AH, BH ; High 8 Bits of Start Addr\r
+ OUT DX, AX ; Set Display Addr High\r
+ \r
+ ; Wait for a Vertical Retrace to smooth out things\r
+ \r
+ MOV DX, INPUT_1 ; Input Status #1 Register\r
+ \r
+@SW_WAIT1:\r
+ IN AL, DX ; Get VGA status\r
+ AND AL, VERT_RETRACE ; Vertical Retrace Start?\r
+ JZ @SW_WAIT1 ; If Not, wait for it\r
+ \r
+ ; Now Set the Horizontal Pixel Pan values\r
+ \r
+ OUT_8 ATTRIB_Ctrl, PIXEL_PAN_REG ; Select Pixel Pan Register\r
+ \r
+ MOV AX, [BP].SW_Xpos ; Get Desired X Offset\r
+ AND AL, 03 ; Get # of Pixels to Pan (0-3)\r
+ SHL AL, 1 ; Shift for 256 Color Mode\r
+ OUT DX, AL ; Fine tune the display!\r
+ \r
+@SW_Exit:\r
+ POP BP ; Restore Saved Registers\r
+ RET 6 ; Exit and Clean up Stack\r
+ \r
+SET_WINDOW ENDP\r
+ \r
+ \r
+;=============\r
+;GET_X_OFFSET%\r
+;=============\r
+;\r
+; Returns the X coordinate of the Pixel currently display\r
+; in the upper left corner of the display\r
+;\r
+; ENTRY: No Parameters are passed\r
+;\r
+; EXIT: AX = Current Horizontal Scroll Offset\r
+;\r
+ \r
+ PUBLIC GET_X_OFFSET\r
+ \r
+GET_X_OFFSET PROC FAR\r
+ \r
+ MOV AX, CURRENT_XOFFSET ; Get current horz offset\r
+ RET ; Exit & Clean Up Stack\r
+ \r
+GET_X_OFFSET ENDP\r
+ \r
+ \r
+;=============\r
+;GET_Y_OFFSET%\r
+;=============\r
+;\r
+; Returns the Y coordinate of the Pixel currently display\r
+; in the upper left corner of the display\r
+;\r
+; ENTRY: No Parameters are passed\r
+;\r
+; EXIT: AX = Current Vertical Scroll Offset\r
+;\r
+ \r
+ PUBLIC GET_Y_OFFSET\r
+ \r
+GET_Y_OFFSET PROC FAR\r
+ \r
+ MOV AX, CURRENT_YOFFSET ; Get current vertical offset\r
+ RET ; Exit & Clean Up Stack\r
+ \r
+GET_Y_OFFSET ENDP\r
+ \r
+ \r
+;============\r
+;SYNC_DISPLAY\r
+;============\r
+;\r
+; Pauses the computer until the next Vertical Retrace starts\r
+;\r
+; ENTRY: No Parameters are passed\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+ \r
+ PUBLIC SYNC_DISPLAY\r
+ \r
+SYNC_DISPLAY PROC FAR\r
+ \r
+ MOV DX, INPUT_1 ; Input Status #1 Register\r
+ \r
+ ; Wait for any current retrace to end\r
+ \r
+@SD_WAIT0:\r
+ IN AL, DX ; Get VGA status\r
+ AND AL, VERT_RETRACE ; In Display mode yet?\r
+ JNZ @SD_WAIT0 ; If Not, wait for it\r
+ \r
+ ; Wait for the start of the next vertical retrace\r
+ \r
+@SD_WAIT1:\r
+ IN AL, DX ; Get VGA status\r
+ AND AL, VERT_RETRACE ; Vertical Retrace Start?\r
+ JZ @SD_WAIT1 ; If Not, wait for it\r
+ \r
+ RET ; Exit & Clean Up Stack\r
+ \r
+SYNC_DISPLAY ENDP\r
+ \r
+ \r
+ ; ===== TEXT DISPLAY ROUTINES =====\r
+ \r
+;==================================================\r
+;GPRINTC (CharNum%, Xpos%, Ypos%, ColorF%, ColorB%)\r
+;==================================================\r
+;\r
+; Draws an ASCII Text Character using the currently selected\r
+; 8x8 font on the active display page. It would be a simple\r
+; exercise to make this routine process variable height fonts.\r
+;\r
+; ENTRY: CharNum = ASCII character # to draw\r
+; Xpos = X position to draw Character at\r
+; Ypos = Y position of to draw Character at\r
+; ColorF = Color to draw text character in\r
+; ColorB = Color to set background to\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+ \r
+GPC_STACK STRUC\r
+ GPC_Width DW ? ; Screen Width-1\r
+ GPC_Lines DB ?,? ; Scan lines to Decode\r
+ GPC_T_SETS DW ? ; Saved Charset Segment\r
+ GPC_T_SETO DW ? ; Saved Charset Offset\r
+ DW ?x4 ; DI, SI, DS, BP\r
+ DD ? ; Caller\r
+ GPC_ColorB DB ?,? ; Background Color\r
+ GPC_ColorF DB ?,? ; Text Color\r
+ GPC_Ypos DW ? ; Y Position to Print at\r
+ GPC_Xpos DW ? ; X position to Print at\r
+ GPC_Char DB ?,? ; Character to Print\r
+GPC_STACK ENDS\r
+ \r
+ PUBLIC GPRINTC\r
+ \r
+GPRINTC PROC FAR\r
+ \r
+ PUSHx BP, DS, SI, DI ; Preserve Important Registers\r
+ SUB SP, 8 ; Allocate WorkSpace on Stack\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+ LES DI, d CURRENT_PAGE ; Point to Active VGA Page\r
+ \r
+ MOV AX, SCREEN_WIDTH ; Get Logical Line Width\r
+ MOV BX, AX ; BX = Screen Width\r
+ DEC BX ; = Screen Width-1\r
+ MOV [BP].GPC_Width, BX ; Save for later use\r
+ \r
+ MUL [BP].GPC_Ypos ; Start of Line = Ypos * Width\r
+ ADD DI, AX ; DI -> Start of Line Ypos\r
+ \r
+ MOV AX, [BP].GPC_Xpos ; Get Xpos of Character\r
+ MOV CX, AX ; Save Copy of Xpos\r
+ SHR AX, 2 ; Bytes into Line = Xpos/4\r
+ ADD DI, AX ; DI -> (Xpos, Ypos)\r
+ \r
+ ;Get Source ADDR of Character Bit Map & Save\r
+ \r
+ MOV AL, [BP].GPC_Char ; Get Character #\r
+ TEST AL, 080h ; Is Hi Bit Set?\r
+ JZ @GPC_LowChar ; Nope, use low char set ptr\r
+ \r
+ AND AL, 07Fh ; Mask Out Hi Bit\r
+ MOV BX, CHARSET_HI ; BX = Char Set Ptr:Offset\r
+ MOV DX, CHARSET_HI+2 ; DX = Char Set Ptr:Segment\r
+ JMP s @GPC_Set_Char ; Go Setup Character Ptr\r
+ \r
+@GPC_LowChar:\r
+ \r
+ MOV BX, CHARSET_LOW ; BX = Char Set Ptr:Offset\r
+ MOV DX, CHARSET_LOW+2 ; DX = Char Set Ptr:Segment\r
+ \r
+@GPC_Set_Char:\r
+ MOV [BP].GPC_T_SETS, DX ; Save Segment on Stack\r
+ \r
+ MOV AH, 0 ; Valid #'s are 0..127\r
+ SHL AX, 3 ; * 8 Bytes Per Bitmap\r
+ ADD BX, AX ; BX = Offset of Selected char\r
+ MOV [BP].GPC_T_SETO, BX ; Save Offset on Stack\r
+ \r
+ AND CX, PLANE_BITS ; Get Plane #\r
+ MOV CH, ALL_PLANES ; Get Initial Plane mask\r
+ SHL CH, CL ; And shift into position\r
+ AND CH, ALL_PLANES ; And mask to lower nibble\r
+ \r
+ MOV AL, 04 ; 4-Plane # = # of initial\r
+ SUB AL, CL ; shifts to align bit mask\r
+ MOV CL, AL ; Shift Count for SHL\r
+ \r
+ ;Get segment of character map\r
+ \r
+ OUT_8 SC_Index, MAP_MASK ; Setup Plane selections\r
+ INC DX ; DX -> SC_Data\r
+ \r
+ MOV AL, 08 ; 8 Lines to Process\r
+ MOV [BP].GPC_Lines, AL ; Save on Stack\r
+ \r
+ MOV DS, [BP].GPC_T_SETS ; Point to character set\r
+ \r
+@GPC_DECODE_CHAR_BYTE:\r
+ \r
+ MOV SI, [BP].GPC_T_SETO ; Get DS:SI = String\r
+ \r
+ MOV BH, [SI] ; Get Bit Map\r
+ INC SI ; Point to Next Line\r
+ MOV [BP].GPC_T_SETO, SI ; And save new Pointer...\r
+ \r
+ CLR AX ; Clear AX\r
+ \r
+ CLR BL ; Clear BL\r
+ ROL BX, CL ; BL holds left edge bits\r
+ MOV SI, BX ; Use as Table Index\r
+ AND SI, CHAR_BITS ; Get Low Bits\r
+ MOV AL, Char_Plane_Data[SI] ; Get Mask in AL\r
+ JZ @GPC_NO_LEFT1BITS ; Skip if No Pixels to set\r
+ \r
+ MOV AH, [BP].GPC_ColorF ; Get Foreground Color\r
+ OUT DX, AL ; Set up Screen Mask\r
+ MOV ES:[DI], AH ; Write Foreground color\r
+ \r
+@GPC_NO_LEFT1BITS:\r
+ XOR AL, CH ; Invert mask for Background\r
+ JZ @GPC_NO_LEFT0BITS ; Hey, no need for this\r
+ \r
+ MOV AH, [BP].GPC_ColorB ; Get background Color\r
+ OUT DX, AL ; Set up Screen Mask\r
+ MOV ES:[DI], AH ; Write Foreground color\r
+ \r
+ ;Now Do Middle/Last Band\r
+ \r
+@GPC_NO_LEFT0BITS:\r
+ INC DI ; Point to next Byte\r
+ ROL BX, 4 ; Shift 4 bits\r
+ \r
+ MOV SI, BX ; Make Lookup Pointer\r
+ AND SI, CHAR_BITS ; Get Low Bits\r
+ MOV AL, Char_Plane_Data[SI] ; Get Mask in AL\r
+ JZ @GPC_NO_MIDDLE1BITS ; Skip if no pixels to set\r
+ \r
+ MOV AH, [BP].GPC_ColorF ; Get Foreground Color\r
+ OUT DX, AL ; Set up Screen Mask\r
+ MOV ES:[DI], AH ; Write Foreground color\r
+ \r
+@GPC_NO_MIDDLE1BITS:\r
+ XOR AL, ALL_PLANES ; Invert mask for Background\r
+ JZ @GPC_NO_MIDDLE0BITS ; Hey, no need for this\r
+ \r
+ MOV AH, [BP].GPC_ColorB ; Get background Color\r
+ OUT DX, AL ; Set up Screen Mask\r
+ MOV ES:[DI], AH ; Write Foreground color\r
+ \r
+@GPC_NO_MIDDLE0BITS:\r
+ XOR CH, ALL_PLANES ; Invert Clip Mask\r
+ CMP CL, 4 ; Aligned by 4?\r
+ JZ @GPC_NEXT_LINE ; If so, Exit now..\r
+ \r
+ INC DI ; Point to next Byte\r
+ ROL BX, 4 ; Shift 4 bits\r
+ \r
+ MOV SI, BX ; Make Lookup Pointer\r
+ AND SI, CHAR_BITS ; Get Low Bits\r
+ MOV AL, Char_Plane_Data[SI] ; Get Mask in AL\r
+ JZ @GPC_NO_RIGHT1BITS ; Skip if No Pixels to set\r
+ \r
+ MOV AH, [BP].GPC_ColorF ; Get Foreground Color\r
+ OUT DX, AL ; Set up Screen Mask\r
+ MOV ES:[DI], AH ; Write Foreground color\r
+ \r
+@GPC_NO_RIGHT1BITS:\r
+ \r
+ XOR AL, CH ; Invert mask for Background\r
+ JZ @GPC_NO_RIGHT0BITS ; Hey, no need for this\r
+ \r
+ MOV AH, [BP].GPC_ColorB ; Get background Color\r
+ OUT DX, AL ; Set up Screen Mask\r
+ MOV ES:[DI], AH ; Write Foreground color\r
+ \r
+@GPC_NO_RIGHT0BITS:\r
+ DEC DI ; Adjust for Next Line Advance\r
+ \r
+@GPC_NEXT_LINE:\r
+ ADD DI, [BP].GPC_Width ; Point to Next Line\r
+ XOR CH, CHAR_BITS ; Flip the Clip mask back\r
+ \r
+ DEC [BP].GPC_Lines ; Count Down Lines\r
+ JZ @GPC_EXIT ; Ok... Done!\r
+ \r
+ JMP @GPC_DECODE_CHAR_BYTE ; Again! Hey!\r
+ \r
+@GPC_EXIT:\r
+ ADD SP, 08 ; Deallocate stack workspace\r
+ POPx DI, SI, DS, BP ; Restore Saved Registers\r
+ RET 10 ; Exit and Clean up Stack\r
+ \r
+GPRINTC ENDP\r
+ \r
+ \r
+;==========================================\r
+;TGPRINTC (CharNum%, Xpos%, Ypos%, ColorF%)\r
+;==========================================\r
+;\r
+; Transparently draws an ASCII Text Character using the\r
+; currently selected 8x8 font on the active display page.\r
+;\r
+; ENTRY: CharNum = ASCII character # to draw\r
+; Xpos = X position to draw Character at\r
+; Ypos = Y position of to draw Character at\r
+; ColorF = Color to draw text character in\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+ \r
+TGP_STACK STRUC\r
+ TGP_Width DW ? ; Screen Width-1\r
+ TGP_Lines DB ?,? ; Scan lines to Decode\r
+ TGP_T_SETS DW ? ; Saved Charset Segment\r
+ TGP_T_SETO DW ? ; Saved Charset Offset\r
+ DW ?x4 ; DI, SI, DS, BP\r
+ DD ? ; Caller\r
+ TGP_ColorF DB ?,? ; Text Color\r
+ TGP_Ypos DW ? ; Y Position to Print at\r
+ TGP_Xpos DW ? ; X position to Print at\r
+ TGP_Char DB ?,? ; Character to Print\r
+TGP_STACK ENDS\r
+ \r
+ PUBLIC TGPRINTC\r
+ \r
+TGPRINTC PROC FAR\r
+ \r
+ PUSHx BP, DS, SI, DI ; Preserve Important Registers\r
+ SUB SP, 8 ; Allocate WorkSpace on Stack\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+ LES DI, d CURRENT_PAGE ; Point to Active VGA Page\r
+ \r
+ MOV AX, SCREEN_WIDTH ; Get Logical Line Width\r
+ MOV BX, AX ; BX = Screen Width\r
+ DEC BX ; = Screen Width-1\r
+ MOV [BP].TGP_Width, BX ; Save for later use\r
+ \r
+ MUL [BP].TGP_Ypos ; Start of Line = Ypos * Width\r
+ ADD DI, AX ; DI -> Start of Line Ypos\r
+ \r
+ MOV AX, [BP].TGP_Xpos ; Get Xpos of Character\r
+ MOV CX, AX ; Save Copy of Xpos\r
+ SHR AX, 2 ; Bytes into Line = Xpos/4\r
+ ADD DI, AX ; DI -> (Xpos, Ypos)\r
+ \r
+ ;Get Source ADDR of Character Bit Map & Save\r
+ \r
+ MOV AL, [BP].TGP_Char ; Get Character #\r
+ TEST AL, 080h ; Is Hi Bit Set?\r
+ JZ @TGP_LowChar ; Nope, use low char set ptr\r
+ \r
+ AND AL, 07Fh ; Mask Out Hi Bit\r
+ MOV BX, CHARSET_HI ; BX = Char Set Ptr:Offset\r
+ MOV DX, CHARSET_HI+2 ; DX = Char Set Ptr:Segment\r
+ JMP s @TGP_Set_Char ; Go Setup Character Ptr\r
+ \r
+@TGP_LowChar:\r
+ \r
+ MOV BX, CHARSET_LOW ; BX = Char Set Ptr:Offset\r
+ MOV DX, CHARSET_LOW+2 ; DX = Char Set Ptr:Segment\r
+ \r
+@TGP_Set_Char:\r
+ MOV [BP].TGP_T_SETS, DX ; Save Segment on Stack\r
+ \r
+ MOV AH, 0 ; Valid #'s are 0..127\r
+ SHL AX, 3 ; * 8 Bytes Per Bitmap\r
+ ADD BX, AX ; BX = Offset of Selected char\r
+ MOV [BP].TGP_T_SETO, BX ; Save Offset on Stack\r
+ \r
+ AND CX, PLANE_BITS ; Get Plane #\r
+ MOV CH, ALL_PLANES ; Get Initial Plane mask\r
+ SHL CH, CL ; And shift into position\r
+ AND CH, ALL_PLANES ; And mask to lower nibble\r
+ \r
+ MOV AL, 04 ; 4-Plane # = # of initial\r
+ SUB AL, CL ; shifts to align bit mask\r
+ MOV CL, AL ; Shift Count for SHL\r
+ \r
+ ;Get segment of character map\r
+ \r
+ OUT_8 SC_Index, MAP_MASK ; Setup Plane selections\r
+ INC DX ; DX -> SC_Data\r
+ \r
+ MOV AL, 08 ; 8 Lines to Process\r
+ MOV [BP].TGP_Lines, AL ; Save on Stack\r
+ \r
+ MOV DS, [BP].TGP_T_SETS ; Point to character set\r
+ \r
+@TGP_DECODE_CHAR_BYTE:\r
+ \r
+ MOV SI, [BP].TGP_T_SETO ; Get DS:SI = String\r
+ \r
+ MOV BH, [SI] ; Get Bit Map\r
+ INC SI ; Point to Next Line\r
+ MOV [BP].TGP_T_SETO, SI ; And save new Pointer...\r
+ \r
+ MOV AH, [BP].TGP_ColorF ; Get Foreground Color\r
+ \r
+ CLR BL ; Clear BL\r
+ ROL BX, CL ; BL holds left edge bits\r
+ MOV SI, BX ; Use as Table Index\r
+ AND SI, CHAR_BITS ; Get Low Bits\r
+ MOV AL, Char_Plane_Data[SI] ; Get Mask in AL\r
+ JZ @TGP_NO_LEFT1BITS ; Skip if No Pixels to set\r
+ \r
+ OUT DX, AL ; Set up Screen Mask\r
+ MOV ES:[DI], AH ; Write Foreground color\r
+ \r
+ ;Now Do Middle/Last Band\r
+ \r
+@TGP_NO_LEFT1BITS:\r
+ \r
+ INC DI ; Point to next Byte\r
+ ROL BX, 4 ; Shift 4 bits\r
+ \r
+ MOV SI, BX ; Make Lookup Pointer\r
+ AND SI, CHAR_BITS ; Get Low Bits\r
+ MOV AL, Char_Plane_Data[SI] ; Get Mask in AL\r
+ JZ @TGP_NO_MIDDLE1BITS ; Skip if no pixels to set\r
+ \r
+ OUT DX, AL ; Set up Screen Mask\r
+ MOV ES:[DI], AH ; Write Foreground color\r
+ \r
+@TGP_NO_MIDDLE1BITS:\r
+ XOR CH, ALL_PLANES ; Invert Clip Mask\r
+ CMP CL, 4 ; Aligned by 4?\r
+ JZ @TGP_NEXT_LINE ; If so, Exit now..\r
+ \r
+ INC DI ; Point to next Byte\r
+ ROL BX, 4 ; Shift 4 bits\r
+ \r
+ MOV SI, BX ; Make Lookup Pointer\r
+ AND SI, CHAR_BITS ; Get Low Bits\r
+ MOV AL, Char_Plane_Data[SI] ; Get Mask in AL\r
+ JZ @TGP_NO_RIGHT1BITS ; Skip if No Pixels to set\r
+ \r
+ OUT DX, AL ; Set up Screen Mask\r
+ MOV ES:[DI], AH ; Write Foreground color\r
+ \r
+@TGP_NO_RIGHT1BITS:\r
+ \r
+ DEC DI ; Adjust for Next Line Advance\r
+ \r
+@TGP_NEXT_LINE:\r
+ ADD DI, [BP].TGP_Width ; Point to Next Line\r
+ XOR CH, CHAR_BITS ; Flip the Clip mask back\r
+ \r
+ DEC [BP].TGP_Lines ; Count Down Lines\r
+ JZ @TGP_EXIT ; Ok... Done!\r
+ \r
+ JMP @TGP_DECODE_CHAR_BYTE ; Again! Hey!\r
+ \r
+@TGP_EXIT:\r
+ ADD SP, 08 ; Deallocate stack workspace\r
+ POPx DI, SI, DS, BP ; Restore Saved Registers\r
+ RET 8 ; Exit and Clean up Stack\r
+ \r
+TGPRINTC ENDP\r
+ \r
+ \r
+;===============================================================\r
+;PRINT_STR (SEG String, MaxLen%, Xpos%, Ypos%, ColorF%, ColorB%)\r
+;===============================================================\r
+;\r
+; Routine to quickly Print a null terminated ASCII string on the\r
+; active display page up to a maximum length.\r
+;\r
+; ENTRY: String = Far Pointer to ASCII string to print\r
+; MaxLen = # of characters to print if no null found\r
+; Xpos = X position to draw Text at\r
+; Ypos = Y position of to draw Text at\r
+; ColorF = Color to draw text in\r
+; ColorB = Color to set background to\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+ \r
+PS_STACK STRUC\r
+ DW ?x4 ; DI, SI, DS, BP\r
+ DD ? ; Caller\r
+ PS_ColorB DW ? ; Background Color\r
+ PS_ColorF DW ? ; Text Color\r
+ PS_Ypos DW ? ; Y Position to Print at\r
+ PS_Xpos DW ? ; X position to Print at\r
+ PS_Len DW ? ; Maximum Length of string to print\r
+ PS_Text DW ?,? ; Far Ptr to Text String\r
+PS_STACK ENDS\r
+ \r
+ PUBLIC PRINT_STR\r
+ \r
+PRINT_STR PROC FAR\r
+ \r
+ PUSHx BP, DS, SI, DI ; Preserve Important Registers\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+@PS_Print_It:\r
+ \r
+ MOV CX, [BP].PS_Len ; Get Remaining text Length\r
+ JCXZ @PS_Exit ; Exit when out of text\r
+ \r
+ LES DI, d [BP].PS_Text ; ES:DI -> Current Char in Text\r
+ MOV AL, ES:[DI] ; AL = Text Character\r
+ AND AX, 00FFh ; Clear High Word\r
+ JZ @PS_Exit ; Exit if null character\r
+ \r
+ DEC [BP].PS_Len ; Remaining Text length--\r
+ INC [BP].PS_Text ; Point to Next text char\r
+ \r
+ ; Set up Call to GPRINTC\r
+ \r
+ PUSH AX ; Set Character Parameter\r
+ MOV BX, [BP].PS_Xpos ; Get Xpos\r
+ PUSH BX ; Set Xpos Parameter\r
+ ADD BX, 8 ; Advance 1 Char to Right\r
+ MOV [BP].PS_Xpos, BX ; Save for next time through\r
+ \r
+ MOV BX, [BP].PS_Ypos ; Get Ypos\r
+ PUSH BX ; Set Ypos Parameter\r
+ \r
+ MOV BX, [BP].PS_ColorF ; Get Text Color\r
+ PUSH BX ; Set ColorF Parameter\r
+ \r
+ MOV BX, [BP].PS_ColorB ; Get Background Color\r
+ PUSH BX ; Set ColorB Parameter\r
+ \r
+ CALL f GPRINTC ; Print Character!\r
+ JMP s @PS_Print_It ; Process next character\r
+ \r
+@PS_Exit:\r
+ POPx DI, SI, DS, BP ; Restore Saved Registers\r
+ RET 14 ; Exit and Clean up Stack\r
+ \r
+PRINT_STR ENDP\r
+ \r
+ \r
+;================================================================\r
+;TPRINT_STR (SEG String, MaxLen%, Xpos%, Ypos%, ColorF%, ColorB%)\r
+;================================================================\r
+;\r
+; Routine to quickly transparently Print a null terminated ASCII\r
+; string on the active display page up to a maximum length.\r
+;\r
+; ENTRY: String = Far Pointer to ASCII string to print\r
+; MaxLen = # of characters to print if no null found\r
+; Xpos = X position to draw Text at\r
+; Ypos = Y position of to draw Text at\r
+; ColorF = Color to draw text in\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+ \r
+TPS_STACK STRUC\r
+ DW ?x4 ; DI, SI, DS, BP\r
+ DD ? ; Caller\r
+ TPS_ColorF DW ? ; Text Color\r
+ TPS_Ypos DW ? ; Y Position to Print at\r
+ TPS_Xpos DW ? ; X position to Print at\r
+ TPS_Len DW ? ; Maximum Length of string to print\r
+ TPS_Text DW ?,? ; Far Ptr to Text String\r
+TPS_STACK ENDS\r
+ \r
+ PUBLIC TPRINT_STR\r
+ \r
+TPRINT_STR PROC FAR\r
+ \r
+ PUSHx BP, DS, SI, DI ; Preserve Important Registers\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+@TPS_Print_It:\r
+ \r
+ MOV CX, [BP].TPS_Len ; Get Remaining text Length\r
+ JCXZ @TPS_Exit ; Exit when out of text\r
+ \r
+ LES DI, d [BP].TPS_Text ; ES:DI -> Current Char in Text\r
+ MOV AL, ES:[DI] ; AL = Text Character\r
+ AND AX, 00FFh ; Clear High Word\r
+ JZ @TPS_Exit ; Exit if null character\r
+ \r
+ DEC [BP].TPS_Len ; Remaining Text length--\r
+ INC [BP].TPS_Text ; Point to Next text char\r
+ \r
+ ; Set up Call to TGPRINTC\r
+ \r
+ PUSH AX ; Set Character Parameter\r
+ MOV BX, [BP].TPS_Xpos ; Get Xpos\r
+ PUSH BX ; Set Xpos Parameter\r
+ ADD BX, 8 ; Advance 1 Char to Right\r
+ MOV [BP].TPS_Xpos, BX ; Save for next time through\r
+ \r
+ MOV BX, [BP].TPS_Ypos ; Get Ypos\r
+ PUSH BX ; Set Ypos Parameter\r
+ \r
+ MOV BX, [BP].TPS_ColorF ; Get Text Color\r
+ PUSH BX ; Set ColorF Parameter\r
+ \r
+ CALL f TGPRINTC ; Print Character!\r
+ JMP s @TPS_Print_It ; Process next character\r
+ \r
+@TPS_Exit:\r
+ POPx DI, SI, DS, BP ; Restore Saved Registers\r
+ RET 12 ; Exit and Clean up Stack\r
+ \r
+TPRINT_STR ENDP\r
+ \r
+ \r
+;===========================================\r
+;SET_DISPLAY_FONT(SEG FontData, FontNumber%)\r
+;===========================================\r
+;\r
+; Allows the user to specify their own font data for\r
+; wither the lower or upper 128 characters.\r
+;\r
+; ENTRY: FontData = Far Pointer to Font Bitmaps\r
+; FontNumber = Which half of set this is\r
+; = 0, Lower 128 characters\r
+; = 1, Upper 128 characters\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+ \r
+SDF_STACK STRUC\r
+ DW ? ; BP\r
+ DD ? ; Caller\r
+ SDF_Which DW ? ; Hi Table/Low Table Flag\r
+ SDF_Font DD ? ; Far Ptr to Font Table\r
+SDF_STACK ENDS\r
+ \r
+ PUBLIC SET_DISPLAY_FONT\r
+ \r
+SET_DISPLAY_FONT PROC FAR\r
+ \r
+ PUSH BP ; Preserve Registers\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+ LES DI, [BP].SDF_Font ; Get Far Ptr to Font\r
+ \r
+ MOV SI, o CHARSET_LOW ; Assume Lower 128 chars\r
+ TEST [BP].SDF_Which, 1 ; Font #1 selected?\r
+ JZ @SDF_Set_Font ; If not, skip ahead\r
+ \r
+ MOV SI, o CHARSET_HI ; Ah, really it's 128-255\r
+ \r
+@SDF_Set_Font:\r
+ MOV [SI], DI ; Set Font Pointer Offset\r
+ MOV [SI+2], ES ; Set Font Pointer Segment\r
+ \r
+ POP BP ; Restore Registers\r
+ RET 6 ; We are Done.. Outa here\r
+ \r
+SET_DISPLAY_FONT ENDP\r
+ \r
+ \r
+ ; ===== BITMAP (SPRITE) DISPLAY ROUTINES =====\r
+ \r
+;======================================================\r
+;DRAW_BITMAP (SEG Image, Xpos%, Ypos%, Width%, Height%)\r
+;======================================================\r
+;\r
+; Draws a variable sized Graphics Bitmap such as a\r
+; picture or an Icon on the current Display Page in\r
+; Mode X. The Bitmap is stored in a linear byte array\r
+; corresponding to (0,0) (1,0), (2,0) .. (Width, Height)\r
+; This is the same linear manner as mode 13h graphics.\r
+;\r
+; ENTRY: Image = Far Pointer to Bitmap Data\r
+; Xpos = X position to Place Upper Left pixel at\r
+; Ypos = Y position to Place Upper Left pixel at\r
+; Width = Width of the Bitmap in Pixels\r
+; Height = Height of the Bitmap in Pixels\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+ \r
+DB_STACK STRUC\r
+ DB_LineO DW ? ; Offset to Next Line\r
+ DB_PixCount DW ? ; (Minimum) # of Pixels/Line\r
+ DB_Start DW ? ; Addr of Upper Left Pixel\r
+ DB_PixSkew DW ? ; # of bytes to Adjust EOL\r
+ DB_SkewFlag DW ? ; Extra Pix on Plane Flag\r
+ DW ?x4 ; DI, SI, DS, BP\r
+ DD ? ; Caller\r
+ DB_Height DW ? ; Height of Bitmap in Pixels\r
+ DB_Width DW ? ; Width of Bitmap in Pixels\r
+ DB_Ypos DW ? ; Y position to Draw Bitmap at\r
+ DB_Xpos DW ? ; X position to Draw Bitmap at\r
+ DB_Image DD ? ; Far Pointer to Graphics Bitmap\r
+DB_STACK ENDS\r
+ \r
+ PUBLIC DRAW_BITMAP\r
+ \r
+DRAW_BITMAP PROC FAR\r
+ \r
+ PUSHx BP, DS, SI, DI ; Preserve Important Registers\r
+ SUB SP, 10 ; Allocate workspace\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+ LES DI, d CURRENT_PAGE ; Point to Active VGA Page\r
+ CLD ; Direction Flag = Forward\r
+ \r
+ MOV AX, [BP].DB_Ypos ; Get UL Corner Ypos\r
+ MUL SCREEN_WIDTH ; AX = Offset to Line Ypos\r
+ \r
+ MOV BX, [BP].DB_Xpos ; Get UL Corner Xpos\r
+ MOV CL, BL ; Save Plane # in CL\r
+ SHR BX, 2 ; Xpos/4 = Offset Into Line\r
+ \r
+ ADD DI, AX ; ES:DI -> Start of Line\r
+ ADD DI, BX ; ES:DI -> Upper Left Pixel\r
+ MOV [BP].DB_Start, DI ; Save Starting Addr\r
+ \r
+ ; Compute line to line offset\r
+ \r
+ MOV BX, [BP].DB_Width ; Get Width of Image\r
+ MOV DX, BX ; Save Copy in DX\r
+ SHR BX, 2 ; /4 = width in bands\r
+ MOV AX, SCREEN_WIDTH ; Get Screen Width\r
+ SUB AX, BX ; - (Bitmap Width/4)\r
+ \r
+ MOV [BP].DB_LineO, AX ; Save Line Width offset\r
+ MOV [BP].DB_PixCount, BX ; Minimum # pix to copy\r
+ \r
+ AND DX, PLANE_BITS ; Get "partial band" size (0-3)\r
+ MOV [BP].DB_PixSkew, DX ; Also End of Line Skew\r
+ MOV [BP].DB_SkewFlag, DX ; Save as Flag/Count\r
+ \r
+ AND CX, PLANE_BITS ; CL = Starting Plane #\r
+ MOV AX, MAP_MASK_PLANE2 ; Plane Mask & Plane Select\r
+ SHL AH, CL ; Select correct Plane\r
+ OUT_16 SC_Index, AX ; Select Plane...\r
+ MOV BH, AH ; BH = Saved Plane Mask\r
+ MOV BL, 4 ; BL = Planes to Copy\r
+ \r
+@DB_COPY_PLANE:\r
+ \r
+ LDS SI, [BP].DB_Image ; DS:SI-> Source Image\r
+ MOV DX, [BP].DB_Height ; # of Lines to Copy\r
+ MOV DI, [BP].DB_Start ; ES:DI-> Dest pos\r
+ \r
+@DB_COPY_LINE:\r
+ MOV CX, [BP].DB_PixCount ; Min # to copy\r
+ \r
+ TEST CL, 0FCh ; 16+PixWide?\r
+ JZ @DB_COPY_REMAINDER ; Nope...\r
+ \r
+ ; Pixel Copy loop has been unrolled to x4\r
+ \r
+@DB_COPY_LOOP:\r
+ MOVSB ; Copy Bitmap Pixel\r
+ ADD SI, 3 ; Skip to Next Byte in same plane\r
+ MOVSB ; Copy Bitmap Pixel\r
+ ADD SI, 3 ; Skip to Next Byte in same plane\r
+ MOVSB ; Copy Bitmap Pixel\r
+ ADD SI, 3 ; Skip to Next Byte in same plane\r
+ MOVSB ; Copy Bitmap Pixel\r
+ ADD SI, 3 ; Skip to Next Byte in same plane\r
+ \r
+ SUB CL, 4 ; Pixels to Copy=-4\r
+ TEST CL, 0FCh ; 4+ Pixels Left?\r
+ JNZ @DB_COPY_LOOP ; if so, do another block\r
+ \r
+@DB_COPY_REMAINDER:\r
+ JCXZ @DB_NEXT_LINE ; Any Pixels left on line\r
+ \r
+@DB_COPY2:\r
+ MOVSB ; Copy Bitmap Pixel\r
+ ADD SI,3 ; Skip to Next Byte in same plane\r
+ LOOPx CX, @DB_COPY2 ; Pixels to Copy--, Loop until done\r
+ \r
+@DB_NEXT_LINE:\r
+ \r
+ ; any Partial Pixels? (some planes only)\r
+ \r
+ OR CX, [BP].DB_SkewFlag ; Get Skew Count\r
+ JZ @DB_NEXT2 ; if no partial pixels\r
+ \r
+ MOVSB ; Copy Bitmap Pixel\r
+ DEC DI ; Back up to align\r
+ DEC SI ; Back up to align\r
+ \r
+@DB_NEXT2:\r
+ ADD SI, [BP].DB_PixSkew ; Adjust Skew\r
+ ADD DI, [BP].DB_LineO ; Set to Next Display Line\r
+ LOOPx DX, @DB_COPY_LINE ; Lines to Copy--, Loop if more\r
+ \r
+ ; Copy Next Plane....\r
+ \r
+ DEC BL ; Planes to Go--\r
+ JZ @DB_Exit ; Hey! We are done\r
+ \r
+ ROL BH, 1 ; Next Plane in line...\r
+ OUT_8 SC_Data, BH ; Select Plane\r
+ \r
+ CMP AL, 12h ; Carry Set if AL=11h\r
+ ADC [BP].DB_Start, 0 ; Screen Addr =+Carry\r
+ INC w [BP].DB_Image ; Start @ Next Byte\r
+ \r
+ SUB [BP].DB_SkewFlag, 1 ; Reduce Planes to Skew\r
+ ADC [BP].DB_SkewFlag, 0 ; Back to 0 if it was -1\r
+ \r
+ JMP s @DB_COPY_PLANE ; Go Copy the Next Plane\r
+ \r
+@DB_Exit:\r
+ ADD SP, 10 ; Deallocate workspace\r
+ POPx DI, SI, DS, BP ; Restore Saved Registers\r
+ RET 12 ; Exit and Clean up Stack\r
+ \r
+DRAW_BITMAP ENDP\r
+ \r
+ \r
+;=======================================================\r
+;TDRAW_BITMAP (SEG Image, Xpos%, Ypos%, Width%, Height%)\r
+;=======================================================\r
+;\r
+; Transparently Draws a variable sized Graphics Bitmap\r
+; such as a picture or an Icon on the current Display Page\r
+; in Mode X. Pixels with a value of 0 are not drawn,\r
+; leaving the previous "background" contents intact.\r
+;\r
+; The Bitmap format is the same as for the DRAW_BITMAP function.\r
+;\r
+; ENTRY: Image = Far Pointer to Bitmap Data\r
+; Xpos = X position to Place Upper Left pixel at\r
+; Ypos = Y position to Place Upper Left pixel at\r
+; Width = Width of the Bitmap in Pixels\r
+; Height = Height of the Bitmap in Pixels\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+ \r
+TB_STACK STRUC\r
+ TB_LineO DW ? ; Offset to Next Line\r
+ TB_PixCount DW ? ; (Minimum) # of Pixels/Line\r
+ TB_Start DW ? ; Addr of Upper Left Pixel\r
+ TB_PixSkew DW ? ; # of bytes to Adjust EOL\r
+ TB_SkewFlag DW ? ; Extra Pix on Plane Flag\r
+ DW ?x4 ; DI, SI, DS, BP\r
+ DD ? ; Caller\r
+ TB_Height DW ? ; Height of Bitmap in Pixels\r
+ TB_Width DW ? ; Width of Bitmap in Pixels\r
+ TB_Ypos DW ? ; Y position to Draw Bitmap at\r
+ TB_Xpos DW ? ; X position to Draw Bitmap at\r
+ TB_Image DD ? ; Far Pointer to Graphics Bitmap\r
+TB_STACK ENDS\r
+ \r
+ PUBLIC TDRAW_BITMAP\r
+ \r
+TDRAW_BITMAP PROC FAR\r
+ \r
+ PUSHx BP, DS, SI, DI ; Preserve Important Registers\r
+ SUB SP, 10 ; Allocate workspace\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+ LES DI, d CURRENT_PAGE ; Point to Active VGA Page\r
+ CLD ; Direction Flag = Forward\r
+ \r
+ MOV AX, [BP].TB_Ypos ; Get UL Corner Ypos\r
+ MUL SCREEN_WIDTH ; AX = Offset to Line Ypos\r
+ \r
+ MOV BX, [BP].TB_Xpos ; Get UL Corner Xpos\r
+ MOV CL, BL ; Save Plane # in CL\r
+ SHR BX, 2 ; Xpos/4 = Offset Into Line\r
+ \r
+ ADD DI, AX ; ES:DI -> Start of Line\r
+ ADD DI, BX ; ES:DI -> Upper Left Pixel\r
+ MOV [BP].TB_Start, DI ; Save Starting Addr\r
+ \r
+ ; Compute line to line offset\r
+ \r
+ MOV BX, [BP].TB_Width ; Get Width of Image\r
+ MOV DX, BX ; Save Copy in DX\r
+ SHR BX, 2 ; /4 = width in bands\r
+ MOV AX, SCREEN_WIDTH ; Get Screen Width\r
+ SUB AX, BX ; - (Bitmap Width/4)\r
+ \r
+ MOV [BP].TB_LineO, AX ; Save Line Width offset\r
+ MOV [BP].TB_PixCount, BX ; Minimum # pix to copy\r
+ \r
+ AND DX, PLANE_BITS ; Get "partial band" size (0-3)\r
+ MOV [BP].TB_PixSkew, DX ; Also End of Line Skew\r
+ MOV [BP].TB_SkewFlag, DX ; Save as Flag/Count\r
+ \r
+ AND CX, PLANE_BITS ; CL = Starting Plane #\r
+ MOV AX, MAP_MASK_PLANE2 ; Plane Mask & Plane Select\r
+ SHL AH, CL ; Select correct Plane\r
+ OUT_16 SC_Index, AX ; Select Plane...\r
+ MOV BH, AH ; BH = Saved Plane Mask\r
+ MOV BL, 4 ; BL = Planes to Copy\r
+ \r
+@TB_COPY_PLANE:\r
+ \r
+ LDS SI, [BP].TB_Image ; DS:SI-> Source Image\r
+ MOV DX, [BP].TB_Height ; # of Lines to Copy\r
+ MOV DI, [BP].TB_Start ; ES:DI-> Dest pos\r
+ \r
+ ; Here AH is set with the value to be considered\r
+ ; "Transparent". It can be changed!\r
+ \r
+ MOV AH, 0 ; Value to Detect 0\r
+ \r
+@TB_COPY_LINE:\r
+ MOV CX, [BP].TB_PixCount ; Min # to copy\r
+ \r
+ TEST CL, 0FCh ; 16+PixWide?\r
+ JZ @TB_COPY_REMAINDER ; Nope...\r
+ \r
+ ; Pixel Copy loop has been unrolled to x4\r
+ \r
+@TB_COPY_LOOP:\r
+ LODSB ; Get Pixel Value in AL\r
+ ADD SI, 3 ; Skip to Next Byte in same plane\r
+ CMP AL, AH ; It is "Transparent"?\r
+ JE @TB_SKIP_01 ; Skip ahead if so\r
+ MOV ES:[DI], AL ; Copy Pixel to VGA screen\r
+ \r
+@TB_SKIP_01:\r
+ LODSB ; Get Pixel Value in AL\r
+ ADD SI, 3 ; Skip to Next Byte in same plane\r
+ CMP AL, AH ; It is "Transparent"?\r
+ JE @TB_SKIP_02 ; Skip ahead if so\r
+ MOV ES:[DI+1], AL ; Copy Pixel to VGA screen\r
+ \r
+@TB_SKIP_02:\r
+ LODSB ; Get Pixel Value in AL\r
+ ADD SI, 3 ; Skip to Next Byte in same plane\r
+ CMP AL, AH ; It is "Transparent"?\r
+ JE @TB_SKIP_03 ; Skip ahead if so\r
+ MOV ES:[DI+2], AL ; Copy Pixel to VGA screen\r
+ \r
+@TB_SKIP_03:\r
+ LODSB ; Get Pixel Value in AL\r
+ ADD SI, 3 ; Skip to Next Byte in same plane\r
+ CMP AL, AH ; It is "Transparent"?\r
+ JE @TB_SKIP_04 ; Skip ahead if so\r
+ MOV ES:[DI+3], AL ; Copy Pixel to VGA screen\r
+ \r
+@TB_SKIP_04:\r
+ ADD DI, 4 ; Adjust Pixel Write Location\r
+ SUB CL, 4 ; Pixels to Copy=-4\r
+ TEST CL, 0FCh ; 4+ Pixels Left?\r
+ JNZ @TB_COPY_LOOP ; if so, do another block\r
+ \r
+@TB_COPY_REMAINDER:\r
+ JCXZ @TB_NEXT_LINE ; Any Pixels left on line\r
+ \r
+@TB_COPY2:\r
+ LODSB ; Get Pixel Value in AL\r
+ ADD SI, 3 ; Skip to Next Byte in same plane\r
+ CMP AL, AH ; It is "Transparent"?\r
+ JE @TB_SKIP_05 ; Skip ahead if so\r
+ MOV ES:[DI], AL ; Copy Pixel to VGA screen\r
+ \r
+@TB_SKIP_05:\r
+ INC DI ; Advance Dest Addr\r
+ LOOPx CX, @TB_COPY2 ; Pixels to Copy--, Loop until done\r
+ \r
+@TB_NEXT_LINE:\r
+ \r
+ ; any Partial Pixels? (some planes only)\r
+ \r
+ OR CX, [BP].TB_SkewFlag ; Get Skew Count\r
+ JZ @TB_NEXT2 ; if no partial pixels\r
+ \r
+ LODSB ; Get Pixel Value in AL\r
+ DEC SI ; Backup to Align\r
+ CMP AL, AH ; It is "Transparent"?\r
+ JE @TB_NEXT2 ; Skip ahead if so\r
+ MOV ES:[DI], AL ; Copy Pixel to VGA screen\r
+ \r
+@TB_NEXT2:\r
+ ADD SI, [BP].TB_PixSkew ; Adjust Skew\r
+ ADD DI, [BP].TB_LineO ; Set to Next Display Line\r
+ LOOPx DX, @TB_COPY_LINE ; Lines to Copy--, Loop if More\r
+ \r
+ ;Copy Next Plane....\r
+ \r
+ DEC BL ; Planes to Go--\r
+ JZ @TB_Exit ; Hey! We are done\r
+ \r
+ ROL BH, 1 ; Next Plane in line...\r
+ OUT_8 SC_Data, BH ; Select Plane\r
+ \r
+ CMP AL, 12h ; Carry Set if AL=11h\r
+ ADC [BP].TB_Start, 0 ; Screen Addr =+Carry\r
+ INC w [BP].TB_Image ; Start @ Next Byte\r
+ \r
+ SUB [BP].TB_SkewFlag, 1 ; Reduce Planes to Skew\r
+ ADC [BP].TB_SkewFlag, 0 ; Back to 0 if it was -1\r
+ \r
+ JMP @TB_COPY_PLANE ; Go Copy the next Plane\r
+ \r
+@TB_Exit:\r
+ ADD SP, 10 ; Deallocate workspace\r
+ POPx DI, SI, DS, BP ; Restore Saved Registers\r
+ RET 12 ; Exit and Clean up Stack\r
+ \r
+TDRAW_BITMAP ENDP\r
+ \r
+ \r
+ ; ==== VIDEO MEMORY to VIDEO MEMORY COPY ROUTINES =====\r
+ \r
+;==================================\r
+;COPY_PAGE (SourcePage%, DestPage%)\r
+;==================================\r
+;\r
+; Duplicate on display page onto another\r
+;\r
+; ENTRY: SourcePage = Display Page # to Duplicate\r
+; DestPage = Display Page # to hold copy\r
+;\r
+; EXIT: No meaningful values returned\r
+;\r
+ \r
+CP_STACK STRUC\r
+ DW ?x4 ; DI, SI, DS, BP\r
+ DD ? ; Caller\r
+ CP_DestP DW ? ; Page to hold copied image\r
+ CP_SourceP DW ? ; Page to Make copy from\r
+CP_STACK ENDS\r
+ \r
+ PUBLIC COPY_PAGE\r
+ \r
+COPY_PAGE PROC FAR\r
+ \r
+ PUSHx BP, DS, SI, DI ; Preserve Important Registers\r
+ MOV BP, SP ; Set up Stack Frame\r
+ CLD ; Block Xfer Forwards\r
+ \r
+ ; Make sure Page #'s are valid\r
+ \r
+ MOV AX, [BP].CP_SourceP ; Get Source Page #\r
+ CMP AX, LAST_PAGE ; is it > Max Page #?\r
+ JAE @CP_Exit ; if so, abort\r
+ \r
+ MOV BX, [BP].CP_DestP ; Get Destination Page #\r
+ CMP BX, LAST_PAGE ; is it > Max Page #?\r
+ JAE @CP_Exit ; if so, abort\r
+ \r
+ CMP AX, BX ; Pages #'s the same?\r
+ JE @CP_Exit ; if so, abort\r
+ \r
+ ; Setup DS:SI and ES:DI to Video Pages\r
+ \r
+ SHL BX, 1 ; Scale index to Word\r
+ MOV DI, PAGE_ADDR[BX] ; Offset to Dest Page\r
+ \r
+ MOV BX, AX ; Index to Source page\r
+ SHL BX, 1 ; Scale index to Word\r
+ MOV SI, PAGE_ADDR[BX] ; Offset to Source Page\r
+ \r
+ MOV CX, PAGE_SIZE ; Get size of Page\r
+ MOV AX, CURRENT_SEGMENT ; Get Video Mem Segment\r
+ MOV ES, AX ; ES:DI -> Dest Page\r
+ MOV DS, AX ; DS:SI -> Source Page\r
+ \r
+ ; Setup VGA registers for Mem to Mem copy\r
+ \r
+ OUT_16 GC_Index, LATCHES_ON ; Data from Latches = on\r
+ OUT_16 SC_Index, ALL_PLANES_ON ; Copy all Planes\r
+ \r
+ ; Note.. Do *NOT* use MOVSW or MOVSD - they will\r
+ ; Screw with the latches which are 8 bits x 4\r
+ \r
+ REP MOVSB ; Copy entire Page!\r
+ \r
+ ; Reset VGA for normal memory access\r
+ \r
+ OUT_16 GC_Index, LATCHES_OFF ; Data from Latches = off\r
+ \r
+@CP_Exit:\r
+ POPx DI, SI, DS, BP ; Restore Saved Registers\r
+ RET 4 ; Exit and Clean up Stack\r
+ \r
+COPY_PAGE ENDP\r
+ \r
+ \r
+;==========================================================================\r
+;COPY_BITMAP (SourcePage%, X1%, Y1%, X2%, Y2%, DestPage%, DestX1%, DestY1%)\r
+;==========================================================================\r
+;\r
+; Copies a Bitmap Image from one Display Page to Another\r
+; This Routine is Limited to copying Images with the same\r
+; Plane Alignment. To Work: (X1 MOD 4) must = (DestX1 MOD 4)\r
+; Copying an Image to the Same Page is supported, but results\r
+; may be defined when the when the rectangular areas\r
+; (X1, Y1) - (X2, Y2) and (DestX1, DestY1) -\r
+; (DestX1+(X2-X1), DestY1+(Y2-Y1)) overlap...\r
+; No Paramter checking to done to insure that\r
+; X2 >= X1 and Y2 >= Y1. Be Careful...\r
+;\r
+; ENTRY: SourcePage = Display Page # with Source Image\r
+; X1 = Upper Left Xpos of Source Image\r
+; Y1 = Upper Left Ypos of Source Image\r
+; X2 = Lower Right Xpos of Source Image\r
+; Y2 = Lower Right Ypos of Source Image\r
+; DestPage = Display Page # to copy Image to\r
+; DestX1 = Xpos to Copy UL Corner of Image to\r
+; DestY1 = Ypos to Copy UL Corner of Image to\r
+;\r
+; EXIT: AX = Success Flag: 0 = Failure / -1= Success\r
+;\r
+ \r
+CB_STACK STRUC\r
+ CB_Height DW ? ; Height of Image in Lines\r
+ CB_Width DW ? ; Width of Image in "bands"\r
+ DW ?x4 ; DI, SI, DS, BP\r
+ DD ? ; Caller\r
+ CB_DestY1 DW ? ; Destination Ypos\r
+ CB_DestX1 DW ? ; Destination Xpos\r
+ CB_DestP DW ? ; Page to Copy Bitmap To\r
+ CB_Y2 DW ? ; LR Ypos of Image\r
+ CB_X2 DW ? ; LR Xpos of Image\r
+ CB_Y1 DW ? ; UL Ypos of Image\r
+ CB_X1 DW ? ; UL Xpos of Image\r
+ CB_SourceP DW ? ; Page containing Source Bitmap\r
+CB_STACK ENDS\r
+ \r
+ PUBLIC COPY_BITMAP\r
+ \r
+COPY_BITMAP PROC FAR\r
+ \r
+ PUSHx BP, DS, SI, DI ; Preserve Important Registers\r
+ SUB SP, 4 ; Allocate WorkSpace on Stack\r
+ MOV BP, SP ; Set up Stack Frame\r
+ \r
+ ; Prep Registers (and keep jumps short!)\r
+ \r
+ MOV ES, CURRENT_SEGMENT ; ES -> VGA Ram\r
+ CLD ; Block Xfer Forwards\r
+ \r
+ ; Make sure Parameters are valid\r
+ \r
+ MOV BX, [BP].CB_SourceP ; Get Source Page #\r
+ CMP BX, LAST_PAGE ; is it > Max Page #?\r
+ JAE @CB_Abort ; if so, abort\r
+ \r
+ MOV CX, [BP].CB_DestP ; Get Destination Page #\r
+ CMP CX, LAST_PAGE ; is it > Max Page #?\r
+ JAE @CB_Abort ; if so, abort\r
+ \r
+ MOV AX, [BP].CB_X1 ; Get Source X1\r
+ XOR AX, [BP].CB_DestX1 ; Compare Bits 0-1\r
+ AND AX, PLANE_BITS ; Check Plane Bits\r
+ JNZ @CB_Abort ; They should cancel out\r
+ \r
+ ; Setup for Copy processing\r
+ \r
+ OUT_8 SC_INDEX, MAP_MASK ; Set up for Plane Select\r
+ OUT_16 GC_Index, LATCHES_ON ; Data from Latches = on\r
+ \r
+ ; Compute Info About Images, Setup ES:SI & ES:DI\r
+ \r
+ MOV AX, [BP].CB_Y2 ; Height of Bitmap in lines\r
+ SUB AX, [BP].CB_Y1 ; is Y2 - Y1 + 1\r
+ INC AX ; (add 1 since were not 0 based)\r
+ MOV [BP].CB_Height, AX ; Save on Stack for later use\r
+ \r
+ MOV AX, [BP].CB_X2 ; Get # of "Bands" of 4 Pixels\r
+ MOV DX, [BP].CB_X1 ; the Bitmap Occupies as X2-X1\r
+ SHR AX, 2 ; Get X2 Band (X2 / 4)\r
+ SHR DX, 2 ; Get X1 Band (X1 / 4)\r
+ SUB AX, DX ; AX = # of Bands - 1\r
+ INC AX ; AX = # of Bands\r
+ MOV [BP].CB_Width, AX ; Save on Stack for later use\r
+ \r
+ SHL BX, 1 ; Scale Source Page to Word\r
+ MOV SI, PAGE_ADDR[BX] ; SI = Offset of Source Page\r
+ MOV AX, [BP].CB_Y1 ; Get Source Y1 Line\r
+ MUL SCREEN_WIDTH ; AX = Offset to Line Y1\r
+ ADD SI, AX ; SI = Offset to Line Y1\r
+ MOV AX, [BP].CB_X1 ; Get Source X1\r
+ SHR AX, 2 ; X1 / 4 = Byte offset\r
+ ADD SI, AX ; SI = Byte Offset to (X1,Y1)\r
+ \r
+ MOV BX, CX ; Dest Page Index to BX\r
+ SHL BX, 1 ; Scale Source Page to Word\r
+ MOV DI, PAGE_ADDR[BX] ; DI = Offset of Dest Page\r
+ MOV AX, [BP].CB_DestY1 ; Get Dest Y1 Line\r
+ MUL SCREEN_WIDTH ; AX = Offset to Line Y1\r
+ ADD DI, AX ; DI = Offset to Line Y1\r
+ MOV AX, [BP].CB_DestX1 ; Get Dest X1\r
+ SHR AX, 2 ; X1 / 4 = Byte offset\r
+ ADD DI, AX ; DI = Byte Offset to (D-X1,D-Y1)\r
+ \r
+ MOV CX, [BP].CB_Width ; CX = Width of Image (Bands)\r
+ DEC CX ; CX = 1?\r
+ JE @CB_Only_One_Band ; 0 Means Image Width of 1 Band\r
+ \r
+ MOV BX, [BP].CB_X1 ; Get Source X1\r
+ AND BX, PLANE_BITS ; Aligned? (bits 0-1 = 00?)\r
+ JZ @CB_Check_Right ; if so, check right alignment\r
+ JNZ @CB_Left_Band ; not aligned? well..\r
+ \r
+@CB_Abort:\r
+ CLR AX ; Return False (Failure)\r
+ JMP @CB_Exit ; and Finish Up\r
+ \r
+ ; Copy when Left & Right Clip Masks overlap...\r
+ \r
+@CB_Only_One_Band:\r
+ MOV BX, [BP].CB_X1 ; Get Left Clip Mask\r
+ AND BX, PLANE_BITS ; Mask out Row #\r
+ MOV AL, Left_Clip_Mask[BX] ; Get Left Edge Mask\r
+ MOV BX, [BP].CB_X2 ; Get Right Clip Mask\r
+ AND BX, PLANE_BITS ; Mask out Row #\r
+ AND AL, Right_Clip_Mask[BX] ; Get Right Edge Mask byte\r
+ \r
+ OUT_8 SC_Data, AL ; Clip For Left & Right Masks\r
+ \r
+ MOV CX, [BP].CB_Height ; CX = # of Lines to Copy\r
+ MOV DX, SCREEN_WIDTH ; DX = Width of Screen\r
+ CLR BX ; BX = Offset into Image\r
+ \r
+@CB_One_Loop:\r
+ MOV AL, ES:[SI+BX] ; Load Latches\r
+ MOV ES:[DI+BX], AL ; Unload Latches\r
+ ADD BX, DX ; Advance Offset to Next Line\r
+ LOOPjz CX, @CB_One_Done ; Exit Loop if Finished\r
+ \r
+ MOV AL, ES:[SI+BX] ; Load Latches\r
+ MOV ES:[DI+BX], AL ; Unload Latches\r
+ ADD BX, DX ; Advance Offset to Next Line\r
+ LOOPx CX, @CB_One_Loop ; Loop until Finished\r
+ \r
+@CB_One_Done:\r
+ JMP @CB_Finish ; Outa Here!\r
+ \r
+ ; Copy Left Edge of Bitmap\r
+ \r
+@CB_Left_Band:\r
+ \r
+ OUT_8 SC_Data, Left_Clip_Mask[BX] ; Set Left Edge Plane Mask\r
+ \r
+ MOV CX, [BP].CB_Height ; CX = # of Lines to Copy\r
+ MOV DX, SCREEN_WIDTH ; DX = Width of Screen\r
+ CLR BX ; BX = Offset into Image\r
+ \r
+@CB_Left_Loop:\r
+ MOV AL, ES:[SI+BX] ; Load Latches\r
+ MOV ES:[DI+BX], AL ; Unload Latches\r
+ ADD BX, DX ; Advance Offset to Next Line\r
+ LOOPjz CX, @CB_Left_Done ; Exit Loop if Finished\r
+ \r
+ MOV AL, ES:[SI+BX] ; Load Latches\r
+ MOV ES:[DI+BX], AL ; Unload Latches\r
+ ADD BX, DX ; Advance Offset to Next Line\r
+ LOOPx CX, @CB_Left_Loop ; Loop until Finished\r
+ \r
+@CB_Left_Done:\r
+ INC DI ; Move Dest Over 1 band\r
+ INC SI ; Move Source Over 1 band\r
+ DEC [BP].CB_Width ; Band Width--\r
+ \r
+ ; Determine if Right Edge of Bitmap needs special copy\r
+ \r
+@CB_Check_Right:\r
+ MOV BX, [BP].CB_X2 ; Get Source X2\r
+ AND BX, PLANE_BITS ; Aligned? (bits 0-1 = 11?)\r
+ CMP BL, 03h ; Plane = 3?\r
+ JE @CB_Copy_Middle ; Copy the Middle then!\r
+ \r
+ ; Copy Right Edge of Bitmap\r
+ \r
+@CB_Right_Band:\r
+ \r
+ OUT_8 SC_Data, Right_Clip_Mask[BX] ; Set Right Edge Plane Mask\r
+ \r
+ DEC [BP].CB_Width ; Band Width--\r
+ MOV CX, [BP].CB_Height ; CX = # of Lines to Copy\r
+ MOV DX, SCREEN_WIDTH ; DX = Width of Screen\r
+ MOV BX, [BP].CB_Width ; BX = Offset to Right Edge\r
+ \r
+@CB_Right_Loop:\r
+ MOV AL, ES:[SI+BX] ; Load Latches\r
+ MOV ES:[DI+BX], AL ; Unload Latches\r
+ ADD BX, DX ; Advance Offset to Next Line\r
+ LOOPjz CX, @CB_Right_Done ; Exit Loop if Finished\r
+ \r
+ MOV AL, ES:[SI+BX] ; Load Latches\r
+ MOV ES:[DI+BX], AL ; Unload Latches\r
+ ADD BX, DX ; Advance Offset to Next Line\r
+ LOOPx CX, @CB_Right_Loop ; Loop until Finished\r
+ \r
+@CB_Right_Done:\r
+ \r
+ ; Copy the Main Block of the Bitmap\r
+ \r
+@CB_Copy_Middle:\r
+ \r
+ MOV CX, [BP].CB_Width ; Get Width Remaining\r
+ JCXZ @CB_Finish ; Exit if Done\r
+ \r
+ OUT_8 SC_Data, ALL_PLANES ; Copy all Planes\r
+ \r
+ MOV DX, SCREEN_WIDTH ; Get Width of Screen minus\r
+ SUB DX, CX ; Image width (for Adjustment)\r
+ MOV AX, [BP].CB_Height ; AX = # of Lines to Copy\r
+ MOV BX, CX ; BX = Quick REP reload count\r
+ MOV CX, ES ; Move VGA Segment\r
+ MOV DS, CX ; Into DS\r
+ \r
+ ; Actual Copy Loop. REP MOVSB does the work\r
+ \r
+@CB_Middle_Copy:\r
+ MOV CX, BX ; Recharge Rep Count\r
+ REP MOVSB ; Move Bands\r
+ LOOPjz AX, @CB_Finish ; Exit Loop if Finished\r
+ \r
+ ADD SI, DX ; Adjust DS:SI to Next Line\r
+ ADD DI, DX ; Adjust ES:DI to Next Line\r
+ \r
+ MOV CX, BX ; Recharge Rep Count\r
+ REP MOVSB ; Move Bands\r
+ \r
+ ADD SI, DX ; Adjust DS:SI to Next Line\r
+ ADD DI, DX ; Adjust ES:DI to Next Line\r
+ LOOPx AX, @CB_Middle_Copy ; Copy Lines until Done\r
+ \r
+@CB_Finish:\r
+ OUT_16 GC_Index, LATCHES_OFF ; Data from Latches = on\r
+ \r
+@CB_Exit:\r
+ ADD SP, 04 ; Deallocate stack workspace\r
+ POPx DI, SI, DS, BP ; Restore Saved Registers\r
+ RET 16 ; Exit and Clean up Stack\r
+ \r
+COPY_BITMAP ENDP\r
+ \r
+ END ; End of Code Segment\r
projects / 16.git / commitdiff