X-Git-Url: http://4ch.mooo.com/gitweb/?a=blobdiff_plain;ds=sidebyside;f=16%2Fxw%2Fmxpf.asm;fp=16%2Fxw%2Fmxpf.asm;h=db0da898f8ae912888c9d34bb9931e95b7047b19;hb=75a35fd2843da7105acc7eee68674131431d0ccb;hp=0000000000000000000000000000000000000000;hpb=1c75464b9fad87da35a11650cab4e63aa532e5fc;p=16.git diff --git a/16/xw/mxpf.asm b/16/xw/mxpf.asm new file mode 100755 index 00000000..db0da898 --- /dev/null +++ b/16/xw/mxpf.asm @@ -0,0 +1,420 @@ +;----------------------------------------------------------- +; +; MXPG.ASM - Convex polygon fill +; Copyright (c) 1994 by Alessandro Scotti +; +;----------------------------------------------------------- +WARN PRO +NOWARN RES +INCLUDE MODEX.DEF + +PUBLIC mxFillPoly + +;----------------------------------------------------------- +; +; "Local" definitions +; +TPOINT STRUC + X DW ? + Y DW ? +TPOINT ENDS + +; Do NOT change order! +TSCAN STRUC + Y1 DW ? + Y2 DW ? +TSCAN ENDS + +MAXSCANCOLUMNS EQU POLYSCANBUFSIZE / SIZE TSCAN + +MX_TEXT SEGMENT USE16 PARA PUBLIC 'CODE' + ASSUME cs:MX_TEXT, ds:NOTHING, es:NOTHING + +EXTRN mx_VideoSegment : WORD +EXTRN mx_CodeSegment : WORD +EXTRN mx_BytesPerLine : WORD +EXTRN mx_ClipX1 : WORD +EXTRN mx_ClipY1 : WORD +EXTRN mx_ClipX2 : WORD +EXTRN mx_ClipY2 : WORD +EXTRN mx_ScanBuffer : NEAR + +;----------------------------------------------------------- +; +; Scans an edge using the DDA (digital differential analyzer) algorithm. +; +; Input: +; DS:BX = pointer to start point (X1, Y1) +; DS:SI = pointer to end point (X2, Y2) +; ES:DI = pointer to edge buffer +; Output: +; ES:DI = updated pointer to edge buffer +; Notes: +; must preserve DS:SI. +; +subScan PROC NEAR + mov cx, ds:[si].X + sub cx, ds:[bx].X ; Get width + jg @@1 + ret +@@1: + push bp ; Save BP + + mov ax, ds:[si].Y + mov bx, ds:[bx].Y + sub ax, bx ; Get height + jg @@T2B ; Scan top to bottom + jl @@B2T ; Scan bottom to top + +; Special case: vertical line + mov ax, bx +@@V: + mov es:[di].Y1, ax + add di, SIZE TSCAN + dec cx + jnz @@V + jmp @@Exit + +; Scan top to bottom +@@T2B: + cwd + div cx + mov bp, ax + xor ax, ax + div cx + xchg ax, bx ; BP:BX = fixed 16:16 step + mov dx, 8000h +@@T2BLoop: + mov es:[di].Y1, ax + add di, SIZE TSCAN + add dx, bx + adc ax, bp + dec cx + jnz @@T2BLoop + jmp @@Exit + +; Scan bottom to top +@@B2T: + neg ax + cwd + div cx + mov bp, ax + xor ax, ax + div cx + xchg ax, bx + mov dx, 8000h +@@B2TLoop: + mov es:[di].Y1, ax + add di, SIZE TSCAN + sub dx, bx + sbb ax, bp + dec cx + jnz @@B2TLoop + +@@Exit: + pop bp ; Restore BP + ret +subScan ENDP + +;----------------------------------------------------------- +; +; Fills a convex polygon with the specified color. +; +; Input: +; Count = number of vertexes +; Map = indexes of points and colors (integer) +; Points = array of points (integer X, Y coordinates) +; Color = base color +; Output: +; none +; Notes: +; vertexes must be in counterclockwise order, arrays are 0-based. +; +mxFillPoly PROC FAR + ARG Color:WORD, \ + Points:DWORD, \ + Map:DWORD, \ + Count:WORD = ARG_SIZE + LOCAL WritePlane:BYTE:2, \ + ScanOffsetT:WORD, \ + ScanOffsetB:WORD, \ + ScanCount:WORD, \ + Holder:WORD, \ + Height:WORD, \ + MinIdxT:WORD, \ + MinIdxB:WORD, \ + MaxIdx:WORD, \ + Width:WORD, \ + BoxX1:WORD, \ + BoxY1:WORD, \ + BoxX2:WORD, \ + BoxY2::WORD = AUTO_SIZE + .enter AUTO_SIZE + .push ds, si, es, di + ASSUME ds:NOTHING + +; Check that at least three vertexes are specified + mov cx, [Count] + cmp cx, 3 + jb @@Exit + +;------------------------------ +; Find bounding box for polygon + les di, [Map] + lds si, [Points] ; Pointer to vertex array + mov [BoxX1], 32767 + mov [BoxX2], -32768 + mov [BoxY1], 32767 + mov [BoxY2], -32768 + + xor dx, dx +@@MinMaxLoop: + mov bx, es:[di] ; Get index of vertex + .shl bx, 2 ; Get offset in point array + add bx, si + +; Check X range +@@CheckMinX: + mov ax, ds:[bx].X ; Get X coordinate + cmp ax, [BoxX1] + jge @@CheckMaxX + mov [BoxX1], ax + mov [MinIdxT], dx + mov [MinIdxB], dx +@@CheckMaxX: + cmp ax, [BoxX2] + jle @@CheckMinY + mov [BoxX2], ax + mov [MaxIdx], dx + +; Check Y range +@@CheckMinY: + mov ax, ds:[bx].Y + cmp ax, [BoxY1] + jge @@CheckMaxY + mov [BoxY1], ax +@@CheckMaxY: + cmp ax, [BoxY2] + jle @@CheckDone + mov [BoxY2], ax + +; Repeat thru all points +@@CheckDone: + inc di ; Next map entry + inc dx + inc di + inc dx + dec cx + jnz @@MinMaxLoop + +;--------------------------------- +; Check if polygon is full clipped + mov ax, [BoxX2] + cmp ax, [mx_ClipX1] ; Is poly full clipped? + jl @@Exit + mov bx, [BoxX1] + cmp bx, [mx_ClipX2] ; Is poly full clipped? + jg @@Exit + sub ax, bx ; Get width + jle @@Exit ; Exit if not positive + mov ax, [BoxY2] + cmp ax, [mx_ClipY1] ; Is poly full clipped? + jl @@Exit + mov bx, [BoxY1] + cmp bx, [mx_ClipY2] ; Is poly full clipped? + jg @@Exit + sub ax, bx ; Get height + jle @@Exit ; Exit if not positive + + dec [Count] + shl [Count], 1 ; We'll work with word offsets + mov es, [mx_CodeSegment] + +;-------------- +; Scan top edge + mov ax, OFFSET mx_ScanBuffer + mov [ScanOffsetT], ax + mov si, [MinIdxT] ; Offset of bottom point index +@@STLoop: + lds bx, [Map] ; DS:BX -> map table + mov di, ds:[bx+si] ; Index of top point #1 + dec si ; Next point + dec si + test si, si + jnl @@ST1 + mov si, [Count] +@@ST1: + mov [MinIdxT], si ; Save new index of top point + mov si, ds:[bx+si] ; Get index of top point #2 + .shl di, 2 ; Convert indexes to offsets + .shl si, 2 + lds bx, [Points] ; DS:BX -> point array + add si, bx ; DS:SI -> top point #2 + add bx, di ; DS:BX -> top point #1 + mov di, [ScanOffsetT] + call subScan ; Scan edge + mov [ScanOffsetT], di + mov si, [MinIdxT] + cmp si, [MaxIdx] ; End of edge? + jne @@STLoop ; No, continue + +;----------------- +; Scan bottom edge + mov ax, OFFSET mx_ScanBuffer + OFFSET Y2 + mov [ScanOffsetB], ax + mov si, [MinIdxB] ; Offset of bottom point index +@@SBLoop: + lds bx, [Map] ; DS:BX -> map table + mov di, ds:[bx+si] ; Index of bottom point #1 + inc si ; Next bottom point + inc si + cmp si, [Count] + jbe @@SB1 + xor si, si +@@SB1: + mov [MinIdxB], si ; Save new index of bottom point + mov si, ds:[bx+si] ; Get index of bottom point #2 + .shl di, 2 ; Convert indexes to offsets + .shl si, 2 + lds bx, [Points] ; DS:BX -> point array + add si, bx ; DS:SI -> top point #2 + add bx, di ; DS:BX -> top point #1 + mov di, [ScanOffsetB] + call subScan ; Scan edge + mov [ScanOffsetB], di + mov si, [MinIdxB] + cmp si, [MaxIdx] ; End of edge? + jne @@SBLoop ; No, continue + +;-------------------- +; Clip left and right + mov si, OFFSET mx_ScanBuffer + mov ax, [BoxX1] + mov cx, [BoxX2] + sub cx, ax ; CX = bounding box width + mov bx, [mx_ClipX1] + sub bx, ax + jle @@ClipL1 ; No need to clip left + sub cx, bx ; Update width + add ax, bx ; BoxX1 = mx_ClipX1 + mov [BoxX1], ax + .shl bx, 2 ; Warning!!! This is an hand-coded + add si, bx ; multiply by the size of TSCAN +@@ClipL1: + mov bx, ax + add bx, cx ; Last scan column + sub bx, [mx_ClipX2] + jle @@ClipL2 ; No need to clip right + sub cx, bx ; Clip right +@@ClipL2: + test cx, cx ; Is clipped width positive? + jle @@Exit ; No, exit + mov [ScanCount], cx ; Save number of columns to draw + mov [ScanOffsetT], si ; Remember offset of (clipped) buffer + mov ds, [mx_CodeSegment] ; DS:SI -> scan buffer + +;------------------------------ +; Check if Y clipping is needed + mov ax, [BoxY1] + cmp ax, [mx_ClipY1] + jl @@ClipTB ; Need to clip top + mov ax, [BoxY2] + cmp ax, [mx_ClipY2] + jg @@ClipTB ; Need to clip bottom + jmp @@ClipYExit ; Skip Y clipping + +;-------------------- +; Clip top and bottom +@@ClipTB: + mov di, cx ; DI = scan count + inc di ; Increment count for pre-loop test + sub si, SIZE TSCAN +@@ClipYLoop: + dec di ; Any column left? + jz @@ClipYExit ; No, exit + add si, SIZE TSCAN + mov ax, ds:[si].Y1 ; Y1 + mov cx, ds:[si].Y2 ; Y2 + mov dx, [mx_ClipY2] + cmp ax, dx ; Full clipped? + jg @@ClipYClip ; Yes, skip this column + cmp cx, dx ; Need to clip bottom? + jle @@ClipY1 ; No, continue +; Clip bottom + mov ds:[si].Y2, dx + mov bx, cx + sub bx, dx ; Clip distance + sub cx, ax ; Height + jle @@ClipYClip + mov cx, ds:[si].Y2 +@@ClipY1: + mov dx, [mx_ClipY1] + cmp cx, dx ; Full top clipped? + jl @@ClipYClip ; Yes, skip + sub cx, ax ; Get height + jle @@ClipYClip ; Skip if not positive + cmp ax, dx ; Need to clip top? + jge @@ClipYLoop ; No, continue +; Clip top + mov ds:[si].Y1, dx ; Y1 = mx_ClipY1 + sub dx, ax ; DX = number of pixels clipped + cmp cx, dx + ja @@ClipYLoop ; Not clipped, continue +@@ClipYClip: + mov ds:[si].Y1, -1 ; Mark column as clipped + jmp @@ClipYLoop +@@ClipYExit: + +;------------- +; Draw columns + mov es, [mx_VideoSegment] + mov si, [ScanOffsetT] + mov cl, BYTE PTR [BoxX1] ; Init write plane + and cl, 03h + mov al, 11h + shl al, cl + mov [WritePlane], al + .shr [BoxX1], 2 +@@DrawLoop: + mov ax, ds:[si].Y1 + test ax, ax ; Was column clipped? + js @@DrawNext ; Yes, skip + mov cx, ds:[si].Y2 + sub cx, ax ; CX = height + jle @@DrawNext + mul [mx_BytesPerLine] ; Get pixel address + add ax, [BoxX1] + mov di, ax + mov ah, [WritePlane] + mov dx, TS + mov al, 02h + out dx, ax + mov ax, [Color] + mov dx, [mx_BytesPerLine] + shr cx, 1 + jnc @@FillScan + mov es:[di], al + add di, dx + jcxz @@DrawNext +@@FillScan: + mov es:[di], al + add di, dx + mov es:[di], al + add di, dx + dec cx + jnz @@FillScan +@@DrawNext: + rol [WritePlane], 1 + adc [BoxX1], 0 ; Bump pointer to video memory if needed + add si, SIZE TSCAN + dec [ScanCount] + jnz @@DrawLoop + +@@Exit: + xor ax, ax + .pop ds, si, es, di + .leave ARG_SIZE +mxFillPoly ENDP + +MX_TEXT ENDS +END