16/tweak16/DETECT.CPP

   1 /*\r
   2  *      Mode detection:\r
   3  *      ---------------\r
   4  *      Currently incompatible with CGA and Hercules modes.\r
   5  *              200-line CGA modes are detected as 100-line.\r
   6  *              640x200x2 is detected as 16-color.\r
   7  *              Hercules not supported at all.\r
   8  *      Monochrome EGA/VGA modes are also *not* supported, due to use of\r
   9  *              different port addresses.\r
  10  *\r
  11  *      Variables of interest:\r
  12  *              hPixels, vPixels - the actual resolution of the mode, in characters\r
  13  *                      in text modes, in pixels in graphics modes.\r
  14  *              adrOffset - the number of addressable bytes between two vertically\r
  15  *                      adjacent pixels, or words between two vertically adjacent\r
  16  *                      characters in text mode.\r
  17  *\r
  18  */\r
  19 \r
  20 #include "detect.hpp"\r
  21 #include "screen.hpp"\r
  22 #include <dos.h>\r
  23 #include <conio.h>\r
  24 \r
  25 \r
  26 \r
  27 void ModeInfo::detectFrom(RegisterTable &regTable)\r
  28         {\r
  29         Register *GCMode = regTable.getRegister(GRACON_ADDR, 0x05);\r
  30         Register *GCMisc = regTable.getRegister(GRACON_ADDR, 0x06);\r
  31         Register *ACMode = regTable.getRegister(ATTRCON_ADDR, 0x10);\r
  32         Register *CRTChde = regTable.getRegister(CRTC_ADDR, 0x01);\r
  33         Register *CRTCoflo = regTable.getRegister(CRTC_ADDR, 0x07);\r
  34         Register *CRTCscan = regTable.getRegister(CRTC_ADDR, 0x09);\r
  35         Register *CRTCvde = regTable.getRegister(CRTC_ADDR, 0x12);\r
  36         Register *CRTCoffs = regTable.getRegister(CRTC_ADDR, 0x13);\r
  37         Register *CRTCmode = regTable.getRegister(CRTC_ADDR, 0x17);\r
  38         Register *SEQmmode = regTable.getRegister(SEQ_ADDR, 0x04);\r
  39 \r
  40         int temp;\r
  41         switch ((*GCMode)(5,2))\r
  42                 {\r
  43                 case 0:\r
  44                         colors = COLOR16;               // might also be COLOR2 !!!\r
  45                         hPixelsPerClock = 8;\r
  46                         break;\r
  47                 case 1:\r
  48                         colors = COLOR4;\r
  49                         hPixelsPerClock = 16;\r
  50                         break;\r
  51                 case 2:\r
  52                         colors = COLOR256;\r
  53                         hPixelsPerClock = 4;\r
  54                         break;\r
  55                 }\r
  56 \r
  57         temp = (**GCMisc & 1 != 0);\r
  58         if (temp == (**ACMode & 1 != 0))\r
  59                 alphaGraph = temp ? GRAPHICS : ALPHA;\r
  60         else\r
  61                 alphaGraph = AG_CONFLICT;\r
  62 \r
  63         if (alphaGraph == ALPHA)\r
  64                 hPixelsPerClock = 1;\r
  65 \r
  66         chain4 = (*SEQmmode)(3,1);\r
  67         countBy2 = (*CRTCmode)(3,1);\r
  68         adrOffset = **CRTCoffs * 2 * (countBy2+1);\r
  69 \r
  70         hClocks = **CRTChde + 1;\r
  71         vClocks =\r
  72                 (**CRTCvde | ((*CRTCoflo)(1,1) << 8) | ((*CRTCoflo)(6,1) << 9)) + 1;\r
  73 \r
  74         xres = hClocks * hPixelsPerClock;\r
  75         vxresBytes = vxres = adrOffset * hPixelsPerClock;\r
  76 \r
  77         if (alphaGraph == ALPHA)\r
  78                 vxresBytes *= 2;\r
  79         else\r
  80                 if (alphaGraph == GRAPHICS)\r
  81                         if (colors == COLOR16)\r
  82                                 vxresBytes /= 8;\r
  83                         else\r
  84                                 if (colors == COLOR256 && !chain4)\r
  85                                         vxresBytes /= 4;\r
  86 \r
  87         lineClocks = (*CRTCscan)(0,4) + 1;\r
  88         if ((*CRTCscan)(7,1) << 5)\r
  89                 lineClocks *= 2;\r
  90         yres = vClocks / lineClocks;\r
  91         spareClocks = vClocks % lineClocks;\r
  92         vyres = (alphaGraph == GRAPHICS ? 65536L : 32768L) / vxresBytes;\r
  93     xpages = float(vxres)/xres;\r
  94         ypages = float(vyres)/yres;\r
  95         }\r
  96 \r
  97 \r
  98 GraphicsAPI *ModeInfo::getGraphicsAPI()\r
  99         {\r
 100         if (alphaGraph == GRAPHICS)\r
 101                 switch(colors)\r
 102                         {\r
 103                         case COLOR16:\r
 104                                 return new Planar16(xres, yres, vxres);\r
 105                         case COLOR256:\r
 106                                 if (chain4)\r
 107                                         return new Chained256(xres, yres, vxres);\r
 108                                 else\r
 109                                         return new Unchained256(xres, yres, vxres);\r
 110                         }\r
 111         return 0;\r
 112         }\r
 113 \r
 114 void ModeInfo::show()\r
 115         {\r
 116         window(editWidth/2+2, editHeight-18, editWidth, editHeight-7);\r
 117         clrscr();\r
 118         textattr(INFO_COLOR);\r
 119         cprintf("This seems to be a %d-color\n\r"\r
 120                         "%s mode.\n\r\n\r"\r
 121                         "Physical resolution: %d x %d\n\r"\r
 122                         "Virtual resolution:  %d x %d\n\r\n\r"\r
 123                         "Page resolution:     %3.1f x %3.1f",\r
 124                         colors,\r
 125                         alphaGraph==ALPHA ? "text" :\r
 126                                 alphaGraph==GRAPHICS ? (chain4 ? "linear graphics" :\r
 127                                                                                                  "planar graphics") :\r
 128                                                                            "graph/text conflict",\r
 129                         xres, yres,\r
 130                         vxres, vyres,\r
 131                         xpages, ypages\r
 132                         );\r
 133         window(1,1,editWidth,editHeight);\r
 134         }\r
 135 \r