reactos/drivers/dd/vga/display/objects/lineto.c

   1 #include "..\vgaddi.h"
   2 #include "..\vgavideo\vgavideo.h"
   3
   4 #include <internal/i386/io.h>
   5
   6 BOOL VGADDILineTo(SURFOBJ *Surface, CLIPOBJ *Clip, BRUSHOBJ *Brush,
   7                   LONG x1, LONG y1, LONG x2, LONG y2,
   8                   RECTL *RectBounds, MIX mix)
   9 {
  10    ULONG x, y, d, i, length, xchange, ychange, error,
  11          iSolidColor, hx, vy;
  12    LONG  deltax, deltay;
  13
  14    iSolidColor = Brush->iSolidColor; // FIXME: Brush Realization...
  15
  16    // FIXME: Implement clipping
  17
  18    x=x1;
  19    y=y1;
  20    deltax=x2-x1;
  21    deltay=y2-y1;
  22
  23    if(deltax<0)
  24    {
  25       xchange=-1;
  26       deltax=-deltax;
  27       hx = x2;
  28    } else
  29    {
  30       xchange=1;
  31       hx = x1;
  32    }
  33
  34    if(deltay<0)
  35    {
  36       ychange=-1;
  37       deltay=-deltay;
  38       vy = y2;
  39    } else
  40    {
  41       ychange=1;
  42       vy = y1;
  43    };
  44
  45    if(y1==y2)
  46    {
  47      return vgaHLine(hx, y1, deltax, iSolidColor);
  48    }
  49    if(x1==x2)
  50    {
  51      return vgaVLine(x1, vy, deltay, iSolidColor);
  52    }
  53
  54   error=0;
  55   i=0;
  56
  57   if(deltax<deltay)
  58   {
  59      length=deltay+1;
  60      while(i<length)
  61      {
  62         vgaPutPixel(x, y, iSolidColor);
  63         y=y+ychange;
  64         error=error+deltax;
  65
  66         if(error>deltay)
  67         {
  68            x=x+xchange;
  69            error=error-deltay;
  70         }
  71         i=i+1;
  72      }
  73   } else
  74   {
  75     length=deltax+1;
  76     while(i<length)
  77     {
  78          vgaPutPixel(x, y, iSolidColor);
  79          x=x+xchange;
  80          error=error+deltay;
  81          if(error>deltax)
  82          {
  83             y=y+ychange;
  84             error=error-deltax;
  85          }
  86          i=i+1;
  87       }
  88    }
  89
  90    return TRUE;
  91 }