apps/window_server/Renderer_vga.cpp

   1 #include "Renderer_vga.h"
   2 #include "assert.h"
   3
   4 #define MIN(a, b) ((a) < (b) ? (a) : (b))
   5
   6 const unsigned char kCursorBits [] = {
   7         0x3f,0x3f,0x00,0x00,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
   8         0x3f,0x3f,0x3f,0x3f,0x00,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
   9         0xff,0x3f,0x3f,0x3f,0x3f,0x00,0x00,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
  10         0xff,0x3f,0x3f,0x3f,0x3f,0x3f,0x3f,0x00,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
  11         0xff,0xff,0x3f,0x3f,0x3f,0x3f,0x3f,0x3f,0x3f,0x00,0xff,0xff,0xff,0xff,0xff,0xff,
  12         0xff,0xff,0xff,0x3f,0x3f,0x3f,0x3f,0x3f,0x3f,0x3f,0x00,0xff,0xff,0xff,0xff,0xff,
  13         0xff,0xff,0xff,0x3f,0x3f,0x3f,0x3f,0x3f,0x3f,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
  14         0xff,0xff,0xff,0xff,0x3f,0x3f,0x3f,0x3f,0x00,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
  15         0xff,0xff,0xff,0xff,0x3f,0x3f,0x3f,0xff,0x3f,0x00,0xff,0xff,0xff,0xff,0xff,0xff,
  16         0xff,0xff,0xff,0xff,0xff,0x3f,0xff,0xff,0xff,0x3f,0x00,0xff,0xff,0xff,0xff,0xff,
  17         0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0x3f,0x00,0xff,0xff,0xff,0xff,
  18         0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0x3f,0x00,0xff,0xff,0xff,
  19         0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0x3f,0x00,0xff,0xff,
  20         0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0x3f,0x00,0xff,
  21         0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0x3f,0xff,
  22         0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff
  23 };
  24
  25 Renderer_vga::Renderer_vga(char *baseAddress, int width, int height, int bytesPerRow)
  26         :       Renderer_8bpp(baseAddress, width, height, bytesPerRow)
  27 {
  28         fCursorX = width / 2;
  29         fCursorY = height / 2;
  30         DrawCursor();
  31 }
  32
  33 const unsigned kBottom = 1;
  34 const unsigned kTop = 2;
  35 const unsigned kLeft = 4;
  36 const unsigned kRight = 8;
  37
  38 #define clipmask(x, y, rect)            \
  39         ({      unsigned mask = 0;                                                              \
  40                 if (x < rect.left) mask |= kLeft;                       \
  41                 else if (x > rect.right) mask |= kRight;        \
  42                 if (y < rect.top) mask |= kTop;                 \
  43                 else if (y > rect.bottom) mask |= kBottom;      \
  44                 mask;})
  45
  46 inline int vert_intersection(int x1, int y1, int x2, int y2, int x)
  47 {
  48         return y1 + (y2 - y1) * (x - x1) / (x2 - x1);
  49 }
  50
  51 inline int horz_intersection(int x1, int y1, int x2, int y2, int y)
  52 {
  53         return x1 + (x2 - x1) * (y - y1) / (y2 - y1);
  54 }
  55
  56 void Renderer_vga::DrawLine(int x1, int y1, int x2, int y2, char color)
  57 {
  58         Rect cursorRect(fCursorX, fCursorY, fCursorX + 16, fCursorY + 16);
  59         bool invalidateCursor = true;
  60
  61         int clippedX1 = x1;
  62         int clippedY1 = y1;
  63         int clippedX2 = x2;
  64         int clippedY2 = y2;
  65         unsigned point1mask = clipmask(clippedX1, clippedY1, cursorRect);
  66         unsigned point2mask = clipmask(clippedX2, clippedY2, cursorRect);
  67         while (point1mask != 0 || point2mask != 0) {
  68                 if ((point1mask & point2mask) != 0) {
  69                         invalidateCursor = false;
  70                         break;
  71                 }
  72
  73                 unsigned  mask = point1mask ? point1mask : point2mask;
  74                 int x = 0;
  75                 int y = 0;
  76                 if (mask & kBottom) {
  77                         y = cursorRect.bottom;
  78                         x = horz_intersection(clippedX1, clippedY1, clippedX2, clippedY2, y);
  79                 } else if (mask & kTop) {
  80                         y = cursorRect.top;
  81                         x = horz_intersection(clippedX1, clippedY1, clippedX2, clippedY2, y);
  82                 } else if (mask & kRight) {
  83                         x = cursorRect.right;
  84                         y = vert_intersection(clippedX1, clippedY1, clippedX2, clippedY2, x);
  85                 } else if (mask & kLeft) {
  86                         x = cursorRect.left;
  87                         y = vert_intersection(clippedX1, clippedY1, clippedX2, clippedY2, x);
  88                 }
  89
  90                 if (point1mask) {
  91                         // Clip point 1
  92                         point1mask = clipmask(x, y, cursorRect);
  93                         clippedX1 = x;
  94                         clippedY1 = y;
  95                 } else {
  96                         // Clip point 2
  97                         point2mask = clipmask(x, y, cursorRect);
  98                         clippedX2 = x;
  99                         clippedY2 = y;
 100                 }
 101         }
 102
 103         if (invalidateCursor)
 104                 EraseCursor();
 105
 106         Renderer_8bpp::DrawLine(x1, y1, x2, y2, color);
 107
 108         if (invalidateCursor)
 109                 DrawCursor();
 110 }
 111
 112 void Renderer_vga::FillRect(int x1, int y1, int x2, int y2, char color)
 113 {
 114
 115         bool invalidateCursor = false;
 116         if (Rect(x1, y1, x2, y2).Intersects(Rect(fCursorX, fCursorY, fCursorX + 16,
 117                 fCursorY + 16))) {
 118                 invalidateCursor = true;
 119                 EraseCursor();
 120         }
 121
 122         Renderer_8bpp::FillRect(x1, y1, x2, y2, color);
 123         if (invalidateCursor)
 124                 DrawCursor();
 125 }
 126
 127 void Renderer_vga::Blit(int x, int y, char image[], int imageWidth,
 128     int imageHeight, int imageBytesPerRow)
 129 {
 130
 131         bool invalidateCursor = false;
 132         if (Rect(x, y, x + imageWidth, y + imageHeight).Intersects(Rect(fCursorX,
 133                 fCursorY, fCursorX + 16, fCursorY + 16))) {
 134                 invalidateCursor = true;
 135                 EraseCursor();
 136         }
 137
 138         Renderer_8bpp::Blit(x, y, image, imageWidth, imageHeight, imageBytesPerRow);
 139         if (invalidateCursor)
 140                 DrawCursor();
 141 }
 142
 143 void Renderer_vga::StretchBlit(const Rect &imageRect, const Rect &displayRect, char image[],
 144         int imageBytesPerRow)
 145 {
 146
 147         bool invalidateCursor = false;
 148         if (displayRect.Intersects(Rect(fCursorX, fCursorY, fCursorX + 16,
 149                 fCursorY + 16))) {
 150                 invalidateCursor = true;
 151                 EraseCursor();
 152         }
 153
 154         Renderer_8bpp::StretchBlit(imageRect, displayRect, image, imageBytesPerRow);
 155
 156         if (invalidateCursor)
 157                 DrawCursor();
 158 }
 159
 160 void Renderer_vga::CopyRect(const Rect &source, const Rect &dest)
 161 {
 162         bool invalidateCursor = false;
 163         Rect cursorRect(fCursorX, fCursorY, fCursorX + 16, fCursorY + 16);
 164         if (cursorRect.Intersects(source) || cursorRect.Intersects(dest)) {
 165                 invalidateCursor = true;
 166                 EraseCursor();
 167         }
 168
 169         Renderer_8bpp::CopyRect(source, dest);
 170         if (invalidateCursor)
 171                 DrawCursor();
 172 }
 173
 174 void Renderer_vga::SetCursorPosition(int x, int  y)
 175 {
 176         EraseCursor();
 177         fCursorX = x;
 178         fCursorY = y;
 179         DrawCursor();
 180 }
 181
 182 void Renderer_vga::EraseCursor()
 183 {
 184         char *screen_ptr = BufferBaseAddress() + fCursorX + fCursorY * BufferBytesPerRow();
 185         char *saveBackground = fSavedBackground;
 186         int cursorDisplayWidth = MIN(16, BufferBytesPerRow() - fCursorX);
 187         int cursorDisplayHeight = MIN(16, BufferHeight() - fCursorY);
 188         int stride = BufferBytesPerRow() - cursorDisplayWidth;
 189
 190         for (int y = 0; y < cursorDisplayHeight; y++) {
 191                 for (int x = 0; x < cursorDisplayWidth; x++) {
 192                         if ((unsigned char) *saveBackground != 0xff)
 193                                 *screen_ptr = *saveBackground;
 194
 195                         screen_ptr++;
 196                         saveBackground++;
 197                 }
 198
 199                 screen_ptr += stride;
 200                 saveBackground += 16 - cursorDisplayWidth;
 201         }
 202 }
 203
 204 void Renderer_vga::DrawCursor()
 205 {
 206         char *screen_ptr = BufferBaseAddress() + fCursorX + fCursorY * BufferBytesPerRow();
 207         char *cursorImage = (char *) kCursorBits;
 208         char *saveBackground = fSavedBackground;
 209         int cursorDisplayWidth = MIN(16, BufferBytesPerRow() - fCursorX);
 210         int cursorDisplayHeight = MIN(16, BufferHeight() - fCursorY);
 211         int stride = BufferBytesPerRow() - cursorDisplayWidth;
 212
 213         for (int y = 0; y < cursorDisplayHeight; y++) {
 214                 for (int x = 0; x < cursorDisplayWidth; x++) {
 215                         if ((unsigned char) *cursorImage != 0xff) {
 216                                 *saveBackground = *screen_ptr;
 217                                 *screen_ptr = *cursorImage;
 218                         } else
 219                                 *saveBackground = 0xff;
 220
 221                         screen_ptr++;
 222                         cursorImage++;
 223                         saveBackground++;
 224                 }
 225
 226                 screen_ptr += stride;
 227                 cursorImage += 16 - cursorDisplayWidth;
 228                 saveBackground += 16 - cursorDisplayWidth;
 229         }
 230 }