void MyCanvas::shadeDeviceRect(const GIRect& rect, GShader* shader)
{
assert(shader != nullptr);
if (rect.isEmpty())
{
printf("Error: ShadeDeviceRect rect is empty can't draw\n");
return;
}
// Get dst bitmap address and offset to the rect top
GPixel* DstPixels = (GPixel*)((char*)Bitmap.pixels() + Bitmap.fRowBytes * rect.top());
// Set the context of the shader to the CTM
float TwoRows[6];
CTM.GetTwoRows(TwoRows);
shader->setContext(TwoRows);
//All rows will have the same number of pixels so we can allocate once for the whole rect
int count = rect.width();
GPixel* row = new GPixel[count];
for (int y = rect.top(); y < rect.bottom(); ++y)
{
shader->shadeRow(rect.left(), y, count, row);
blendRow(DstPixels, rect.left(), row, count);
DstPixels = (GPixel*)((char*)DstPixels + Bitmap.fRowBytes);
}
delete[] row;
}
static void srcover_rect(const GBitmap& bitmap, const GIRect& rect, const GPixel& color) {
unsigned a = GPixel_GetA(color);
if (0 == a) {
return;
}
RowProc proc = (255 == a) ? src_row : srcover_row;
const int width = rect.width();
for (int y = rect.top(); y < rect.bottom(); ++y) {
proc(get_addr(bitmap, rect.x(), y), width, color);
}
}
static void src_rect(const GBitmap& bitmap, const GIRect& rect, const GPixel& color) {
const int width = rect.width();
for (int y = rect.top(); y < rect.bottom(); ++y) {
src_row(get_addr(bitmap, rect.x(), y), width, color);
}
}
