static inline void test_premul(skiatest::Reporter* reporter) {
for (int a = 0; a <= 255; a++) {
for (int x = 0; x <= 255; x++) {
SkColor c0 = SkColorSetARGB(a, x, x, x);
SkPMColor p0 = SkPreMultiplyColor(c0);
SkColor c1 = SkUnPreMultiply::PMColorToColor(p0);
SkPMColor p1 = SkPreMultiplyColor(c1);
// we can't promise that c0 == c1, since c0 -> p0 is a many to one
// function, however, we can promise that p0 -> c1 -> p1 : p0 == p1
REPORTER_ASSERT(reporter, p0 == p1);
{
int ax = SkMulDiv255Ceiling(x, a);
REPORTER_ASSERT(reporter, ax <= a);
}
}
}
}
void putImageData(ByteArray*& source, const IntSize& sourceSize, const IntRect& sourceRect, const IntPoint& destPoint,
SkDevice* dstDevice, const IntSize& size)
{
ASSERT(sourceRect.width() > 0);
ASSERT(sourceRect.height() > 0);
int originX = sourceRect.x();
int destX = destPoint.x() + sourceRect.x();
ASSERT(destX >= 0);
ASSERT(destX < size.width());
ASSERT(originX >= 0);
ASSERT(originX < sourceRect.maxX());
int endX = destPoint.x() + sourceRect.maxX();
ASSERT(endX <= size.width());
int numColumns = endX - destX;
int originY = sourceRect.y();
int destY = destPoint.y() + sourceRect.y();
ASSERT(destY >= 0);
ASSERT(destY < size.height());
ASSERT(originY >= 0);
ASSERT(originY < sourceRect.maxY());
int endY = destPoint.y() + sourceRect.maxY();
ASSERT(endY <= size.height());
int numRows = endY - destY;
unsigned srcBytesPerRow = 4 * sourceSize.width();
SkBitmap deviceBitmap = dstDevice->accessBitmap(true);
SkAutoLockPixels deviceAutoLock(deviceBitmap);
// If the device's bitmap doesn't have pixels we will make a temp and call writePixels on the device.
bool temporaryBitmap = !deviceBitmap.getPixels();
SkBitmap destBitmap;
if (temporaryBitmap) {
destBitmap.setConfig(SkBitmap::kARGB_8888_Config, numColumns, numRows, srcBytesPerRow);
if (!destBitmap.allocPixels())
CRASH();
} else
deviceBitmap.extractSubset(&destBitmap, SkIRect::MakeXYWH(destX, destY, numColumns, numRows));
// Whether we made a temporary or not destBitmap is always configured to be written at 0,0
SkAutoLockPixels destAutoLock(destBitmap);
const unsigned char* srcRow = source->data() + originY * srcBytesPerRow + originX * 4;
for (int y = 0; y < numRows; ++y) {
SkPMColor* destRow = destBitmap.getAddr32(0, y);
for (int x = 0; x < numColumns; ++x) {
const unsigned char* srcPixel = &srcRow[x * 4];
if (multiplied == Unmultiplied) {
unsigned char alpha = srcPixel[3];
unsigned char r = SkMulDiv255Ceiling(srcPixel[0], alpha);
unsigned char g = SkMulDiv255Ceiling(srcPixel[1], alpha);
unsigned char b = SkMulDiv255Ceiling(srcPixel[2], alpha);
destRow[x] = SkPackARGB32(alpha, r, g, b);
} else
destRow[x] = SkPackARGB32(srcPixel[3], srcPixel[0], srcPixel[1], srcPixel[2]);
}
srcRow += srcBytesPerRow;
}
// If we used a temporary then write it to the device
if (temporaryBitmap)
dstDevice->writePixels(destBitmap, destX, destY);
}
