// static
SkBitmap ImageOperations::Resize(const SkBitmap& source,
ResizeMethod method,
int dest_width, int dest_height,
const SkIRect& dest_subset,
void* dest_pixels /* = nullptr */) {
if (method == ImageOperations::RESIZE_SUBPIXEL)
return ResizeSubpixel(source, dest_width, dest_height, dest_subset);
else
return ResizeBasic(source, method, dest_width, dest_height, dest_subset,
dest_pixels);
}
// static
SkBitmap ImageOperations::Resize(const SkBitmap& source,
ResizeMethod method,
int dest_width, int dest_height,
const SkIRect& dest_subset)
{
if(method == ImageOperations::RESIZE_SUBPIXEL)
{
return ResizeSubpixel(source, dest_width, dest_height, dest_subset);
}
else
{
return ResizeBasic(source, method, dest_width, dest_height, dest_subset);
}
}
// static
SkBitmap ImageOperations::ResizeSubpixel(const SkBitmap& source,
int dest_width, int dest_height,
const SkIRect& dest_subset) {
// Currently only works on Linux/BSD because these are the only platforms
// where SkFontHost::GetSubpixelOrder is defined.
#if defined(XP_UNIX)
// Understand the display.
const SkFontHost::LCDOrder order = SkFontHost::GetSubpixelOrder();
const SkFontHost::LCDOrientation orientation =
SkFontHost::GetSubpixelOrientation();
// Decide on which dimension, if any, to deploy subpixel rendering.
int w = 1;
int h = 1;
switch (orientation) {
case SkFontHost::kHorizontal_LCDOrientation:
w = dest_width < source.width() ? 3 : 1;
break;
case SkFontHost::kVertical_LCDOrientation:
h = dest_height < source.height() ? 3 : 1;
break;
}
// Resize the image.
const int width = dest_width * w;
const int height = dest_height * h;
SkIRect subset = { dest_subset.fLeft, dest_subset.fTop,
dest_subset.fLeft + dest_subset.width() * w,
dest_subset.fTop + dest_subset.height() * h };
SkBitmap img = ResizeBasic(source, ImageOperations::RESIZE_LANCZOS3, width,
height, subset);
const int row_words = img.rowBytes() / 4;
if (w == 1 && h == 1)
return img;
// Render into subpixels.
SkBitmap result;
SkImageInfo info = SkImageInfo::Make(dest_subset.width(),
dest_subset.height(),
kBGRA_8888_SkColorType,
kPremul_SkAlphaType);
result.allocPixels(info);
if (!result.readyToDraw())
return img;
SkAutoLockPixels locker(img);
if (!img.readyToDraw())
return img;
uint32_t* src_row = img.getAddr32(0, 0);
uint32_t* dst_row = result.getAddr32(0, 0);
for (int y = 0; y < dest_subset.height(); y++) {
uint32_t* src = src_row;
uint32_t* dst = dst_row;
for (int x = 0; x < dest_subset.width(); x++, src += w, dst++) {
uint8_t r = 0, g = 0, b = 0, a = 0;
switch (order) {
case SkFontHost::kRGB_LCDOrder:
switch (orientation) {
case SkFontHost::kHorizontal_LCDOrientation:
r = SkGetPackedR32(src[0]);
g = SkGetPackedG32(src[1]);
b = SkGetPackedB32(src[2]);
a = SkGetPackedA32(src[1]);
break;
case SkFontHost::kVertical_LCDOrientation:
r = SkGetPackedR32(src[0 * row_words]);
g = SkGetPackedG32(src[1 * row_words]);
b = SkGetPackedB32(src[2 * row_words]);
a = SkGetPackedA32(src[1 * row_words]);
break;
}
break;
case SkFontHost::kBGR_LCDOrder:
switch (orientation) {
case SkFontHost::kHorizontal_LCDOrientation:
b = SkGetPackedB32(src[0]);
g = SkGetPackedG32(src[1]);
r = SkGetPackedR32(src[2]);
a = SkGetPackedA32(src[1]);
break;
case SkFontHost::kVertical_LCDOrientation:
b = SkGetPackedB32(src[0 * row_words]);
g = SkGetPackedG32(src[1 * row_words]);
r = SkGetPackedR32(src[2 * row_words]);
a = SkGetPackedA32(src[1 * row_words]);
break;
}
break;
case SkFontHost::kNONE_LCDOrder:
break;
}
// Premultiplied alpha is very fragile.
a = a > r ? a : r;
a = a > g ? a : g;
a = a > b ? a : b;
*dst = SkPackARGB32(a, r, g, b);
}
src_row += h * row_words;
dst_row += result.rowBytes() / 4;
}
result.setAlphaType(img.alphaType());
return result;
#else
return SkBitmap();
#endif // OS_POSIX && !OS_MACOSX && !defined(OS_ANDROID)
}