skia2/docs/examples/gpu4444diff.cpp

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// Copyright 2020 Google LLC.
// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
#include "tools/fiddle/examples.h"
REG_FIDDLE_SRGB(gpu4444diff, 260, 260, false, 3, 0, false) {
void draw(SkCanvas* canvas) {
canvas->scale(16, 16);
SkBitmap bitmap;
SkImageInfo imageInfo = SkImageInfo::Make(2, 2, kARGB_4444_SkColorType, kPremul_SkAlphaType);
bitmap.allocPixels(imageInfo);
SkCanvas offscreen(bitmap);
offscreen.clear(SK_ColorGREEN);
canvas->drawBitmap(bitmap, 0, 0);
offscreen.clear(SK_ColorGRAY);
canvas->drawBitmap(bitmap, 2, 2);
auto pack4444 = [](unsigned a, unsigned r, unsigned g, unsigned b) -> uint16_t {
return (a << 0) | (b << 4) | (g << 8) | (r << 12);
};
uint16_t red4444[] = { pack4444(0xF, 0xF, 0x0, 0x0), pack4444(0xF, 0xb, 0x0, 0x0),
pack4444(0xF, 0x9, 0x0, 0x0), pack4444(0xF, 0x5, 0x0, 0x0) };
uint16_t blue4444[] = { pack4444(0xF, 0x0, 0x0, 0x0F), pack4444(0xF, 0x0, 0x0, 0x0b),
pack4444(0xF, 0x0, 0x0, 0x09), pack4444(0xF, 0x0, 0x0, 0x05) };
SkImageInfo pixInfo = SkImageInfo::Make(2, 2, kARGB_4444_SkColorType, kPremul_SkAlphaType);
SkPixmap redPixmap(imageInfo, &red4444, 4);
if (bitmap.writePixels(redPixmap, 0, 0)) {
canvas->drawBitmap(bitmap, 4, 4);
}
SkPixmap bluePixmap(imageInfo, &blue4444, 4);
if (bitmap.writePixels(bluePixmap, 0, 0)) {
canvas->drawBitmap(bitmap, 6, 6);
}
}
} // END FIDDLE