skia2/docs/examples/dither1.cpp

// 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(dither1, 256, 100, false, 0) {
void draw(SkCanvas* canvas) {
    SkBitmap bm16;
    bm16.allocPixels(SkImageInfo::Make(32, 32, kRGB_565_SkColorType, kOpaque_SkAlphaType));
    SkCanvas c16(bm16);
    SkPaint colorPaint;
    for (auto dither : {false, true}) {
        colorPaint.setDither(dither);
        for (auto colors : {0xFF333333, 0xFF666666, 0xFF999999, 0xFFCCCCCC}) {
            for (auto mask : {0xFFFF0000, 0xFF00FF00, 0xFF0000FF, 0xFFFFFFFF}) {
                colorPaint.setColor(colors & mask);
                c16.drawRect({0, 0, 8, 4}, colorPaint);
                c16.translate(8, 0);
            }
            c16.translate(-32, 4);
        }
    }
    canvas->scale(8, 8);
    canvas->drawImage(bm16.asImage(), 0, 0);
}

}  // END FIDDLE