skia2/docs/examples/UnpremulBugs.cpp
Hal Canary 6c8422c671 add more docs/examples from named fiddles.
ignore offscreen, srgb, and animated fiddles for now.

Change-Id: I923131b684865698e6cda138b004930e11f504d5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/263713
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2020-01-14 19:22:26 +00:00

54 lines
1.9 KiB
C++

// 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(UnpremulBugs, 400, 400, false, 6) {
void fill(SkBitmap & b, SkColor c, int n) {
for (int y = 0; y < n; y++) {
for (int x = 0; x < n; x++) {
*(b.getAddr32(x, y)) = c;
}
}
}
void doCell(SkCanvas* canvas, float x, float y, SkAlphaType at, SkColor c, int n) {
SkImageInfo info = SkImageInfo::MakeS32(n, n, at);
SkBitmap bmp;
bmp.allocPixels(info);
fill(bmp, c, n);
sk_sp<SkImage> img = SkImage::MakeFromBitmap(bmp);
SkPaint paint;
const SkTileMode tile = SkTileMode::kRepeat;
paint.setShader(img->makeShader(tile, tile, nullptr));
canvas->drawRect(SkRect::MakeXYWH(x, y, 50, 50), paint);
}
void draw(SkCanvas* canvas) {
canvas->clear(SK_ColorBLACK);
doCell(canvas, 0, 0, kPremul_SkAlphaType, 0x80404040, 2);
doCell(canvas, 0, 50, kUnpremul_SkAlphaType, 0x80808080, 2);
doCell(canvas, 50, 0, kPremul_SkAlphaType, 0x80808080, 2);
doCell(canvas, 50, 50, kUnpremul_SkAlphaType, 0x80FFFFFF, 2);
doCell(canvas, 110, 0, kPremul_SkAlphaType, 0x80404040, 1);
doCell(canvas, 110, 50, kUnpremul_SkAlphaType, 0x80808080, 1);
doCell(canvas, 160, 0, kPremul_SkAlphaType, 0x80808080, 1);
doCell(canvas, 160, 50, kUnpremul_SkAlphaType, 0x80FFFFFF, 1);
SkFont font(nullptr, 12);
SkPaint paint;
paint.setColor(SK_ColorWHITE);
canvas->drawString("Premul", 220, 20, font, paint);
canvas->drawString("Unpremul", 220, 70, font, paint);
canvas->drawString("Gray", 5, 120, font, paint);
canvas->drawString("White", 55, 120, font, paint);
canvas->drawString("Gray", 115, 120, font, paint);
canvas->drawString("White", 165, 120, font, paint);
canvas->drawString("2x2", 40, 150, font, paint);
canvas->drawString("1x1", 150, 150, font, paint);
}
} // END FIDDLE