1// Copyright 2020 Google LLC.
2// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
3#include "tools/fiddle/examples.h"
4REG_FIDDLE(UnpremulBugs, 400, 400, false, 6) {
5void fill(SkBitmap & b, SkColor c, int n) {
6    for (int y = 0; y < n; y++) {
7        for (int x = 0; x < n; x++) {
8            *(b.getAddr32(x, y)) = c;
9        }
10    }
11}
12
13void doCell(SkCanvas* canvas, float x, float y, SkAlphaType at, SkColor c, int n) {
14    SkImageInfo info = SkImageInfo::MakeS32(n, n, at);
15    SkBitmap bmp;
16    bmp.allocPixels(info);
17    fill(bmp, c, n);
18    sk_sp<SkImage> img = bmp.asImage();
19
20    SkPaint paint;
21    const SkTileMode tile = SkTileMode::kRepeat;
22
23    paint.setShader(img->makeShader(tile, tile, SkSamplingOptions()));
24    canvas->drawRect(SkRect::MakeXYWH(x, y, 50, 50), paint);
25}
26
27void draw(SkCanvas* canvas) {
28    canvas->clear(SK_ColorBLACK);
29
30    doCell(canvas, 0, 0, kPremul_SkAlphaType, 0x80404040, 2);
31    doCell(canvas, 0, 50, kUnpremul_SkAlphaType, 0x80808080, 2);
32    doCell(canvas, 50, 0, kPremul_SkAlphaType, 0x80808080, 2);
33    doCell(canvas, 50, 50, kUnpremul_SkAlphaType, 0x80FFFFFF, 2);
34
35    doCell(canvas, 110, 0, kPremul_SkAlphaType, 0x80404040, 1);
36    doCell(canvas, 110, 50, kUnpremul_SkAlphaType, 0x80808080, 1);
37    doCell(canvas, 160, 0, kPremul_SkAlphaType, 0x80808080, 1);
38    doCell(canvas, 160, 50, kUnpremul_SkAlphaType, 0x80FFFFFF, 1);
39
40    SkFont font(nullptr, 12);
41    SkPaint paint;
42    paint.setColor(SK_ColorWHITE);
43    canvas->drawString("Premul", 220, 20, font, paint);
44    canvas->drawString("Unpremul", 220, 70, font, paint);
45    canvas->drawString("Gray", 5, 120, font, paint);
46    canvas->drawString("White", 55, 120, font, paint);
47    canvas->drawString("Gray", 115, 120, font, paint);
48    canvas->drawString("White", 165, 120, font, paint);
49
50    canvas->drawString("2x2", 40, 150, font, paint);
51    canvas->drawString("1x1", 150, 150, font, paint);
52}
53}  // END FIDDLE
54