1/*
2 * Copyright 2017 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include "gm.h"
9
10#include "SkBlurMaskFilter.h"
11#include "SkColorFilter.h"
12#include "SkImage.h"
13#include "SkShader.h"
14
15static SkBitmap make_alpha_image(int w, int h) {
16    SkBitmap bm;
17    bm.allocPixels(SkImageInfo::MakeA8(w, h));
18    bm.eraseARGB(10, 0, 0 , 0);
19    for (int y = 0; y < bm.height(); ++y) {
20        for (int x = y; x < bm.width(); ++x) {
21            *bm.getAddr8(x, y) = 0xFF;
22        }
23    }
24    bm.setImmutable();
25    return bm;
26}
27
28static sk_sp<SkColorFilter> make_color_filter() {
29    SkScalar colorMatrix[20] = {
30        1, 0, 0,   0,   0,
31        0, 1, 0,   0,   0,
32        0, 0, 0.5, 0.5, 0,
33        0, 0, 0.5, 0.5, 0}; // mix G and A.
34    return SkColorFilter::MakeMatrixFilterRowMajor255(colorMatrix);
35}
36
37DEF_SIMPLE_GM(alpha_image, canvas, 256, 256) {
38    auto image = SkImage::MakeFromBitmap(make_alpha_image(96, 96));
39    SkPaint paint;
40
41    paint.setColorFilter(make_color_filter());
42    paint.setMaskFilter(SkBlurMaskFilter::Make(kNormal_SkBlurStyle, 10.0f, 0));
43    canvas->drawImage(image.get(), 16, 16, &paint);
44
45    paint.setColorFilter(nullptr);
46    paint.setShader(SkShader::MakeColorShader(SK_ColorCYAN));
47    canvas->drawImage(image.get(), 144, 16, &paint);
48
49    paint.setColorFilter(make_color_filter());
50    canvas->drawImage(image.get(), 16, 144, &paint);
51
52    paint.setMaskFilter(nullptr);
53    canvas->drawImage(image.get(), 144, 144, &paint);
54}
55