1 /*
2 * Copyright 2013 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 #include "SkBitmap.h"
10 #include "SkCanvas.h"
11 #include "SkColorData.h"
12
13 /**
14 * This GM checks that bitmap pixels are unpremultiplied before being exported
15 * to other formats. If unpremultiplication is implemented properly, this
16 * GM should come out completely white. If not, this GM looks like a row of two
17 * greyscale gradients above a row of grey lines.
18 * This tests both the ARGB4444 and ARGB8888 bitmap configurations.
19 */
20
21 constexpr int SLIDE_SIZE = 256;
22
init_bitmap(SkColorType ct,SkBitmap * bitmap)23 static void init_bitmap(SkColorType ct, SkBitmap* bitmap) {
24 bitmap->allocPixels(SkImageInfo::Make(SLIDE_SIZE, SLIDE_SIZE, ct,
25 kPremul_SkAlphaType));
26 bitmap->eraseColor(SK_ColorWHITE);
27 }
28
make_argb8888_gradient()29 static SkBitmap make_argb8888_gradient() {
30 SkBitmap bitmap;
31 init_bitmap(kN32_SkColorType, &bitmap);
32 for (int y = 0; y < SLIDE_SIZE; y++) {
33 uint32_t* dst = bitmap.getAddr32(0, y);
34 for (int x = 0; x < SLIDE_SIZE; x++) {
35 dst[x] = SkPackARGB32(y, y, y, y);
36 }
37 }
38 return bitmap;
39 }
40
make_argb4444_gradient()41 static SkBitmap make_argb4444_gradient() {
42 SkBitmap bitmap;
43 init_bitmap(kARGB_4444_SkColorType, &bitmap);
44 // Using draw rather than readPixels to suppress dither
45 SkPaint paint;
46 paint.setBlendMode(SkBlendMode::kSrc);
47 SkCanvas{ bitmap }.drawBitmap(make_argb8888_gradient(), 0, 0, &paint);
48 return bitmap;
49 }
50
make_argb8888_stripes()51 static SkBitmap make_argb8888_stripes() {
52 SkBitmap bitmap;
53 init_bitmap(kN32_SkColorType, &bitmap);
54 uint8_t rowColor = 0;
55 for (int y = 0; y < SLIDE_SIZE; y++) {
56 uint32_t* dst = bitmap.getAddr32(0, y);
57 for (int x = 0; x < SLIDE_SIZE; x++) {
58 dst[x] = SkPackARGB32(rowColor, rowColor,
59 rowColor, rowColor);
60 }
61 if (rowColor == 0) {
62 rowColor = 255;
63 } else {
64 rowColor = 0;
65 }
66 }
67 return bitmap;
68 }
69
make_argb4444_stripes()70 static SkBitmap make_argb4444_stripes() {
71 SkBitmap bitmap;
72 init_bitmap(kARGB_4444_SkColorType, &bitmap);
73 // Using draw rather than readPixels to suppress dither
74 SkPaint paint;
75 paint.setBlendMode(SkBlendMode::kSrc);
76 SkCanvas{ bitmap }.drawBitmap(make_argb8888_stripes(), 0, 0, &paint);
77 return bitmap;
78 }
79
80 namespace skiagm {
81
82 class BitmapPremulGM : public GM {
83 public:
BitmapPremulGM()84 BitmapPremulGM() {
85 this->setBGColor(SK_ColorWHITE);
86 }
87
88 protected:
onShortName()89 SkString onShortName() override {
90 return SkString("bitmap_premul");
91 }
92
onISize()93 SkISize onISize() override {
94 return SkISize::Make(SLIDE_SIZE * 2, SLIDE_SIZE * 2);
95 }
96
onDraw(SkCanvas * canvas)97 void onDraw(SkCanvas* canvas) override {
98 SkScalar slideSize = SkIntToScalar(SLIDE_SIZE);
99 canvas->drawBitmap(make_argb8888_gradient(), 0, 0);
100 canvas->drawBitmap(make_argb4444_gradient(), slideSize, 0);
101 canvas->drawBitmap(make_argb8888_stripes(), 0, slideSize);
102 canvas->drawBitmap(make_argb4444_stripes(), slideSize, slideSize);
103 }
104
105 private:
106 typedef GM INHERITED;
107 };
108
109 DEF_GM( return new BitmapPremulGM; )
110 }
111