1 /*
2 * Copyright 2019 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/gm.h"
9 #include "include/core/SkCanvas.h"
10 #include "include/core/SkColor.h"
11 #include "include/core/SkColorFilter.h"
12 #include "include/core/SkFont.h"
13 #include "include/core/SkFontTypes.h"
14 #include "include/core/SkImage.h"
15 #include "include/core/SkImageInfo.h"
16 #include "include/core/SkOverdrawCanvas.h"
17 #include "include/core/SkPaint.h"
18 #include "include/core/SkRect.h"
19 #include "include/core/SkRefCnt.h"
20 #include "include/core/SkSurface.h"
21 #include "include/core/SkTypes.h"
22 #include "include/effects/SkOverdrawColorFilter.h"
23 #include "tools/fonts/FontToolUtils.h"
24
25 #define WIDTH 500
26 #define HEIGHT 500
27
28 static const SkColor kOverdrawColors[6] = {
29 0x00000000, 0x5fff0000, 0x2f0000ff, 0x2f00ff00, 0x3fff0000, 0x7fff0000,
30 };
31
32
DEF_SIMPLE_GM_BG(overdraw_canvas,canvas,WIDTH,HEIGHT,SK_ColorWHITE)33 DEF_SIMPLE_GM_BG(overdraw_canvas, canvas, WIDTH, HEIGHT, SK_ColorWHITE) {
34 // Set up the overdraw canvas.
35 SkImageInfo offscreenInfo = SkImageInfo::MakeA8(WIDTH, HEIGHT);
36 sk_sp<SkSurface> offscreen = SkSurfaces::Raster(offscreenInfo);
37 SkFont font = ToolUtils::DefaultPortableFont();
38 auto c = offscreen->getCanvas();
39
40 SkOverdrawCanvas overdrawCanvas(c);
41
42 overdrawCanvas.drawRect(SkRect::MakeLTRB(10, 10, 200, 200), SkPaint());
43 overdrawCanvas.drawRect(SkRect::MakeLTRB(20, 20, 190, 190), SkPaint());
44 overdrawCanvas.drawRect(SkRect::MakeLTRB(30, 30, 180, 180), SkPaint());
45 overdrawCanvas.drawRect(SkRect::MakeLTRB(40, 40, 170, 170), SkPaint());
46 overdrawCanvas.drawRect(SkRect::MakeLTRB(50, 50, 160, 160), SkPaint());
47 overdrawCanvas.drawRect(SkRect::MakeLTRB(60, 60, 150, 150), SkPaint());
48
49 char text[] = "Ae_p";
50 overdrawCanvas.drawSimpleText(text, 4, SkTextEncoding::kUTF8, 300, 300, font, SkPaint());
51
52 sk_sp<SkImage> counts = offscreen->makeImageSnapshot();
53
54 // Draw overdraw colors to the canvas. The color filter will convert counts to colors.
55 SkPaint paint;
56 paint.setColorFilter(SkOverdrawColorFilter::MakeWithSkColors(kOverdrawColors));
57 canvas->drawImage(counts.get(), 0.0f, 0.0f, SkSamplingOptions(), &paint);
58 canvas->drawString("This is some text:", 180, 300, font, SkPaint());
59 }
60
overdraw_text_grid(bool useCTM)61 static sk_sp<SkImage> overdraw_text_grid(bool useCTM) {
62 auto surface = SkSurfaces::Raster(SkImageInfo::MakeA8(256, 512));
63 auto canvas = SkOverdrawCanvas(surface->getCanvas());
64
65 SkPaint paint;
66 paint.setColor(SK_ColorWHITE);
67
68 SkFont font = ToolUtils::DefaultPortableFont();
69
70 for (int n = 1; n <= 20; n++) {
71 const float x = 10.0f;
72 const float y = n * 20.0f;
73
74 for (int i = 0; i < n * 10; i++) {
75 const char* text = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
76 if (useCTM) {
77 canvas.save();
78 canvas.translate(x, y);
79 canvas.drawString(text, 0, 0, font, paint);
80 canvas.restore();
81 } else {
82 canvas.drawString(text, x, y, font, paint);
83 }
84 }
85 }
86 return surface->makeImageSnapshot();
87 }
88
89 // This GM tests the underlying problem from skbug.com/13732. Text drawn through an overdraw
90 // canvas would have the CTM applied twice. If everything is working, both images generated should
91 // look identical. When the bug was present, the second image would have the lines "double spaced",
92 // because the translations were applied twice.
93 DEF_SIMPLE_GM_BG(overdraw_text_xform, canvas, 512, 512, SK_ColorBLACK) {
94 SkPaint imgPaint;
95 imgPaint.setColor(SK_ColorWHITE);
96 canvas->drawImage(overdraw_text_grid(false), 0, 0, SkFilterMode::kNearest, &imgPaint);
97 canvas->drawImage(overdraw_text_grid( true), 256, 0, SkFilterMode::kNearest, &imgPaint);
98 }
99