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