xref: /aosp_15_r20/external/skia/gm/scaledrects.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2023 Google LLC
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/SkPaint.h"
11 #include "include/core/SkRect.h"
12 #include "include/core/SkString.h"
13 
14 namespace skiagm {
15 
16 // From crbug.com/1442854. Draws two rects (equivalent in device space) but which vary wildly
17 // in their sizes and scales. In both cases the clip is what is actually determining the
18 // final drawn geometry. For the red rectangle case the inverted skews were becoming very small and
19 // ran afoul of some logic in the DMSAA code that zeroed them out.
20 class ScaledRectsGM : public GM {
21 public:
ScaledRectsGM()22     ScaledRectsGM() {
23         this->setBGColor(0xFFCCCCCC);
24     }
25 
26 protected:
getName() const27     SkString getName() const override { return SkString("scaledrects"); }
28 
getISize()29     SkISize getISize() override { return SkISize::Make(128, 64); }
30 
onDraw(SkCanvas * canvas)31     void onDraw(SkCanvas* canvas) override {
32         canvas->clipRect(SkRect::MakeXYWH(10, 50, 100, 10));
33 
34         {
35             SkPaint blue;
36             blue.setColor(SK_ColorBLUE);
37 
38             canvas->setMatrix(SkMatrix::MakeAll( 3.0f, -0.5f, 0.0f,
39                                                 -0.5f, -3.0f, 0.0f,
40                                                  0.0f,  0.0f, 1.0f));
41 
42             canvas->drawRect(SkRect::MakeXYWH(-1000, -1000, 2000, 2000), blue);
43         }
44 
45         {
46             SkPaint red;
47             red.setColor(SK_ColorRED);
48             red.setBlendMode(SkBlendMode::kPlus);
49 
50             canvas->setMatrix(SkMatrix::MakeAll(3000.0f,  -500.0f, 0.0f,
51                                                 -500.0f, -3000.0f, 0.0f,
52                                                    0.0f,     0.0f, 1.0f));
53 
54             canvas->drawRect(SkRect::MakeXYWH(-1, -1, 2, 2), red);
55         }
56     }
57 };
58 
59 //////////////////////////////////////////////////////////////////////////////
60 
61 DEF_GM(return new ScaledRectsGM;)
62 
63 }  // namespace skiagm
64