xref: /aosp_15_r20/external/skia/gm/clipshader.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2 * Copyright 2011 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/SkPaint.h"
12 #include "include/core/SkPoint.h"
13 #include "include/core/SkRect.h"
14 #include "include/core/SkScalar.h"
15 #include "include/core/SkSurface.h"
16 #include "include/effects/SkGradientShader.h"
17 #include "tools/Resources.h"
18 
19 
20 // This tests using clip shader and then changing the canvas matrix before drawing. It also verifies
21 // that we don't incorrectly disable linear filtering of a clip image shader.
22 DEF_SIMPLE_GM(clipshadermatrix, canvas, 145, 128) {
23     auto clipSurface = SkSurfaces::Raster(SkImageInfo::MakeA8({70, 60}));
24     // Hard edged oval clip
25     clipSurface->getCanvas()->drawOval(SkRect::MakeXYWH(0, 10, 64, 44), SkPaint{});
26     auto clipShader = clipSurface->makeImageSnapshot()->makeShader(
27             SkTileMode::kDecal, SkTileMode::kDecal, SkFilterMode::kLinear);
28 
29     canvas->translate(5, 0);
30     for (auto tx : {0.f, 68.5f}) {
31         for (auto ty : {0.f, 66.5f}) {
32             canvas->save();
33 
34             canvas->translate(tx, ty);
35             canvas->clipShader(clipShader);
36             canvas->translate(-tx, -ty);
37 
38             SkMatrix m;
39             m.setSkew(0.03f, 0.f);
40             m.setPerspY( 0.0007f);
41             m.setPerspX(-0.002f);
42             m.setScaleX(1.2f); m.setScaleY(0.8f);
43             m.preRotate(30.f);
44             canvas->concat(m);
45 
46             SkPoint center = {64, 64};
47             SkAssertResult(m.invert(&m));
48             center = m.mapPoint(center);
49             SkColor colors[] {SK_ColorYELLOW,  SK_ColorGREEN, SK_ColorBLUE,
50                               SK_ColorMAGENTA, SK_ColorCYAN , SK_ColorYELLOW};
51             auto gradient = SkGradientShader::MakeRadial(
52                     center,
53                     /*radius=*/32.f,
54                     colors,
55                     /*pos=*/nullptr,
56                     std::size(colors),
57                     SkTileMode::kMirror,
58                     /*flags=*/0,
59                     /*localMatrix=*/nullptr);
60 
61             SkPaint paint;
62             paint.setShader(std::move(gradient));
63             canvas->drawPaint(paint);
64 
65             canvas->restore();
66         }
67     }
68 }
69