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 "DecodeFile.h"
9 #include "SampleCode.h"
10 #include "SkView.h"
11 #include "SkCanvas.h"
12 #include "SkGradientShader.h"
13 #include "SkGraphics.h"
14 #include "SkPath.h"
15 #include "SkRegion.h"
16 #include "SkShader.h"
17 #include "SkUtils.h"
18 #include "SkColorPriv.h"
19 #include "SkColorFilter.h"
20 #include "SkTime.h"
21 #include "SkTypeface.h"
22
make_bitmapfade(const SkBitmap & bm)23 static sk_sp<SkShader> make_bitmapfade(const SkBitmap& bm) {
24 SkPoint pts[2];
25 SkColor colors[2];
26
27 pts[0].set(0, 0);
28 pts[1].set(0, SkIntToScalar(bm.height()));
29 colors[0] = SK_ColorBLACK;
30 colors[1] = SkColorSetARGB(0, 0, 0, 0);
31 auto shaderA = SkGradientShader::MakeLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
32
33 auto shaderB = SkShader::MakeBitmapShader(bm,
34 SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);
35
36 return SkShader::MakeComposeShader(std::move(shaderB), std::move(shaderA), SkBlendMode::kDstIn);
37 }
38
39 class ShaderView : public SampleView {
40 public:
41 sk_sp<SkShader> fShader;
42 SkBitmap fBitmap;
43
ShaderView()44 ShaderView() {
45 decode_file("/skimages/logo.gif", &fBitmap);
46
47 SkPoint pts[2];
48 SkColor colors[2];
49
50 pts[0].set(0, 0);
51 pts[1].set(SkIntToScalar(100), 0);
52 colors[0] = SK_ColorRED;
53 colors[1] = SK_ColorBLUE;
54 auto shaderA = SkGradientShader::MakeLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
55
56 pts[0].set(0, 0);
57 pts[1].set(0, SkIntToScalar(100));
58 colors[0] = SK_ColorBLACK;
59 colors[1] = SkColorSetARGB(0x80, 0, 0, 0);
60 auto shaderB = SkGradientShader::MakeLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
61
62 fShader = SkShader::MakeComposeShader(std::move(shaderA), std::move(shaderB),
63 SkBlendMode::kDstIn);
64 }
65
66 protected:
67 // overrides from SkEventSink
onQuery(SkEvent * evt)68 bool onQuery(SkEvent* evt) override {
69 if (SampleCode::TitleQ(*evt)) {
70 SampleCode::TitleR(evt, "Shaders");
71 return true;
72 }
73 return this->INHERITED::onQuery(evt);
74 }
75
onDrawContent(SkCanvas * canvas)76 void onDrawContent(SkCanvas* canvas) override {
77 canvas->drawBitmap(fBitmap, 0, 0);
78
79 canvas->translate(20, 120);
80
81 SkPaint paint;
82 SkRect r;
83
84 paint.setColor(SK_ColorGREEN);
85 canvas->drawRect(SkRect::MakeWH(100, 100), paint);
86 paint.setShader(fShader);
87 canvas->drawRect(SkRect::MakeWH(100, 100), paint);
88
89 canvas->translate(SkIntToScalar(110), 0);
90
91 int w = fBitmap.width();
92 int h = fBitmap.height();
93 w = 120;
94 h = 80;
95 r.set(0, 0, SkIntToScalar(w), SkIntToScalar(h));
96
97 paint.setShader(nullptr);
98 canvas->drawRect(r, paint);
99 paint.setShader(make_bitmapfade(fBitmap));
100 canvas->drawRect(r, paint);
101 }
102
103 private:
104 typedef SampleView INHERITED;
105 };
106
107 //////////////////////////////////////////////////////////////////////////////
108
MyFactory()109 static SkView* MyFactory() { return new ShaderView; }
110 static SkViewRegister reg(MyFactory);
111
