bitmapshader.cpp revision e5957f67d00c04c0fbf88809df510426e74fe40a 
1
2/*
3 * Copyright 2013 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8#include "gm.h"
9
10#include "SkBitmap.h"
11#include "SkPaint.h"
12#include "SkShader.h"
13
14namespace skiagm {
15
16static void draw_bm(SkBitmap* bm) {
17    SkPaint bluePaint;
18    bluePaint.setColor(SK_ColorBLUE);
19
20    bm->allocN32Pixels(20, 20);
21    bm->eraseColor(SK_ColorRED);
22
23    SkCanvas canvas(*bm);
24    canvas.drawCircle(10, 10, 5, bluePaint);
25}
26
27static void draw_mask(SkBitmap* bm) {
28    SkPaint circlePaint;
29    circlePaint.setColor(SK_ColorBLACK);
30
31    bm->allocPixels(SkImageInfo::MakeA8(20, 20));
32    bm->eraseColor(SK_ColorTRANSPARENT);
33
34    SkCanvas canvas(*bm);
35    canvas.drawCircle(10, 10, 10, circlePaint);
36}
37
38static void adopt_shader(SkPaint* paint, SkShader* shader) {
39    paint->setShader(shader);
40    SkSafeUnref(shader);
41}
42
43class BitmapShaderGM : public GM {
44public:
45
46    BitmapShaderGM() {
47        this->setBGColor(SK_ColorGRAY);
48        draw_bm(&fBitmap);
49        draw_mask(&fMask);
50    }
51
52protected:
53    virtual SkString onShortName() {
54        return SkString("bitmapshaders");
55    }
56
57    virtual SkISize onISize() {
58        return SkISize::Make(75, 100);
59    }
60
61    virtual void onDraw(SkCanvas* canvas) {
62        SkPaint paint;
63
64        adopt_shader(&paint, SkShader::CreateBitmapShader(fBitmap, SkShader::kClamp_TileMode,
65                                                          SkShader::kClamp_TileMode));
66
67        // draw the shader with a bitmap mask
68        canvas->drawBitmap(fMask, 0, 0, &paint);
69        canvas->drawBitmap(fMask, 30, 0, &paint);
70
71        canvas->translate(0, 25);
72
73        canvas->drawCircle(10, 10, 10, paint);
74        canvas->drawCircle(40, 10, 10, paint); // no blue circle expected
75
76        canvas->translate(0, 25);
77
78        adopt_shader(&paint, SkShader::CreateBitmapShader(fMask, SkShader::kRepeat_TileMode,
79                                                          SkShader::kRepeat_TileMode));
80        paint.setColor(SK_ColorRED);
81
82        // draw the mask using the shader and a color
83        canvas->drawRect(SkRect::MakeXYWH(0, 0, 20, 20), paint);
84        canvas->drawRect(SkRect::MakeXYWH(30, 0, 20, 20), paint);
85    }
86
87private:
88    SkBitmap fBitmap;
89    SkBitmap fMask;
90
91    typedef GM INHERITED;
92};
93
94//////////////////////////////////////////////////////////////////////////////
95
96static GM* MyFactory(void*) { return new BitmapShaderGM; }
97static GMRegistry reg(MyFactory);
98
99}
100