1/*
2 * Copyright 2013 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.h"
9#include "SkCanvas.h"
10#include "SkGradientShader.h"
11
12class AlphaGradientsGM : public skiagm::GM {
13public:
14    AlphaGradientsGM() {}
15
16protected:
17    virtual SkString onShortName() SK_OVERRIDE {
18        return SkString("alphagradients");
19    }
20
21    virtual SkISize onISize() SK_OVERRIDE {
22        return SkISize::Make(640, 480);
23    }
24
25    static void draw_grad(SkCanvas* canvas, const SkRect& r,
26                          SkColor c0, SkColor c1, bool doPreMul) {
27        SkColor colors[] = { c0, c1 };
28        SkPoint pts[] = { { r.fLeft, r.fTop }, { r.fRight, r.fBottom } };
29        SkPaint paint;
30        uint32_t flags = doPreMul ? SkGradientShader::kInterpolateColorsInPremul_Flag : 0;
31        SkShader* s = SkGradientShader::CreateLinear(pts, colors, NULL, 2,
32                                                     SkShader::kClamp_TileMode, flags, NULL);
33        paint.setShader(s)->unref();
34        canvas->drawRect(r, paint);
35
36        paint.setShader(NULL);
37        paint.setStyle(SkPaint::kStroke_Style);
38        canvas->drawRect(r, paint);
39    }
40
41    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
42        static const struct {
43            SkColor fColor0;
44            SkColor fColor1;
45        } gRec[] = {
46            { 0xFFFFFFFF, 0x00000000 },
47            { 0xFFFFFFFF, 0x00FF0000 },
48            { 0xFFFFFFFF, 0x00FFFF00 },
49            { 0xFFFFFFFF, 0x00FFFFFF },
50            { 0xFFFF0000, 0x00000000 },
51            { 0xFFFF0000, 0x00FF0000 },
52            { 0xFFFF0000, 0x00FFFF00 },
53            { 0xFFFF0000, 0x00FFFFFF },
54            { 0xFF0000FF, 0x00000000 },
55            { 0xFF0000FF, 0x00FF0000 },
56            { 0xFF0000FF, 0x00FFFF00 },
57            { 0xFF0000FF, 0x00FFFFFF },
58        };
59
60        SkRect r = SkRect::MakeWH(300, 30);
61
62        canvas->translate(10, 10);
63
64        for (int doPreMul = 0; doPreMul <= 1; ++doPreMul) {
65            canvas->save();
66            for (size_t i = 0; i < SK_ARRAY_COUNT(gRec); ++i) {
67                draw_grad(canvas, r, gRec[i].fColor0, gRec[i].fColor1, SkToBool(doPreMul));
68                canvas->translate(0, r.height() + 8);
69            }
70            canvas->restore();
71            canvas->translate(r.width() + 10, 0);
72        }
73    }
74
75    virtual uint32_t onGetFlags() const { return kSkipPipe_Flag | kSkipTiled_Flag; }
76
77private:
78    typedef skiagm::GM INHERITED;
79};
80
81DEF_GM( return SkNEW(AlphaGradientsGM); )
82