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 "SkPaint.h"
11#include "SkPath.h"
12#include "SkRect.h"
13
14namespace skiagm {
15
16/*
17 * This GM exercises the flags to SkCanvas::save(). The canvas' save() and
18 * restore actions can be limited to only a portion of the canvas' state through
19 * the use of flags when calling save.
20 */
21class CanvasStateGM : public GM {
22    SkSize  fSize;
23    enum {
24        WIDTH = 150,
25        HEIGHT = 150,
26    };
27
28    SkPaint fFillPaint;
29    SkPaint fStrokePaint;
30
31    SkPath fPath;
32
33    SkRect fOutlineRect;
34    SkRect fFillRect;
35
36
37public:
38    CanvasStateGM() {
39        fSize.set(SkIntToScalar(WIDTH), SkIntToScalar(HEIGHT));
40
41        fFillPaint.setColor(SK_ColorRED);
42        fFillPaint.setStyle(SkPaint::kFill_Style);
43
44        fStrokePaint.setColor(SK_ColorBLUE);
45        fStrokePaint.setStyle(SkPaint::kStroke_Style);
46        fStrokePaint.setStrokeWidth(1);
47
48        fPath.moveTo(25, 25);
49        fPath.lineTo(125, 25);
50        fPath.lineTo(75, 125);
51        fPath.close();
52
53        fOutlineRect = SkRect::MakeXYWH(1, 1, WIDTH-2, HEIGHT-2);
54        fFillRect = SkRect::MakeXYWH(10, 10, WIDTH-20, HEIGHT-20);
55    }
56
57protected:
58    virtual SkString onShortName() SK_OVERRIDE {
59        return SkString("canvas-state");
60    }
61
62    virtual SkISize onISize() SK_OVERRIDE {
63        return SkISize::Make(WIDTH*3, HEIGHT*4);
64    }
65
66    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
67
68        SkCanvas::SaveFlags flags[] = { SkCanvas::kMatrix_SaveFlag,
69                                        SkCanvas::kClip_SaveFlag,
70                                        SkCanvas::kMatrixClip_SaveFlag };
71
72        // columns -- flags
73        // rows -- permutations of setting the clip and matrix
74        for (int i = 0; i < static_cast<int>(SK_ARRAY_COUNT(flags)); ++i) {
75            for (int j = 0; j < 2; ++j) {
76                for (int k = 0; k < 2; ++k) {
77                    this->drawTestPattern(i, (2*j)+k, canvas, flags[i],
78                                          SkToBool(j), SkToBool(k));
79                }
80            }
81        }
82    }
83
84
85    virtual uint32_t onGetFlags() const SK_OVERRIDE { return kSkipPicture_Flag; }
86
87private:
88    void drawTestPattern(int x, int y, SkCanvas* canvas,
89                         SkCanvas::SaveFlags flags, bool doClip, bool doScale) {
90        canvas->save();
91        canvas->translate(SkIntToScalar(x*WIDTH), SkIntToScalar(y*HEIGHT));
92
93        canvas->drawRect(fOutlineRect, fStrokePaint);
94        canvas->save(flags);
95        if(doClip) {
96            canvas->clipPath(fPath);
97        }
98        if (doScale) {
99            canvas->scale(SkDoubleToScalar(0.5), SkDoubleToScalar(0.5));
100        }
101        canvas->restore();
102        canvas->drawRect(fFillRect, fFillPaint);
103
104        canvas->restore();
105    }
106
107    typedef GM INHERITED;
108};
109
110//////////////////////////////////////////////////////////////////////////////
111
112class CanvasLayerStateGM : public GM {
113public:
114    CanvasLayerStateGM() {
115        fBluePaint.setColor(SK_ColorBLUE);
116        fBluePaint.setStyle(SkPaint::kFill_Style);
117
118        fRect = SkRect::MakeXYWH(SPACER, SPACER, WIDTH-(2*SPACER), (HEIGHT-(2*SPACER)) / 7);
119    }
120
121protected:
122    virtual SkString onShortName() SK_OVERRIDE {
123        return SkString("canvas-layer-state");
124    }
125
126    virtual SkISize onISize() SK_OVERRIDE {
127        return SkISize::Make(WIDTH, HEIGHT);
128    }
129
130    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
131
132        // clear the canvas to red
133        canvas->drawColor(SK_ColorRED);
134
135#ifdef SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG
136        // both rects should appear
137        drawTestPattern(canvas, 255, SkCanvas::kARGB_NoClipLayer_SaveFlag);
138
139        canvas->translate(0, 2*(fRect.height() + 10));
140
141        // only the top rect should appear
142        drawTestPattern(canvas, 255, SkCanvas::kARGB_ClipLayer_SaveFlag);
143
144        canvas->translate(0, 2*(fRect.height() + 10));
145
146        // only the bottom rect should appear
147        drawTestPattern(canvas, 0, SkCanvas::kARGB_NoClipLayer_SaveFlag);
148#endif
149    }
150
151    virtual uint32_t onGetFlags() const SK_OVERRIDE { return kSkipGPU_Flag; }
152
153private:
154    // draw a rect within the layer's bounds and again outside the layer's bounds
155    void drawTestPattern(SkCanvas* canvas, U8CPU layerAlpha, SkCanvas::SaveFlags flags) {
156        canvas->saveLayerAlpha(&fRect, layerAlpha, flags);
157        canvas->drawRect(fRect, fBluePaint);
158        canvas->translate(0, fRect.height() + 10);
159        canvas->drawRect(fRect, fBluePaint);
160        canvas->restore();
161    }
162
163    enum {
164        WIDTH = 400,
165        HEIGHT = 400,
166        SPACER = 10,
167    };
168
169    SkPaint fBluePaint;
170    SkRect fRect;
171
172    typedef GM INHERITED;
173};
174
175//////////////////////////////////////////////////////////////////////////////
176
177DEF_GM( return SkNEW(CanvasStateGM); )
178DEF_GM( return SkNEW(CanvasLayerStateGM); )
179
180} // end namespace
181