textblobtransforms.cpp revision 567ff2f6143ecb993dbedede402a43feb71c420a 
1/*
2 * Copyright 2015 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
10#include "Resources.h"
11#include "SkCanvas.h"
12#include "SkGradientShader.h"
13#include "SkStream.h"
14#include "SkTextBlob.h"
15#include "SkTypeface.h"
16
17namespace skiagm {
18class TextBlobTransforms : public GM {
19public:
20    // This gm tests that textblobs can be translated, rotated, and scaled
21    TextBlobTransforms() {}
22
23protected:
24    void onOnceBeforeDraw() override {
25        SkTextBlobBuilder builder;
26
27        // make textblob.  To stress distance fields, we choose sizes appropriately
28        SkPaint paint;
29        paint.setTextSize(162);
30        const char* text = "A";
31        sk_tool_utils::set_portable_typeface(&paint);
32
33        SkRect bounds;
34        paint.measureText(text, strlen(text), &bounds);
35        sk_tool_utils::add_to_text_blob(&builder, text, paint, 0, 0);
36
37        // Medium
38        SkScalar xOffset = bounds.width() + 5;
39        paint.setTextSize(72);
40        text = "B";
41        sk_tool_utils::add_to_text_blob(&builder, text, paint, xOffset, 0);
42
43        paint.measureText(text, strlen(text), &bounds);
44        SkScalar yOffset = bounds.height();
45
46        // Small
47        paint.setTextSize(32);
48        text = "C";
49        sk_tool_utils::add_to_text_blob(&builder, text, paint, xOffset, -yOffset - 10);
50
51        // build
52        fBlob.reset(builder.build());
53    }
54
55    SkString onShortName() override {
56        return SkString("textblobtransforms");
57    }
58
59    SkISize onISize() override {
60        return SkISize::Make(kWidth, kHeight);
61    }
62
63    void onDraw(SkCanvas* canvas) override {
64
65        canvas->drawColor(SK_ColorGRAY);
66
67        SkPaint paint;
68
69        SkRect bounds = fBlob->bounds();
70        canvas->translate(20, 20);
71
72        // Colors were chosen to map to pairs of canonical colors.  The GPU Backend will cache A8
73        // Texture Blobs based on the canonical color they map to.  Canonical colors are used to
74        // create masks.  For A8 there are 8 of them.
75        //SkColor colors[] = {SK_ColorCYAN, SK_ColorLTGRAY, SK_ColorYELLOW, SK_ColorWHITE};
76
77        SkScalar xOffset = SkScalarCeilToScalar(bounds.width());
78        SkScalar yOffset = SkScalarCeilToScalar(bounds.height());
79        // first translate
80        canvas->translate(xOffset, 2 * yOffset);
81        canvas->drawTextBlob(fBlob, 0, 0, paint);
82        canvas->translate(-xOffset, 0);
83        canvas->drawTextBlob(fBlob, 0, 0, paint);
84        canvas->translate(2 * xOffset, 0);
85        canvas->drawTextBlob(fBlob, 0, 0, paint);
86        canvas->translate(-xOffset, -yOffset);
87        canvas->drawTextBlob(fBlob, 0, 0, paint);
88        canvas->translate(0, 2 * yOffset);
89        canvas->drawTextBlob(fBlob, 0, 0, paint);
90
91        // now rotate
92        canvas->translate(4 * xOffset, -yOffset);
93        canvas->rotate(180.f);
94        canvas->drawTextBlob(fBlob, 0, 0, paint);
95        canvas->rotate(-180.f);
96        canvas->translate(0, -yOffset);
97        canvas->rotate(-180.f);
98        canvas->drawTextBlob(fBlob, 0, 0, paint);
99        canvas->rotate(270.f);
100        canvas->drawTextBlob(fBlob, 0, 0, paint);
101        canvas->rotate(-90.f);
102        canvas->translate(-xOffset, yOffset);
103        canvas->rotate(-90.f);
104        canvas->drawTextBlob(fBlob, 0, 0, paint);
105        canvas->rotate(90.f);
106
107        // and scales
108        canvas->translate(- 3 * xOffset, 3 * yOffset);
109        canvas->scale(1.5f, 1.5f);
110        canvas->drawTextBlob(fBlob, 0, 0, paint);
111        canvas->translate(xOffset, 0);
112        canvas->scale(.25f, .25f);
113        canvas->drawTextBlob(fBlob, 0, 0, paint);
114        canvas->translate(xOffset, 0);
115        canvas->scale(3.f, 2.f);
116        canvas->drawTextBlob(fBlob, 0, 0, paint);
117
118        // finally rotates, scales, and translates together
119        canvas->translate(xOffset, 0);
120        canvas->rotate(23.f);
121        canvas->scale(.33f, .5f);
122        canvas->drawTextBlob(fBlob, 0, 0, paint);
123
124        canvas->rotate(-46.f);
125        canvas->translate(xOffset, 0);
126        canvas->scale(1.2f, 1.1f);
127        canvas->drawTextBlob(fBlob, 0, 0, paint);
128
129        canvas->rotate(46.f);
130        canvas->translate(xOffset, 0);
131        canvas->scale(1.1f, 1.2f);
132        canvas->drawTextBlob(fBlob, 0, 0, paint);
133
134        canvas->rotate(46.f);
135        canvas->translate(xOffset, 0);
136        canvas->scale(.95f, 1.1f);
137        canvas->drawTextBlob(fBlob, 0, 0, paint);
138
139        canvas->rotate(46.f);
140        canvas->translate(xOffset, 0);
141        canvas->scale(1.3f, .7f);
142        canvas->drawTextBlob(fBlob, 0, 0, paint);
143
144        canvas->rotate(46.f);
145        canvas->translate(xOffset, 0);
146        canvas->scale(.8f, 1.1f);
147        canvas->drawTextBlob(fBlob, 0, 0, paint);
148
149        canvas->rotate(10.f);
150        canvas->translate(xOffset, 0);
151        canvas->scale(1.f, 5.f);
152        canvas->drawTextBlob(fBlob, 0, 0, paint);
153
154        canvas->rotate(5.f);
155        canvas->translate(xOffset, 0);
156        canvas->scale(5.f, 1.f);
157        canvas->drawTextBlob(fBlob, 0, 0, paint);
158    }
159
160private:
161    SkAutoTUnref<const SkTextBlob> fBlob;
162
163    static const int kWidth = 1000;
164    static const int kHeight = 1200;
165
166    typedef GM INHERITED;
167};
168
169//////////////////////////////////////////////////////////////////////////////
170
171DEF_GM( return SkNEW(TextBlobTransforms); )
172}
173