1 /*
2  * Copyright 2014 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 
12 /**
13  * This test exercises drawPosTextH and drawPosText with every text align.
14  */
15 static const int kWidth = 480;
16 static const int kHeight = 600;
17 static const SkScalar kTextHeight = 64.0f;
18 static const int kMaxStringLength = 12;
19 
20 namespace skiagm {
21 
22 class GlyphPosAlignGM : public GM {
23 protected:
24 
onShortName()25     SkString onShortName() override {
26         return SkString("glyph_pos_align");
27     }
28 
onISize()29     SkISize onISize() override { return SkISize::Make(kWidth, kHeight); }
30 
onDraw(SkCanvas * canvas)31     void onDraw(SkCanvas* canvas) override {
32         canvas->clear(SK_ColorBLACK);
33 
34         SkPaint paint;
35         paint.setTextSize(kTextHeight);
36         paint.setFakeBoldText(true);
37         const SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE };
38         const SkPoint pts[] = {{0, 0}, {kWidth, kHeight}};
39         SkAutoTUnref<SkShader> grad(SkGradientShader::CreateLinear(pts, colors, NULL,
40                                                                    SK_ARRAY_COUNT(colors),
41                                                                    SkShader::kMirror_TileMode));
42         paint.setShader(grad);
43 
44 
45         paint.setTextAlign(SkPaint::kRight_Align);
46         drawTestCase(canvas, "Right Align", kTextHeight, paint);
47 
48         paint.setTextAlign(SkPaint::kCenter_Align);
49         drawTestCase(canvas, "Center Align", 4 * kTextHeight, paint);
50 
51         paint.setTextAlign(SkPaint::kLeft_Align);
52         drawTestCase(canvas, "Left Align", 7 * kTextHeight, paint);
53     }
54 
drawTestCase(SkCanvas * canvas,const char * text,SkScalar y,const SkPaint & paint)55     void drawTestCase(SkCanvas* canvas, const char* text, SkScalar y, const SkPaint& paint) {
56         SkScalar widths[kMaxStringLength];
57         SkScalar posX[kMaxStringLength];
58         SkPoint pos[kMaxStringLength];
59         int length = SkToInt(strlen(text));
60         SkASSERT(length <= kMaxStringLength);
61 
62         paint.getTextWidths(text, length, widths);
63 
64         float originX;
65         switch (paint.getTextAlign()) {
66             case SkPaint::kRight_Align: originX = 1; break;
67             case SkPaint::kCenter_Align: originX = 0.5f; break;
68             case SkPaint::kLeft_Align: originX = 0; break;
69             default: SkFAIL("Invalid paint origin"); return;
70         }
71 
72         float x = kTextHeight;
73         for (int i = 0; i < length; ++i) {
74             posX[i] = x + originX * widths[i];
75             pos[i].set(posX[i], i ? pos[i - 1].y() + 3 : y + kTextHeight);
76             x += widths[i];
77         }
78 
79         canvas->drawPosTextH(text, length, posX, y, paint);
80         canvas->drawPosText(text, length, pos, paint);
81     }
82 
83 private:
84 
85     typedef GM INHERITED;
86 };
87 
88 //////////////////////////////////////////////////////////////////////////////
89 
GlyphPosAlignFactory(void *)90 static GM* GlyphPosAlignFactory(void*) {
91     return new GlyphPosAlignGM();
92 }
93 
94 static GMRegistry reg(GlyphPosAlignFactory);
95 
96 }
97