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 "SkCanvas.h"
9 #include "SkColor.h"
10 #include "SkGradientShader.h"
11 #include "SkMatrix.h"
12 #include "SkPaint.h"
13 #include "SkPoint.h"
14 #include "SkRect.h"
15 #include "SkRefCnt.h"
16 #include "SkScalar.h"
17 #include "SkSize.h"
18 #include "SkString.h"
19
20 #include "gm.h"
21
22 static const SkColor gColors[] = {
23 SK_ColorRED, SK_ColorYELLOW
24 };
25
26 // These annoying defines are necessary, because the only other alternative
27 // is to use SkIntToScalar(...) everywhere.
28 static const SkScalar sZero = 0;
29 static const SkScalar sHalf = SK_ScalarHalf;
30 static const SkScalar sOne = SK_Scalar1;
31
32 // These arrays define the gradient stop points
33 // as x1, y1, x2, y2 per gradient to draw.
34 static const SkPoint linearPts[][2] = {
35 {{sZero, sZero}, {sOne, sZero}},
36 {{sZero, sZero}, {sZero, sOne}},
37 {{sOne, sZero}, {sZero, sZero}},
38 {{sZero, sOne}, {sZero, sZero}},
39
40 {{sZero, sZero}, {sOne, sOne}},
41 {{sOne, sOne}, {sZero, sZero}},
42 {{sOne, sZero}, {sZero, sOne}},
43 {{sZero, sOne}, {sOne, sZero}}
44 };
45
46 static const SkPoint radialPts[][2] = {
47 {{sZero, sHalf}, {sOne, sHalf}},
48 {{sHalf, sZero}, {sHalf, sOne}},
49 {{sOne, sHalf}, {sZero, sHalf}},
50 {{sHalf, sOne}, {sHalf, sZero}},
51
52 {{sZero, sZero}, {sOne, sOne}},
53 {{sOne, sOne}, {sZero, sZero}},
54 {{sOne, sZero}, {sZero, sOne}},
55 {{sZero, sOne}, {sOne, sZero}}
56 };
57
58 // These define the pixels allocated to each gradient image.
59 static const SkScalar TESTGRID_X = SkIntToScalar(200);
60 static const SkScalar TESTGRID_Y = SkIntToScalar(200);
61
62 static const int IMAGES_X = 4; // number of images per row
63
make_linear_gradient(const SkPoint pts[2])64 static SkShader* make_linear_gradient(const SkPoint pts[2]) {
65 return SkGradientShader::CreateLinear(pts, gColors, NULL, SK_ARRAY_COUNT(gColors),
66 SkShader::kClamp_TileMode, NULL);
67 }
68
make_radial_gradient(const SkPoint pts[2])69 static SkShader* make_radial_gradient(const SkPoint pts[2]) {
70 SkPoint center;
71 center.set(SkScalarAve(pts[0].fX, pts[1].fX),
72 SkScalarAve(pts[0].fY, pts[1].fY));
73 float radius = (center - pts[0]).length();
74 return SkGradientShader::CreateRadial(center, radius, gColors, NULL, SK_ARRAY_COUNT(gColors),
75 SkShader::kClamp_TileMode, NULL);
76 }
77
draw_gradients(SkCanvas * canvas,SkShader * (* makeShader)(const SkPoint[2]),const SkPoint ptsArray[][2],int numImages)78 static void draw_gradients(SkCanvas* canvas, SkShader* (*makeShader)(const SkPoint[2]),
79 const SkPoint ptsArray[][2], int numImages) {
80 // Use some nice prime numbers for the rectangle and matrix with
81 // different scaling along the x and y axes (which is the bug this
82 // test addresses, where incorrect order of operations mixed up the axes)
83 SkRect rectGrad = {
84 SkIntToScalar(43), SkIntToScalar(61),
85 SkIntToScalar(181), SkIntToScalar(167) };
86 SkMatrix shaderMat;
87 shaderMat.setScale(rectGrad.width(), rectGrad.height());
88 shaderMat.postTranslate(rectGrad.left(), rectGrad.top());
89
90 canvas->save();
91 for (int i = 0; i < numImages; i++) {
92 // Advance line downwards if necessary.
93 if (i % IMAGES_X == 0 && i != 0) {
94 canvas->restore();
95 canvas->translate(0, TESTGRID_Y);
96 canvas->save();
97 }
98
99 // Setup shader and draw.
100 SkAutoTUnref<SkShader> shader(makeShader(*ptsArray));
101 shader->setLocalMatrix(shaderMat);
102
103 SkPaint paint;
104 paint.setShader(shader);
105 canvas->drawRect(rectGrad, paint);
106
107 // Advance to next position.
108 canvas->translate(TESTGRID_X, 0);
109 ptsArray++;
110 }
111 canvas->restore();
112 }
113
114 namespace skiagm {
115
116 class GradientMatrixGM : public GM {
117 public:
GradientMatrixGM()118 GradientMatrixGM() {
119 this->setBGColor(0xFFDDDDDD);
120 }
121
122 protected:
onShortName()123 SkString onShortName() SK_OVERRIDE {
124 return SkString("gradient_matrix");
125 }
126
onISize()127 virtual SkISize onISize() SK_OVERRIDE {
128 return SkISize::Make(800, 800);
129 }
130
onDraw(SkCanvas * canvas)131 virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
132 draw_gradients(canvas, &make_linear_gradient,
133 linearPts, SK_ARRAY_COUNT(linearPts));
134
135 canvas->translate(0, TESTGRID_Y);
136
137 draw_gradients(canvas, &make_radial_gradient,
138 radialPts, SK_ARRAY_COUNT(radialPts));
139 }
140
141 private:
142 typedef GM INHERITED;
143 };
144
145 DEF_GM( return new GradientMatrixGM; )
146 }
147