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 #include "sk_tool_utils.h"
22
23 constexpr SkColor gColors[] = {
24 SK_ColorRED, SK_ColorYELLOW
25 };
26
27 // These annoying defines are necessary, because the only other alternative
28 // is to use SkIntToScalar(...) everywhere.
29 constexpr SkScalar sZero = 0;
30 constexpr SkScalar sHalf = SK_ScalarHalf;
31 constexpr SkScalar sOne = SK_Scalar1;
32
33 // These arrays define the gradient stop points
34 // as x1, y1, x2, y2 per gradient to draw.
35 constexpr SkPoint linearPts[][2] = {
36 {{sZero, sZero}, {sOne, sZero}},
37 {{sZero, sZero}, {sZero, sOne}},
38 {{sOne, sZero}, {sZero, sZero}},
39 {{sZero, sOne}, {sZero, sZero}},
40
41 {{sZero, sZero}, {sOne, sOne}},
42 {{sOne, sOne}, {sZero, sZero}},
43 {{sOne, sZero}, {sZero, sOne}},
44 {{sZero, sOne}, {sOne, sZero}}
45 };
46
47 constexpr SkPoint radialPts[][2] = {
48 {{sZero, sHalf}, {sOne, sHalf}},
49 {{sHalf, sZero}, {sHalf, sOne}},
50 {{sOne, sHalf}, {sZero, sHalf}},
51 {{sHalf, sOne}, {sHalf, sZero}},
52
53 {{sZero, sZero}, {sOne, sOne}},
54 {{sOne, sOne}, {sZero, sZero}},
55 {{sOne, sZero}, {sZero, sOne}},
56 {{sZero, sOne}, {sOne, sZero}}
57 };
58
59 // These define the pixels allocated to each gradient image.
60 constexpr SkScalar TESTGRID_X = SkIntToScalar(200);
61 constexpr SkScalar TESTGRID_Y = SkIntToScalar(200);
62
63 constexpr int IMAGES_X = 4; // number of images per row
64
make_linear_gradient(const SkPoint pts[2],const SkMatrix & localMatrix)65 static sk_sp<SkShader> make_linear_gradient(const SkPoint pts[2], const SkMatrix& localMatrix) {
66 return SkGradientShader::MakeLinear(pts, gColors, nullptr, SK_ARRAY_COUNT(gColors),
67 SkShader::kClamp_TileMode, 0, &localMatrix);
68 }
69
make_radial_gradient(const SkPoint pts[2],const SkMatrix & localMatrix)70 static sk_sp<SkShader> make_radial_gradient(const SkPoint pts[2], const SkMatrix& localMatrix) {
71 SkPoint center;
72 center.set(SkScalarAve(pts[0].fX, pts[1].fX),
73 SkScalarAve(pts[0].fY, pts[1].fY));
74 float radius = (center - pts[0]).length();
75 return SkGradientShader::MakeRadial(center, radius, gColors, nullptr, SK_ARRAY_COUNT(gColors),
76 SkShader::kClamp_TileMode, 0, &localMatrix);
77 }
78
draw_gradients(SkCanvas * canvas,sk_sp<SkShader> (* makeShader)(const SkPoint[2],const SkMatrix &),const SkPoint ptsArray[][2],int numImages)79 static void draw_gradients(SkCanvas* canvas,
80 sk_sp<SkShader> (*makeShader)(const SkPoint[2], const SkMatrix&),
81 const SkPoint ptsArray[][2], int numImages) {
82 // Use some nice prime numbers for the rectangle and matrix with
83 // different scaling along the x and y axes (which is the bug this
84 // test addresses, where incorrect order of operations mixed up the axes)
85 SkRect rectGrad = {
86 SkIntToScalar(43), SkIntToScalar(61),
87 SkIntToScalar(181), SkIntToScalar(167) };
88 SkMatrix shaderMat;
89 shaderMat.setScale(rectGrad.width(), rectGrad.height());
90 shaderMat.postTranslate(rectGrad.left(), rectGrad.top());
91
92 canvas->save();
93 for (int i = 0; i < numImages; i++) {
94 // Advance line downwards if necessary.
95 if (i % IMAGES_X == 0 && i != 0) {
96 canvas->restore();
97 canvas->translate(0, TESTGRID_Y);
98 canvas->save();
99 }
100
101 SkPaint paint;
102 paint.setShader(makeShader(*ptsArray, shaderMat));
103 canvas->drawRect(rectGrad, paint);
104
105 // Advance to next position.
106 canvas->translate(TESTGRID_X, 0);
107 ptsArray++;
108 }
109 canvas->restore();
110 }
111
112 DEF_SIMPLE_GM_BG(gradient_matrix, canvas, 800, 800,
113 sk_tool_utils::color_to_565(0xFFDDDDDD)) {
114 draw_gradients(canvas, &make_linear_gradient,
115 linearPts, SK_ARRAY_COUNT(linearPts));
116
117 canvas->translate(0, TESTGRID_Y);
118
119 draw_gradients(canvas, &make_radial_gradient,
120 radialPts, SK_ARRAY_COUNT(radialPts));
121 }
122