xref: /aosp_15_r20/external/skia/tests/ShaderOpacityTest.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2011 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 "include/core/SkAlphaType.h"
9 #include "include/core/SkBitmap.h"
10 #include "include/core/SkColor.h"
11 #include "include/core/SkImageInfo.h"
12 #include "include/core/SkPoint.h"
13 #include "include/core/SkRefCnt.h"
14 #include "include/core/SkSamplingOptions.h"
15 #include "include/core/SkScalar.h"
16 #include "include/core/SkShader.h"
17 #include "include/core/SkTileMode.h"
18 #include "include/effects/SkGradientShader.h"
19 #include "src/shaders/SkShaderBase.h"
20 #include "tests/Test.h"
21 
test_bitmap(skiatest::Reporter * reporter)22 static void test_bitmap(skiatest::Reporter* reporter) {
23     SkImageInfo info = SkImageInfo::MakeN32Premul(2, 2);
24 
25     SkBitmap bmp;
26     bmp.setInfo(info);
27 
28     // test 1: bitmap without pixel data
29     auto shader = bmp.makeShader(SkSamplingOptions());
30     REPORTER_ASSERT(reporter, shader);
31     REPORTER_ASSERT(reporter, !shader->isOpaque());
32 
33     // From this point on, we have pixels
34     bmp.allocPixels(info);
35 
36     // test 2: not opaque by default
37     shader = bmp.makeShader(SkSamplingOptions());
38     REPORTER_ASSERT(reporter, shader);
39     REPORTER_ASSERT(reporter, !shader->isOpaque());
40 
41     // test 3: explicitly opaque
42     bmp.setAlphaType(kOpaque_SkAlphaType);
43     shader = bmp.makeShader(SkSamplingOptions());
44     REPORTER_ASSERT(reporter, shader);
45     REPORTER_ASSERT(reporter, shader->isOpaque());
46 
47     // test 4: explicitly not opaque
48     bmp.setAlphaType(kPremul_SkAlphaType);
49     shader = bmp.makeShader(SkSamplingOptions());
50     REPORTER_ASSERT(reporter, shader);
51     REPORTER_ASSERT(reporter, !shader->isOpaque());
52 }
53 
test_gradient(skiatest::Reporter * reporter)54 static void test_gradient(skiatest::Reporter* reporter) {
55     SkPoint pts[2];
56     pts[0].iset(0, 0);
57     pts[1].iset(1, 0);
58     SkColor colors[2];
59     SkScalar pos[2] = {SkIntToScalar(0), SkIntToScalar(1)};
60     int count = 2;
61     SkTileMode mode = SkTileMode::kClamp;
62 
63     // test 1: all opaque
64     colors[0] = SkColorSetARGB(0xFF, 0, 0, 0);
65     colors[1] = SkColorSetARGB(0xFF, 0, 0, 0);
66     auto grad = SkGradientShader::MakeLinear(pts, colors, pos, count, mode);
67     REPORTER_ASSERT(reporter, grad);
68     REPORTER_ASSERT(reporter, grad->isOpaque());
69 
70     // test 2: all 0 alpha
71     colors[0] = SkColorSetARGB(0, 0, 0, 0);
72     colors[1] = SkColorSetARGB(0, 0, 0, 0);
73     grad = SkGradientShader::MakeLinear(pts, colors, pos, count, mode);
74     REPORTER_ASSERT(reporter, grad);
75     REPORTER_ASSERT(reporter, !grad->isOpaque());
76 
77     // test 3: one opaque, one transparent
78     colors[0] = SkColorSetARGB(0xFF, 0, 0, 0);
79     colors[1] = SkColorSetARGB(0x40, 0, 0, 0);
80     grad = SkGradientShader::MakeLinear(pts, colors, pos, count, mode);
81     REPORTER_ASSERT(reporter, grad);
82     REPORTER_ASSERT(reporter, !grad->isOpaque());
83 
84     // test 4: test 3, swapped
85     colors[0] = SkColorSetARGB(0x40, 0, 0, 0);
86     colors[1] = SkColorSetARGB(0xFF, 0, 0, 0);
87     grad = SkGradientShader::MakeLinear(pts, colors, pos, count, mode);
88     REPORTER_ASSERT(reporter, grad);
89     REPORTER_ASSERT(reporter, !grad->isOpaque());
90 }
91 
test_color(skiatest::Reporter * reporter)92 static void test_color(skiatest::Reporter* reporter) {
93     sk_sp<SkShader> colorShader1 = SkShaders::Color(SkColorSetARGB(0,0,0,0));
94     REPORTER_ASSERT(reporter, !colorShader1->isOpaque());
95     sk_sp<SkShader> colorShader2 = SkShaders::Color(SkColorSetARGB(0xFF,0,0,0));
96     REPORTER_ASSERT(reporter, colorShader2->isOpaque());
97     sk_sp<SkShader> colorShader3 = SkShaders::Color(SkColorSetARGB(0x7F,0,0,0));
98     REPORTER_ASSERT(reporter, !colorShader3->isOpaque());
99 }
100 
test_matrix(skiatest::Reporter * reporter)101 static void test_matrix(skiatest::Reporter* reporter) {
102     sk_sp<SkShader> colorShader1 = SkShaders::Color(SkColorSetARGB(0,0,0,0));
103     REPORTER_ASSERT(reporter, !colorShader1->isOpaque());
104     sk_sp<SkShader> colorShader2 = SkShaders::Color(SkColorSetARGB(0xFF,0,0,0));
105     REPORTER_ASSERT(reporter, colorShader2->isOpaque());
106 
107     static const SkMatrix kMatrix = SkMatrix::Scale(1,  1);
108 
109     sk_sp<SkShader> lm1 = colorShader1->makeWithLocalMatrix(kMatrix);
110     REPORTER_ASSERT(reporter, !lm1->isOpaque());
111     sk_sp<SkShader> lm2 = colorShader2->makeWithLocalMatrix(kMatrix);
112     REPORTER_ASSERT(reporter, lm2->isOpaque());
113 
114     sk_sp<SkShader> ctm1 = as_SB(colorShader1)->makeWithCTM(kMatrix);
115     REPORTER_ASSERT(reporter, !ctm1->isOpaque());
116     sk_sp<SkShader> ctm2 = as_SB(colorShader2)->makeWithCTM(kMatrix);
117     REPORTER_ASSERT(reporter, ctm2->isOpaque());
118 }
119 
DEF_TEST(ShaderOpacity,reporter)120 DEF_TEST(ShaderOpacity, reporter) {
121     test_gradient(reporter);
122     test_color(reporter);
123     test_bitmap(reporter);
124     test_matrix(reporter);
125 }
126