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 "SkBitmap.h"
9 #include "SkColorShader.h"
10 #include "SkGradientShader.h"
11 #include "SkShader.h"
12 #include "Test.h"
13 
14 static void test_bitmap(skiatest::Reporter* reporter) {
15     SkImageInfo info = SkImageInfo::MakeN32Premul(2, 2);
16 
17     SkBitmap bmp;
18     bmp.setInfo(info);
19 
20     // test 1: bitmap without pixel data
21     auto shader = SkShader::MakeBitmapShader(bmp,
22         SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);
23     REPORTER_ASSERT(reporter, shader);
24     REPORTER_ASSERT(reporter, !shader->isOpaque());
25 
26     // From this point on, we have pixels
27     bmp.allocPixels(info);
28 
29     // test 2: not opaque by default
30     shader = SkShader::MakeBitmapShader(bmp,
31         SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);
32     REPORTER_ASSERT(reporter, shader);
33     REPORTER_ASSERT(reporter, !shader->isOpaque());
34 
35     // test 3: explicitly opaque
36     bmp.setAlphaType(kOpaque_SkAlphaType);
37     shader = SkShader::MakeBitmapShader(bmp,
38         SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);
39     REPORTER_ASSERT(reporter, shader);
40     REPORTER_ASSERT(reporter, shader->isOpaque());
41 
42     // test 4: explicitly not opaque
43     bmp.setAlphaType(kPremul_SkAlphaType);
44     shader = SkShader::MakeBitmapShader(bmp,
45         SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);
46     REPORTER_ASSERT(reporter, shader);
47     REPORTER_ASSERT(reporter, !shader->isOpaque());
48 }
49 
50 static void test_gradient(skiatest::Reporter* reporter) {
51     SkPoint pts[2];
52     pts[0].iset(0, 0);
53     pts[1].iset(1, 0);
54     SkColor colors[2];
55     SkScalar pos[2] = {SkIntToScalar(0), SkIntToScalar(1)};
56     int count = 2;
57     SkShader::TileMode mode = SkShader::kClamp_TileMode;
58 
59     // test 1: all opaque
60     colors[0] = SkColorSetARGB(0xFF, 0, 0, 0);
61     colors[1] = SkColorSetARGB(0xFF, 0, 0, 0);
62     auto grad = SkGradientShader::MakeLinear(pts, colors, pos, count, mode);
63     REPORTER_ASSERT(reporter, grad);
64     REPORTER_ASSERT(reporter, grad->isOpaque());
65 
66     // test 2: all 0 alpha
67     colors[0] = SkColorSetARGB(0, 0, 0, 0);
68     colors[1] = SkColorSetARGB(0, 0, 0, 0);
69     grad = SkGradientShader::MakeLinear(pts, colors, pos, count, mode);
70     REPORTER_ASSERT(reporter, grad);
71     REPORTER_ASSERT(reporter, !grad->isOpaque());
72 
73     // test 3: one opaque, one transparent
74     colors[0] = SkColorSetARGB(0xFF, 0, 0, 0);
75     colors[1] = SkColorSetARGB(0x40, 0, 0, 0);
76     grad = SkGradientShader::MakeLinear(pts, colors, pos, count, mode);
77     REPORTER_ASSERT(reporter, grad);
78     REPORTER_ASSERT(reporter, !grad->isOpaque());
79 
80     // test 4: test 3, swapped
81     colors[0] = SkColorSetARGB(0x40, 0, 0, 0);
82     colors[1] = SkColorSetARGB(0xFF, 0, 0, 0);
83     grad = SkGradientShader::MakeLinear(pts, colors, pos, count, mode);
84     REPORTER_ASSERT(reporter, grad);
85     REPORTER_ASSERT(reporter, !grad->isOpaque());
86 }
87 
88 static void test_color(skiatest::Reporter* reporter) {
89     SkColorShader colorShader1(SkColorSetARGB(0,0,0,0));
90     REPORTER_ASSERT(reporter, !colorShader1.isOpaque());
91     SkColorShader colorShader2(SkColorSetARGB(0xFF,0,0,0));
92     REPORTER_ASSERT(reporter, colorShader2.isOpaque());
93     SkColorShader colorShader3(SkColorSetARGB(0x7F,0,0,0));
94     REPORTER_ASSERT(reporter, !colorShader3.isOpaque());
95 }
96 
97 DEF_TEST(ShaderOpacity, reporter) {
98     test_gradient(reporter);
99     test_color(reporter);
100     test_bitmap(reporter);
101 }
102