1 /*
2  * Copyright 2015 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 "SkImage.h"
11 #include "SkRandom.h"
12 #include "SkSurface.h"
13 
make_image()14 static sk_sp<SkImage> make_image() {
15     const SkImageInfo info = SkImageInfo::MakeN32Premul(319, 52);
16     auto surface(SkSurface::MakeRaster(info));
17     SkCanvas* canvas = surface->getCanvas();
18     canvas->drawColor(0xFFF8F8F8);
19 
20     SkPaint paint;
21     paint.setAntiAlias(true);
22 
23     paint.setStyle(SkPaint::kStroke_Style);
24     for (int i = 0; i < 20; ++i) {
25         canvas->drawCircle(-4, 25, 20, paint);
26         canvas->translate(25, 0);
27     }
28     return surface->makeImageSnapshot();
29 }
30 
31 DEF_SIMPLE_GM(mipmap, canvas, 400, 200) {
32     sk_sp<SkImage> img(make_image());//SkImage::NewFromEncoded(data));
33 
34     SkPaint paint;
35     const SkRect dst = SkRect::MakeWH(177, 15);
36 
37     SkString str;
38     str.printf("scale %g %g", dst.width() / img->width(), dst.height() / img->height());
39 //    canvas->drawString(str, 300, 100, SkFont(nullptr, 30), paint);
40 
41     canvas->translate(20, 20);
42     for (int i = 0; i < 4; ++i) {
43         paint.setFilterQuality(SkFilterQuality(i));
44         canvas->drawImageRect(img.get(), dst, &paint);
45         canvas->translate(0, 20);
46     }
47     canvas->drawImage(img.get(), 20, 20, nullptr);
48 }
49 
50 ///////////////////////////////////////////////////////////////////////////////////////////////////
51 
52 // create a circle image computed raw, so we can wrap it as a linear or srgb image
make(sk_sp<SkColorSpace> cs)53 static sk_sp<SkImage> make(sk_sp<SkColorSpace> cs) {
54     const int N = 100;
55     SkImageInfo info = SkImageInfo::Make(N, N, kN32_SkColorType, kPremul_SkAlphaType, cs);
56     SkBitmap bm;
57     bm.allocPixels(info);
58 
59     for (int y = 0; y < N; ++y) {
60         for (int x = 0; x < N; ++x) {
61             *bm.getAddr32(x, y) = (x ^ y) & 1 ? 0xFFFFFFFF : 0xFF000000;
62         }
63     }
64     bm.setImmutable();
65     return SkImage::MakeFromBitmap(bm);
66 }
67 
show_mips(SkCanvas * canvas,SkImage * img)68 static void show_mips(SkCanvas* canvas, SkImage* img) {
69     SkPaint paint;
70     paint.setFilterQuality(kMedium_SkFilterQuality);
71 
72     // Want to ensure we never draw fractional pixels, so we use an IRect
73     SkIRect dst = SkIRect::MakeWH(img->width(), img->height());
74     while (dst.width() > 5) {
75         canvas->drawImageRect(img, SkRect::Make(dst), &paint);
76         dst.offset(dst.width() + 10, 0);
77         dst.fRight = dst.fLeft + dst.width()/2;
78         dst.fBottom = dst.fTop + dst.height()/2;
79     }
80 }
81 
82 /*
83  *  Ensure that in L32 drawing mode, both images/mips look the same as each other, and
84  *  their mips are darker than the original (since the mips should ignore the gamma in L32).
85  *
86  *  Ensure that in S32 drawing mode, all images/mips look the same, and look correct (i.e.
87  *  the mip levels match the original in brightness).
88  */
89 DEF_SIMPLE_GM(mipmap_srgb, canvas, 260, 230) {
90     sk_sp<SkImage> limg = make(nullptr);
91     sk_sp<SkImage> simg = make(SkColorSpace::MakeSRGB());
92 
93     canvas->translate(10, 10);
94     show_mips(canvas, limg.get());
95     canvas->translate(0, limg->height() + 10.0f);
96     show_mips(canvas, simg.get());
97 }
98 
99 ///////////////////////////////////////////////////////////////////////////////////////////////////
100 
101 // create a gradient image computed raw, so we can wrap it as a linear or srgb image
make_g8_gradient(sk_sp<SkColorSpace> cs)102 static sk_sp<SkImage> make_g8_gradient(sk_sp<SkColorSpace> cs) {
103     const int N = 100;
104     SkImageInfo info = SkImageInfo::Make(N, N, kGray_8_SkColorType, kOpaque_SkAlphaType, cs);
105     SkBitmap bm;
106     bm.allocPixels(info);
107 
108     for (int y = 0; y < N; ++y) {
109         for (int x = 0; x < N; ++x) {
110             *bm.getAddr8(x, y) = static_cast<uint8_t>(255.0f * ((x + y) / (2.0f * (N - 1))));
111         }
112     }
113     bm.setImmutable();
114     return SkImage::MakeFromBitmap(bm);
115 }
116 
show_mips_only(SkCanvas * canvas,SkImage * img)117 static void show_mips_only(SkCanvas* canvas, SkImage* img) {
118     SkPaint paint;
119     paint.setFilterQuality(kMedium_SkFilterQuality);
120 
121     // Want to ensure we never draw fractional pixels, so we use an IRect
122     SkIRect dst = SkIRect::MakeWH(img->width() / 2, img->height() / 2);
123     while (dst.width() > 5) {
124         canvas->drawImageRect(img, SkRect::Make(dst), &paint);
125         dst.offset(dst.width() + 10, 0);
126         dst.fRight = dst.fLeft + dst.width() / 2;
127         dst.fBottom = dst.fTop + dst.height() / 2;
128     }
129 }
130 
131 /*
132  *  Ensure that in L32 drawing mode, both images/mips look the same as each other, and
133  *  their mips are darker than the original (since the mips should ignore the gamma in L32).
134  *
135  *  Ensure that in S32 drawing mode, all images/mips look the same, and look correct (i.e.
136  *  the mip levels match the original in brightness).
137  */
138 DEF_SIMPLE_GM(mipmap_gray8_srgb, canvas, 260, 230) {
139     sk_sp<SkImage> limg = make_g8_gradient(nullptr);
140     sk_sp<SkImage> simg = make_g8_gradient(SkColorSpace::MakeSRGB());
141 
142     canvas->translate(10, 10);
143     show_mips_only(canvas, limg.get());
144     canvas->translate(0, limg->height() + 10.0f);
145     show_mips_only(canvas, simg.get());
146 }
147