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 "SkBlurImageFilter.h"
11 #include "SkColorFilterImageFilter.h"
12 #include "SkModeColorFilter.h"
13 #include "SkMorphologyImageFilter.h"
14 #include "SkOffsetImageFilter.h"
15 #include "SkSurface.h"
16 #include "sk_tool_utils.h"
17 
18 static sk_sp<SkImage> make_image(SkCanvas* rootCanvas) {
19     SkImageInfo info = SkImageInfo::MakeN32Premul(100, 100);
20     auto surface(sk_tool_utils::makeSurface(rootCanvas, info));
21 
22     SkPaint paint;
23     paint.setAntiAlias(true);
24     paint.setColor(SK_ColorRED);
25     surface->getCanvas()->drawCircle(50, 50, 50, paint);
26     return surface->makeImageSnapshot();
27 }
28 
29 static void show_image(SkCanvas* canvas, SkImage* image, sk_sp<SkImageFilter> filter) {
30     SkPaint paint;
31     paint.setStyle(SkPaint::kStroke_Style);
32     SkRect r = SkRect::MakeIWH(image->width(), image->height()).makeOutset(SK_ScalarHalf,
33                                                                            SK_ScalarHalf);
34     canvas->drawRect(r, paint);
35 
36     paint.setStyle(SkPaint::kFill_Style);
37     paint.setImageFilter(filter);
38     canvas->drawImage(image, 0, 0, &paint);
39 }
40 
41 typedef sk_sp<SkImageFilter> (*ImageFilterFactory)();
42 
43 // +[]{...} did not work on windows (VS)
44 // (ImageFilterFactory)[]{...} did not work on linux (gcc)
45 // hence this cast function
46 template <typename T> ImageFilterFactory IFCCast(T arg) { return arg; }
47 
48 // Show the effect of localmatriximagefilter with various matrices, on various filters
49 DEF_SIMPLE_GM(localmatriximagefilter, canvas, 640, 640) {
50     sk_sp<SkImage> image0(make_image(canvas));
51 
52     const ImageFilterFactory factories[] = {
53         IFCCast([]{ return SkBlurImageFilter::Make(8, 8, nullptr); }),
54         IFCCast([]{ return SkDilateImageFilter::Make(8, 8, nullptr); }),
55         IFCCast([]{ return SkErodeImageFilter::Make(8, 8, nullptr); }),
56         IFCCast([]{ return SkOffsetImageFilter::Make(8, 8, nullptr); }),
57     };
58 
59     const SkMatrix matrices[] = {
60         SkMatrix::MakeScale(SK_ScalarHalf, SK_ScalarHalf),
61         SkMatrix::MakeScale(2, 2),
62         SkMatrix::MakeTrans(10, 10)
63     };
64 
65     const SkScalar spacer = image0->width() * 3.0f / 2;
66 
67     canvas->translate(40, 40);
68     for (auto&& factory : factories) {
69         sk_sp<SkImageFilter> filter(factory());
70 
71         canvas->save();
72         show_image(canvas, image0.get(), filter);
73         for (const auto& matrix : matrices) {
74             sk_sp<SkImageFilter> localFilter(filter->makeWithLocalMatrix(matrix));
75             canvas->translate(spacer, 0);
76             show_image(canvas, image0.get(), std::move(localFilter));
77         }
78         canvas->restore();
79         canvas->translate(0, spacer);
80     }
81 }
82