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 #include "sk_tool_utils.h"
8 #include "SampleCode.h"
9 #include "SkView.h"
10 #include "SkCanvas.h"
11 #include "SkColorFilter.h"
12 #include "SkPaint.h"
13 #include "SkShader.h"
14
inflate5To8(int x)15 static int inflate5To8(int x) {
16 return (x << 3) | (x >> 2);
17 }
18
trunc5(int x)19 static int trunc5(int x) {
20 return x >> 3;
21 }
22
23 #define SK_R16_BITS 5
24
25 #ifdef SK_DEBUG
round5_slow(int x)26 static int round5_slow(int x) {
27 int orig = x & 7;
28 int fake = x >> 5;
29 int trunc = x >> 3;
30
31 int diff = fake - orig;
32
33 int bias = 0;
34 if (diff > 4) {
35 bias = -1;
36 } else if (diff < -4) {
37 bias = 1;
38 }
39 return trunc + bias;
40 }
41 #endif
42
round5_fast(int x)43 static int round5_fast(int x) {
44 int result = x + 3 - (x >> 5) + (x >> 7);
45 result >>= 3;
46 #ifdef SK_DEBUG
47 {
48 int r2 = round5_slow(x);
49 SkASSERT(r2 == result);
50 }
51 #endif
52 return result;
53 }
54
test_5bits()55 static void test_5bits() {
56 int e0 = 0;
57 int e1 = 0;
58 int e2 = 0;
59 int ae0 = 0;
60 int ae1 = 0;
61 int ae2 = 0;
62 for (int i = 0; i < 256; i++) {
63 int t0 = trunc5(i);
64 int t1 = round5_fast(i);
65 int t2 = trunc5(i);
66 int v0 = inflate5To8(t0);
67 int v1 = inflate5To8(t1);
68 int v2 = inflate5To8(t2);
69 int err0 = i - v0;
70 int err1 = i - v1;
71 int err2 = i - v2;
72 SkDebugf("--- %3d : trunc=%3d (%2d) round:%3d (%2d) \n"/*new:%d (%2d)\n"*/, i,
73 v0, err0, v1, err1, v2, err2);
74
75
76 e0 += err0;
77 e1 += err1;
78 e2 += err2;
79 ae0 += SkAbs32(err0);
80 ae1 += SkAbs32(err1);
81 ae2 += SkAbs32(err2);
82 }
83 SkDebugf("--- trunc: %d %d round: %d %d new: %d %d\n", e0, ae0, e1, ae1, e2, ae2);
84 }
85
createBitmap(int n)86 static SkBitmap createBitmap(int n) {
87 SkBitmap bitmap;
88 bitmap.allocN32Pixels(n, n);
89 bitmap.eraseColor(SK_ColorTRANSPARENT);
90
91 SkCanvas canvas(bitmap);
92 SkRect r;
93 r.set(0, 0, SkIntToScalar(n), SkIntToScalar(n));
94 r.inset(SK_Scalar1, SK_Scalar1);
95
96 SkPaint paint;
97 paint.setAntiAlias(true);
98
99 paint.setColor(SK_ColorRED);
100 canvas.drawOval(r, paint);
101
102 r.inset(SK_Scalar1*n/4, SK_Scalar1*n/4);
103 paint.setBlendMode(SkBlendMode::kSrc);
104 paint.setColor(0x800000FF);
105 canvas.drawOval(r, paint);
106
107 return bitmap;
108 }
109
110 class ColorFilterView : public SampleView {
111 SkBitmap fBitmap;
112 sk_sp<SkShader> fShader;
113 enum {
114 N = 64
115 };
116 public:
ColorFilterView()117 ColorFilterView() {
118 fBitmap = createBitmap(N);
119 fShader = sk_tool_utils::create_checkerboard_shader(
120 0xFFCCCCCC, 0xFFFFFFFF, 12);
121
122 if (false) { // avoid bit rot, suppress warning
123 test_5bits();
124 }
125 }
126
127 protected:
128 // overrides from SkEventSink
onQuery(SkEvent * evt)129 virtual bool onQuery(SkEvent* evt) {
130 if (SampleCode::TitleQ(*evt)) {
131 SampleCode::TitleR(evt, "ColorFilter");
132 return true;
133 }
134 return this->INHERITED::onQuery(evt);
135 }
136
onDrawBackground(SkCanvas * canvas)137 virtual void onDrawBackground(SkCanvas* canvas) {
138 SkPaint paint;
139 paint.setShader(fShader);
140 canvas->drawPaint(paint);
141 }
142
onDrawContent(SkCanvas * canvas)143 virtual void onDrawContent(SkCanvas* canvas) {
144 if (false) {
145 SkPaint p;
146 p.setAntiAlias(true);
147 SkRect r = { 20.4f, 10, 20.6f, 20 };
148 canvas->drawRect(r, p);
149 r.set(30.9f, 10, 31.1f, 20);
150 canvas->drawRect(r, p);
151 return;
152 }
153
154 static const SkBlendMode gModes[] = {
155 SkBlendMode::kClear,
156 SkBlendMode::kSrc,
157 SkBlendMode::kDst,
158 SkBlendMode::kSrcOver,
159 SkBlendMode::kDstOver,
160 SkBlendMode::kSrcIn,
161 SkBlendMode::kDstIn,
162 SkBlendMode::kSrcOut,
163 SkBlendMode::kDstOut,
164 SkBlendMode::kSrcATop,
165 SkBlendMode::kDstATop,
166 SkBlendMode::kXor,
167 SkBlendMode::kPlus,
168 SkBlendMode::kModulate,
169 };
170
171 static const SkColor gColors[] = {
172 0xFF000000,
173 0x80000000,
174 0xFF00FF00,
175 0x8000FF00,
176 0x00000000,
177 };
178
179 float scale = 1.5f;
180 SkPaint paint;
181 canvas->translate(N / 8, N / 8);
182
183 for (size_t y = 0; y < SK_ARRAY_COUNT(gColors); y++) {
184 for (size_t x = 0; x < SK_ARRAY_COUNT(gModes); x++) {
185 paint.setColorFilter(SkColorFilter::MakeModeFilter(gColors[y], gModes[x]));
186 canvas->drawBitmap(fBitmap, x * N * 1.25f, y * N * scale, &paint);
187 }
188 }
189
190 }
191
192 private:
193 typedef SampleView INHERITED;
194 };
195
196 //////////////////////////////////////////////////////////////////////////////
197
MyFactory()198 static SkView* MyFactory() { return new ColorFilterView; }
199 static SkViewRegister reg(MyFactory);
200