1 /*
2 * Copyright 2016 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 "SkRasterPipeline.h"
9 #include "SkPM4f.h"
10
SkRasterPipeline(SkArenaAlloc * alloc)11 SkRasterPipeline::SkRasterPipeline(SkArenaAlloc* alloc) : fAlloc(alloc) {
12 this->reset();
13 }
reset()14 void SkRasterPipeline::reset() {
15 fStages = nullptr;
16 fNumStages = 0;
17 fSlotsNeeded = 1; // We always need one extra slot for just_return().
18 }
19
append(StockStage stage,void * ctx)20 void SkRasterPipeline::append(StockStage stage, void* ctx) {
21 SkASSERT(stage != from_srgb);
22 this->unchecked_append(stage, ctx);
23 }
unchecked_append(StockStage stage,void * ctx)24 void SkRasterPipeline::unchecked_append(StockStage stage, void* ctx) {
25 fStages = fAlloc->make<StageList>( StageList{fStages, stage, ctx} );
26 fNumStages += 1;
27 fSlotsNeeded += ctx ? 2 : 1;
28 }
29
extend(const SkRasterPipeline & src)30 void SkRasterPipeline::extend(const SkRasterPipeline& src) {
31 if (src.empty()) {
32 return;
33 }
34 auto stages = fAlloc->makeArrayDefault<StageList>(src.fNumStages);
35
36 int n = src.fNumStages;
37 const StageList* st = src.fStages;
38 while (n --> 1) {
39 stages[n] = *st;
40 stages[n].prev = &stages[n-1];
41 st = st->prev;
42 }
43 stages[0] = *st;
44 stages[0].prev = fStages;
45
46 fStages = &stages[src.fNumStages - 1];
47 fNumStages += src.fNumStages;
48 fSlotsNeeded += src.fSlotsNeeded - 1; // Don't double count just_returns().
49 }
50
dump() const51 void SkRasterPipeline::dump() const {
52 SkDebugf("SkRasterPipeline, %d stages (in reverse)\n", fNumStages);
53 for (auto st = fStages; st; st = st->prev) {
54 const char* name = "";
55 switch (st->stage) {
56 #define M(x) case x: name = #x; break;
57 SK_RASTER_PIPELINE_STAGES(M)
58 #undef M
59 }
60 SkDebugf("\t%s\n", name);
61 }
62 SkDebugf("\n");
63 }
64
65 //#define TRACK_COLOR_HISTOGRAM
66 #ifdef TRACK_COLOR_HISTOGRAM
67 static int gBlack;
68 static int gWhite;
69 static int gColor;
70 #define INC_BLACK gBlack++
71 #define INC_WHITE gWhite++
72 #define INC_COLOR gColor++
73 #else
74 #define INC_BLACK
75 #define INC_WHITE
76 #define INC_COLOR
77 #endif
78
append_uniform_color(SkArenaAlloc * alloc,const SkPM4f & c)79 void SkRasterPipeline::append_uniform_color(SkArenaAlloc* alloc, const SkPM4f& c) {
80 if (c.r() == 0 && c.g() == 0 && c.b() == 0 && c.a() == 1) {
81 this->append(black_color);
82 INC_BLACK;
83 } else if (c.r() == 1 && c.g() == 1 && c.b() == 1 && c.a() == 1) {
84 this->append(white_color);
85 INC_WHITE;
86 } else {
87 float* storage = alloc->makeArray<float>(4);
88 memcpy(storage, c.fVec, 4 * sizeof(float));
89 this->append(uniform_color, storage);
90 INC_COLOR;
91 }
92
93 #ifdef TRACK_COLOR_HISTOGRAM
94 SkDebugf("B=%d W=%d C=%d\n", gBlack, gWhite, gColor);
95 #endif
96 }
97
98 #undef INC_BLACK
99 #undef INC_WHITE
100 #undef INC_COLOR
101
102 // It's pretty easy to start with sound premultiplied linear floats, pack those
103 // to sRGB encoded bytes, then read them back to linear floats and find them not
104 // quite premultiplied, with a color channel just a smidge greater than the alpha
105 // channel. This can happen basically any time we have different transfer
106 // functions for alpha and colors... sRGB being the only one we draw into.
107
108 // This is an annoying problem with no known good solution. So apply the clamp hammer.
109
append_from_srgb(SkAlphaType at)110 void SkRasterPipeline::append_from_srgb(SkAlphaType at) {
111 this->unchecked_append(from_srgb, nullptr);
112 if (at == kPremul_SkAlphaType) {
113 this->append(SkRasterPipeline::clamp_a);
114 }
115 }
116
append_from_srgb_dst(SkAlphaType at)117 void SkRasterPipeline::append_from_srgb_dst(SkAlphaType at) {
118 this->unchecked_append(from_srgb_dst, nullptr);
119 if (at == kPremul_SkAlphaType) {
120 this->append(SkRasterPipeline::clamp_a_dst);
121 }
122 }
123
124 //static int gCounts[5] = { 0, 0, 0, 0, 0 };
125
append_matrix(SkArenaAlloc * alloc,const SkMatrix & matrix)126 void SkRasterPipeline::append_matrix(SkArenaAlloc* alloc, const SkMatrix& matrix) {
127 SkMatrix::TypeMask mt = matrix.getType();
128 #if 0
129 if (mt > 4) mt = 4;
130 gCounts[mt] += 1;
131 SkDebugf("matrices: %d %d %d %d %d\n",
132 gCounts[0], gCounts[1], gCounts[2], gCounts[3], gCounts[4]);
133 #endif
134
135 // Based on a histogram of skps, we determined the following special cases were common, more
136 // or fewer can be used if client behaviors change.
137
138 if (mt == SkMatrix::kIdentity_Mask) {
139 return;
140 }
141 if (mt == SkMatrix::kTranslate_Mask) {
142 float* trans = alloc->makeArrayDefault<float>(2);
143 trans[0] = matrix.getTranslateX();
144 trans[1] = matrix.getTranslateY();
145 this->append(SkRasterPipeline::matrix_translate, trans);
146 } else if ((mt | (SkMatrix::kScale_Mask | SkMatrix::kTranslate_Mask)) ==
147 (SkMatrix::kScale_Mask | SkMatrix::kTranslate_Mask)) {
148 float* scaleTrans = alloc->makeArrayDefault<float>(4);
149 scaleTrans[0] = matrix.getTranslateX();
150 scaleTrans[1] = matrix.getTranslateY();
151 scaleTrans[2] = matrix.getScaleX();
152 scaleTrans[3] = matrix.getScaleY();
153 this->append(SkRasterPipeline::matrix_scale_translate, scaleTrans);
154 } else {
155 float* storage = alloc->makeArrayDefault<float>(9);
156 if (matrix.asAffine(storage)) {
157 // note: asAffine and the 2x3 stage really only need 6 entries
158 this->append(SkRasterPipeline::matrix_2x3, storage);
159 } else {
160 matrix.get9(storage);
161 this->append(SkRasterPipeline::matrix_perspective, storage);
162 }
163 }
164 }
165