Line data Source code
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 : #ifndef SkRasterPipeline_DEFINED
9 : #define SkRasterPipeline_DEFINED
10 :
11 : #include "SkImageInfo.h"
12 : #include "SkNx.h"
13 : #include "SkTArray.h"
14 : #include "SkTypes.h"
15 : #include <vector>
16 :
17 : /**
18 : * SkRasterPipeline provides a cheap way to chain together a pixel processing pipeline.
19 : *
20 : * It's particularly designed for situations where the potential pipeline is extremely
21 : * combinatoric: {N dst formats} x {M source formats} x {K mask formats} x {C transfer modes} ...
22 : * No one wants to write specialized routines for all those combinations, and if we did, we'd
23 : * end up bloating our code size dramatically. SkRasterPipeline stages can be chained together
24 : * at runtime, so we can scale this problem linearly rather than combinatorically.
25 : *
26 : * Each stage is represented by a function conforming to a common interface, SkRasterPipeline::Fn,
27 : * and by an arbitrary context pointer. Fn's arguments, and sometimes custom calling convention,
28 : * are designed to maximize the amount of data we can pass along the pipeline cheaply.
29 : * On many machines all arguments stay in registers the entire time.
30 : *
31 : * The meaning of the arguments to Fn are sometimes fixed:
32 : * - The Stage* always represents the current stage, mainly providing access to ctx().
33 : * - The first size_t is always the destination x coordinate.
34 : * (If you need y, put it in your context.)
35 : * - The second size_t is always tail: 0 when working on a full 4-pixel slab,
36 : * or 1..3 when using only the bottom 1..3 lanes of each register.
37 : * - By the time the shader's done, the first four vectors should hold source red,
38 : * green, blue, and alpha, up to 4 pixels' worth each.
39 : *
40 : * Sometimes arguments are flexible:
41 : * - In the shader, the first four vectors can be used for anything, e.g. sample coordinates.
42 : * - The last four vectors are scratch registers that can be used to communicate between
43 : * stages; transfer modes use these to hold the original destination pixel components.
44 : *
45 : * On some platforms the last four vectors are slower to work with than the other arguments.
46 : *
47 : * When done mutating its arguments and/or context, a stage can either:
48 : * 1) call st->next() with its mutated arguments, chaining to the next stage of the pipeline; or
49 : * 2) return, indicating the pipeline is complete for these pixels.
50 : *
51 : * Some stages that typically return are those that write a color to a destination pointer,
52 : * but any stage can short-circuit the rest of the pipeline by returning instead of calling next().
53 : */
54 :
55 : // TODO: There may be a better place to stuff tail, e.g. in the bottom alignment bits of
56 : // the Stage*. This mostly matters on 64-bit Windows where every register is precious.
57 :
58 : #define SK_RASTER_PIPELINE_STAGES(M) \
59 : M(move_src_dst) M(move_dst_src) M(swap) \
60 : M(clamp_0) M(clamp_1) M(clamp_a) \
61 : M(unpremul) M(premul) \
62 : M(set_rgb) M(swap_rb) \
63 : M(from_srgb) M(to_srgb) \
64 : M(from_2dot2) M(to_2dot2) \
65 : M(constant_color) M(seed_shader) \
66 : M(load_a8) M(store_a8) \
67 : M(load_g8) \
68 : M(load_565) M(store_565) \
69 : M(load_4444) M(store_4444) \
70 : M(load_f16) M(store_f16) \
71 : M(load_f32) M(store_f32) \
72 : M(load_8888) M(store_8888) \
73 : M(load_u16_be) M(load_rgb_u16_be) M(store_u16_be) \
74 : M(load_tables_u16_be) M(load_tables_rgb_u16_be) \
75 : M(load_tables) \
76 : M(scale_u8) M(scale_1_float) \
77 : M(lerp_u8) M(lerp_565) M(lerp_1_float) \
78 : M(dstatop) M(dstin) M(dstout) M(dstover) \
79 : M(srcatop) M(srcin) M(srcout) M(srcover) \
80 : M(clear) M(modulate) M(multiply) M(plus_) M(screen) M(xor_) \
81 : M(colorburn) M(colordodge) M(darken) M(difference) \
82 : M(exclusion) M(hardlight) M(lighten) M(overlay) M(softlight) \
83 : M(luminance_to_alpha) \
84 : M(matrix_2x3) M(matrix_3x4) M(matrix_4x5) \
85 : M(matrix_perspective) \
86 : M(parametric_r) M(parametric_g) M(parametric_b) \
87 : M(parametric_a) \
88 : M(table_r) M(table_g) M(table_b) M(table_a) \
89 : M(color_lookup_table) M(lab_to_xyz) \
90 : M(clamp_x) M(mirror_x) M(repeat_x) \
91 : M(clamp_y) M(mirror_y) M(repeat_y) \
92 : M(gather_a8) M(gather_g8) M(gather_i8) \
93 : M(gather_565) M(gather_4444) M(gather_8888) M(gather_f16) \
94 : M(bilinear_nx) M(bilinear_px) M(bilinear_ny) M(bilinear_py) \
95 : M(bicubic_n3x) M(bicubic_n1x) M(bicubic_p1x) M(bicubic_p3x) \
96 : M(bicubic_n3y) M(bicubic_n1y) M(bicubic_p1y) M(bicubic_p3y) \
97 : M(save_xy) M(accumulate) \
98 : M(linear_gradient) \
99 : M(linear_gradient_2stops) \
100 : M(byte_tables) M(byte_tables_rgb) \
101 : M(shader_adapter) \
102 : M(rgb_to_hsl) \
103 : M(hsl_to_rgb)
104 :
105 1566 : class SkRasterPipeline {
106 : public:
107 : SkRasterPipeline();
108 :
109 : enum StockStage {
110 : #define M(stage) stage,
111 : SK_RASTER_PIPELINE_STAGES(M)
112 : #undef M
113 : };
114 : void append(StockStage, void* = nullptr);
115 4 : void append(StockStage stage, const void* ctx) { this->append(stage, const_cast<void*>(ctx)); }
116 :
117 : // Append all stages to this pipeline.
118 : void extend(const SkRasterPipeline&);
119 :
120 : // Runs the pipeline walking x through [x,x+n).
121 : void run(size_t x, size_t n) const;
122 :
123 : void dump() const;
124 :
125 : struct Stage {
126 : StockStage stage;
127 : void* ctx;
128 : };
129 :
130 : // Conversion from sRGB can be subtly tricky when premultiplication is involved.
131 : // Use these helpers to keep things sane.
132 : void append_from_srgb(SkAlphaType);
133 :
134 1 : bool empty() const { return fStages.empty(); }
135 :
136 : private:
137 : bool run_with_jumper(size_t x, size_t n) const;
138 :
139 : std::vector<Stage> fStages;
140 : };
141 :
142 : #endif//SkRasterPipeline_DEFINED
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