| /* |
| * Copyright 2016 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef SkRasterPipeline_DEFINED |
| #define SkRasterPipeline_DEFINED |
| |
| #include "SkNx.h" |
| #include "SkTArray.h" |
| #include "SkTypes.h" |
| |
| /** |
| * SkRasterPipeline provides a cheap way to chain together a pixel processing pipeline. |
| * |
| * It's particularly designed for situations where the potential pipeline is extremely |
| * combinatoric: {N dst formats} x {M source formats} x {K mask formats} x {C transfer modes} ... |
| * No one wants to write specialized routines for all those combinations, and if we did, we'd |
| * end up bloating our code size dramatically. SkRasterPipeline stages can be chained together |
| * at runtime, so we can scale this problem linearly rather than combinatorically. |
| * |
| * Each stage is represented by a function conforming to a common interface, SkRasterPipeline::Fn, |
| * and by an arbitrary context pointer. Fn's arguments, and sometimes custom calling convention, |
| * are designed to maximize the amount of data we can pass along the pipeline cheaply. |
| * On many machines all arguments stay in registers the entire time. |
| * |
| * The meaning of the arguments to Fn are sometimes fixed: |
| * - The Stage* always represents the current stage, mainly providing access to ctx(). |
| * - The first size_t is always the destination x coordinate. |
| * (If you need y, put it in your context.) |
| * - The second size_t is always tail: 0 when working on a full 4-pixel slab, |
| * or 1..3 when using only the bottom 1..3 lanes of each register. |
| * - By the time the shader's done, the first four vectors should hold source red, |
| * green, blue, and alpha, up to 4 pixels' worth each. |
| * |
| * Sometimes arguments are flexible: |
| * - In the shader, the first four vectors can be used for anything, e.g. sample coordinates. |
| * - The last four vectors are scratch registers that can be used to communicate between |
| * stages; transfer modes use these to hold the original destination pixel components. |
| * |
| * On some platforms the last four vectors are slower to work with than the other arguments. |
| * |
| * When done mutating its arguments and/or context, a stage can either: |
| * 1) call st->next() with its mutated arguments, chaining to the next stage of the pipeline; or |
| * 2) return, indicating the pipeline is complete for these pixels. |
| * |
| * Some stages that typically return are those that write a color to a destination pointer, |
| * but any stage can short-circuit the rest of the pipeline by returning instead of calling next(). |
| */ |
| |
| // TODO: There may be a better place to stuff tail, e.g. in the bottom alignment bits of |
| // the Stage*. This mostly matters on 64-bit Windows where every register is precious. |
| |
| class SkRasterPipeline { |
| public: |
| struct Stage; |
| #if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_AVX2 |
| using V = Sk8f; |
| #else |
| using V = Sk4f; |
| #endif |
| using Fn = void(SK_VECTORCALL *)(Stage*, size_t, size_t, V,V,V,V, |
| V,V,V,V); |
| |
| struct Stage { |
| template <typename T> |
| T ctx() { return static_cast<T>(fCtx); } |
| |
| void SK_VECTORCALL next(size_t x, size_t tail, V v0, V v1, V v2, V v3, |
| V v4, V v5, V v6, V v7) { |
| // Stages are logically a pipeline, and physically are contiguous in an array. |
| // To get to the next stage, we just increment our pointer to the next array element. |
| ((Fn)fNext)(this+1, x,tail, v0,v1,v2,v3, v4,v5,v6,v7); |
| } |
| |
| // It makes next() a good bit cheaper if we hold the next function to call here, |
| // rather than logically simpler choice of the function implementing this stage. |
| void (*fNext)(); |
| void* fCtx; |
| }; |
| |
| |
| SkRasterPipeline(); |
| |
| // Run the pipeline constructed with append(), walking x through [x,x+n), |
| // generally in 4-pixel steps, with perhaps one jagged tail step. |
| void run(size_t x, size_t n); |
| void run(size_t n) { this->run(0, n); } |
| |
| enum StockStage { |
| just_return, |
| |
| store_565, |
| store_srgb, |
| store_f16, |
| |
| load_s_565, |
| load_s_srgb, |
| load_s_f16, |
| |
| load_d_565, |
| load_d_srgb, |
| load_d_f16, |
| |
| scale_u8, |
| |
| lerp_u8, |
| lerp_565, |
| lerp_constant_float, |
| |
| constant_color, |
| |
| dst, |
| dstatop, |
| dstin, |
| dstout, |
| dstover, |
| srcatop, |
| srcin, |
| srcout, |
| srcover, |
| clear, |
| modulate, |
| multiply, |
| plus_, |
| screen, |
| xor_, |
| colorburn, |
| colordodge, |
| darken, |
| difference, |
| exclusion, |
| hardlight, |
| lighten, |
| overlay, |
| softlight, |
| |
| kNumStockStages, |
| }; |
| void append(StockStage, void* = nullptr); |
| void append(StockStage stage, const void* ctx) { this->append(stage, const_cast<void*>(ctx)); } |
| |
| // Append all stages to this pipeline. |
| void extend(const SkRasterPipeline&); |
| |
| private: |
| using Stages = SkSTArray<10, Stage, /*MEM_COPY=*/true>; |
| |
| void append(void (*body)(), void (*tail)(), void*); |
| |
| Stages fBody, |
| fTail; |
| void (*fBodyStart)() = nullptr; |
| void (*fTailStart)() = nullptr; |
| }; |
| |
| #endif//SkRasterPipeline_DEFINED |