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 
8 #include "SkBitmapProcShader.h"
9 
10 #include "SkArenaAlloc.h"
11 #include "SkBitmapProcState.h"
12 #include "SkBitmapProvider.h"
13 #include "SkXfermodePriv.h"
14 
only_scale_and_translate(const SkMatrix & matrix)15 static bool only_scale_and_translate(const SkMatrix& matrix) {
16     unsigned mask = SkMatrix::kTranslate_Mask | SkMatrix::kScale_Mask;
17     return (matrix.getType() & ~mask) == 0;
18 }
19 
20 class BitmapProcInfoContext : public SkShader::Context {
21 public:
22     // The info has been allocated elsewhere, but we are responsible for calling its destructor.
BitmapProcInfoContext(const SkShader & shader,const SkShader::ContextRec & rec,SkBitmapProcInfo * info)23     BitmapProcInfoContext(const SkShader& shader, const SkShader::ContextRec& rec,
24                             SkBitmapProcInfo* info)
25         : INHERITED(shader, rec)
26         , fInfo(info)
27     {
28         fFlags = 0;
29         if (fInfo->fPixmap.isOpaque() && (255 == this->getPaintAlpha())) {
30             fFlags |= SkShader::kOpaqueAlpha_Flag;
31         }
32 
33         if (1 == fInfo->fPixmap.height() && only_scale_and_translate(this->getTotalInverse())) {
34             fFlags |= SkShader::kConstInY32_Flag;
35         }
36     }
37 
getFlags() const38     uint32_t getFlags() const override { return fFlags; }
39 
40 private:
41     SkBitmapProcInfo*   fInfo;
42     uint32_t            fFlags;
43 
44     typedef SkShader::Context INHERITED;
45 };
46 
47 ///////////////////////////////////////////////////////////////////////////////////////////////////
48 
49 class BitmapProcShaderContext : public BitmapProcInfoContext {
50 public:
BitmapProcShaderContext(const SkShader & shader,const SkShader::ContextRec & rec,SkBitmapProcState * state)51     BitmapProcShaderContext(const SkShader& shader, const SkShader::ContextRec& rec,
52                             SkBitmapProcState* state)
53         : INHERITED(shader, rec, state)
54         , fState(state)
55     {}
56 
shadeSpan(int x,int y,SkPMColor dstC[],int count)57     void shadeSpan(int x, int y, SkPMColor dstC[], int count) override {
58         const SkBitmapProcState& state = *fState;
59         if (state.getShaderProc32()) {
60             state.getShaderProc32()(&state, x, y, dstC, count);
61             return;
62         }
63 
64         const int BUF_MAX = 128;
65         uint32_t buffer[BUF_MAX];
66         SkBitmapProcState::MatrixProc   mproc = state.getMatrixProc();
67         SkBitmapProcState::SampleProc32 sproc = state.getSampleProc32();
68         const int max = state.maxCountForBufferSize(sizeof(buffer[0]) * BUF_MAX);
69 
70         SkASSERT(state.fPixmap.addr());
71 
72         for (;;) {
73             int n = SkTMin(count, max);
74             SkASSERT(n > 0 && n < BUF_MAX*2);
75             mproc(state, buffer, n, x, y);
76             sproc(state, buffer, n, dstC);
77 
78             if ((count -= n) == 0) {
79                 break;
80             }
81             SkASSERT(count > 0);
82             x += n;
83             dstC += n;
84         }
85     }
86 
asAShadeProc(void ** ctx)87     ShadeProc asAShadeProc(void** ctx) override {
88         if (fState->getShaderProc32()) {
89             *ctx = fState;
90             return (ShadeProc)fState->getShaderProc32();
91         }
92         return nullptr;
93     }
94 
95 private:
96     SkBitmapProcState*  fState;
97 
98     typedef BitmapProcInfoContext INHERITED;
99 };
100 
101 ///////////////////////////////////////////////////////////////////////////////////////////////////
102 #include "SkLinearBitmapPipeline.h"
103 #include "SkPM4f.h"
104 
105 class LinearPipelineContext : public BitmapProcInfoContext {
106 public:
LinearPipelineContext(const SkShader & shader,const SkShader::ContextRec & rec,SkBitmapProcInfo * info,SkArenaAlloc * alloc)107     LinearPipelineContext(const SkShader& shader, const SkShader::ContextRec& rec,
108                           SkBitmapProcInfo* info, SkArenaAlloc* alloc)
109         : INHERITED(shader, rec, info), fAllocator{alloc}
110     {
111         // Save things off in case we need to build a blitter pipeline.
112         fSrcPixmap = info->fPixmap;
113         fAlpha = SkColorGetA(info->fPaintColor) / 255.0f;
114         fFilterQuality = info->fFilterQuality;
115         fMatrixTypeMask = info->fRealInvMatrix.getType();
116 
117         fShaderPipeline = alloc->make<SkLinearBitmapPipeline>(
118             info->fRealInvMatrix, info->fFilterQuality,
119             info->fTileModeX, info->fTileModeY,
120             info->fPaintColor,
121             info->fPixmap,
122             fAllocator);
123 
124         // To implement the old shadeSpan entry-point, we need to efficiently convert our native
125         // floats into SkPMColor. The SkXfermode::D32Procs do exactly that.
126         //
127         fSrcModeProc = SkXfermode::GetD32Proc(SkBlendMode::kSrc, 0);
128     }
129 
shadeSpan4f(int x,int y,SkPM4f dstC[],int count)130     void shadeSpan4f(int x, int y, SkPM4f dstC[], int count) override {
131         fShaderPipeline->shadeSpan4f(x, y, dstC, count);
132     }
133 
shadeSpan(int x,int y,SkPMColor dstC[],int count)134     void shadeSpan(int x, int y, SkPMColor dstC[], int count) override {
135         const int N = 128;
136         SkPM4f  tmp[N];
137 
138         while (count > 0) {
139             const int n = SkTMin(count, N);
140             fShaderPipeline->shadeSpan4f(x, y, tmp, n);
141             fSrcModeProc(SkBlendMode::kSrc, dstC, tmp, n, nullptr);
142             dstC += n;
143             x += n;
144             count -= n;
145         }
146     }
147 
onChooseBlitProcs(const SkImageInfo & dstInfo,BlitState * state)148     bool onChooseBlitProcs(const SkImageInfo& dstInfo, BlitState* state) override {
149         if ((fBlitterPipeline = SkLinearBitmapPipeline::ClonePipelineForBlitting(
150             *fShaderPipeline,
151             fMatrixTypeMask,
152             fFilterQuality, fSrcPixmap,
153             fAlpha, state->fMode, dstInfo, fAllocator)))
154         {
155             state->fStorage[0] = fBlitterPipeline;
156             state->fBlitBW = &LinearPipelineContext::ForwardToPipeline;
157 
158             return true;
159         }
160 
161         return false;
162     }
163 
ForwardToPipeline(BlitState * state,int x,int y,const SkPixmap & dst,int count)164     static void ForwardToPipeline(BlitState* state, int x, int y, const SkPixmap& dst, int count) {
165         SkLinearBitmapPipeline* pipeline = static_cast<SkLinearBitmapPipeline*>(state->fStorage[0]);
166         void* addr = dst.writable_addr32(x, y);
167         pipeline->blitSpan(x, y, addr, count);
168     }
169 
170 private:
171     // Store the allocator from the context creation incase we are asked to build a blitter.
172     SkArenaAlloc*           fAllocator;
173     SkLinearBitmapPipeline* fShaderPipeline;
174     SkLinearBitmapPipeline* fBlitterPipeline;
175     SkXfermode::D32Proc     fSrcModeProc;
176     SkPixmap                fSrcPixmap;
177     float                   fAlpha;
178     SkMatrix::TypeMask      fMatrixTypeMask;
179     SkFilterQuality         fFilterQuality;
180 
181     typedef BitmapProcInfoContext INHERITED;
182 };
183 
184 ///////////////////////////////////////////////////////////////////////////////////////////////////
185 
choose_linear_pipeline(const SkShader::ContextRec & rec,const SkImageInfo & srcInfo)186 static bool choose_linear_pipeline(const SkShader::ContextRec& rec, const SkImageInfo& srcInfo) {
187     // If we get here, we can reasonably use either context, respect the caller's preference
188     //
189     bool needsPremul = srcInfo.alphaType() == kUnpremul_SkAlphaType;
190     bool needsSwizzle = srcInfo.bytesPerPixel() == 4 && srcInfo.colorType() != kN32_SkColorType;
191     return SkShader::ContextRec::kPM4f_DstType == rec.fPreferredDstType
192            || needsPremul || needsSwizzle;
193 }
194 
ContextSize(const ContextRec & rec,const SkImageInfo & srcInfo)195 size_t SkBitmapProcLegacyShader::ContextSize(const ContextRec& rec, const SkImageInfo& srcInfo) {
196     size_t size0 = sizeof(BitmapProcShaderContext) + sizeof(SkBitmapProcState);
197     size_t size1 = sizeof(LinearPipelineContext) + sizeof(SkBitmapProcInfo);
198     size_t s = SkTMax(size0, size1);
199     return s;
200 }
201 
MakeContext(const SkShader & shader,TileMode tmx,TileMode tmy,const SkBitmapProvider & provider,const ContextRec & rec,SkArenaAlloc * alloc)202 SkShader::Context* SkBitmapProcLegacyShader::MakeContext(
203     const SkShader& shader, TileMode tmx, TileMode tmy,
204     const SkBitmapProvider& provider, const ContextRec& rec, SkArenaAlloc* alloc)
205 {
206     SkMatrix totalInverse;
207     // Do this first, so we know the matrix can be inverted.
208     if (!shader.computeTotalInverse(rec, &totalInverse)) {
209         return nullptr;
210     }
211 
212     // Decide if we can/want to use the new linear pipeline
213     bool useLinearPipeline = choose_linear_pipeline(rec, provider.info());
214 
215     if (useLinearPipeline) {
216         SkBitmapProcInfo* info = alloc->make<SkBitmapProcInfo>(provider, tmx, tmy);
217         if (!info->init(totalInverse, *rec.fPaint)) {
218             return nullptr;
219         }
220 
221         return alloc->make<LinearPipelineContext>(shader, rec, info, alloc);
222     } else {
223         SkBitmapProcState* state = alloc->make<SkBitmapProcState>(provider, tmx, tmy);
224         if (!state->setup(totalInverse, *rec.fPaint)) {
225             return nullptr;
226         }
227         return alloc->make<BitmapProcShaderContext>(shader, rec, state);
228     }
229 }
230