Extract most of the mutable state of SkShader into a separate Context object.

src/core/SkBlitter_RGB16.cpp

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkBlitRow.h"
@@ skipping 89 matching lines @@
     virtual void blitAntiH(int x, int y, const SkAlpha* antialias,
                            const int16_t* runs);
 
 private:
     typedef SkRGB16_Opaque_Blitter INHERITED;
 };
 #endif
 
 class SkRGB16_Shader_Blitter : public SkShaderBlitter {
 public:
-    SkRGB16_Shader_Blitter(const SkBitmap& device, const SkPaint& paint);
+    SkRGB16_Shader_Blitter(const SkBitmap& device, const SkPaint& paint,
+                           SkShader::Context* shaderContext);
     virtual ~SkRGB16_Shader_Blitter();
     virtual void blitH(int x, int y, int width);
     virtual void blitAntiH(int x, int y, const SkAlpha* antialias,
                            const int16_t* runs);
     virtual void blitRect(int x, int y, int width, int height);
 
 protected:
     SkPMColor*      fBuffer;
     SkBlitRow::Proc fOpaqueProc;
     SkBlitRow::Proc fAlphaProc;
 
 private:
     // illegal
     SkRGB16_Shader_Blitter& operator=(const SkRGB16_Shader_Blitter&);
 
     typedef SkShaderBlitter INHERITED;
 };
 
 // used only if the shader can perform shadSpan16
 class SkRGB16_Shader16_Blitter : public SkRGB16_Shader_Blitter {
 public:
-    SkRGB16_Shader16_Blitter(const SkBitmap& device, const SkPaint& paint);
+    SkRGB16_Shader16_Blitter(const SkBitmap& device, const SkPaint& paint,
+                             SkShader::Context* shaderContext);
     virtual void blitH(int x, int y, int width);
     virtual void blitAntiH(int x, int y, const SkAlpha* antialias,
                            const int16_t* runs);
     virtual void blitRect(int x, int y, int width, int height);
 
 private:
     typedef SkRGB16_Shader_Blitter INHERITED;
 };
 
 class SkRGB16_Shader_Xfermode_Blitter : public SkShaderBlitter {
 public:
-    SkRGB16_Shader_Xfermode_Blitter(const SkBitmap& device, const SkPaint& paint);
+    SkRGB16_Shader_Xfermode_Blitter(const SkBitmap& device, const SkPaint& paint,
+                                    SkShader::Context* shaderContext);
     virtual ~SkRGB16_Shader_Xfermode_Blitter();
     virtual void blitH(int x, int y, int width);
     virtual void blitAntiH(int x, int y, const SkAlpha* antialias,
                            const int16_t* runs);
 
 private:
     SkXfermode* fXfermode;
     SkPMColor*  fBuffer;
     uint8_t*    fAAExpand;
 
@@ skipping 517 matching lines @@
 
     while (--height >= 0) {
         blend32_16_row(src32, device, width);
         device = (uint16_t*)((char*)device + deviceRB);
     }
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 SkRGB16_Shader16_Blitter::SkRGB16_Shader16_Blitter(const SkBitmap& device,
-                                                   const SkPaint& paint)
-    : SkRGB16_Shader_Blitter(device, paint) {
+                                                   const SkPaint& paint,
+                                                   SkShader::Context* shaderContext)
+    : SkRGB16_Shader_Blitter(device, paint, shaderContext) {
     SkASSERT(SkShader::CanCallShadeSpan16(fShaderFlags));
 }
 
 void SkRGB16_Shader16_Blitter::blitH(int x, int y, int width) {
     SkASSERT(x + width <= fDevice.width());
 
     uint16_t* SK_RESTRICT device = fDevice.getAddr16(x, y);
-    SkShader*   shader = fShader;

[scroggo, 2014/03/24 21:24:46]

More instances of caching a value and not using the cache. It might be worth
investigating how that happened. It seems we might want to cache fShaderContext.

[Dominik Grewe, 2014/03/26 17:22:22]

I didn't realize we can't always rely on the compiler do to it for us. Will
update it wherever necessary.

 
-    int alpha = shader->getSpan16Alpha();
+    int alpha = fShaderContext->getSpan16Alpha();
     if (0xFF == alpha) {
-        shader->shadeSpan16(x, y, device, width);
+        fShaderContext->shadeSpan16(x, y, device, width);
     } else {
         uint16_t* span16 = (uint16_t*)fBuffer;
-        shader->shadeSpan16(x, y, span16, width);
+        fShaderContext->shadeSpan16(x, y, span16, width);
         SkBlendRGB16(span16, device, SkAlpha255To256(alpha), width);
     }
 }
 
 void SkRGB16_Shader16_Blitter::blitRect(int x, int y, int width, int height) {
-    SkShader*   shader = fShader;
     uint16_t*   dst = fDevice.getAddr16(x, y);
     size_t      dstRB = fDevice.rowBytes();
-    int         alpha = shader->getSpan16Alpha();
+    int         alpha = fShaderContext->getSpan16Alpha();
 
     if (0xFF == alpha) {
         if (fShaderFlags & SkShader::kConstInY16_Flag) {
             // have the shader blit directly into the device the first time
-            shader->shadeSpan16(x, y, dst, width);
+            fShaderContext->shadeSpan16(x, y, dst, width);
             // and now just memcpy that line on the subsequent lines
             if (--height > 0) {
                 const uint16_t* orig = dst;
                 do {
                     dst = (uint16_t*)((char*)dst + dstRB);
                     memcpy(dst, orig, width << 1);
                 } while (--height);
             }
         } else {    // need to call shadeSpan16 for every line
             do {
-                shader->shadeSpan16(x, y, dst, width);
+                fShaderContext->shadeSpan16(x, y, dst, width);
                 y += 1;
                 dst = (uint16_t*)((char*)dst + dstRB);
             } while (--height);
         }
     } else {
         int scale = SkAlpha255To256(alpha);
         uint16_t* span16 = (uint16_t*)fBuffer;
         if (fShaderFlags & SkShader::kConstInY16_Flag) {
-            shader->shadeSpan16(x, y, span16, width);
+            fShaderContext->shadeSpan16(x, y, span16, width);
             do {
                 SkBlendRGB16(span16, dst, scale, width);
                 dst = (uint16_t*)((char*)dst + dstRB);
             } while (--height);
         } else {
             do {
-                shader->shadeSpan16(x, y, span16, width);
+                fShaderContext->shadeSpan16(x, y, span16, width);
                 SkBlendRGB16(span16, dst, scale, width);
                 y += 1;
                 dst = (uint16_t*)((char*)dst + dstRB);
             } while (--height);
         }
     }
 }
 
 void SkRGB16_Shader16_Blitter::blitAntiH(int x, int y,
                                          const SkAlpha* SK_RESTRICT antialias,
                                          const int16_t* SK_RESTRICT runs) {
-    SkShader*   shader = fShader;
     SkPMColor* SK_RESTRICT span = fBuffer;
     uint16_t* SK_RESTRICT device = fDevice.getAddr16(x, y);
 
-    int alpha = shader->getSpan16Alpha();
+    int alpha = fShaderContext->getSpan16Alpha();
     uint16_t* span16 = (uint16_t*)span;
 
     if (0xFF == alpha) {
         for (;;) {
             int count = *runs;
             if (count <= 0) {
                 break;
             }
             SkASSERT(count <= fDevice.width()); // don't overrun fBuffer
 
             int aa = *antialias;
             if (aa == 255) {
                 // go direct to the device!
-                shader->shadeSpan16(x, y, device, count);
+                fShaderContext->shadeSpan16(x, y, device, count);
             } else if (aa) {
-                shader->shadeSpan16(x, y, span16, count);
+                fShaderContext->shadeSpan16(x, y, span16, count);
                 SkBlendRGB16(span16, device, SkAlpha255To256(aa), count);
             }
             device += count;
             runs += count;
             antialias += count;
             x += count;
         }
     } else {  // span alpha is < 255
         alpha = SkAlpha255To256(alpha);
         for (;;) {
             int count = *runs;
             if (count <= 0) {
                 break;
             }
             SkASSERT(count <= fDevice.width()); // don't overrun fBuffer
 
             int aa = SkAlphaMul(*antialias, alpha);
             if (aa) {
-                shader->shadeSpan16(x, y, span16, count);
+                fShaderContext->shadeSpan16(x, y, span16, count);
                 SkBlendRGB16(span16, device, SkAlpha255To256(aa), count);
             }
 
             device += count;
             runs += count;
             antialias += count;
             x += count;
         }
     }
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 SkRGB16_Shader_Blitter::SkRGB16_Shader_Blitter(const SkBitmap& device,
-                                               const SkPaint& paint)
-: INHERITED(device, paint) {
+                                               const SkPaint& paint,
+                                               SkShader::Context* shaderContext)
+: INHERITED(device, paint, shaderContext) {
     SkASSERT(paint.getXfermode() == NULL);
 
     fBuffer = (SkPMColor*)sk_malloc_throw(device.width() * sizeof(SkPMColor));
 
     // compute SkBlitRow::Procs
     unsigned flags = 0;
 
     uint32_t shaderFlags = fShaderFlags;
     // shaders take care of global alpha, so we never set it in SkBlitRow
     if (!(shaderFlags & SkShader::kOpaqueAlpha_Flag)) {
@@ skipping 10 matching lines @@
                                      SkBitmap::kRGB_565_Config);
 }
 
 SkRGB16_Shader_Blitter::~SkRGB16_Shader_Blitter() {
     sk_free(fBuffer);
 }
 
 void SkRGB16_Shader_Blitter::blitH(int x, int y, int width) {
     SkASSERT(x + width <= fDevice.width());
 
-    fShader->shadeSpan(x, y, fBuffer, width);
+    fShaderContext->shadeSpan(x, y, fBuffer, width);
     // shaders take care of global alpha, so we pass 0xFF (should be ignored)
     fOpaqueProc(fDevice.getAddr16(x, y), fBuffer, width, 0xFF, x, y);
 }
 
 void SkRGB16_Shader_Blitter::blitRect(int x, int y, int width, int height) {
-    SkShader*       shader = fShader;
     SkBlitRow::Proc proc = fOpaqueProc;
     SkPMColor*      buffer = fBuffer;
     uint16_t*       dst = fDevice.getAddr16(x, y);
     size_t          dstRB = fDevice.rowBytes();
 
     if (fShaderFlags & SkShader::kConstInY32_Flag) {
-        shader->shadeSpan(x, y, buffer, width);
+        fShaderContext->shadeSpan(x, y, buffer, width);
         do {
             proc(dst, buffer, width, 0xFF, x, y);
             y += 1;
             dst = (uint16_t*)((char*)dst + dstRB);
         } while (--height);
     } else {
         do {
-            shader->shadeSpan(x, y, buffer, width);
+            fShaderContext->shadeSpan(x, y, buffer, width);
             proc(dst, buffer, width, 0xFF, x, y);
             y += 1;
             dst = (uint16_t*)((char*)dst + dstRB);
         } while (--height);
     }
 }
 
 static inline int count_nonzero_span(const int16_t runs[], const SkAlpha aa[]) {
     int count = 0;
     for (;;) {
         int n = *runs;
         if (n == 0 || *aa == 0) {
             break;
         }
         runs += n;
         aa += n;
         count += n;
     }
     return count;
 }
 
 void SkRGB16_Shader_Blitter::blitAntiH(int x, int y,
                                        const SkAlpha* SK_RESTRICT antialias,
                                        const int16_t* SK_RESTRICT runs) {
-    SkShader*   shader = fShader;
     SkPMColor* SK_RESTRICT span = fBuffer;
     uint16_t* SK_RESTRICT device = fDevice.getAddr16(x, y);
 
     for (;;) {
         int count = *runs;
         if (count <= 0) {
             break;
         }
         int aa = *antialias;
         if (0 == aa) {
             device += count;
             runs += count;
             antialias += count;
             x += count;
             continue;
         }
 
         int nonZeroCount = count + count_nonzero_span(runs + count, antialias + count);
 
         SkASSERT(nonZeroCount <= fDevice.width()); // don't overrun fBuffer
-        shader->shadeSpan(x, y, span, nonZeroCount);
+        fShaderContext->shadeSpan(x, y, span, nonZeroCount);
 
         SkPMColor* localSpan = span;
         for (;;) {
             SkBlitRow::Proc proc = (aa == 0xFF) ? fOpaqueProc : fAlphaProc;
             proc(device, localSpan, count, aa, x, y);
 
             x += count;
             device += count;
             runs += count;
             antialias += count;
             nonZeroCount -= count;
             if (nonZeroCount == 0) {
                 break;
             }
             localSpan += count;
             SkASSERT(nonZeroCount > 0);
             count = *runs;
             SkASSERT(count > 0);
             aa = *antialias;
         }
     }
 }
 
 ///////////////////////////////////////////////////////////////////////
 
 SkRGB16_Shader_Xfermode_Blitter::SkRGB16_Shader_Xfermode_Blitter(
-                                const SkBitmap& device, const SkPaint& paint)
-: INHERITED(device, paint) {
+                                const SkBitmap& device, const SkPaint& paint,
+                                SkShader::Context* shaderContext)
+: INHERITED(device, paint, shaderContext) {
     fXfermode = paint.getXfermode();
     SkASSERT(fXfermode);
     fXfermode->ref();
 
     int width = device.width();
     fBuffer = (SkPMColor*)sk_malloc_throw((width + (SkAlign4(width) >> 2)) * sizeof(SkPMColor));
     fAAExpand = (uint8_t*)(fBuffer + width);
 }
 
 SkRGB16_Shader_Xfermode_Blitter::~SkRGB16_Shader_Xfermode_Blitter() {
     fXfermode->unref();
     sk_free(fBuffer);
 }
 
 void SkRGB16_Shader_Xfermode_Blitter::blitH(int x, int y, int width) {
     SkASSERT(x + width <= fDevice.width());
 
     uint16_t*   device = fDevice.getAddr16(x, y);
     SkPMColor*  span = fBuffer;
 
-    fShader->shadeSpan(x, y, span, width);
+    fShaderContext->shadeSpan(x, y, span, width);
     fXfermode->xfer16(device, span, width, NULL);
 }
 
 void SkRGB16_Shader_Xfermode_Blitter::blitAntiH(int x, int y,
                                 const SkAlpha* SK_RESTRICT antialias,
                                 const int16_t* SK_RESTRICT runs) {
-    SkShader*   shader = fShader;
     SkXfermode* mode = fXfermode;
     SkPMColor* SK_RESTRICT span = fBuffer;
     uint8_t* SK_RESTRICT aaExpand = fAAExpand;
     uint16_t* SK_RESTRICT device = fDevice.getAddr16(x, y);
 
     for (;;) {
         int count = *runs;
         if (count <= 0) {
             break;
         }
         int aa = *antialias;
         if (0 == aa) {
             device += count;
             runs += count;
             antialias += count;
             x += count;
             continue;
         }
 
         int nonZeroCount = count + count_nonzero_span(runs + count,
                                                       antialias + count);
 
         SkASSERT(nonZeroCount <= fDevice.width()); // don't overrun fBuffer
-        shader->shadeSpan(x, y, span, nonZeroCount);
+        fShaderContext->shadeSpan(x, y, span, nonZeroCount);
 
         x += nonZeroCount;
         SkPMColor* localSpan = span;
         for (;;) {
             if (aa == 0xFF) {
                 mode->xfer16(device, localSpan, count, NULL);
             } else {
                 SkASSERT(aa);
                 memset(aaExpand, aa, count);
                 mode->xfer16(device, localSpan, count, aaExpand);
@@ skipping 10 matching lines @@
             count = *runs;
             SkASSERT(count > 0);
             aa = *antialias;
         }
     }
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 SkBlitter* SkBlitter_ChooseD565(const SkBitmap& device, const SkPaint& paint,
+        SkShader::Context* shaderContext,
         SkTBlitterAllocator* allocator) {
     SkASSERT(allocator != NULL);
 
     SkBlitter* blitter;
     SkShader* shader = paint.getShader();
     SkXfermode* mode = paint.getXfermode();
 
     // we require a shader if there is an xfermode, handled by our caller
     SkASSERT(NULL == mode || NULL != shader);
 
     if (shader) {
+        SkASSERT(shaderContext != NULL);
         if (mode) {
-            blitter = allocator->createT<SkRGB16_Shader_Xfermode_Blitter>(device, paint);
-        } else if (shader->canCallShadeSpan16()) {
-            blitter = allocator->createT<SkRGB16_Shader16_Blitter>(device, paint);
+            blitter = allocator->createT<SkRGB16_Shader_Xfermode_Blitter>(device, paint,
+                                                                          shaderContext);
+        } else if (shaderContext->canCallShadeSpan16()) {
+            blitter = allocator->createT<SkRGB16_Shader16_Blitter>(device, paint, shaderContext);
         } else {
-            blitter = allocator->createT<SkRGB16_Shader_Blitter>(device, paint);
+            blitter = allocator->createT<SkRGB16_Shader_Blitter>(device, paint, shaderContext);
         }
     } else {
         // no shader, no xfermode, (and we always ignore colorfilter)
         SkColor color = paint.getColor();
         if (0 == SkColorGetA(color)) {
             blitter = allocator->createT<SkNullBlitter>();
 #ifdef USE_BLACK_BLITTER
         } else if (SK_ColorBLACK == color) {
             blitter = allocator->createT<SkRGB16_Black_Blitter>(device, paint);
 #endif
         } else if (0xFF == SkColorGetA(color)) {
             blitter = allocator->createT<SkRGB16_Opaque_Blitter>(device, paint);
         } else {
             blitter = allocator->createT<SkRGB16_Blitter>(device, paint);
         }
     }
 
     return blitter;
 }