Revert of add support for new bitmapshader context (patchset #5 id:80001 of https://codereview.chromium.org/1757993002/ )

Reason for revert:
oops, need to update bench to know about the large size needed for the new shader

Original issue's description:
> add support for new bitmapshader context
>
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1757993002
>
> Committed: https://skia.googlesource.com/skia/+/19cef56344b5a5f26f802d7be34c44af36b7e797

TBR=herb@google.com,mtklein@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1763743002

gm/SkLinearBitmapPipelineGM.cpp

@@ -60,7 +60,7 @@ static void draw_rect_orig(SkCanvas* canvas, const SkRect& r, SkColor c, const S
     SkAutoTUnref<SkImage> image{SkImage::NewRasterCopy(
         info, pmsrc.addr32(), pmsrc.rowBytes())};
     SkPaint paint;
-    int32_t storage[300];
+    int32_t storage[200];
     SkShader* shader = image->newShader(SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);
     if (useBilerp) {
         paint.setFilterQuality(SkFilterQuality::kLow_SkFilterQuality);

src/core/SkBitmapProcShader.cpp

@@ -27,7 +27,8 @@ static bool only_scale_and_translate(const SkMatrix& matrix) {
 
 class BitmapProcInfoContext : public SkShader::Context {
 public:
-    // The info has been allocated elsewhere, but we are responsible for calling its destructor.
+    // The context takes ownership of the info. It will call its destructor
+    // but will NOT free the memory.
     BitmapProcInfoContext(const SkShader& shader, const SkShader::ContextRec& rec,
                             SkBitmapProcInfo* info)
         : INHERITED(shader, rec)
@@ -44,6 +45,8 @@ public:
     }
 
     ~BitmapProcInfoContext() override {
+        // The bitmap proc state has been created outside of the context on memory that will be freed
+        // elsewhere. Only call the destructor but leave the freeing of the memory to the caller.
         fInfo->~SkBitmapProcInfo();
     }
     
@@ -60,6 +63,8 @@ private:
 
 class BitmapProcShaderContext : public BitmapProcInfoContext {
 public:
+    // The context takes ownership of the state. It will call its destructor
+    // but will NOT free the memory.
     BitmapProcShaderContext(const SkShader& shader, const SkShader::ContextRec& rec,
                             SkBitmapProcState* state)
         : INHERITED(shader, rec, state)
@@ -111,80 +116,11 @@ private:
 };
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
-#include "SkLinearBitmapPipeline.h"
-#include "SkPM4f.h"
-#include "SkXfermode.h"
 
-class LinearPipelineContext : public BitmapProcInfoContext {
-public:
-    LinearPipelineContext(const SkShader& shader, const SkShader::ContextRec& rec,
-                          SkBitmapProcInfo* info)
-        : INHERITED(shader, rec, info)
-        , fPipeline(info->fInvMatrix, info->fFilterQuality, info->fTileModeX, info->fTileModeY,
-                    info->fPixmap)
-    {
-        // To implement the old shadeSpan entry-point, we need to efficiently convert our native
-        // floats into SkPMColor. The SkXfermode::D32Procs do exactly that.
-        //
-        sk_sp<SkXfermode> xfer(SkXfermode::Create(SkXfermode::kSrc_Mode));
-        fXferProc = SkXfermode::GetD32Proc(xfer.get(), 0);
-    }
-
-    void shadeSpan4f(int x, int y, SkPM4f dstC[], int count) override {
-        fPipeline.shadeSpan4f(x, y, dstC, count);
-    }
-
-    void shadeSpan(int x, int y, SkPMColor dstC[], int count) override {
-        const int N = 128;
-        SkPM4f  tmp[N];
-
-        while (count > 0) {
-            const int n = SkTMin(count, N);
-            fPipeline.shadeSpan4f(x, y, tmp, n);
-            fXferProc(nullptr, dstC, tmp, n, nullptr);
-            dstC += n;
-            x += n;
-            count -= n;
-        }
-    }
-
-private:
-    SkLinearBitmapPipeline  fPipeline;
-    SkXfermode::D32Proc     fXferProc;
-
-    typedef BitmapProcInfoContext INHERITED;
-};
-
-///////////////////////////////////////////////////////////////////////////////////////////////////
-
-static bool choose_linear_pipeline(const SkShader::ContextRec& rec, const SkImageInfo& srcInfo) {
-    // These src attributes are not supported in the new 4f context (yet)
-    //
-    if (srcInfo.bytesPerPixel() < 4 ||
-        kRGBA_F16_SkColorType == srcInfo.colorType()) {
-        return false;
-    }
-
-#if 0   // later we may opt-in to the new code even if the client hasn't requested it...
-    // These src attributes are only supported in the new 4f context
-    //
-    if (srcInfo.isSRGB() ||
-        kUnpremul_SkAlphaType == srcInfo.alphaType() ||
-        (4 == srcInfo.bytesPerPixel() && kN32_SkColorType != srcInfo.colorType()))
-    {
-        return true;
-    }
-#endif
-
-    // If we get here, we can reasonably use either context, respect the caller's preference
-    //
-    return SkShader::ContextRec::kPM4f_DstType == rec.fPreferredDstType;
-}
-
-size_t SkBitmapProcShader::ContextSize(const ContextRec& rec, const SkImageInfo& srcInfo) {
-    size_t size0 = sizeof(BitmapProcShaderContext) + sizeof(SkBitmapProcState);
-    size_t size1 = sizeof(LinearPipelineContext) + sizeof(SkBitmapProcInfo);
-    return SkTMax(size0, size1);
+size_t SkBitmapProcShader::ContextSize(const ContextRec& rec) {
+    // The SkBitmapProcState is stored outside of the context object, with the context holding
+    // a pointer to it.
+    return sizeof(BitmapProcShaderContext) + sizeof(SkBitmapProcState);
 }
 
 SkShader::Context* SkBitmapProcShader::MakeContext(const SkShader& shader,
@@ -197,32 +133,16 @@ SkShader::Context* SkBitmapProcShader::MakeContext(const SkShader& shader,
         return nullptr;
     }
 
-    // Decide if we can/want to use the new linear pipeine
-    bool useLinearPipeline = choose_linear_pipeline(rec, provider.info());
-    if (SkShader::kMirror_TileMode == tmx || SkShader::kMirror_TileMode == tmy) {
-        useLinearPipeline = false;
-    }
-    if (totalInverse.hasPerspective()) {
-        useLinearPipeline = false;
-    }
-
-    if (useLinearPipeline) {
-        void* infoStorage = (char*)storage + sizeof(LinearPipelineContext);
-        SkBitmapProcInfo* info = new (infoStorage) SkBitmapProcInfo(provider, tmx, tmy);
-        if (!info->init(totalInverse, *rec.fPaint)) {
-            info->~SkBitmapProcInfo();
-            return nullptr;
-        }
-        return new (storage) LinearPipelineContext(shader, rec, info);
-    } else {
     void* stateStorage = (char*)storage + sizeof(BitmapProcShaderContext);
     SkBitmapProcState* state = new (stateStorage) SkBitmapProcState(provider, tmx, tmy);
+
+    SkASSERT(state);
     if (!state->setup(totalInverse, *rec.fPaint)) {
         state->~SkBitmapProcState();
         return nullptr;
     }
+
     return new (storage) BitmapProcShaderContext(shader, rec, state);
-    }
 }
 
 SkShader::Context* SkBitmapProcShader::onCreateContext(const ContextRec& rec, void* storage) const {

src/core/SkBitmapProcShader.h

@@ -21,9 +21,7 @@ public:
 
     bool isOpaque() const override;
 
-    size_t contextSize(const ContextRec& rec) const override {
-        return ContextSize(rec, fRawBitmap.info());
-    }
+    size_t contextSize(const ContextRec& rec) const override { return ContextSize(rec); }
 
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkBitmapProcShader)
@@ -38,13 +36,13 @@ protected:
     Context* onCreateContext(const ContextRec&, void* storage) const override;
     bool onIsABitmap(SkBitmap*, SkMatrix*, TileMode*) const override;
 
-    SkBitmap    fRawBitmap;
+    SkBitmap    fRawBitmap;   // experimental for RLE encoding
     uint8_t     fTileModeX, fTileModeY;
 
 private:
     friend class SkImageShader;
 
-    static size_t ContextSize(const ContextRec&, const SkImageInfo& srcInfo);
+    static size_t ContextSize(const ContextRec&);
     static Context* MakeContext(const SkShader&, TileMode tmx, TileMode tmy,
                                 const SkBitmapProvider&, const ContextRec&, void* storage);
 
@@ -56,7 +54,7 @@ private:
 // an Sk3DBlitter in SkDraw.cpp
 // Note that some contexts may contain other contexts (e.g. for compose shaders), but we've not
 // yet found a situation where the size below isn't big enough.
-typedef SkSmallAllocator<3, 2100> SkTBlitterAllocator;
+typedef SkSmallAllocator<3, 1500> SkTBlitterAllocator;
 
 // If alloc is non-nullptr, it will be used to allocate the returned SkShader, and MUST outlive
 // the SkShader.

src/core/SkComposeShader.cpp

@@ -31,9 +31,9 @@ SkComposeShader::~SkComposeShader() {
 }
 
 size_t SkComposeShader::contextSize(const ContextRec& rec) const {
-    return SkAlign16(sizeof(ComposeShaderContext))
-         + SkAlign16(fShaderA->contextSize(rec))
-         + SkAlign16(fShaderB->contextSize(rec));
+    return sizeof(ComposeShaderContext)
+        + fShaderA->contextSize(rec)
+        + fShaderB->contextSize(rec);
 }
 
 class SkAutoAlphaRestore {
@@ -76,8 +76,8 @@ template <typename T> void safe_call_destructor(T* obj) {
 }
 
 SkShader::Context* SkComposeShader::onCreateContext(const ContextRec& rec, void* storage) const {
-    char* aStorage = (char*) storage + SkAlign16(sizeof(ComposeShaderContext));
-    char* bStorage = aStorage + SkAlign16(fShaderA->contextSize(rec));
+    char* aStorage = (char*) storage + sizeof(ComposeShaderContext);
+    char* bStorage = aStorage + fShaderA->contextSize(rec);
 
     // we preconcat our localMatrix (if any) with the device matrix
     // before calling our sub-shaders

src/core/SkShader.cpp

@@ -86,9 +86,6 @@ bool SkShader::asLuminanceColor(SkColor* colorPtr) const {
 }
 
 SkShader::Context* SkShader::createContext(const ContextRec& rec, void* storage) const {
-    // We currently require 16byte alignment for some of our subclasses, so assert that here.
-    SkASSERT(SkIsAlign16((intptr_t)storage));
-
     if (!this->computeTotalInverse(rec, nullptr)) {
         return nullptr;
     }

src/image/SkImageShader.cpp

@@ -43,7 +43,7 @@ bool SkImageShader::isOpaque() const {
 }
 
 size_t SkImageShader::contextSize(const ContextRec& rec) const {
-    return SkBitmapProcShader::ContextSize(rec, SkBitmapProvider(fImage).info());
+    return SkBitmapProcShader::ContextSize(rec);
 }
 
 SkShader::Context* SkImageShader::onCreateContext(const ContextRec& rec, void* storage) const {

tests/SkColor4fTest.cpp

@@ -149,7 +149,7 @@ DEF_TEST(Color4f_shader, reporter) {
 
     SkPaint paint;
     for (const auto& rec : recs) {
-        uint32_t storage[300];
+        uint32_t storage[200];
         paint.setShader(rec.fFact())->unref();
         // Encourage 4f context selection. At some point we may need
         // to instantiate two separate contexts for optimal 4b/4f selection.