Revert "alpha threshold bitmap shader"

This reverts commit r11122.

git-svn-id: http://skia.googlecode.com/svn/trunk/src@11123 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/effects/SkBitmapAlphaThresholdShader.cpp b/effects/SkBitmapAlphaThresholdShader.cpp
deleted file mode 100644
index 67a3c3f..0000000
--- a/effects/SkBitmapAlphaThresholdShader.cpp
+++ /dev/null
@@ -1,311 +0,0 @@
-/*
- * Copyright 2013 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "SkBitmapAlphaThresholdShader.h"
-
-class BATShader : public SkShader {
-public:
-    SK_DECLARE_INST_COUNT(SkThresholdShader);
-
-    BATShader(const SkBitmap& bitmap, SkRegion region, U8CPU);
-    BATShader(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {
-        // We should probably do something here.
-    }
-    
-    
-    virtual void shadeSpan(int x, int y, SkPMColor[], int count) SK_OVERRIDE {};
-    
-#if SK_SUPPORT_GPU
-    virtual GrEffectRef* asNewEffect(GrContext* context, const SkPaint& paint) const SK_OVERRIDE;
-#endif
-    
-    SK_DEVELOPER_TO_STRING();
-    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(BATShader)
-    
-private:
-    SkBitmap fBitmap;
-    SkRegion fRegion;
-    U8CPU    fThreshold;
-    
-    typedef SkShader INHERITED;
-};
-
-SkShader* SkBitmapAlphaThresholdShader::Create(const SkBitmap& bitmap,
-                                               const SkRegion& region,
-                                               U8CPU threshold) {
-    SkASSERT(threshold < 256);
-    return SkNEW_ARGS(BATShader, (bitmap, region, threshold));
-}
-
-BATShader::BATShader(const SkBitmap& bitmap, SkRegion region, U8CPU threshold)
-: fBitmap(bitmap)
-, fRegion(region)
-, fThreshold(threshold) {
-};
-
-
-#ifdef SK_DEVELOPER
-void BATShader::toString(SkString* str) const {
-    str->append("BATShader: (");
-
-    fBitmap.toString(str);
-
-    this->INHERITED::toString(str);
-
-    str->append(")");
-}
-#endif
-
-#if SK_SUPPORT_GPU
-#include "GrContext.h"
-#include "GrEffect.h"
-#include "gl/GrGLEffect.h"
-#include "gl/GrGLEffectMatrix.h"
-#include "GrTBackendEffectFactory.h"
-#include "GrTextureAccess.h"
-
-#include "SkGr.h"
-
-/**
- * Could create specializations for some simple cases:
- *  - The region is empty.
- *  - The region fully contains the bitmap.
- *  - The regions is 1 rect (or maybe a small number of rects).
- */
-class ThresholdEffect : public GrEffect {
-public:
-    virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE {
-        return GrTBackendEffectFactory<ThresholdEffect>::getInstance();
-    }
-
-    static GrEffectRef* Create(GrTexture* bmpTexture, const SkMatrix& bmpMatrix,
-                               GrTexture* maskTexture, const SkMatrix& maskMatrix,
-                               U8CPU threshold) {
-        SkScalar thresh = SkIntToScalar(threshold) / 255;
-
-        AutoEffectUnref effect(SkNEW_ARGS(ThresholdEffect, (bmpTexture, bmpMatrix,
-                                                            maskTexture, maskMatrix,
-                                                            thresh)));
-        return CreateEffectRef(effect);
-    }
-
-    virtual void getConstantColorComponents(GrColor* color,
-                                            uint32_t* validFlags) const SK_OVERRIDE {
-        if ((kA_GrColorComponentFlag & *validFlags) && 0 == GrColorUnpackA(*color)) {
-            return;
-        }
-        *validFlags = 0;
-        return;
-    }
-
-    static const char* Name() { return "Bitmap Alpha Threshold"; }
-
-    class GLEffect : public GrGLEffect {
-    public:
-        GLEffect(const GrBackendEffectFactory& factory,
-                    const GrDrawEffect& e)
-        : GrGLEffect(factory)
-        , fBmpMatrix(GrEffect::kLocal_CoordsType)
-        , fMaskMatrix(GrEffect::kLocal_CoordsType)
-        , fPrevThreshold(-SK_Scalar1) {
-        }
-
-        virtual void emitCode(GrGLShaderBuilder* builder,
-                                const GrDrawEffect& drawEffect,
-                                EffectKey key,
-                                const char* outputColor,
-                                const char* inputColor,
-                                const TextureSamplerArray& samplers) SK_OVERRIDE {
-            SkString bmpCoord;
-            SkString maskCoord;
-
-            GrSLType bmpCoordType = fBmpMatrix.emitCode(builder, key, &bmpCoord, NULL, "Bmp");
-            EffectKey maskMatrixKey = key >> GrGLEffectMatrix::kKeyBits;
-            GrSLType maskCoordType = fMaskMatrix.emitCode(builder,
-                                                          maskMatrixKey,
-                                                          &maskCoord,
-                                                          NULL,
-                                                          "Mask");
-
-            // put bitmap color in "color"
-            builder->fsCodeAppend("\t\tvec4 color = ");
-            builder->fsAppendTextureLookup(samplers[0], bmpCoord.c_str(), bmpCoordType);
-            builder->fsCodeAppend(";\n");
-
-            // put alpha from mask texture in "mask"
-            builder->fsCodeAppend("\t\tfloat mask = ");
-            builder->fsAppendTextureLookup(samplers[1], maskCoord.c_str(), maskCoordType);
-            builder->fsCodeAppend(".a;\n");
-
-            const char* threshold;
-
-            fThresholdUniHandle = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
-                                                      kFloat_GrSLType,
-                                                      "threshold",
-                                                      &threshold);
-            builder->fsCodeAppendf("\t\tfloat thresh = %s;\n", threshold);
-
-            builder->fsCodeAppend("\t\tif (mask < 0.5) {\n"
-                                    "\t\t\tif (color.a > thresh) {\n"
-                                    "\t\t\t\tfloat scale = thresh / color.a;\n"
-                                    "\t\t\t\tcolor.rgb *= scale;\n"
-                                    "\t\t\t\tcolor.a = thresh;\n"
-                                    "\t\t\t}\n"
-                                    "\t\t} else if (color.a < thresh) {\n"
-                                    "\t\t\tfloat scale = thresh / color.a;\n"
-                                    "\t\t\tcolor.rgb *= scale;\n"
-                                    "\t\t\tcolor.a = thresh;\n"
-                                    "\t\t}\n");
-
-            builder->fsCodeAppend("color = ");
-            SkString outStr;
-            outStr.appendf("\t\t%s = ", outputColor);
-            GrGLSLModulatef<4>(&outStr, inputColor, "color");
-            outStr.append(";\n");
-            builder->fsCodeAppend(outStr.c_str());
-        }
-
-        virtual void setData(const GrGLUniformManager& uman, const GrDrawEffect& e) SK_OVERRIDE {
-            const ThresholdEffect& effect = e.castEffect<ThresholdEffect>();
-            fBmpMatrix.setData(uman, effect.fBmpMatrix, e, effect.fBmpAccess.getTexture());
-            fMaskMatrix.setData(uman, effect.fMaskMatrix, e, effect.fMaskAccess.getTexture());
-            if (fPrevThreshold != effect.fThreshold) {
-                uman.set1f(fThresholdUniHandle, effect.fThreshold);
-            }
-        }
-
-        static inline EffectKey GenKey(const GrDrawEffect& e, const GrGLCaps&) {
-            const ThresholdEffect& effect = e.castEffect<ThresholdEffect>();
-
-            EffectKey bmpMKey = GrGLEffectMatrix::GenKey(effect.fBmpMatrix,
-                                                         e,
-                                                         GrEffect::kLocal_CoordsType,
-                                                         effect.fBmpAccess.getTexture());
-            EffectKey maskMKey = GrGLEffectMatrix::GenKey(effect.fMaskMatrix,
-                                                          e,
-                                                          GrEffect::kLocal_CoordsType,
-                                                          effect.fMaskAccess.getTexture());
-            return bmpMKey | (maskMKey << GrGLEffectMatrix::kKeyBits);
-        }
-
-    private:
-        GrGLEffectMatrix fBmpMatrix;
-        GrGLEffectMatrix fMaskMatrix;
-
-        GrGLUniformManager::UniformHandle fThresholdUniHandle;
-        SkScalar                          fPrevThreshold;
-    };
-
-    GR_DECLARE_EFFECT_TEST;
-
-private:
-    ThresholdEffect(GrTexture* bmpTexture, const SkMatrix& bmpMatrix,
-                    GrTexture* maskTexture, const SkMatrix& maskMatrix,
-                    SkScalar threshold)
-    : fBmpAccess(bmpTexture, GrTextureParams())
-    , fMaskAccess(maskTexture, GrTextureParams())
-    , fBmpMatrix(bmpMatrix)
-    , fMaskMatrix(maskMatrix)
-    , fThreshold(threshold) {
-        this->addTextureAccess(&fBmpAccess);
-        this->addTextureAccess(&fMaskAccess);
-    }
-
-    virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE {
-        const ThresholdEffect& e = CastEffect<ThresholdEffect>(other);
-        return e.fBmpAccess.getTexture() == fBmpAccess.getTexture() &&
-               e.fMaskAccess.getTexture() == fMaskAccess.getTexture() &&
-               e.fBmpMatrix == fBmpMatrix &&
-               e.fMaskMatrix == fMaskMatrix &&
-               e.fThreshold == fThreshold;
-    }
-
-    GrTextureAccess fBmpAccess;
-    GrTextureAccess fMaskAccess;
-
-    SkMatrix fBmpMatrix;
-    SkMatrix fMaskMatrix;
-
-    SkScalar fThreshold;
-};
-
-GR_DEFINE_EFFECT_TEST(ThresholdEffect);
-
-GrEffectRef* ThresholdEffect::TestCreate(SkMWCRandom* rand,
-                                         GrContext*,
-                                         const GrDrawTargetCaps&,
-                                         GrTexture* textures[]) {
-    GrTexture* bmpTex = textures[GrEffectUnitTest::kSkiaPMTextureIdx];
-    GrTexture* maskTex = textures[GrEffectUnitTest::kAlphaTextureIdx];
-    U8CPU thresh = rand->nextU() % 0xff;
-    return ThresholdEffect::Create(bmpTex, SkMatrix::I(), maskTex, SkMatrix::I(), thresh);
-}
-
-GrEffectRef* BATShader::asNewEffect(GrContext* context, const SkPaint& paint) const {
-    SkMatrix localInverse;
-    if (!this->getLocalMatrix().invert(&localInverse)) {
-        return NULL;
-    }
-
-    GrTextureDesc maskDesc;
-    if (context->isConfigRenderable(kAlpha_8_GrPixelConfig)) {
-        maskDesc.fConfig = kAlpha_8_GrPixelConfig;
-    } else {
-        maskDesc.fConfig = kRGBA_8888_GrPixelConfig;
-    }
-    maskDesc.fFlags = kRenderTarget_GrTextureFlagBit | kNoStencil_GrTextureFlagBit;
-    const SkIRect& bounds = fRegion.getBounds();
-    // Add one pixel of border to ensure that clamp mode will be all zeros
-    // the outside.
-    maskDesc.fWidth = bounds.width() + 2;
-    maskDesc.fHeight = bounds.height() + 2;
-    GrAutoScratchTexture ast(context, maskDesc, GrContext::kApprox_ScratchTexMatch);
-    GrTexture*  maskTexture = ast.texture();
-    if (NULL == maskTexture) {
-        return false;
-    }
-
-    GrPaint grPaint;
-    grPaint.setBlendFunc(kOne_GrBlendCoeff, kZero_GrBlendCoeff);
-    SkRegion::Iterator iter(fRegion);
-    context->setRenderTarget(maskTexture->asRenderTarget());
-    context->clear(NULL, 0x0);
-
-    // offset to ensure border is zero on top/left
-    SkMatrix matrix;
-    matrix.setTranslate(SK_Scalar1, SK_Scalar1);
-    context->setMatrix(matrix);
-
-    while (!iter.done()) {
-        SkRect rect = SkRect::MakeFromIRect(iter.rect());
-        context->drawRect(grPaint, rect);
-        iter.next();
-    }
-
-    GrTexture* bmpTexture = GrLockAndRefCachedBitmapTexture(context, fBitmap, NULL);
-    if (NULL == bmpTexture) {
-        return NULL;
-    }
-
-    SkMatrix bmpMatrix = localInverse;
-    bmpMatrix.postIDiv(bmpTexture->width(), bmpTexture->height());
-
-    SkMatrix maskMatrix = localInverse;
-    // compensate for the border
-    maskMatrix.postTranslate(SK_Scalar1, SK_Scalar1);
-    maskMatrix.postIDiv(maskTexture->width(), maskTexture->height());
-
-    GrEffectRef* effect = ThresholdEffect::Create(bmpTexture, bmpMatrix,
-                                                  maskTexture, maskMatrix,
-                                                  fThreshold);
-
-    GrUnlockAndUnrefCachedBitmapTexture(bmpTexture);
-
-    return effect;
-}
-
-#endif
diff --git a/gpu/SkGpuDevice.cpp b/gpu/SkGpuDevice.cpp
index ea8a06e..571b8a0 100644
--- a/gpu/SkGpuDevice.cpp
+++ b/gpu/SkGpuDevice.cpp
@@ -535,11 +535,6 @@
         return skPaint2GrPaintNoShader(dev, skPaint, false, constantColor, grPaint);
     }
 
-    // SkShader::asNewEffect() may do offscreen rendering. Setup default drawing state
-    // Also require shader to set the render target .
-    GrContext::AutoWideOpenIdentityDraw awo(dev->context(), NULL);
-    GrContext::AutoRenderTarget(dev->context(), NULL);
-
     // setup the shader as the first color effect on the paint
     SkAutoTUnref<GrEffectRef> effect(shader->asNewEffect(dev->context(), skPaint));
     if (NULL != effect.get()) {