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 /*

  * Copyright 2011 Google Inc.

  *

  * Use of this source code is governed by a BSD-style license that can be

  * found in the LICENSE file.

  */

 #include "SkPDFShader.h"

 #include "SkData.h"

 #include "SkPDFCatalog.h"

 #include "SkPDFDevice.h"

 #include "SkPDFFormXObject.h"

 #include "SkPDFGraphicState.h"

 #include "SkPDFResourceDict.h"

 #include "SkPDFUtils.h"

 #include "SkScalar.h"

 #include "SkStream.h"

 #include "SkTemplates.h"

 #include "SkThread.h"

 #include "SkTSet.h"

 #include "SkTypes.h"

 static bool inverseTransformBBox(const SkMatrix& matrix, SkRect* bbox) {

     SkMatrix inverse;

     if (!matrix.invert(&inverse)) {

         return false;

     }

     inverse.mapRect(bbox);

     return true;

 }

 static void unitToPointsMatrix(const SkPoint pts[2], SkMatrix* matrix) {

     SkVector    vec = pts[1] - pts[0];

     SkScalar    mag = vec.length();

     SkScalar    inv = mag ? SkScalarInvert(mag) : 0;

     vec.scale(inv);

     matrix->setSinCos(vec.fY, vec.fX);

     matrix->preScale(mag, mag);

     matrix->postTranslate(pts[0].fX, pts[0].fY);

 }

 /* Assumes t + startOffset is on the stack and does a linear interpolation on t

    between startOffset and endOffset from prevColor to curColor (for each color

    component), leaving the result in component order on the stack. It assumes

    there are always 3 components per color.

    @param range                  endOffset - startOffset

    @param curColor[components]   The current color components.

    @param prevColor[components]  The previous color components.

    @param result                 The result ps function.

  */

 static void interpolateColorCode(SkScalar range, SkScalar* curColor,

                                  SkScalar* prevColor, SkString* result) {

     SkASSERT(range != SkIntToScalar(0));

     static const int kColorComponents = 3;

     // Figure out how to scale each color component.

     SkScalar multiplier[kColorComponents];

     for (int i = 0; i < kColorComponents; i++) {

         multiplier[i] = SkScalarDiv(curColor[i] - prevColor[i], range);

     }

     // Calculate when we no longer need to keep a copy of the input parameter t.

     // If the last component to use t is i, then dupInput[0..i - 1] = true

     // and dupInput[i .. components] = false.

     bool dupInput[kColorComponents];

     dupInput[kColorComponents - 1] = false;

     for (int i = kColorComponents - 2; i >= 0; i--) {

         dupInput[i] = dupInput[i + 1] || multiplier[i + 1] != 0;

     }

     if (!dupInput[0] && multiplier[0] == 0) {

         result->append("pop ");

     }

     for (int i = 0; i < kColorComponents; i++) {

         // If the next components needs t and this component will consume a

         // copy, make another copy.

         if (dupInput[i] && multiplier[i] != 0) {

             result->append("dup ");

         }

         if (multiplier[i] == 0) {

             result->appendScalar(prevColor[i]);

             result->append(" ");

         } else {

             if (multiplier[i] != 1) {

                 result->appendScalar(multiplier[i]);

                 result->append(" mul ");

             }

             if (prevColor[i] != 0) {

                 result->appendScalar(prevColor[i]);

                 result->append(" add ");

             }

         }

         if (dupInput[i]) {

             result->append("exch\n");

         }

     }

 }

 /* Generate Type 4 function code to map t=[0,1) to the passed gradient,

    clamping at the edges of the range.  The generated code will be of the form:

        if (t < 0) {

            return colorData[0][r,g,b];

        } else {

            if (t < info.fColorOffsets[1]) {

                return linearinterpolation(colorData[0][r,g,b],

                                           colorData[1][r,g,b]);

            } else {

                if (t < info.fColorOffsets[2]) {

                    return linearinterpolation(colorData[1][r,g,b],

                                               colorData[2][r,g,b]);

                } else {

                 ...    } else {

                            return colorData[info.fColorCount - 1][r,g,b];

                        }

                 ...

            }

        }

  */

 static void gradientFunctionCode(const SkShader::GradientInfo& info,

                                  SkString* result) {

     /* We want to linearly interpolate from the previous color to the next.

        Scale the colors from 0..255 to 0..1 and determine the multipliers

        for interpolation.

        C{r,g,b}(t, section) = t - offset_(section-1) + t * Multiplier{r,g,b}.

      */

     static const int kColorComponents = 3;

     typedef SkScalar ColorTuple[kColorComponents];

     SkAutoSTMalloc<4, ColorTuple> colorDataAlloc(info.fColorCount);

     ColorTuple *colorData = colorDataAlloc.get();

     const SkScalar scale = SkScalarInvert(SkIntToScalar(255));

     for (int i = 0; i < info.fColorCount; i++) {

         colorData[i][0] = SkScalarMul(SkColorGetR(info.fColors[i]), scale);

         colorData[i][1] = SkScalarMul(SkColorGetG(info.fColors[i]), scale);

         colorData[i][2] = SkScalarMul(SkColorGetB(info.fColors[i]), scale);

     }

     // Clamp the initial color.

     result->append("dup 0 le {pop ");

     result->appendScalar(colorData[0][0]);

     result->append(" ");

     result->appendScalar(colorData[0][1]);

     result->append(" ");

     result->appendScalar(colorData[0][2]);

     result->append(" }\n");

     // The gradient colors.

     int gradients = 0;

     for (int i = 1 ; i < info.fColorCount; i++) {

         if (info.fColorOffsets[i] == info.fColorOffsets[i - 1]) {

             continue;

         }

         gradients++;

         result->append("{dup ");

         result->appendScalar(info.fColorOffsets[i]);

         result->append(" le {");

         if (info.fColorOffsets[i - 1] != 0) {

             result->appendScalar(info.fColorOffsets[i - 1]);

             result->append(" sub\n");

         }

         interpolateColorCode(info.fColorOffsets[i] - info.fColorOffsets[i - 1],

                              colorData[i], colorData[i - 1], result);

         result->append("}\n");

     }

     // Clamp the final color.

     result->append("{pop ");

     result->appendScalar(colorData[info.fColorCount - 1][0]);

     result->append(" ");

     result->appendScalar(colorData[info.fColorCount - 1][1]);

     result->append(" ");

     result->appendScalar(colorData[info.fColorCount - 1][2]);

     for (int i = 0 ; i < gradients + 1; i++) {

         result->append("} ifelse\n");

     }

 }

 /* Map a value of t on the stack into [0, 1) for Repeat or Mirror tile mode. */

 static void tileModeCode(SkShader::TileMode mode, SkString* result) {

     if (mode == SkShader::kRepeat_TileMode) {

         result->append("dup truncate sub\n");  // Get the fractional part.

         result->append("dup 0 le {1 add} if\n");  // Map (-1,0) => (0,1)

         return;

     }

     if (mode == SkShader::kMirror_TileMode) {

         // Map t mod 2 into [0, 1, 1, 0].

         //               Code                     Stack

         result->append("abs "                 // Map negative to positive.

                        "dup "                 // t.s t.s

                        "truncate "            // t.s t

                        "dup "                 // t.s t t

                        "cvi "                 // t.s t T

                        "2 mod "               // t.s t (i mod 2)

                        "1 eq "                // t.s t true|false

                        "3 1 roll "            // true|false t.s t

                        "sub "                 // true|false 0.s

                        "exch "                // 0.s true|false

                        "{1 exch sub} if\n");  // 1 - 0.s|0.s

     }

 }

 /**

  *  Returns PS function code that applies inverse perspective

  *  to a x, y point.

  *  The function assumes that the stack has at least two elements,

  *  and that the top 2 elements are numeric values.

  *  After executing this code on a PS stack, the last 2 elements are updated

  *  while the rest of the stack is preserved intact.

  *  inversePerspectiveMatrix is the inverse perspective matrix.

  */

 static SkString apply_perspective_to_coordinates(

         const SkMatrix& inversePerspectiveMatrix) {

     SkString code;

     if (!inversePerspectiveMatrix.hasPerspective()) {

         return code;

     }

     // Perspective matrix should be:

     // 1   0  0

     // 0   1  0

     // p0 p1 p2

     const SkScalar p0 = inversePerspectiveMatrix[SkMatrix::kMPersp0];

     const SkScalar p1 = inversePerspectiveMatrix[SkMatrix::kMPersp1];

     const SkScalar p2 = inversePerspectiveMatrix[SkMatrix::kMPersp2];

     // y = y / (p2 + p0 x + p1 y)

     // x = x / (p2 + p0 x + p1 y)

     // Input on stack: x y

     code.append(" dup ");               // x y y

     code.appendScalar(p1);              // x y y p1

     code.append(" mul "                 // x y y*p1

                 " 2 index ");           // x y y*p1 x

     code.appendScalar(p0);              // x y y p1 x p0

     code.append(" mul ");               // x y y*p1 x*p0

     code.appendScalar(p2);              // x y y p1 x*p0 p2

     code.append(" add "                 // x y y*p1 x*p0+p2

                 "add "                  // x y y*p1+x*p0+p2

                 "3 1 roll "             // y*p1+x*p0+p2 x y

                 "2 index "              // z x y y*p1+x*p0+p2

                 "div "                  // y*p1+x*p0+p2 x y/(y*p1+x*p0+p2)

                 "3 1 roll "             // y/(y*p1+x*p0+p2) y*p1+x*p0+p2 x

                 "exch "                 // y/(y*p1+x*p0+p2) x y*p1+x*p0+p2

                 "div "                  // y/(y*p1+x*p0+p2) x/(y*p1+x*p0+p2)

                 "exch\n");              // x/(y*p1+x*p0+p2) y/(y*p1+x*p0+p2)

     return code;

 }

 static SkString linearCode(const SkShader::GradientInfo& info,

                            const SkMatrix& perspectiveRemover) {

     SkString function("{");

     function.append(apply_perspective_to_coordinates(perspectiveRemover));

     function.append("pop\n");  // Just ditch the y value.

     tileModeCode(info.fTileMode, &function);

     gradientFunctionCode(info, &function);

     function.append("}");

     return function;

 }

 static SkString radialCode(const SkShader::GradientInfo& info,

                            const SkMatrix& perspectiveRemover) {

     SkString function("{");

     function.append(apply_perspective_to_coordinates(perspectiveRemover));

     // Find the distance from the origin.

     function.append("dup "      // x y y

                     "mul "      // x y^2

                     "exch "     // y^2 x

                     "dup "      // y^2 x x

                     "mul "      // y^2 x^2

                     "add "      // y^2+x^2

                     "sqrt\n");  // sqrt(y^2+x^2)

     tileModeCode(info.fTileMode, &function);

     gradientFunctionCode(info, &function);

     function.append("}");

     return function;

 }

 /* The math here is all based on the description in Two_Point_Radial_Gradient,

    with one simplification, the coordinate space has been scaled so that

    Dr = 1.  This means we don't need to scale the entire equation by 1/Dr^2.

  */

 static SkString twoPointRadialCode(const SkShader::GradientInfo& info,

                                    const SkMatrix& perspectiveRemover) {

     SkScalar dx = info.fPoint[0].fX - info.fPoint[1].fX;

     SkScalar dy = info.fPoint[0].fY - info.fPoint[1].fY;

     SkScalar sr = info.fRadius[0];

     SkScalar a = SkScalarMul(dx, dx) + SkScalarMul(dy, dy) - SK_Scalar1;

     bool posRoot = info.fRadius[1] > info.fRadius[0];

     // We start with a stack of (x y), copy it and then consume one copy in

     // order to calculate b and the other to calculate c.

     SkString function("{");

     function.append(apply_perspective_to_coordinates(perspectiveRemover));

     function.append("2 copy ");

     // Calculate -b and b^2.

     function.appendScalar(dy);

     function.append(" mul exch ");

     function.appendScalar(dx);

     function.append(" mul add ");

     function.appendScalar(sr);

     function.append(" sub 2 mul neg dup dup mul\n");

     // Calculate c

     function.append("4 2 roll dup mul exch dup mul add ");

     function.appendScalar(SkScalarMul(sr, sr));

     function.append(" sub\n");

     // Calculate the determinate

     function.appendScalar(SkScalarMul(SkIntToScalar(4), a));

     function.append(" mul sub abs sqrt\n");

     // And then the final value of t.

     if (posRoot) {

         function.append("sub ");

     } else {

         function.append("add ");

     }

     function.appendScalar(SkScalarMul(SkIntToScalar(2), a));

     function.append(" div\n");

     tileModeCode(info.fTileMode, &function);

     gradientFunctionCode(info, &function);

     function.append("}");

     return function;

 }

 /* Conical gradient shader, based on the Canvas spec for radial gradients

    See: http://www.w3.org/TR/2dcontext/#dom-context-2d-createradialgradient

  */

 static SkString twoPointConicalCode(const SkShader::GradientInfo& info,

                                     const SkMatrix& perspectiveRemover) {

     SkScalar dx = info.fPoint[1].fX - info.fPoint[0].fX;

     SkScalar dy = info.fPoint[1].fY - info.fPoint[0].fY;

     SkScalar r0 = info.fRadius[0];

     SkScalar dr = info.fRadius[1] - info.fRadius[0];

     SkScalar a = SkScalarMul(dx, dx) + SkScalarMul(dy, dy) -

                  SkScalarMul(dr, dr);

     // First compute t, if the pixel falls outside the cone, then we'll end

     // with 'false' on the stack, otherwise we'll push 'true' with t below it

     // We start with a stack of (x y), copy it and then consume one copy in

     // order to calculate b and the other to calculate c.

     SkString function("{");

     function.append(apply_perspective_to_coordinates(perspectiveRemover));

     function.append("2 copy ");

     // Calculate b and b^2; b = -2 * (y * dy + x * dx + r0 * dr).

     function.appendScalar(dy);

     function.append(" mul exch ");

     function.appendScalar(dx);

     function.append(" mul add ");

     function.appendScalar(SkScalarMul(r0, dr));

     function.append(" add -2 mul dup dup mul\n");

     // c = x^2 + y^2 + radius0^2

     function.append("4 2 roll dup mul exch dup mul add ");

     function.appendScalar(SkScalarMul(r0, r0));

     function.append(" sub dup 4 1 roll\n");

     // Contents of the stack at this point: c, b, b^2, c

     // if a = 0, then we collapse to a simpler linear case

     if (a == 0) {

         // t = -c/b

         function.append("pop pop div neg dup ");

         // compute radius(t)

         function.appendScalar(dr);

         function.append(" mul ");

         function.appendScalar(r0);

         function.append(" add\n");

         // if r(t) < 0, then it's outside the cone

         function.append("0 lt {pop false} {true} ifelse\n");

     } else {

         // quadratic case: the Canvas spec wants the largest

         // root t for which radius(t) > 0

         // compute the discriminant (b^2 - 4ac)

         function.appendScalar(SkScalarMul(SkIntToScalar(4), a));

         function.append(" mul sub dup\n");

         // if d >= 0, proceed

         function.append("0 ge {\n");

         // an intermediate value we'll use to compute the roots:

         // q = -0.5 * (b +/- sqrt(d))

         function.append("sqrt exch dup 0 lt {exch -1 mul} if");

         function.append(" add -0.5 mul dup\n");

         // first root = q / a

         function.appendScalar(a);

         function.append(" div\n");

         // second root = c / q

         function.append("3 1 roll div\n");

         // put the larger root on top of the stack

         function.append("2 copy gt {exch} if\n");

         // compute radius(t) for larger root

         function.append("dup ");

         function.appendScalar(dr);

         function.append(" mul ");

         function.appendScalar(r0);

         function.append(" add\n");

         // if r(t) > 0, we have our t, pop off the smaller root and we're done

         function.append(" 0 gt {exch pop true}\n");

         // otherwise, throw out the larger one and try the smaller root

         function.append("{pop dup\n");

         function.appendScalar(dr);

         function.append(" mul ");

         function.appendScalar(r0);

         function.append(" add\n");

         // if r(t) < 0, push false, otherwise the smaller root is our t

         function.append("0 le {pop false} {true} ifelse\n");

         function.append("} ifelse\n");

         // d < 0, clear the stack and push false

         function.append("} {pop pop pop false} ifelse\n");

     }

     // if the pixel is in the cone, proceed to compute a color

     function.append("{");

     tileModeCode(info.fTileMode, &function);

     gradientFunctionCode(info, &function);

     // otherwise, just write black

     function.append("} {0 0 0} ifelse }");

     return function;

 }

 static SkString sweepCode(const SkShader::GradientInfo& info,

                           const SkMatrix& perspectiveRemover) {

     SkString function("{exch atan 360 div\n");

     tileModeCode(info.fTileMode, &function);

     gradientFunctionCode(info, &function);

     function.append("}");

     return function;

 }

 class SkPDFShader::State {

 public:

     SkShader::GradientType fType;

     SkShader::GradientInfo fInfo;

     SkAutoFree fColorData;    // This provides storage for arrays in fInfo.

     SkMatrix fCanvasTransform;

     SkMatrix fShaderTransform;

     SkIRect fBBox;

     SkBitmap fImage;

     uint32_t fPixelGeneration;

     SkShader::TileMode fImageTileModes[2];

     State(const SkShader& shader, const SkMatrix& canvasTransform,

           const SkIRect& bbox);

     bool operator==(const State& b) const;

     SkPDFShader::State* CreateAlphaToLuminosityState() const;

     SkPDFShader::State* CreateOpaqueState() const;

     bool GradientHasAlpha() const;

 private:

     State(const State& other);

     State operator=(const State& rhs);

     void AllocateGradientInfoStorage();

 };

 class SkPDFFunctionShader : public SkPDFDict, public SkPDFShader {

     SK_DECLARE_INST_COUNT(SkPDFFunctionShader)

 public:

     explicit SkPDFFunctionShader(SkPDFShader::State* state);

     virtual ~SkPDFFunctionShader() {

         if (isValid()) {

             RemoveShader(this);

         }

         fResources.unrefAll();

     }

     virtual bool isValid() { return fResources.count() > 0; }

     void getResources(const SkTSet<SkPDFObject*>& knownResourceObjects,

                       SkTSet<SkPDFObject*>* newResourceObjects) {

         GetResourcesHelper(&fResources,

                            knownResourceObjects,

                            newResourceObjects);

     }

 private:

     static SkPDFObject* RangeObject();

     SkTDArray<SkPDFObject*> fResources;

     SkAutoTDelete<const SkPDFShader::State> fState;

     SkPDFStream* makePSFunction(const SkString& psCode, SkPDFArray* domain);

     typedef SkPDFDict INHERITED;

 };

 /**

  * A shader for PDF gradients. This encapsulates the function shader

  * inside a tiling pattern while providing a common pattern interface.

  * The encapsulation allows the use of a SMask for transparency gradients.

  */

 class SkPDFAlphaFunctionShader : public SkPDFStream, public SkPDFShader {

 public:

     explicit SkPDFAlphaFunctionShader(SkPDFShader::State* state);

     virtual ~SkPDFAlphaFunctionShader() {

         if (isValid()) {

             RemoveShader(this);

         }

     }

     virtual bool isValid() {

         return fColorShader.get() != NULL;

     }

 private:

     SkAutoTDelete<const SkPDFShader::State> fState;

     SkPDFGraphicState* CreateSMaskGraphicState();

     void getResources(const SkTSet<SkPDFObject*>& knownResourceObjects,

                       SkTSet<SkPDFObject*>* newResourceObjects) {

         fResourceDict->getReferencedResources(knownResourceObjects,

                                               newResourceObjects,

                                               true);

     }

     SkAutoTUnref<SkPDFObject> fColorShader;

     SkAutoTUnref<SkPDFResourceDict> fResourceDict;

 };

 class SkPDFImageShader : public SkPDFStream, public SkPDFShader {

 public:

     explicit SkPDFImageShader(SkPDFShader::State* state);

     virtual ~SkPDFImageShader() {

         if (isValid()) {

             RemoveShader(this);

         }

         fResources.unrefAll();

     }

     virtual bool isValid() { return size() > 0; }

     void getResources(const SkTSet<SkPDFObject*>& knownResourceObjects,

                       SkTSet<SkPDFObject*>* newResourceObjects) {

         GetResourcesHelper(&fResources.toArray(),

                            knownResourceObjects,

                            newResourceObjects);

     }

 private:

     SkTSet<SkPDFObject*> fResources;

     SkAutoTDelete<const SkPDFShader::State> fState;

 };

 SkPDFShader::SkPDFShader() {}

 // static

 SkPDFObject* SkPDFShader::GetPDFShaderByState(State* inState) {

     SkPDFObject* result;

     SkAutoTDelete<State> shaderState(inState);

     if (shaderState.get()->fType == SkShader::kNone_GradientType &&

             shaderState.get()->fImage.isNull()) {

         // TODO(vandebo) This drops SKComposeShader on the floor.  We could

         // handle compose shader by pulling things up to a layer, drawing with

         // the first shader, applying the xfer mode and drawing again with the

         // second shader, then applying the layer to the original drawing.

         return NULL;

     }

     ShaderCanonicalEntry entry(NULL, shaderState.get());

     int index = CanonicalShaders().find(entry);

     if (index >= 0) {

         result = CanonicalShaders()[index].fPDFShader;

         result->ref();

         return result;

     }

     bool valid = false;

     // The PDFShader takes ownership of the shaderSate.

     if (shaderState.get()->fType == SkShader::kNone_GradientType) {

         SkPDFImageShader* imageShader =

             new SkPDFImageShader(shaderState.detach());

         valid = imageShader->isValid();

         result = imageShader;

     } else {

         if (shaderState.get()->GradientHasAlpha()) {

             SkPDFAlphaFunctionShader* gradientShader =

                 SkNEW_ARGS(SkPDFAlphaFunctionShader, (shaderState.detach()));

             valid = gradientShader->isValid();

             result = gradientShader;

         } else {

             SkPDFFunctionShader* functionShader =

                 SkNEW_ARGS(SkPDFFunctionShader, (shaderState.detach()));

             valid = functionShader->isValid();

             result = functionShader;

         }

     }

     if (!valid) {

         delete result;

         return NULL;

     }

     entry.fPDFShader = result;

     CanonicalShaders().push(entry);

     return result;  // return the reference that came from new.

 }

 // static

 void SkPDFShader::RemoveShader(SkPDFObject* shader) {

     SkAutoMutexAcquire lock(CanonicalShadersMutex());

     ShaderCanonicalEntry entry(shader, NULL);

     int index = CanonicalShaders().find(entry);

     SkASSERT(index >= 0);

     CanonicalShaders().removeShuffle(index);

 }

 // static

 SkPDFObject* SkPDFShader::GetPDFShader(const SkShader& shader,

                                        const SkMatrix& matrix,

                                        const SkIRect& surfaceBBox) {

     SkAutoMutexAcquire lock(CanonicalShadersMutex());

     return GetPDFShaderByState(

             SkNEW_ARGS(State, (shader, matrix, surfaceBBox)));

 }

 // static

 SkTDArray<SkPDFShader::ShaderCanonicalEntry>& SkPDFShader::CanonicalShaders() {

     // This initialization is only thread safe with gcc.

     static SkTDArray<ShaderCanonicalEntry> gCanonicalShaders;

     return gCanonicalShaders;

 }

 // static

 SkBaseMutex& SkPDFShader::CanonicalShadersMutex() {

     // This initialization is only thread safe with gcc or when

     // POD-style mutex initialization is used.

     SK_DECLARE_STATIC_MUTEX(gCanonicalShadersMutex);

     return gCanonicalShadersMutex;

 }

 // static

 SkPDFObject* SkPDFFunctionShader::RangeObject() {

     // This initialization is only thread safe with gcc.

     static SkPDFArray* range = NULL;

     // This method is only used with CanonicalShadersMutex, so it's safe to

     // populate domain.

     if (range == NULL) {

         range = new SkPDFArray;

         range->reserve(6);

         range->appendInt(0);

         range->appendInt(1);

         range->appendInt(0);

         range->appendInt(1);

         range->appendInt(0);

         range->appendInt(1);

     }

     return range;

 }

 static SkPDFResourceDict* get_gradient_resource_dict(

         SkPDFObject* functionShader,

         SkPDFObject* gState) {

     SkPDFResourceDict* dict = new SkPDFResourceDict();

     if (functionShader != NULL) {

         dict->insertResourceAsReference(

                 SkPDFResourceDict::kPattern_ResourceType, 0, functionShader);

     }

     if (gState != NULL) {

         dict->insertResourceAsReference(

                 SkPDFResourceDict::kExtGState_ResourceType, 0, gState);

     }

     return dict;

 }

 static void populate_tiling_pattern_dict(SkPDFDict* pattern,

                                       SkRect& bbox, SkPDFDict* resources,

                                       const SkMatrix& matrix) {

     const int kTiling_PatternType = 1;

     const int kColoredTilingPattern_PaintType = 1;

     const int kConstantSpacing_TilingType = 1;

     pattern->insertName("Type", "Pattern");

     pattern->insertInt("PatternType", kTiling_PatternType);

     pattern->insertInt("PaintType", kColoredTilingPattern_PaintType);

     pattern->insertInt("TilingType", kConstantSpacing_TilingType);

     pattern->insert("BBox", SkPDFUtils::RectToArray(bbox))->unref();

     pattern->insertScalar("XStep", bbox.width());

     pattern->insertScalar("YStep", bbox.height());

     pattern->insert("Resources", resources);

     if (!matrix.isIdentity()) {

         pattern->insert("Matrix", SkPDFUtils::MatrixToArray(matrix))->unref();

     }

 }

 /**

  * Creates a content stream which fills the pattern P0 across bounds.

  * @param gsIndex A graphics state resource index to apply, or <0 if no

  * graphics state to apply.

  */

 static SkStream* create_pattern_fill_content(int gsIndex, SkRect& bounds) {

     SkDynamicMemoryWStream content;

     if (gsIndex >= 0) {

         SkPDFUtils::ApplyGraphicState(gsIndex, &content);

     }

     SkPDFUtils::ApplyPattern(0, &content);

     SkPDFUtils::AppendRectangle(bounds, &content);

     SkPDFUtils::PaintPath(SkPaint::kFill_Style, SkPath::kEvenOdd_FillType,

                           &content);

     return content.detachAsStream();

 }

 /**

  * Creates a ExtGState with the SMask set to the luminosityShader in

  * luminosity mode. The shader pattern extends to the bbox.

  */

 SkPDFGraphicState* SkPDFAlphaFunctionShader::CreateSMaskGraphicState() {

     SkRect bbox;

     bbox.set(fState.get()->fBBox);

     SkAutoTUnref<SkPDFObject> luminosityShader(

             SkPDFShader::GetPDFShaderByState(

                  fState->CreateAlphaToLuminosityState()));

     SkAutoTUnref<SkStream> alphaStream(create_pattern_fill_content(-1, bbox));

     SkAutoTUnref<SkPDFResourceDict>

         resources(get_gradient_resource_dict(luminosityShader, NULL));

     SkAutoTUnref<SkPDFFormXObject> alphaMask(

             new SkPDFFormXObject(alphaStream.get(), bbox, resources.get()));

     return SkPDFGraphicState::GetSMaskGraphicState(

             alphaMask.get(), false,

             SkPDFGraphicState::kLuminosity_SMaskMode);

 }

 SkPDFAlphaFunctionShader::SkPDFAlphaFunctionShader(SkPDFShader::State* state)

         : fState(state) {

     SkRect bbox;

     bbox.set(fState.get()->fBBox);

     fColorShader.reset(

             SkPDFShader::GetPDFShaderByState(state->CreateOpaqueState()));

     // Create resource dict with alpha graphics state as G0 and

     // pattern shader as P0, then write content stream.

     SkAutoTUnref<SkPDFGraphicState> alphaGs(CreateSMaskGraphicState());

     fResourceDict.reset(

             get_gradient_resource_dict(fColorShader.get(), alphaGs.get()));

     SkAutoTUnref<SkStream> colorStream(

             create_pattern_fill_content(0, bbox));

     setData(colorStream.get());

     populate_tiling_pattern_dict(this, bbox, fResourceDict.get(),

                                  SkMatrix::I());

 }

 // Finds affine and persp such that in = affine * persp.

 // but it returns the inverse of perspective matrix.

 static bool split_perspective(const SkMatrix in, SkMatrix* affine,

                               SkMatrix* perspectiveInverse) {

     const SkScalar p2 = in[SkMatrix::kMPersp2];

     if (SkScalarNearlyZero(p2)) {

         return false;

     }

     const SkScalar zero = SkIntToScalar(0);

     const SkScalar one = SkIntToScalar(1);

     const SkScalar sx = in[SkMatrix::kMScaleX];

     const SkScalar kx = in[SkMatrix::kMSkewX];

     const SkScalar tx = in[SkMatrix::kMTransX];

     const SkScalar ky = in[SkMatrix::kMSkewY];

     const SkScalar sy = in[SkMatrix::kMScaleY];

     const SkScalar ty = in[SkMatrix::kMTransY];

     const SkScalar p0 = in[SkMatrix::kMPersp0];

     const SkScalar p1 = in[SkMatrix::kMPersp1];

     // Perspective matrix would be:

     // 1  0  0

     // 0  1  0

     // p0 p1 p2

     // But we need the inverse of persp.

     perspectiveInverse->setAll(one,          zero,       zero,

                                zero,         one,        zero,

                                -p0/p2,     -p1/p2,     1/p2);

     affine->setAll(sx - p0 * tx / p2,       kx - p1 * tx / p2,      tx / p2,

                    ky - p0 * ty / p2,       sy - p1 * ty / p2,      ty / p2,

                    zero,                    zero,                   one);

     return true;

 }

 SkPDFFunctionShader::SkPDFFunctionShader(SkPDFShader::State* state)

         : SkPDFDict("Pattern"),

           fState(state) {

     SkString (*codeFunction)(const SkShader::GradientInfo& info,

                              const SkMatrix& perspectiveRemover) = NULL;

     SkPoint transformPoints[2];

     // Depending on the type of the gradient, we want to transform the

     // coordinate space in different ways.

     const SkShader::GradientInfo* info = &fState.get()->fInfo;

     transformPoints[0] = info->fPoint[0];

     transformPoints[1] = info->fPoint[1];

     switch (fState.get()->fType) {

         case SkShader::kLinear_GradientType:

             codeFunction = &linearCode;

             break;

         case SkShader::kRadial_GradientType:

             transformPoints[1] = transformPoints[0];

             transformPoints[1].fX += info->fRadius[0];

             codeFunction = &radialCode;

             break;

         case SkShader::kRadial2_GradientType: {

             // Bail out if the radii are the same.  Empty fResources signals

             // an error and isValid will return false.

             if (info->fRadius[0] == info->fRadius[1]) {

                 return;

             }

             transformPoints[1] = transformPoints[0];

             SkScalar dr = info->fRadius[1] - info->fRadius[0];

             transformPoints[1].fX += dr;

             codeFunction = &twoPointRadialCode;

             break;

         }

         case SkShader::kConical_GradientType: {

             transformPoints[1] = transformPoints[0];

             transformPoints[1].fX += SK_Scalar1;

             codeFunction = &twoPointConicalCode;

             break;

         }

         case SkShader::kSweep_GradientType:

             transformPoints[1] = transformPoints[0];

             transformPoints[1].fX += SK_Scalar1;

             codeFunction = &sweepCode;

             break;

         case SkShader::kColor_GradientType:

         case SkShader::kNone_GradientType:

         default:

             return;

     }

     // Move any scaling (assuming a unit gradient) or translation

     // (and rotation for linear gradient), of the final gradient from

     // info->fPoints to the matrix (updating bbox appropriately).  Now

     // the gradient can be drawn on on the unit segment.

     SkMatrix mapperMatrix;

     unitToPointsMatrix(transformPoints, &mapperMatrix);

     SkMatrix finalMatrix = fState.get()->fCanvasTransform;

     finalMatrix.preConcat(fState.get()->fShaderTransform);

     finalMatrix.preConcat(mapperMatrix);

     // Preserves as much as posible in the final matrix, and only removes

     // the perspective. The inverse of the perspective is stored in

     // perspectiveInverseOnly matrix and has 3 useful numbers

     // (p0, p1, p2), while everything else is either 0 or 1.

     // In this way the shader will handle it eficiently, with minimal code.

     SkMatrix perspectiveInverseOnly = SkMatrix::I();

     if (finalMatrix.hasPerspective()) {

         if (!split_perspective(finalMatrix,

                                &finalMatrix, &perspectiveInverseOnly)) {

             return;

         }

     }

     SkRect bbox;

     bbox.set(fState.get()->fBBox);

     if (!inverseTransformBBox(finalMatrix, &bbox)) {

         return;

     }

     SkAutoTUnref<SkPDFArray> domain(new SkPDFArray);

     domain->reserve(4);

     domain->appendScalar(bbox.fLeft);

     domain->appendScalar(bbox.fRight);

     domain->appendScalar(bbox.fTop);

     domain->appendScalar(bbox.fBottom);

     SkString functionCode;

     // The two point radial gradient further references fState.get()->fInfo

     // in translating from x, y coordinates to the t parameter. So, we have

     // to transform the points and radii according to the calculated matrix.

     if (fState.get()->fType == SkShader::kRadial2_GradientType) {

         SkShader::GradientInfo twoPointRadialInfo = *info;

         SkMatrix inverseMapperMatrix;

         if (!mapperMatrix.invert(&inverseMapperMatrix)) {

             return;

         }

         inverseMapperMatrix.mapPoints(twoPointRadialInfo.fPoint, 2);

         twoPointRadialInfo.fRadius[0] =

             inverseMapperMatrix.mapRadius(info->fRadius[0]);

         twoPointRadialInfo.fRadius[1] =

             inverseMapperMatrix.mapRadius(info->fRadius[1]);

         functionCode = codeFunction(twoPointRadialInfo, perspectiveInverseOnly);

     } else {

         functionCode = codeFunction(*info, perspectiveInverseOnly);

     }

     SkAutoTUnref<SkPDFDict> pdfShader(new SkPDFDict);

     pdfShader->insertInt("ShadingType", 1);

     pdfShader->insertName("ColorSpace", "DeviceRGB");

     pdfShader->insert("Domain", domain.get());

     SkPDFStream* function = makePSFunction(functionCode, domain.get());

     pdfShader->insert("Function", new SkPDFObjRef(function))->unref();

     fResources.push(function);  // Pass ownership to resource list.

     insertInt("PatternType", 2);

     insert("Matrix", SkPDFUtils::MatrixToArray(finalMatrix))->unref();

     insert("Shading", pdfShader.get());

 }

 SkPDFImageShader::SkPDFImageShader(SkPDFShader::State* state) : fState(state) {

     fState.get()->fImage.lockPixels();

     // The image shader pattern cell will be drawn into a separate device

     // in pattern cell space (no scaling on the bitmap, though there may be

     // translations so that all content is in the device, coordinates > 0).

     // Map clip bounds to shader space to ensure the device is large enough

     // to handle fake clamping.

     SkMatrix finalMatrix = fState.get()->fCanvasTransform;

     finalMatrix.preConcat(fState.get()->fShaderTransform);

     SkRect deviceBounds;

     deviceBounds.set(fState.get()->fBBox);

     if (!inverseTransformBBox(finalMatrix, &deviceBounds)) {

         return;

     }

     const SkBitmap* image = &fState.get()->fImage;

     SkRect bitmapBounds;

     image->getBounds(&bitmapBounds);

     // For tiling modes, the bounds should be extended to include the bitmap,

     // otherwise the bitmap gets clipped out and the shader is empty and awful.

     // For clamp modes, we're only interested in the clip region, whether

     // or not the main bitmap is in it.

     SkShader::TileMode tileModes[2];

     tileModes[0] = fState.get()->fImageTileModes[0];

     tileModes[1] = fState.get()->fImageTileModes[1];

     if (tileModes[0] != SkShader::kClamp_TileMode ||

             tileModes[1] != SkShader::kClamp_TileMode) {

         deviceBounds.join(bitmapBounds);

     }

     SkMatrix unflip;

     unflip.setTranslate(0, SkScalarRoundToScalar(deviceBounds.height()));

     unflip.preScale(SK_Scalar1, -SK_Scalar1);

     SkISize size = SkISize::Make(SkScalarRoundToInt(deviceBounds.width()),

                                  SkScalarRoundToInt(deviceBounds.height()));

     // TODO(edisonn): should we pass here the DCT encoder of the destination device?

     // TODO(edisonn): NYI Perspective, use SkPDFDeviceFlattener.

     SkPDFDevice pattern(size, size, unflip);

     SkCanvas canvas(&pattern);

     SkRect patternBBox;

     image->getBounds(&patternBBox);

     // Translate the canvas so that the bitmap origin is at (0, 0).

     canvas.translate(-deviceBounds.left(), -deviceBounds.top());

     patternBBox.offset(-deviceBounds.left(), -deviceBounds.top());

     // Undo the translation in the final matrix

     finalMatrix.preTranslate(deviceBounds.left(), deviceBounds.top());

     // If the bitmap is out of bounds (i.e. clamp mode where we only see the

     // stretched sides), canvas will clip this out and the extraneous data

     // won't be saved to the PDF.

     canvas.drawBitmap(*image, 0, 0);

     SkScalar width = SkIntToScalar(image->width());

     SkScalar height = SkIntToScalar(image->height());

     // Tiling is implied.  First we handle mirroring.

     if (tileModes[0] == SkShader::kMirror_TileMode) {

         SkMatrix xMirror;

         xMirror.setScale(-1, 1);

         xMirror.postTranslate(2 * width, 0);

         canvas.drawBitmapMatrix(*image, xMirror);

         patternBBox.fRight += width;

     }

     if (tileModes[1] == SkShader::kMirror_TileMode) {

         SkMatrix yMirror;

         yMirror.setScale(SK_Scalar1, -SK_Scalar1);

         yMirror.postTranslate(0, 2 * height);

         canvas.drawBitmapMatrix(*image, yMirror);

         patternBBox.fBottom += height;

     }

     if (tileModes[0] == SkShader::kMirror_TileMode &&

             tileModes[1] == SkShader::kMirror_TileMode) {

         SkMatrix mirror;

         mirror.setScale(-1, -1);

         mirror.postTranslate(2 * width, 2 * height);

         canvas.drawBitmapMatrix(*image, mirror);

     }

     // Then handle Clamping, which requires expanding the pattern canvas to

     // cover the entire surfaceBBox.

     // If both x and y are in clamp mode, we start by filling in the corners.

     // (Which are just a rectangles of the corner colors.)

     if (tileModes[0] == SkShader::kClamp_TileMode &&

             tileModes[1] == SkShader::kClamp_TileMode) {

         SkPaint paint;

         SkRect rect;

         rect = SkRect::MakeLTRB(deviceBounds.left(), deviceBounds.top(), 0, 0);

         if (!rect.isEmpty()) {

             paint.setColor(image->getColor(0, 0));

             canvas.drawRect(rect, paint);

         }

         rect = SkRect::MakeLTRB(width, deviceBounds.top(),

                                 deviceBounds.right(), 0);

         if (!rect.isEmpty()) {

             paint.setColor(image->getColor(image->width() - 1, 0));

             canvas.drawRect(rect, paint);

         }

         rect = SkRect::MakeLTRB(width, height,

                                 deviceBounds.right(), deviceBounds.bottom());

         if (!rect.isEmpty()) {

             paint.setColor(image->getColor(image->width() - 1,

                                            image->height() - 1));

             canvas.drawRect(rect, paint);

         }

         rect = SkRect::MakeLTRB(deviceBounds.left(), height,

                                 0, deviceBounds.bottom());

         if (!rect.isEmpty()) {

             paint.setColor(image->getColor(0, image->height() - 1));

             canvas.drawRect(rect, paint);

         }

     }

     // Then expand the left, right, top, then bottom.

     if (tileModes[0] == SkShader::kClamp_TileMode) {

         SkIRect subset = SkIRect::MakeXYWH(0, 0, 1, image->height());

         if (deviceBounds.left() < 0) {

             SkBitmap left;

             SkAssertResult(image->extractSubset(&left, subset));

             SkMatrix leftMatrix;

             leftMatrix.setScale(-deviceBounds.left(), 1);

             leftMatrix.postTranslate(deviceBounds.left(), 0);

             canvas.drawBitmapMatrix(left, leftMatrix);

             if (tileModes[1] == SkShader::kMirror_TileMode) {

                 leftMatrix.postScale(SK_Scalar1, -SK_Scalar1);

                 leftMatrix.postTranslate(0, 2 * height);

                 canvas.drawBitmapMatrix(left, leftMatrix);

             }

             patternBBox.fLeft = 0;

         }

         if (deviceBounds.right() > width) {

             SkBitmap right;

             subset.offset(image->width() - 1, 0);

             SkAssertResult(image->extractSubset(&right, subset));

             SkMatrix rightMatrix;

             rightMatrix.setScale(deviceBounds.right() - width, 1);

             rightMatrix.postTranslate(width, 0);

             canvas.drawBitmapMatrix(right, rightMatrix);

             if (tileModes[1] == SkShader::kMirror_TileMode) {

                 rightMatrix.postScale(SK_Scalar1, -SK_Scalar1);

                 rightMatrix.postTranslate(0, 2 * height);

                 canvas.drawBitmapMatrix(right, rightMatrix);

             }

             patternBBox.fRight = deviceBounds.width();

         }

     }

     if (tileModes[1] == SkShader::kClamp_TileMode) {

         SkIRect subset = SkIRect::MakeXYWH(0, 0, image->width(), 1);

         if (deviceBounds.top() < 0) {

             SkBitmap top;

             SkAssertResult(image->extractSubset(&top, subset));

             SkMatrix topMatrix;

             topMatrix.setScale(SK_Scalar1, -deviceBounds.top());

             topMatrix.postTranslate(0, deviceBounds.top());

             canvas.drawBitmapMatrix(top, topMatrix);

             if (tileModes[0] == SkShader::kMirror_TileMode) {

                 topMatrix.postScale(-1, 1);

                 topMatrix.postTranslate(2 * width, 0);

                 canvas.drawBitmapMatrix(top, topMatrix);

             }

             patternBBox.fTop = 0;

         }

         if (deviceBounds.bottom() > height) {

             SkBitmap bottom;

             subset.offset(0, image->height() - 1);

             SkAssertResult(image->extractSubset(&bottom, subset));

             SkMatrix bottomMatrix;

             bottomMatrix.setScale(SK_Scalar1, deviceBounds.bottom() - height);

             bottomMatrix.postTranslate(0, height);

             canvas.drawBitmapMatrix(bottom, bottomMatrix);

             if (tileModes[0] == SkShader::kMirror_TileMode) {

                 bottomMatrix.postScale(-1, 1);

                 bottomMatrix.postTranslate(2 * width, 0);

                 canvas.drawBitmapMatrix(bottom, bottomMatrix);

             }

             patternBBox.fBottom = deviceBounds.height();

         }

     }

     // Put the canvas into the pattern stream (fContent).

     SkAutoTUnref<SkStream> content(pattern.content());

     setData(content.get());

     SkPDFResourceDict* resourceDict = pattern.getResourceDict();

     resourceDict->getReferencedResources(fResources, &fResources, false);

     populate_tiling_pattern_dict(this, patternBBox,

                                  pattern.getResourceDict(), finalMatrix);

     fState.get()->fImage.unlockPixels();

 }

 SkPDFStream* SkPDFFunctionShader::makePSFunction(const SkString& psCode,

                                                  SkPDFArray* domain) {

     SkAutoDataUnref funcData(SkData::NewWithCopy(psCode.c_str(),

                                                  psCode.size()));

     SkPDFStream* result = new SkPDFStream(funcData.get());

     result->insertInt("FunctionType", 4);

     result->insert("Domain", domain);

     result->insert("Range", RangeObject());

     return result;

 }

 SkPDFShader::ShaderCanonicalEntry::ShaderCanonicalEntry(SkPDFObject* pdfShader,

                                                         const State* state)

     : fPDFShader(pdfShader),

       fState(state) {

 }

 bool SkPDFShader::ShaderCanonicalEntry::operator==(

         const ShaderCanonicalEntry& b) const {

     return fPDFShader == b.fPDFShader ||

            (fState != NULL && b.fState != NULL && *fState == *b.fState);

 }

 bool SkPDFShader::State::operator==(const SkPDFShader::State& b) const {

     if (fType != b.fType ||

             fCanvasTransform != b.fCanvasTransform ||

             fShaderTransform != b.fShaderTransform ||

             fBBox != b.fBBox) {

         return false;

     }

     if (fType == SkShader::kNone_GradientType) {

         if (fPixelGeneration != b.fPixelGeneration ||

                 fPixelGeneration == 0 ||

                 fImageTileModes[0] != b.fImageTileModes[0] ||

                 fImageTileModes[1] != b.fImageTileModes[1]) {

             return false;

         }

     } else {

         if (fInfo.fColorCount != b.fInfo.fColorCount ||

                 memcmp(fInfo.fColors, b.fInfo.fColors,

                        sizeof(SkColor) * fInfo.fColorCount) != 0 ||

                 memcmp(fInfo.fColorOffsets, b.fInfo.fColorOffsets,

                        sizeof(SkScalar) * fInfo.fColorCount) != 0 ||

                 fInfo.fPoint[0] != b.fInfo.fPoint[0] ||

                 fInfo.fTileMode != b.fInfo.fTileMode) {

             return false;

         }

         switch (fType) {

             case SkShader::kLinear_GradientType:

                 if (fInfo.fPoint[1] != b.fInfo.fPoint[1]) {

                     return false;

                 }

                 break;

             case SkShader::kRadial_GradientType:

                 if (fInfo.fRadius[0] != b.fInfo.fRadius[0]) {

                     return false;

                 }

                 break;

             case SkShader::kRadial2_GradientType:

             case SkShader::kConical_GradientType:

                 if (fInfo.fPoint[1] != b.fInfo.fPoint[1] ||

                         fInfo.fRadius[0] != b.fInfo.fRadius[0] ||

                         fInfo.fRadius[1] != b.fInfo.fRadius[1]) {

                     return false;

                 }

                 break;

             case SkShader::kSweep_GradientType:

             case SkShader::kNone_GradientType:

             case SkShader::kColor_GradientType:

                 break;

         }

     }

     return true;

 }

 SkPDFShader::State::State(const SkShader& shader,

                           const SkMatrix& canvasTransform, const SkIRect& bbox)

         : fCanvasTransform(canvasTransform),

           fBBox(bbox),

           fPixelGeneration(0) {

     fInfo.fColorCount = 0;

     fInfo.fColors = NULL;

     fInfo.fColorOffsets = NULL;

     fShaderTransform = shader.getLocalMatrix();

     fImageTileModes[0] = fImageTileModes[1] = SkShader::kClamp_TileMode;

     fType = shader.asAGradient(&fInfo);

     if (fType == SkShader::kNone_GradientType) {

         SkShader::BitmapType bitmapType;

         SkMatrix matrix;

         bitmapType = shader.asABitmap(&fImage, &matrix, fImageTileModes);

         if (bitmapType != SkShader::kDefault_BitmapType) {

             fImage.reset();

             return;

         }

         SkASSERT(matrix.isIdentity());

         fPixelGeneration = fImage.getGenerationID();

     } else {

         AllocateGradientInfoStorage();

         shader.asAGradient(&fInfo);

     }

 }

 SkPDFShader::State::State(const SkPDFShader::State& other)

   : fType(other.fType),

     fCanvasTransform(other.fCanvasTransform),

     fShaderTransform(other.fShaderTransform),

     fBBox(other.fBBox)

 {

     // Only gradients supported for now, since that is all that is used.

     // If needed, image state copy constructor can be added here later.

     SkASSERT(fType != SkShader::kNone_GradientType);

     if (fType != SkShader::kNone_GradientType) {

         fInfo = other.fInfo;

         AllocateGradientInfoStorage();

         for (int i = 0; i < fInfo.fColorCount; i++) {

             fInfo.fColors[i] = other.fInfo.fColors[i];

             fInfo.fColorOffsets[i] = other.fInfo.fColorOffsets[i];

         }

     }

 }

 /**

  * Create a copy of this gradient state with alpha assigned to RGB luminousity.

  * Only valid for gradient states.

  */

 SkPDFShader::State* SkPDFShader::State::CreateAlphaToLuminosityState() const {

     SkASSERT(fType != SkShader::kNone_GradientType);

     SkPDFShader::State* newState = new SkPDFShader::State(*this);

     for (int i = 0; i < fInfo.fColorCount; i++) {

         SkAlpha alpha = SkColorGetA(fInfo.fColors[i]);

         newState->fInfo.fColors[i] = SkColorSetARGB(255, alpha, alpha, alpha);

     }

     return newState;

 }

 /**

  * Create a copy of this gradient state with alpha set to fully opaque

  * Only valid for gradient states.

  */

 SkPDFShader::State* SkPDFShader::State::CreateOpaqueState() const {

     SkASSERT(fType != SkShader::kNone_GradientType);

     SkPDFShader::State* newState = new SkPDFShader::State(*this);

     for (int i = 0; i < fInfo.fColorCount; i++) {

         newState->fInfo.fColors[i] = SkColorSetA(fInfo.fColors[i],

                                                  SK_AlphaOPAQUE);

     }

     return newState;

 }

 /**

  * Returns true if state is a gradient and the gradient has alpha.

  */

 bool SkPDFShader::State::GradientHasAlpha() const {

     if (fType == SkShader::kNone_GradientType) {

         return false;

     }

     for (int i = 0; i < fInfo.fColorCount; i++) {

         SkAlpha alpha = SkColorGetA(fInfo.fColors[i]);

         if (alpha != SK_AlphaOPAQUE) {

             return true;

         }

     }

     return false;

 }

 void SkPDFShader::State::AllocateGradientInfoStorage() {

     fColorData.set(sk_malloc_throw(

                fInfo.fColorCount * (sizeof(SkColor) + sizeof(SkScalar))));

     fInfo.fColors = reinterpret_cast<SkColor*>(fColorData.get());

     fInfo.fColorOffsets =

             reinterpret_cast<SkScalar*>(fInfo.fColors + fInfo.fColorCount);

 }