Separate Canvas JNI code from the implementation.

This introduces Canvas.h which is a pure virtual interface that
is intended to be used by both Skia and HWUI implementation. To help
stage this transition this CL only introduces the interface and Skia
implementation.  The interface is not intended to be final and will
undoubtedly go through iterations in both style and location as we
look to introduce the HWUI implementation.

BUG:15672762
Change-Id: Ibaccdddb87d3b9358f4f0c1d317ead5282d4ee16

1 files changed, 773 insertions, 0 deletions

diff --git a/core/jni/android/graphics/SkiaCanvas.cpp b/core/jni/android/graphics/SkiaCanvas.cpp
new file mode 100644
index 0000000..a4e0d28
--- /dev/null
+++ b/core/jni/android/graphics/SkiaCanvas.cpp
@@ -0,0 +1,773 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "jni.h"
+#include "Canvas.h"
+#include "GraphicsJNI.h"
+#include <android_runtime/AndroidRuntime.h>
+
+#include "SkCanvas.h"
+#include "SkClipStack.h"
+#include "SkDevice.h"
+#include "SkDeque.h"
+#include "SkDrawFilter.h"
+#include "SkGraphics.h"
+#include "SkPorterDuff.h"
+#include "SkShader.h"
+#include "SkTArray.h"
+#include "SkTemplates.h"
+
+#include <minikin/Layout.h>
+#include "MinikinSkia.h"
+#include "MinikinUtils.h"
+
+#include "TypefaceImpl.h"
+
+#include "unicode/ubidi.h"
+#include "unicode/ushape.h"
+
+#include <utils/Log.h>
+
+namespace android {
+
+// Holds an SkCanvas reference plus additional native data.
+class SkiaCanvas : public Canvas {
+public:
+    SkiaCanvas(SkBitmap* bitmap);
+
+    SkiaCanvas(SkCanvas* canvas) : mCanvas(canvas) {
+        SkASSERT(canvas);
+    }
+
+    virtual SkCanvas* getSkCanvas() {
+        return mCanvas.get();
+    }
+
+    virtual void setBitmap(SkBitmap* bitmap, bool copyState);
+
+    virtual bool isOpaque();
+    virtual int width();
+    virtual int height();
+
+    virtual int getSaveCount() const;
+    virtual int save(SkCanvas::SaveFlags flags);
+    virtual void restore();
+    virtual void restoreToCount(int saveCount);
+
+    virtual int saveLayer(float left, float top, float right, float bottom,
+                const SkPaint* paint, SkCanvas::SaveFlags flags);
+    virtual int saveLayerAlpha(float left, float top, float right, float bottom,
+            int alpha, SkCanvas::SaveFlags flags);
+
+    virtual void getMatrix(SkMatrix* outMatrix) const;
+    virtual void setMatrix(const SkMatrix& matrix);
+    virtual void concat(const SkMatrix& matrix);
+    virtual void rotate(float degrees);
+    virtual void scale(float sx, float sy);
+    virtual void skew(float sx, float sy);
+    virtual void translate(float dx, float dy);
+
+    virtual bool getClipBounds(SkRect* outRect) const;
+    virtual bool quickRejectRect(float left, float top, float right, float bottom) const;
+    virtual bool quickRejectPath(const SkPath& path) const;
+    virtual bool clipRect(float left, float top, float right, float bottom, SkRegion::Op op);
+    virtual bool clipPath(const SkPath* path, SkRegion::Op op);
+    virtual bool clipRegion(const SkRegion* region, SkRegion::Op op);
+
+    virtual void setDrawFilter(SkDrawFilter* drawFilter);
+
+    virtual void drawColor(int color, SkXfermode::Mode mode);
+    virtual void drawPaint(const SkPaint& paint);
+
+    virtual void drawPoint(float x, float y, const SkPaint& paint);
+    virtual void drawPoints(const float* points, int count, const SkPaint& paint);
+    virtual void drawLine(float startX, float startY, float stopX, float stopY,
+            const SkPaint& paint);
+    virtual void drawLines(const float* points, int count, const SkPaint& paint);
+    virtual void drawRect(float left, float top, float right, float bottom, const SkPaint& paint);
+    virtual void drawRoundRect(float left, float top, float right, float bottom,
+            float rx, float ry, const SkPaint& paint);
+    virtual void drawCircle(float x, float y, float radius, const SkPaint& paint);
+    virtual void drawOval(float left, float top, float right, float bottom, const SkPaint& paint);
+    virtual void drawArc(float left, float top, float right, float bottom,
+            float startAngle, float sweepAngle, bool useCenter, const SkPaint& paint);
+    virtual void drawPath(const SkPath& path, const SkPaint& paint);
+    virtual void drawVertices(SkCanvas::VertexMode vertexMode, int vertexCount,
+            const float* verts, const float* tex, const int* colors,
+            const uint16_t* indices, int indexCount, const SkPaint& paint);
+
+    virtual void drawBitmap(const SkBitmap& bitmap, float left, float top, const SkPaint* paint);
+    virtual void drawBitmap(const SkBitmap& bitmap, const SkMatrix& matrix, const SkPaint* paint);
+    virtual void drawBitmap(const SkBitmap& bitmap, float srcLeft, float srcTop,
+            float srcRight, float srcBottom, float dstLeft, float dstTop,
+            float dstRight, float dstBottom, const SkPaint* paint);
+    virtual void drawBitmapMesh(const SkBitmap& bitmap, int meshWidth, int meshHeight,
+            const float* vertices, const int* colors, const SkPaint* paint);
+
+    virtual void drawText(const uint16_t* text, int start, int count, int contextCount,
+            float x, float y, int bidiFlags, const SkPaint& paint, TypefaceImpl* typeface);
+    virtual void drawPosText(const uint16_t* text, const float* positions, int count,
+            int posCount, const SkPaint& paint);
+    virtual void drawTextOnPath(const uint16_t* glyphs, int count, const SkPath& path,
+            float hOffset, float vOffset, const SkPaint& paint);
+
+private:
+    struct SaveRec {
+        int                 saveCount;
+        SkCanvas::SaveFlags saveFlags;
+    };
+
+    void recordPartialSave(SkCanvas::SaveFlags flags);
+    void saveClipsForFrame(SkTArray<SkClipStack::Element>& clips, int frameSaveCount);
+    void applyClips(const SkTArray<SkClipStack::Element>& clips);
+
+    void drawPoints(const float* points, int count, const SkPaint& paint,
+                    SkCanvas::PointMode mode);
+    void drawTextDecorations(float x, float y, float length, const SkPaint& paint);
+
+    SkAutoTUnref<SkCanvas> mCanvas;
+    SkAutoTDelete<SkDeque> mSaveStack; // lazily allocated, tracks partial saves.
+};
+
+// Construct an SkCanvas from the bitmap.
+static SkCanvas* createCanvas(SkBitmap* bitmap) {
+    if (bitmap) {
+        return SkNEW_ARGS(SkCanvas, (*bitmap));
+    }
+
+    // Create an empty bitmap device to prevent callers from crashing
+    // if they attempt to draw into this canvas.
+    SkBitmap emptyBitmap;
+    return new SkCanvas(emptyBitmap);
+}
+
+Canvas* Canvas::create_canvas(SkBitmap* bitmap) {
+    return new SkiaCanvas(bitmap);
+}
+
+Canvas* Canvas::create_canvas(SkCanvas* skiaCanvas) {
+    return new SkiaCanvas(skiaCanvas);
+}
+
+SkiaCanvas::SkiaCanvas(SkBitmap* bitmap) {
+    mCanvas.reset(createCanvas(bitmap));
+}
+
+// ----------------------------------------------------------------------------
+// Canvas state operations: Replace Bitmap
+// ----------------------------------------------------------------------------
+
+class ClipCopier : public SkCanvas::ClipVisitor {
+public:
+    ClipCopier(SkCanvas* dstCanvas) : m_dstCanvas(dstCanvas) {}
+
+    virtual void clipRect(const SkRect& rect, SkRegion::Op op, bool antialias) {
+        m_dstCanvas->clipRect(rect, op, antialias);
+    }
+    virtual void clipRRect(const SkRRect& rrect, SkRegion::Op op, bool antialias) {
+        m_dstCanvas->clipRRect(rrect, op, antialias);
+    }
+    virtual void clipPath(const SkPath& path, SkRegion::Op op, bool antialias) {
+        m_dstCanvas->clipPath(path, op, antialias);
+    }
+
+private:
+    SkCanvas* m_dstCanvas;
+};
+
+void SkiaCanvas::setBitmap(SkBitmap* bitmap, bool copyState) {
+    SkCanvas* newCanvas = createCanvas(bitmap);
+    SkASSERT(newCanvas);
+
+    if (copyState) {
+        // Copy the canvas matrix & clip state.
+        newCanvas->setMatrix(mCanvas->getTotalMatrix());
+        if (NULL != mCanvas->getDevice() && NULL != newCanvas->getDevice()) {
+            ClipCopier copier(newCanvas);
+            mCanvas->replayClips(&copier);
+        }
+    }
+
+    // unrefs the existing canvas
+    mCanvas.reset(newCanvas);
+
+    // clean up the old save stack
+    mSaveStack.reset(NULL);
+}
+
+// ----------------------------------------------------------------------------
+// Canvas state operations
+// ----------------------------------------------------------------------------
+
+bool SkiaCanvas::isOpaque() {
+    return mCanvas->getDevice()->accessBitmap(false).isOpaque();
+}
+
+int SkiaCanvas::width() {
+    return mCanvas->getBaseLayerSize().width();
+}
+
+int SkiaCanvas::height() {
+    return mCanvas->getBaseLayerSize().height();
+}
+
+// ----------------------------------------------------------------------------
+// Canvas state operations: Save (layer)
+// ----------------------------------------------------------------------------
+
+int SkiaCanvas::getSaveCount() const {
+    return mCanvas->getSaveCount();
+}
+
+int SkiaCanvas::save(SkCanvas::SaveFlags flags) {
+    int count = mCanvas->save();
+    recordPartialSave(flags);
+    return count;
+}
+
+void SkiaCanvas::restore() {
+    const SaveRec* rec = (NULL == mSaveStack.get())
+            ? NULL
+            : static_cast<SaveRec*>(mSaveStack->back());
+    int currentSaveCount = mCanvas->getSaveCount() - 1;
+    SkASSERT(NULL == rec || currentSaveCount >= rec->saveCount);
+
+    if (NULL == rec || rec->saveCount != currentSaveCount) {
+        // Fast path - no record for this frame.
+        mCanvas->restore();
+        return;
+    }
+
+    bool preserveMatrix = !(rec->saveFlags & SkCanvas::kMatrix_SaveFlag);
+    bool preserveClip   = !(rec->saveFlags & SkCanvas::kClip_SaveFlag);
+
+    SkMatrix savedMatrix;
+    if (preserveMatrix) {
+        savedMatrix = mCanvas->getTotalMatrix();
+    }
+
+    SkTArray<SkClipStack::Element> savedClips;
+    if (preserveClip) {
+        saveClipsForFrame(savedClips, currentSaveCount);
+    }
+
+    mCanvas->restore();
+
+    if (preserveMatrix) {
+        mCanvas->setMatrix(savedMatrix);
+    }
+
+    if (preserveClip && !savedClips.empty()) {
+        applyClips(savedClips);
+    }
+
+    mSaveStack->pop_back();
+}
+
+void SkiaCanvas::restoreToCount(int restoreCount) {
+    while (mCanvas->getSaveCount() > restoreCount) {
+        this->restore();
+    }
+}
+
+int SkiaCanvas::saveLayer(float left, float top, float right, float bottom,
+            const SkPaint* paint, SkCanvas::SaveFlags flags) {
+    SkRect bounds = SkRect::MakeLTRB(left, top, right, bottom);
+    int count = mCanvas->saveLayer(&bounds, paint, flags | SkCanvas::kMatrixClip_SaveFlag);
+    recordPartialSave(flags);
+    return count;
+}
+
+int SkiaCanvas::saveLayerAlpha(float left, float top, float right, float bottom,
+        int alpha, SkCanvas::SaveFlags flags) {
+    SkRect bounds = SkRect::MakeLTRB(left, top, right, bottom);
+    int count = mCanvas->saveLayerAlpha(&bounds, alpha, flags | SkCanvas::kMatrixClip_SaveFlag);
+    recordPartialSave(flags);
+    return count;
+}
+
+// ----------------------------------------------------------------------------
+// functions to emulate legacy SaveFlags (i.e. independent matrix/clip flags)
+// ----------------------------------------------------------------------------
+
+void SkiaCanvas::recordPartialSave(SkCanvas::SaveFlags flags) {
+    // A partial save is a save operation which doesn't capture the full canvas state.
+    // (either kMatrix_SaveFlags or kClip_SaveFlag is missing).
+
+    // Mask-out non canvas state bits.
+    flags = static_cast<SkCanvas::SaveFlags>(flags & SkCanvas::kMatrixClip_SaveFlag);
+
+    if (SkCanvas::kMatrixClip_SaveFlag == flags) {
+        // not a partial save.
+        return;
+    }
+
+    if (NULL == mSaveStack.get()) {
+        mSaveStack.reset(SkNEW_ARGS(SkDeque, (sizeof(struct SaveRec), 8)));
+    }
+
+    SaveRec* rec = static_cast<SaveRec*>(mSaveStack->push_back());
+    // Store the save counter in the SkClipStack domain.
+    // (0-based, equal to the number of save ops on the stack).
+    rec->saveCount = mCanvas->getSaveCount() - 1;
+    rec->saveFlags = flags;
+}
+
+void SkiaCanvas::saveClipsForFrame(SkTArray<SkClipStack::Element>& clips, int frameSaveCount) {
+    SkClipStack::Iter clipIterator(*mCanvas->getClipStack(),
+                                   SkClipStack::Iter::kTop_IterStart);
+    while (const SkClipStack::Element* elem = clipIterator.next()) {
+        if (elem->getSaveCount() < frameSaveCount) {
+            // done with the current frame.
+            break;
+        }
+        SkASSERT(elem->getSaveCount() == frameSaveCount);
+        clips.push_back(*elem);
+    }
+}
+
+void SkiaCanvas::applyClips(const SkTArray<SkClipStack::Element>& clips) {
+    ClipCopier clipCopier(mCanvas);
+
+    // The clip stack stores clips in device space.
+    SkMatrix origMatrix = mCanvas->getTotalMatrix();
+    mCanvas->resetMatrix();
+
+    // We pushed the clips in reverse order.
+    for (int i = clips.count() - 1; i >= 0; --i) {
+        clips[i].replay(&clipCopier);
+    }
+
+    mCanvas->setMatrix(origMatrix);
+}
+
+// ----------------------------------------------------------------------------
+// Canvas state operations: Matrix
+// ----------------------------------------------------------------------------
+
+void SkiaCanvas::getMatrix(SkMatrix* outMatrix) const {
+    *outMatrix = mCanvas->getTotalMatrix();
+}
+
+void SkiaCanvas::setMatrix(const SkMatrix& matrix) {
+    mCanvas->setMatrix(matrix);
+}
+
+void SkiaCanvas::concat(const SkMatrix& matrix) {
+    mCanvas->concat(matrix);
+}
+
+void SkiaCanvas::rotate(float degrees) {
+    mCanvas->rotate(degrees);
+}
+
+void SkiaCanvas::scale(float sx, float sy) {
+    mCanvas->scale(sx, sy);
+}
+
+void SkiaCanvas::skew(float sx, float sy) {
+    mCanvas->skew(sx, sy);
+}
+
+void SkiaCanvas::translate(float dx, float dy) {
+    mCanvas->translate(dx, dy);
+}
+
+// ----------------------------------------------------------------------------
+// Canvas state operations: Clips
+// ----------------------------------------------------------------------------
+
+// This function is a mirror of SkCanvas::getClipBounds except that it does
+// not outset the edge of the clip to account for anti-aliasing. There is
+// a skia bug to investigate pushing this logic into back into skia.
+// (see https://code.google.com/p/skia/issues/detail?id=1303)
+bool SkiaCanvas::getClipBounds(SkRect* outRect) const {
+    SkIRect ibounds;
+    if (!mCanvas->getClipDeviceBounds(&ibounds)) {
+        return false;
+    }
+
+    SkMatrix inverse;
+    // if we can't invert the CTM, we can't return local clip bounds
+    if (!mCanvas->getTotalMatrix().invert(&inverse)) {
+        if (outRect) {
+            outRect->setEmpty();
+        }
+        return false;
+    }
+
+    if (NULL != outRect) {
+        SkRect r = SkRect::Make(ibounds);
+        inverse.mapRect(outRect, r);
+    }
+    return true;
+}
+
+bool SkiaCanvas::quickRejectRect(float left, float top, float right, float bottom) const {
+    SkRect bounds = SkRect::MakeLTRB(left, top, right, bottom);
+    return mCanvas->quickReject(bounds);
+}
+
+bool SkiaCanvas::quickRejectPath(const SkPath& path) const {
+    return mCanvas->quickReject(path);
+}
+
+bool SkiaCanvas::clipRect(float left, float top, float right, float bottom, SkRegion::Op op) {
+    SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
+    mCanvas->clipRect(rect, op);
+    return mCanvas->isClipEmpty();
+}
+
+bool SkiaCanvas::clipPath(const SkPath* path, SkRegion::Op op) {
+    mCanvas->clipPath(*path, op);
+    return mCanvas->isClipEmpty();
+}
+
+bool SkiaCanvas::clipRegion(const SkRegion* region, SkRegion::Op op) {
+    SkPath rgnPath;
+    if (region->getBoundaryPath(&rgnPath)) {
+        // The region is specified in device space.
+        SkMatrix savedMatrix = mCanvas->getTotalMatrix();
+        mCanvas->resetMatrix();
+        mCanvas->clipPath(rgnPath, op);
+        mCanvas->setMatrix(savedMatrix);
+    } else {
+        mCanvas->clipRect(SkRect::MakeEmpty(), op);
+    }
+    return mCanvas->isClipEmpty();
+}
+
+// ----------------------------------------------------------------------------
+// Canvas state operations: Filters
+// ----------------------------------------------------------------------------
+
+void SkiaCanvas::setDrawFilter(SkDrawFilter* drawFilter) {
+    mCanvas->setDrawFilter(drawFilter);
+}
+
+// ----------------------------------------------------------------------------
+// Canvas draw operations
+// ----------------------------------------------------------------------------
+
+void SkiaCanvas::drawColor(int color, SkXfermode::Mode mode) {
+    mCanvas->drawColor(color, mode);
+}
+
+void SkiaCanvas::drawPaint(const SkPaint& paint) {
+    mCanvas->drawPaint(paint);
+}
+
+// ----------------------------------------------------------------------------
+// Canvas draw operations: Geometry
+// ----------------------------------------------------------------------------
+
+void SkiaCanvas::drawPoints(const float* points, int count, const SkPaint& paint,
+                            SkCanvas::PointMode mode) {
+    // convert the floats into SkPoints
+    count >>= 1;    // now it is the number of points
+    SkAutoSTMalloc<32, SkPoint> storage(count);
+    SkPoint* pts = storage.get();
+    for (int i = 0; i < count; i++) {
+        pts[i].set(points[0], points[1]);
+        points += 2;
+    }
+    mCanvas->drawPoints(mode, count, pts, paint);
+}
+
+
+void SkiaCanvas::drawPoint(float x, float y, const SkPaint& paint) {
+    mCanvas->drawPoint(x, y, paint);
+}
+
+void SkiaCanvas::drawPoints(const float* points, int count, const SkPaint& paint) {
+    this->drawPoints(points, count, paint, SkCanvas::kPoints_PointMode);
+}
+
+void SkiaCanvas::drawLine(float startX, float startY, float stopX, float stopY,
+                          const SkPaint& paint) {
+    mCanvas->drawLine(startX, startY, stopX, stopY, paint);
+}
+
+void SkiaCanvas::drawLines(const float* points, int count, const SkPaint& paint) {
+    this->drawPoints(points, count, paint, SkCanvas::kLines_PointMode);
+}
+
+void SkiaCanvas::drawRect(float left, float top, float right, float bottom,
+        const SkPaint& paint) {
+    mCanvas->drawRectCoords(left, top, right, bottom, paint);
+
+}
+
+void SkiaCanvas::drawRoundRect(float left, float top, float right, float bottom,
+        float rx, float ry, const SkPaint& paint) {
+    SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
+    mCanvas->drawRoundRect(rect, rx, ry, paint);
+}
+
+void SkiaCanvas::drawCircle(float x, float y, float radius, const SkPaint& paint) {
+    mCanvas->drawCircle(x, y, radius, paint);
+}
+
+void SkiaCanvas::drawOval(float left, float top, float right, float bottom, const SkPaint& paint) {
+    SkRect oval = SkRect::MakeLTRB(left, top, right, bottom);
+    mCanvas->drawOval(oval, paint);
+}
+
+void SkiaCanvas::drawArc(float left, float top, float right, float bottom,
+        float startAngle, float sweepAngle, bool useCenter, const SkPaint& paint) {
+    SkRect arc = SkRect::MakeLTRB(left, top, right, bottom);
+    mCanvas->drawArc(arc, startAngle, sweepAngle, useCenter, paint);
+}
+
+void SkiaCanvas::drawPath(const SkPath& path, const SkPaint& paint) {
+    mCanvas->drawPath(path, paint);
+}
+
+void SkiaCanvas::drawVertices(SkCanvas::VertexMode vertexMode, int vertexCount,
+                              const float* verts, const float* texs, const int* colors,
+                              const uint16_t* indices, int indexCount, const SkPaint& paint) {
+#ifndef SK_SCALAR_IS_FLOAT
+    SkDEBUGFAIL("SkScalar must be a float for these conversions to be valid");
+#endif
+    const int ptCount = vertexCount >> 1;
+    mCanvas->drawVertices(vertexMode, ptCount, (SkPoint*)verts, (SkPoint*)texs,
+                          (SkColor*)colors, NULL, indices, indexCount, paint);
+}
+
+// ----------------------------------------------------------------------------
+// Canvas draw operations: Bitmaps
+// ----------------------------------------------------------------------------
+
+void SkiaCanvas::drawBitmap(const SkBitmap& bitmap, float left, float top, const SkPaint* paint) {
+    mCanvas->drawBitmap(bitmap, left, top, paint);
+}
+
+void SkiaCanvas::drawBitmap(const SkBitmap& bitmap, const SkMatrix& matrix, const SkPaint* paint) {
+    mCanvas->drawBitmapMatrix(bitmap, matrix, paint);
+}
+
+void SkiaCanvas::drawBitmap(const SkBitmap& bitmap, float srcLeft, float srcTop,
+                            float srcRight, float srcBottom, float dstLeft, float dstTop,
+                            float dstRight, float dstBottom, const SkPaint* paint) {
+    SkRect srcRect = SkRect::MakeLTRB(srcLeft, srcTop, srcRight, srcBottom);
+    SkRect dstRect = SkRect::MakeLTRB(dstLeft, dstTop, dstRight, dstBottom);
+    mCanvas->drawBitmapRectToRect(bitmap, &srcRect, dstRect, paint);
+}
+
+void SkiaCanvas::drawBitmapMesh(const SkBitmap& bitmap, int meshWidth, int meshHeight,
+        const float* vertices, const int* colors, const SkPaint* paint) {
+
+    const int ptCount = (meshWidth + 1) * (meshHeight + 1);
+    const int indexCount = meshWidth * meshHeight * 6;
+
+    /*  Our temp storage holds 2 or 3 arrays.
+        texture points [ptCount * sizeof(SkPoint)]
+        optionally vertex points [ptCount * sizeof(SkPoint)] if we need a
+            copy to convert from float to fixed
+        indices [ptCount * sizeof(uint16_t)]
+    */
+    ssize_t storageSize = ptCount * sizeof(SkPoint); // texs[]
+    storageSize += indexCount * sizeof(uint16_t);  // indices[]
+
+
+#ifndef SK_SCALAR_IS_FLOAT
+    SkDEBUGFAIL("SkScalar must be a float for these conversions to be valid");
+#endif
+    SkAutoMalloc storage(storageSize);
+    SkPoint* texs = (SkPoint*)storage.get();
+    uint16_t* indices = (uint16_t*)(texs + ptCount);
+
+    // cons up texture coordinates and indices
+    {
+        const SkScalar w = SkIntToScalar(bitmap.width());
+        const SkScalar h = SkIntToScalar(bitmap.height());
+        const SkScalar dx = w / meshWidth;
+        const SkScalar dy = h / meshHeight;
+
+        SkPoint* texsPtr = texs;
+        SkScalar y = 0;
+        for (int i = 0; i <= meshHeight; i++) {
+            if (i == meshHeight) {
+                y = h;  // to ensure numerically we hit h exactly
+            }
+            SkScalar x = 0;
+            for (int j = 0; j < meshWidth; j++) {
+                texsPtr->set(x, y);
+                texsPtr += 1;
+                x += dx;
+            }
+            texsPtr->set(w, y);
+            texsPtr += 1;
+            y += dy;
+        }
+        SkASSERT(texsPtr - texs == ptCount);
+    }
+
+    // cons up indices
+    {
+        uint16_t* indexPtr = indices;
+        int index = 0;
+        for (int i = 0; i < meshHeight; i++) {
+            for (int j = 0; j < meshWidth; j++) {
+                // lower-left triangle
+                *indexPtr++ = index;
+                *indexPtr++ = index + meshWidth + 1;
+                *indexPtr++ = index + meshWidth + 2;
+                // upper-right triangle
+                *indexPtr++ = index;
+                *indexPtr++ = index + meshWidth + 2;
+                *indexPtr++ = index + 1;
+                // bump to the next cell
+                index += 1;
+            }
+            // bump to the next row
+            index += 1;
+        }
+        SkASSERT(indexPtr - indices == indexCount);
+        SkASSERT((char*)indexPtr - (char*)storage.get() == storageSize);
+    }
+
+    // double-check that we have legal indices
+#ifdef SK_DEBUG
+    {
+        for (int i = 0; i < indexCount; i++) {
+            SkASSERT((unsigned)indices[i] < (unsigned)ptCount);
+        }
+    }
+#endif
+
+    // cons-up a shader for the bitmap
+    SkPaint tmpPaint;
+    if (paint) {
+        tmpPaint = *paint;
+    }
+    SkShader* shader = SkShader::CreateBitmapShader(bitmap,
+                                                    SkShader::kClamp_TileMode,
+                                                    SkShader::kClamp_TileMode);
+    SkSafeUnref(tmpPaint.setShader(shader));
+
+    mCanvas->drawVertices(SkCanvas::kTriangles_VertexMode, ptCount, (SkPoint*)vertices,
+                         texs, (const SkColor*)colors, NULL, indices,
+                         indexCount, tmpPaint);
+}
+
+// ----------------------------------------------------------------------------
+// Canvas draw operations: Text
+// ----------------------------------------------------------------------------
+
+class DrawTextFunctor {
+public:
+    DrawTextFunctor(const Layout& layout, SkCanvas* canvas, float x, float y, SkPaint* paint,
+                uint16_t* glyphs, SkPoint* pos)
+            : layout(layout), canvas(canvas), x(x), y(y), paint(paint), glyphs(glyphs),
+                pos(pos) { }
+
+    void operator()(size_t start, size_t end) {
+        for (size_t i = start; i < end; i++) {
+            glyphs[i] = layout.getGlyphId(i);
+            pos[i].fX = x + layout.getX(i);
+            pos[i].fY = y + layout.getY(i);
+        }
+        canvas->drawPosText(glyphs + start, (end - start) << 1, pos + start, *paint);
+    }
+private:
+    const Layout& layout;
+    SkCanvas* canvas;
+    float x;
+    float y;
+    SkPaint* paint;
+    uint16_t* glyphs;
+    SkPoint* pos;
+};
+
+void SkiaCanvas::drawText(const uint16_t* text, int start, int count, int contextCount,
+        float x, float y, int bidiFlags, const SkPaint& paint, TypefaceImpl* typeface) {
+    Layout layout;
+    std::string css = MinikinUtils::setLayoutProperties(&layout, &paint, bidiFlags, typeface);
+    layout.doLayout(text, start, count, contextCount, css);
+
+    size_t nGlyphs = layout.nGlyphs();
+    uint16_t* glyphs = new uint16_t[nGlyphs];
+    SkPoint* pos = new SkPoint[nGlyphs];
+
+    SkPaint paintCopy(paint);
+    x += MinikinUtils::xOffsetForTextAlign(&paintCopy, layout);
+    paintCopy.setTextAlign(SkPaint::kLeft_Align);
+    paintCopy.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
+
+    DrawTextFunctor f(layout, mCanvas, x, y, &paintCopy, glyphs, pos);
+    MinikinUtils::forFontRun(layout, &paintCopy, f);
+    drawTextDecorations(x, y, layout.getAdvance(), paintCopy);
+
+    delete[] glyphs;
+    delete[] pos;
+}
+
+// Same values used by Skia
+#define kStdStrikeThru_Offset   (-6.0f / 21.0f)
+#define kStdUnderline_Offset    (1.0f / 9.0f)
+#define kStdUnderline_Thickness (1.0f / 18.0f)
+
+void SkiaCanvas::drawTextDecorations(float x, float y, float length, const SkPaint& paint) {
+    uint32_t flags;
+    SkDrawFilter* drawFilter = mCanvas->getDrawFilter();
+    if (drawFilter) {
+        SkPaint paintCopy(paint);
+        drawFilter->filter(&paintCopy, SkDrawFilter::kText_Type);
+        flags = paintCopy.getFlags();
+    } else {
+        flags = paint.getFlags();
+    }
+    if (flags & (SkPaint::kUnderlineText_Flag | SkPaint::kStrikeThruText_Flag)) {
+        SkScalar left = x;
+        SkScalar right = x + length;
+        float textSize = paint.getTextSize();
+        float strokeWidth = fmax(textSize * kStdUnderline_Thickness, 1.0f);
+        if (flags & SkPaint::kUnderlineText_Flag) {
+            SkScalar top = y + textSize * kStdUnderline_Offset - 0.5f * strokeWidth;
+            SkScalar bottom = y + textSize * kStdUnderline_Offset + 0.5f * strokeWidth;
+            mCanvas->drawRectCoords(left, top, right, bottom, paint);
+        }
+        if (flags & SkPaint::kStrikeThruText_Flag) {
+            SkScalar top = y + textSize * kStdStrikeThru_Offset - 0.5f * strokeWidth;
+            SkScalar bottom = y + textSize * kStdStrikeThru_Offset + 0.5f * strokeWidth;
+            mCanvas->drawRectCoords(left, top, right, bottom, paint);
+        }
+    }
+}
+
+void SkiaCanvas::drawPosText(const uint16_t* text, const float* positions, int count, int posCount,
+        const SkPaint& paint) {
+    SkPoint* posPtr = posCount > 0 ? new SkPoint[posCount] : NULL;
+    int indx;
+    for (indx = 0; indx < posCount; indx++) {
+        posPtr[indx].fX = positions[indx << 1];
+        posPtr[indx].fY = positions[(indx << 1) + 1];
+    }
+
+    SkPaint paintCopy(paint);
+    paintCopy.setTextEncoding(SkPaint::kUTF16_TextEncoding);
+    mCanvas->drawPosText(text, count, posPtr, paintCopy);
+
+    delete[] posPtr;
+}
+
+void SkiaCanvas::drawTextOnPath(const uint16_t* glyphs, int count, const SkPath& path,
+        float hOffset, float vOffset, const SkPaint& paint) {
+    mCanvas->drawTextOnPathHV(glyphs, count, path, hOffset, vOffset, paint);
+}
+
+} // namespace android