diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/src/core/SkScalerContext.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/src/core/SkScalerContext.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,990 @@
+
+/*
+ * Copyright 2006 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#include "SkScalerContext.h"
+#include "SkColorPriv.h"
+#include "SkDescriptor.h"
+#include "SkDraw.h"
+#include "SkFontHost.h"
+#include "SkGlyph.h"
+#include "SkMaskFilter.h"
+#include "SkMaskGamma.h"
+#include "SkReadBuffer.h"
+#include "SkWriteBuffer.h"
+#include "SkPathEffect.h"
+#include "SkRasterizer.h"
+#include "SkRasterClip.h"
+#include "SkStroke.h"
+#include "SkThread.h"
+
+#ifdef SK_BUILD_FOR_ANDROID
+    #include "SkTypeface_android.h"
+#endif
+
+#define ComputeBWRowBytes(width)        (((unsigned)(width) + 7) >> 3)
+
+void SkGlyph::toMask(SkMask* mask) const {
+    SkASSERT(mask);
+
+    mask->fImage = (uint8_t*)fImage;
+    mask->fBounds.set(fLeft, fTop, fLeft + fWidth, fTop + fHeight);
+    mask->fRowBytes = this->rowBytes();
+    mask->fFormat = static_cast<SkMask::Format>(fMaskFormat);
+}
+
+size_t SkGlyph::computeImageSize() const {
+    const size_t size = this->rowBytes() * fHeight;
+
+    switch (fMaskFormat) {
+        case SkMask::k3D_Format:
+            return 3 * size;
+        default:
+            return size;
+    }
+}
+
+void SkGlyph::zeroMetrics() {
+    fAdvanceX = 0;
+    fAdvanceY = 0;
+    fWidth    = 0;
+    fHeight   = 0;
+    fTop      = 0;
+    fLeft     = 0;
+    fRsbDelta = 0;
+    fLsbDelta = 0;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+#ifdef SK_DEBUG
+    #define DUMP_RECx
+#endif
+
+static SkFlattenable* load_flattenable(const SkDescriptor* desc, uint32_t tag,
+                                       SkFlattenable::Type ft) {
+    SkFlattenable*  obj = NULL;
+    uint32_t        len;
+    const void*     data = desc->findEntry(tag, &len);
+
+    if (data) {
+        SkReadBuffer buffer(data, len);
+        obj = buffer.readFlattenable(ft);
+        SkASSERT(buffer.offset() == buffer.size());
+    }
+    return obj;
+}
+
+SkScalerContext::SkScalerContext(SkTypeface* typeface, const SkDescriptor* desc)
+    : fRec(*static_cast<const Rec*>(desc->findEntry(kRec_SkDescriptorTag, NULL)))
+
+    , fBaseGlyphCount(0)
+    , fTypeface(SkRef(typeface))
+    , fPathEffect(static_cast<SkPathEffect*>(load_flattenable(desc, kPathEffect_SkDescriptorTag,
+                                             SkFlattenable::kSkPathEffect_Type)))
+    , fMaskFilter(static_cast<SkMaskFilter*>(load_flattenable(desc, kMaskFilter_SkDescriptorTag,
+                                             SkFlattenable::kSkMaskFilter_Type)))
+    , fRasterizer(static_cast<SkRasterizer*>(load_flattenable(desc, kRasterizer_SkDescriptorTag,
+                                             SkFlattenable::kSkRasterizer_Type)))
+      // Initialize based on our settings. Subclasses can also force this.
+    , fGenerateImageFromPath(fRec.fFrameWidth > 0 || fPathEffect != NULL || fRasterizer != NULL)
+
+    , fNextContext(NULL)
+
+    , fPreBlend(fMaskFilter ? SkMaskGamma::PreBlend() : SkScalerContext::GetMaskPreBlend(fRec))
+    , fPreBlendForFilter(fMaskFilter ? SkScalerContext::GetMaskPreBlend(fRec)
+                                     : SkMaskGamma::PreBlend())
+{
+#ifdef DUMP_REC
+    desc->assertChecksum();
+    SkDebugf("SkScalerContext checksum %x count %d length %d\n",
+             desc->getChecksum(), desc->getCount(), desc->getLength());
+    SkDebugf(" textsize %g prescale %g preskew %g post [%g %g %g %g]\n",
+        rec->fTextSize, rec->fPreScaleX, rec->fPreSkewX, rec->fPost2x2[0][0],
+        rec->fPost2x2[0][1], rec->fPost2x2[1][0], rec->fPost2x2[1][1]);
+    SkDebugf("  frame %g miter %g hints %d framefill %d format %d join %d\n",
+        rec->fFrameWidth, rec->fMiterLimit, rec->fHints, rec->fFrameAndFill,
+        rec->fMaskFormat, rec->fStrokeJoin);
+    SkDebugf("  pathEffect %x maskFilter %x\n",
+             desc->findEntry(kPathEffect_SkDescriptorTag, NULL),
+        desc->findEntry(kMaskFilter_SkDescriptorTag, NULL));
+#endif
+#ifdef SK_BUILD_FOR_ANDROID
+    uint32_t len;
+    const void* data = desc->findEntry(kAndroidOpts_SkDescriptorTag, &len);
+    if (data) {
+        SkReadBuffer buffer(data, len);
+        fPaintOptionsAndroid.unflatten(buffer);
+        SkASSERT(buffer.offset() == buffer.size());
+    }
+#endif
+}
+
+SkScalerContext::~SkScalerContext() {
+    SkDELETE(fNextContext);
+
+    SkSafeUnref(fPathEffect);
+    SkSafeUnref(fMaskFilter);
+    SkSafeUnref(fRasterizer);
+}
+
+// Return the context associated with the next logical typeface, or NULL if
+// there are no more entries in the fallback chain.
+SkScalerContext* SkScalerContext::allocNextContext() const {
+#ifdef SK_BUILD_FOR_ANDROID
+    SkTypeface* newFace = SkAndroidNextLogicalTypeface(fRec.fFontID,
+                                                       fRec.fOrigFontID,
+                                                       fPaintOptionsAndroid);
+    if (0 == newFace) {
+        return NULL;
+    }
+
+    SkAutoTUnref<SkTypeface> aur(newFace);
+    uint32_t newFontID = newFace->uniqueID();
+
+    SkWriteBuffer androidBuffer;
+    fPaintOptionsAndroid.flatten(androidBuffer);
+
+    SkAutoDescriptor    ad(sizeof(fRec) + androidBuffer.bytesWritten()
+                           + SkDescriptor::ComputeOverhead(2));
+    SkDescriptor*       desc = ad.getDesc();
+
+    desc->init();
+    SkScalerContext::Rec* newRec =
+    (SkScalerContext::Rec*)desc->addEntry(kRec_SkDescriptorTag,
+                                          sizeof(fRec), &fRec);
+    androidBuffer.writeToMemory(desc->addEntry(kAndroidOpts_SkDescriptorTag,
+                                               androidBuffer.bytesWritten(), NULL));
+
+    newRec->fFontID = newFontID;
+    desc->computeChecksum();
+
+    return newFace->createScalerContext(desc);
+#else
+    return NULL;
+#endif
+}
+
+/*  Return the next context, creating it if its not already created, but return
+    NULL if the fonthost says there are no more fonts to fallback to.
+ */
+SkScalerContext* SkScalerContext::getNextContext() {
+    SkScalerContext* next = fNextContext;
+    // if next is null, then either it isn't cached yet, or we're at the
+    // end of our possible chain
+    if (NULL == next) {
+        next = this->allocNextContext();
+        if (NULL == next) {
+            return NULL;
+        }
+        // next's base is our base + our local count
+        next->setBaseGlyphCount(fBaseGlyphCount + this->getGlyphCount());
+        // cache the answer
+        fNextContext = next;
+    }
+    return next;
+}
+
+SkScalerContext* SkScalerContext::getGlyphContext(const SkGlyph& glyph) {
+    unsigned glyphID = glyph.getGlyphID();
+    SkScalerContext* ctx = this;
+    for (;;) {
+        unsigned count = ctx->getGlyphCount();
+        if (glyphID < count) {
+            break;
+        }
+        glyphID -= count;
+        ctx = ctx->getNextContext();
+        if (NULL == ctx) {
+//            SkDebugf("--- no context for glyph %x\n", glyph.getGlyphID());
+            // just return the original context (this)
+            return this;
+        }
+    }
+    return ctx;
+}
+
+SkScalerContext* SkScalerContext::getContextFromChar(SkUnichar uni,
+                                                     uint16_t* glyphID) {
+    SkScalerContext* ctx = this;
+    for (;;) {
+        const uint16_t glyph = ctx->generateCharToGlyph(uni);
+        if (glyph) {
+            if (NULL != glyphID) {
+                *glyphID = glyph;
+            }
+            break;  // found it
+        }
+        ctx = ctx->getNextContext();
+        if (NULL == ctx) {
+            return NULL;
+        }
+    }
+    return ctx;
+}
+
+#ifdef SK_BUILD_FOR_ANDROID
+SkFontID SkScalerContext::findTypefaceIdForChar(SkUnichar uni) {
+    SkScalerContext* ctx = this->getContextFromChar(uni, NULL);
+    if (NULL != ctx) {
+        return ctx->fRec.fFontID;
+    } else {
+        return 0;
+    }
+}
+
+/*  This loops through all available fallback contexts (if needed) until it
+    finds some context that can handle the unichar and return it.
+
+    As this is somewhat expensive operation, it should only be done on the first
+    char of a run.
+ */
+unsigned SkScalerContext::getBaseGlyphCount(SkUnichar uni) {
+    SkScalerContext* ctx = this->getContextFromChar(uni, NULL);
+    if (NULL != ctx) {
+        return ctx->fBaseGlyphCount;
+    } else {
+        SkDEBUGF(("--- no context for char %x\n", uni));
+        return this->fBaseGlyphCount;
+    }
+}
+#endif
+
+/*  This loops through all available fallback contexts (if needed) until it
+    finds some context that can handle the unichar. If all fail, returns 0
+ */
+uint16_t SkScalerContext::charToGlyphID(SkUnichar uni) {
+
+    uint16_t tempID;
+    SkScalerContext* ctx = this->getContextFromChar(uni, &tempID);
+    if (NULL == ctx) {
+        return 0; // no more contexts, return missing glyph
+    }
+    // add the ctx's base, making glyphID unique for chain of contexts
+    unsigned glyphID = tempID + ctx->fBaseGlyphCount;
+    // check for overflow of 16bits, since our glyphID cannot exceed that
+    if (glyphID > 0xFFFF) {
+        glyphID = 0;
+    }
+    return SkToU16(glyphID);
+}
+
+SkUnichar SkScalerContext::glyphIDToChar(uint16_t glyphID) {
+    SkScalerContext* ctx = this;
+    unsigned rangeEnd = 0;
+    do {
+        unsigned rangeStart = rangeEnd;
+
+        rangeEnd += ctx->getGlyphCount();
+        if (rangeStart <= glyphID && glyphID < rangeEnd) {
+            return ctx->generateGlyphToChar(glyphID - rangeStart);
+        }
+        ctx = ctx->getNextContext();
+    } while (NULL != ctx);
+    return 0;
+}
+
+void SkScalerContext::getAdvance(SkGlyph* glyph) {
+    // mark us as just having a valid advance
+    glyph->fMaskFormat = MASK_FORMAT_JUST_ADVANCE;
+    // we mark the format before making the call, in case the impl
+    // internally ends up calling its generateMetrics, which is OK
+    // albeit slower than strictly necessary
+    this->getGlyphContext(*glyph)->generateAdvance(glyph);
+}
+
+void SkScalerContext::getMetrics(SkGlyph* glyph) {
+    this->getGlyphContext(*glyph)->generateMetrics(glyph);
+
+    // for now we have separate cache entries for devkerning on and off
+    // in the future we might share caches, but make our measure/draw
+    // code make the distinction. Thus we zap the values if the caller
+    // has not asked for them.
+    if ((fRec.fFlags & SkScalerContext::kDevKernText_Flag) == 0) {
+        // no devkern, so zap the fields
+        glyph->fLsbDelta = glyph->fRsbDelta = 0;
+    }
+
+    // if either dimension is empty, zap the image bounds of the glyph
+    if (0 == glyph->fWidth || 0 == glyph->fHeight) {
+        glyph->fWidth   = 0;
+        glyph->fHeight  = 0;
+        glyph->fTop     = 0;
+        glyph->fLeft    = 0;
+        glyph->fMaskFormat = 0;
+        return;
+    }
+
+    if (fGenerateImageFromPath) {
+        SkPath      devPath, fillPath;
+        SkMatrix    fillToDevMatrix;
+
+        this->internalGetPath(*glyph, &fillPath, &devPath, &fillToDevMatrix);
+
+        if (fRasterizer) {
+            SkMask  mask;
+
+            if (fRasterizer->rasterize(fillPath, fillToDevMatrix, NULL,
+                                       fMaskFilter, &mask,
+                                       SkMask::kJustComputeBounds_CreateMode)) {
+                glyph->fLeft    = mask.fBounds.fLeft;
+                glyph->fTop     = mask.fBounds.fTop;
+                glyph->fWidth   = SkToU16(mask.fBounds.width());
+                glyph->fHeight  = SkToU16(mask.fBounds.height());
+            } else {
+                goto SK_ERROR;
+            }
+        } else {
+            // just use devPath
+            SkIRect ir;
+            devPath.getBounds().roundOut(&ir);
+
+            if (ir.isEmpty() || !ir.is16Bit()) {
+                goto SK_ERROR;
+            }
+            glyph->fLeft    = ir.fLeft;
+            glyph->fTop     = ir.fTop;
+            glyph->fWidth   = SkToU16(ir.width());
+            glyph->fHeight  = SkToU16(ir.height());
+
+            if (glyph->fWidth > 0) {
+                switch (fRec.fMaskFormat) {
+                case SkMask::kLCD16_Format:
+                case SkMask::kLCD32_Format:
+                    glyph->fWidth += 2;
+                    glyph->fLeft -= 1;
+                    break;
+                default:
+                    break;
+                }
+            }
+        }
+    }
+
+    if (SkMask::kARGB32_Format != glyph->fMaskFormat) {
+        glyph->fMaskFormat = fRec.fMaskFormat;
+    }
+
+    // If we are going to create the mask, then we cannot keep the color
+    if ((fGenerateImageFromPath || fMaskFilter) &&
+            SkMask::kARGB32_Format == glyph->fMaskFormat) {
+        glyph->fMaskFormat = SkMask::kA8_Format;
+    }
+
+    if (fMaskFilter) {
+        SkMask      src, dst;
+        SkMatrix    matrix;
+
+        glyph->toMask(&src);
+        fRec.getMatrixFrom2x2(&matrix);
+
+        src.fImage = NULL;  // only want the bounds from the filter
+        if (fMaskFilter->filterMask(&dst, src, matrix, NULL)) {
+            if (dst.fBounds.isEmpty() || !dst.fBounds.is16Bit()) {
+                goto SK_ERROR;
+            }
+            SkASSERT(dst.fImage == NULL);
+            glyph->fLeft    = dst.fBounds.fLeft;
+            glyph->fTop     = dst.fBounds.fTop;
+            glyph->fWidth   = SkToU16(dst.fBounds.width());
+            glyph->fHeight  = SkToU16(dst.fBounds.height());
+            glyph->fMaskFormat = dst.fFormat;
+        }
+    }
+    return;
+
+SK_ERROR:
+    // draw nothing 'cause we failed
+    glyph->fLeft    = 0;
+    glyph->fTop     = 0;
+    glyph->fWidth   = 0;
+    glyph->fHeight  = 0;
+    // put a valid value here, in case it was earlier set to
+    // MASK_FORMAT_JUST_ADVANCE
+    glyph->fMaskFormat = fRec.fMaskFormat;
+}
+
+#define SK_SHOW_TEXT_BLIT_COVERAGE 0
+
+static void applyLUTToA8Mask(const SkMask& mask, const uint8_t* lut) {
+    uint8_t* SK_RESTRICT dst = (uint8_t*)mask.fImage;
+    unsigned rowBytes = mask.fRowBytes;
+
+    for (int y = mask.fBounds.height() - 1; y >= 0; --y) {
+        for (int x = mask.fBounds.width() - 1; x >= 0; --x) {
+            dst[x] = lut[dst[x]];
+        }
+        dst += rowBytes;
+    }
+}
+
+template<bool APPLY_PREBLEND>
+static void pack4xHToLCD16(const SkBitmap& src, const SkMask& dst,
+                           const SkMaskGamma::PreBlend& maskPreBlend) {
+#define SAMPLES_PER_PIXEL 4
+#define LCD_PER_PIXEL 3
+    SkASSERT(kAlpha_8_SkColorType == src.colorType());
+    SkASSERT(SkMask::kLCD16_Format == dst.fFormat);
+
+    const int sample_width = src.width();
+    const int height = src.height();
+
+    uint16_t* dstP = (uint16_t*)dst.fImage;
+    size_t dstRB = dst.fRowBytes;
+    // An N tap FIR is defined by
+    // out[n] = coeff[0]*x[n] + coeff[1]*x[n-1] + ... + coeff[N]*x[n-N]
+    // or
+    // out[n] = sum(i, 0, N, coeff[i]*x[n-i])
+
+    // The strategy is to use one FIR (different coefficients) for each of r, g, and b.
+    // This means using every 4th FIR output value of each FIR and discarding the rest.
+    // The FIRs are aligned, and the coefficients reach 5 samples to each side of their 'center'.
+    // (For r and b this is technically incorrect, but the coeffs outside round to zero anyway.)
+
+    // These are in some fixed point repesentation.
+    // Adding up to more than one simulates ink spread.
+    // For implementation reasons, these should never add up to more than two.
+
+    // Coefficients determined by a gausian where 5 samples = 3 std deviations (0x110 'contrast').
+    // Calculated using tools/generate_fir_coeff.py
+    // With this one almost no fringing is ever seen, but it is imperceptibly blurry.
+    // The lcd smoothed text is almost imperceptibly different from gray,
+    // but is still sharper on small stems and small rounded corners than gray.
+    // This also seems to be about as wide as one can get and only have a three pixel kernel.
+    // TODO: caculate these at runtime so parameters can be adjusted (esp contrast).
+    static const unsigned int coefficients[LCD_PER_PIXEL][SAMPLES_PER_PIXEL*3] = {
+        //The red subpixel is centered inside the first sample (at 1/6 pixel), and is shifted.
+        { 0x03, 0x0b, 0x1c, 0x33,  0x40, 0x39, 0x24, 0x10,  0x05, 0x01, 0x00, 0x00, },
+        //The green subpixel is centered between two samples (at 1/2 pixel), so is symetric
+        { 0x00, 0x02, 0x08, 0x16,  0x2b, 0x3d, 0x3d, 0x2b,  0x16, 0x08, 0x02, 0x00, },
+        //The blue subpixel is centered inside the last sample (at 5/6 pixel), and is shifted.
+        { 0x00, 0x00, 0x01, 0x05,  0x10, 0x24, 0x39, 0x40,  0x33, 0x1c, 0x0b, 0x03, },
+    };
+
+    for (int y = 0; y < height; ++y) {
+        const uint8_t* srcP = src.getAddr8(0, y);
+
+        // TODO: this fir filter implementation is straight forward, but slow.
+        // It should be possible to make it much faster.
+        for (int sample_x = -4, pixel_x = 0; sample_x < sample_width + 4; sample_x += 4, ++pixel_x) {
+            int fir[LCD_PER_PIXEL] = { 0 };
+            for (int sample_index = SkMax32(0, sample_x - 4), coeff_index = sample_index - (sample_x - 4)
+                ; sample_index < SkMin32(sample_x + 8, sample_width)
+                ; ++sample_index, ++coeff_index)
+            {
+                int sample_value = srcP[sample_index];
+                for (int subpxl_index = 0; subpxl_index < LCD_PER_PIXEL; ++subpxl_index) {
+                    fir[subpxl_index] += coefficients[subpxl_index][coeff_index] * sample_value;
+                }
+            }
+            for (int subpxl_index = 0; subpxl_index < LCD_PER_PIXEL; ++subpxl_index) {
+                fir[subpxl_index] /= 0x100;
+                fir[subpxl_index] = SkMin32(fir[subpxl_index], 255);
+            }
+
+            U8CPU r = sk_apply_lut_if<APPLY_PREBLEND>(fir[0], maskPreBlend.fR);
+            U8CPU g = sk_apply_lut_if<APPLY_PREBLEND>(fir[1], maskPreBlend.fG);
+            U8CPU b = sk_apply_lut_if<APPLY_PREBLEND>(fir[2], maskPreBlend.fB);
+#if SK_SHOW_TEXT_BLIT_COVERAGE
+            r = SkMax32(r, 10); g = SkMax32(g, 10); b = SkMax32(b, 10);
+#endif
+            dstP[pixel_x] = SkPack888ToRGB16(r, g, b);
+        }
+        dstP = (uint16_t*)((char*)dstP + dstRB);
+    }
+}
+
+template<bool APPLY_PREBLEND>
+static void pack4xHToLCD32(const SkBitmap& src, const SkMask& dst,
+                           const SkMaskGamma::PreBlend& maskPreBlend) {
+    SkASSERT(kAlpha_8_SkColorType == src.colorType());
+    SkASSERT(SkMask::kLCD32_Format == dst.fFormat);
+
+    const int width = dst.fBounds.width();
+    const int height = dst.fBounds.height();
+    SkPMColor* dstP = (SkPMColor*)dst.fImage;
+    size_t dstRB = dst.fRowBytes;
+
+    for (int y = 0; y < height; ++y) {
+        const uint8_t* srcP = src.getAddr8(0, y);
+
+        // TODO: need to use fir filter here as well.
+        for (int x = 0; x < width; ++x) {
+            U8CPU r = sk_apply_lut_if<APPLY_PREBLEND>(*srcP++, maskPreBlend.fR);
+            U8CPU g = sk_apply_lut_if<APPLY_PREBLEND>(*srcP++, maskPreBlend.fG);
+            U8CPU b = sk_apply_lut_if<APPLY_PREBLEND>(*srcP++, maskPreBlend.fB);
+            dstP[x] = SkPackARGB32(0xFF, r, g, b);
+        }
+        dstP = (SkPMColor*)((char*)dstP + dstRB);
+    }
+}
+
+static inline int convert_8_to_1(unsigned byte) {
+    SkASSERT(byte <= 0xFF);
+    return byte >> 7;
+}
+
+static uint8_t pack_8_to_1(const uint8_t alpha[8]) {
+    unsigned bits = 0;
+    for (int i = 0; i < 8; ++i) {
+        bits <<= 1;
+        bits |= convert_8_to_1(alpha[i]);
+    }
+    return SkToU8(bits);
+}
+
+static void packA8ToA1(const SkMask& mask, const uint8_t* src, size_t srcRB) {
+    const int height = mask.fBounds.height();
+    const int width = mask.fBounds.width();
+    const int octs = width >> 3;
+    const int leftOverBits = width & 7;
+
+    uint8_t* dst = mask.fImage;
+    const int dstPad = mask.fRowBytes - SkAlign8(width)/8;
+    SkASSERT(dstPad >= 0);
+
+    const int srcPad = srcRB - width;
+    SkASSERT(srcPad >= 0);
+
+    for (int y = 0; y < height; ++y) {
+        for (int i = 0; i < octs; ++i) {
+            *dst++ = pack_8_to_1(src);
+            src += 8;
+        }
+        if (leftOverBits > 0) {
+            unsigned bits = 0;
+            int shift = 7;
+            for (int i = 0; i < leftOverBits; ++i, --shift) {
+                bits |= convert_8_to_1(*src++) << shift;
+            }
+            *dst++ = bits;
+        }
+        src += srcPad;
+        dst += dstPad;
+    }
+}
+
+static void generateMask(const SkMask& mask, const SkPath& path,
+                         const SkMaskGamma::PreBlend& maskPreBlend) {
+    SkPaint paint;
+
+    int srcW = mask.fBounds.width();
+    int srcH = mask.fBounds.height();
+    int dstW = srcW;
+    int dstH = srcH;
+    int dstRB = mask.fRowBytes;
+
+    SkMatrix matrix;
+    matrix.setTranslate(-SkIntToScalar(mask.fBounds.fLeft),
+                        -SkIntToScalar(mask.fBounds.fTop));
+
+    SkBitmap::Config config = SkBitmap::kA8_Config;
+    paint.setAntiAlias(SkMask::kBW_Format != mask.fFormat);
+    switch (mask.fFormat) {
+        case SkMask::kBW_Format:
+            dstRB = 0;  // signals we need a copy
+            break;
+        case SkMask::kA8_Format:
+            break;
+        case SkMask::kLCD16_Format:
+        case SkMask::kLCD32_Format:
+            // TODO: trigger off LCD orientation
+            dstW = 4*dstW - 8;
+            matrix.setTranslate(-SkIntToScalar(mask.fBounds.fLeft + 1),
+                                -SkIntToScalar(mask.fBounds.fTop));
+            matrix.postScale(SkIntToScalar(4), SK_Scalar1);
+            dstRB = 0;  // signals we need a copy
+            break;
+        default:
+            SkDEBUGFAIL("unexpected mask format");
+    }
+
+    SkRasterClip clip;
+    clip.setRect(SkIRect::MakeWH(dstW, dstH));
+
+    SkBitmap bm;
+    bm.setConfig(config, dstW, dstH, dstRB);
+
+    if (0 == dstRB) {
+        if (!bm.allocPixels()) {
+            // can't allocate offscreen, so empty the mask and return
+            sk_bzero(mask.fImage, mask.computeImageSize());
+            return;
+        }
+        bm.lockPixels();
+    } else {
+        bm.setPixels(mask.fImage);
+    }
+    sk_bzero(bm.getPixels(), bm.getSafeSize());
+
+    SkDraw  draw;
+    draw.fRC    = &clip;
+    draw.fClip  = &clip.bwRgn();
+    draw.fMatrix = &matrix;
+    draw.fBitmap = &bm;
+    draw.drawPath(path, paint);
+
+    switch (mask.fFormat) {
+        case SkMask::kBW_Format:
+            packA8ToA1(mask, bm.getAddr8(0, 0), bm.rowBytes());
+            break;
+        case SkMask::kA8_Format:
+            if (maskPreBlend.isApplicable()) {
+                applyLUTToA8Mask(mask, maskPreBlend.fG);
+            }
+            break;
+        case SkMask::kLCD16_Format:
+            if (maskPreBlend.isApplicable()) {
+                pack4xHToLCD16<true>(bm, mask, maskPreBlend);
+            } else {
+                pack4xHToLCD16<false>(bm, mask, maskPreBlend);
+            }
+            break;
+        case SkMask::kLCD32_Format:
+            if (maskPreBlend.isApplicable()) {
+                pack4xHToLCD32<true>(bm, mask, maskPreBlend);
+            } else {
+                pack4xHToLCD32<false>(bm, mask, maskPreBlend);
+            }
+            break;
+        default:
+            break;
+    }
+}
+
+static void extract_alpha(const SkMask& dst,
+                          const SkPMColor* srcRow, size_t srcRB) {
+    int width = dst.fBounds.width();
+    int height = dst.fBounds.height();
+    int dstRB = dst.fRowBytes;
+    uint8_t* dstRow = dst.fImage;
+
+    for (int y = 0; y < height; ++y) {
+        for (int x = 0; x < width; ++x) {
+            dstRow[x] = SkGetPackedA32(srcRow[x]);
+        }
+        // zero any padding on each row
+        for (int x = width; x < dstRB; ++x) {
+            dstRow[x] = 0;
+        }
+        dstRow += dstRB;
+        srcRow = (const SkPMColor*)((const char*)srcRow + srcRB);
+    }
+}
+
+void SkScalerContext::getImage(const SkGlyph& origGlyph) {
+    const SkGlyph*  glyph = &origGlyph;
+    SkGlyph         tmpGlyph;
+
+    // in case we need to call generateImage on a mask-format that is different
+    // (i.e. larger) than what our caller allocated by looking at origGlyph.
+    SkAutoMalloc tmpGlyphImageStorage;
+
+    // If we are going to draw-from-path, then we cannot generate color, since
+    // the path only makes a mask. This case should have been caught up in
+    // generateMetrics().
+    SkASSERT(!fGenerateImageFromPath ||
+             SkMask::kARGB32_Format != origGlyph.fMaskFormat);
+
+    if (fMaskFilter) {   // restore the prefilter bounds
+        tmpGlyph.init(origGlyph.fID);
+
+        // need the original bounds, sans our maskfilter
+        SkMaskFilter* mf = fMaskFilter;
+        fMaskFilter = NULL;             // temp disable
+        this->getMetrics(&tmpGlyph);
+        fMaskFilter = mf;               // restore
+
+        // we need the prefilter bounds to be <= filter bounds
+        SkASSERT(tmpGlyph.fWidth <= origGlyph.fWidth);
+        SkASSERT(tmpGlyph.fHeight <= origGlyph.fHeight);
+
+        if (tmpGlyph.fMaskFormat == origGlyph.fMaskFormat) {
+            tmpGlyph.fImage = origGlyph.fImage;
+        } else {
+            tmpGlyphImageStorage.reset(tmpGlyph.computeImageSize());
+            tmpGlyph.fImage = tmpGlyphImageStorage.get();
+        }
+        glyph = &tmpGlyph;
+    }
+
+    if (fGenerateImageFromPath) {
+        SkPath      devPath, fillPath;
+        SkMatrix    fillToDevMatrix;
+        SkMask      mask;
+
+        this->internalGetPath(*glyph, &fillPath, &devPath, &fillToDevMatrix);
+        glyph->toMask(&mask);
+
+        if (fRasterizer) {
+            mask.fFormat = SkMask::kA8_Format;
+            sk_bzero(glyph->fImage, mask.computeImageSize());
+
+            if (!fRasterizer->rasterize(fillPath, fillToDevMatrix, NULL,
+                                        fMaskFilter, &mask,
+                                        SkMask::kJustRenderImage_CreateMode)) {
+                return;
+            }
+            if (fPreBlend.isApplicable()) {
+                applyLUTToA8Mask(mask, fPreBlend.fG);
+            }
+        } else {
+            SkASSERT(SkMask::kARGB32_Format != mask.fFormat);
+            generateMask(mask, devPath, fPreBlend);
+        }
+    } else {
+        this->getGlyphContext(*glyph)->generateImage(*glyph);
+    }
+
+    if (fMaskFilter) {
+        SkMask      srcM, dstM;
+        SkMatrix    matrix;
+
+        // the src glyph image shouldn't be 3D
+        SkASSERT(SkMask::k3D_Format != glyph->fMaskFormat);
+
+        SkAutoSMalloc<32*32> a8storage;
+        glyph->toMask(&srcM);
+        if (SkMask::kARGB32_Format == srcM.fFormat) {
+            // now we need to extract the alpha-channel from the glyph's image
+            // and copy it into a temp buffer, and then point srcM at that temp.
+            srcM.fFormat = SkMask::kA8_Format;
+            srcM.fRowBytes = SkAlign4(srcM.fBounds.width());
+            size_t size = srcM.computeImageSize();
+            a8storage.reset(size);
+            srcM.fImage = (uint8_t*)a8storage.get();
+            extract_alpha(srcM,
+                          (const SkPMColor*)glyph->fImage, glyph->rowBytes());
+        }
+
+        fRec.getMatrixFrom2x2(&matrix);
+
+        if (fMaskFilter->filterMask(&dstM, srcM, matrix, NULL)) {
+            int width = SkFastMin32(origGlyph.fWidth, dstM.fBounds.width());
+            int height = SkFastMin32(origGlyph.fHeight, dstM.fBounds.height());
+            int dstRB = origGlyph.rowBytes();
+            int srcRB = dstM.fRowBytes;
+
+            const uint8_t* src = (const uint8_t*)dstM.fImage;
+            uint8_t* dst = (uint8_t*)origGlyph.fImage;
+
+            if (SkMask::k3D_Format == dstM.fFormat) {
+                // we have to copy 3 times as much
+                height *= 3;
+            }
+
+            // clean out our glyph, since it may be larger than dstM
+            //sk_bzero(dst, height * dstRB);
+
+            while (--height >= 0) {
+                memcpy(dst, src, width);
+                src += srcRB;
+                dst += dstRB;
+            }
+            SkMask::FreeImage(dstM.fImage);
+
+            if (fPreBlendForFilter.isApplicable()) {
+                applyLUTToA8Mask(srcM, fPreBlendForFilter.fG);
+            }
+        }
+    }
+}
+
+void SkScalerContext::getPath(const SkGlyph& glyph, SkPath* path) {
+    this->internalGetPath(glyph, NULL, path, NULL);
+}
+
+void SkScalerContext::getFontMetrics(SkPaint::FontMetrics* fm) {
+    // All of this complexity should go away when we change generateFontMetrics
+    // to just take one parameter (since it knows if it is vertical or not)
+    SkPaint::FontMetrics* mx = NULL;
+    SkPaint::FontMetrics* my = NULL;
+    if (fRec.fFlags & kVertical_Flag) {
+        mx = fm;
+    } else {
+        my = fm;
+    }
+    this->generateFontMetrics(mx, my);
+}
+
+SkUnichar SkScalerContext::generateGlyphToChar(uint16_t glyph) {
+    return 0;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+void SkScalerContext::internalGetPath(const SkGlyph& glyph, SkPath* fillPath,
+                                  SkPath* devPath, SkMatrix* fillToDevMatrix) {
+    SkPath  path;
+
+    this->getGlyphContext(glyph)->generatePath(glyph, &path);
+
+    if (fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag) {
+        SkFixed dx = glyph.getSubXFixed();
+        SkFixed dy = glyph.getSubYFixed();
+        if (dx | dy) {
+            path.offset(SkFixedToScalar(dx), SkFixedToScalar(dy));
+        }
+    }
+
+    if (fRec.fFrameWidth > 0 || fPathEffect != NULL) {
+        // need the path in user-space, with only the point-size applied
+        // so that our stroking and effects will operate the same way they
+        // would if the user had extracted the path themself, and then
+        // called drawPath
+        SkPath      localPath;
+        SkMatrix    matrix, inverse;
+
+        fRec.getMatrixFrom2x2(&matrix);
+        if (!matrix.invert(&inverse)) {
+            // assume fillPath and devPath are already empty.
+            return;
+        }
+        path.transform(inverse, &localPath);
+        // now localPath is only affected by the paint settings, and not the canvas matrix
+
+        SkStrokeRec rec(SkStrokeRec::kFill_InitStyle);
+
+        if (fRec.fFrameWidth > 0) {
+            rec.setStrokeStyle(fRec.fFrameWidth,
+                               SkToBool(fRec.fFlags & kFrameAndFill_Flag));
+            // glyphs are always closed contours, so cap type is ignored,
+            // so we just pass something.
+            rec.setStrokeParams(SkPaint::kButt_Cap,
+                                (SkPaint::Join)fRec.fStrokeJoin,
+                                fRec.fMiterLimit);
+        }
+
+        if (fPathEffect) {
+            SkPath effectPath;
+            if (fPathEffect->filterPath(&effectPath, localPath, &rec, NULL)) {
+                localPath.swap(effectPath);
+            }
+        }
+
+        if (rec.needToApply()) {
+            SkPath strokePath;
+            if (rec.applyToPath(&strokePath, localPath)) {
+                localPath.swap(strokePath);
+            }
+        }
+
+        // now return stuff to the caller
+        if (fillToDevMatrix) {
+            *fillToDevMatrix = matrix;
+        }
+        if (devPath) {
+            localPath.transform(matrix, devPath);
+        }
+        if (fillPath) {
+            fillPath->swap(localPath);
+        }
+    } else {   // nothing tricky to do
+        if (fillToDevMatrix) {
+            fillToDevMatrix->reset();
+        }
+        if (devPath) {
+            if (fillPath == NULL) {
+                devPath->swap(path);
+            } else {
+                *devPath = path;
+            }
+        }
+
+        if (fillPath) {
+            fillPath->swap(path);
+        }
+    }
+
+    if (devPath) {
+        devPath->updateBoundsCache();
+    }
+    if (fillPath) {
+        fillPath->updateBoundsCache();
+    }
+}
+
+
+void SkScalerContextRec::getMatrixFrom2x2(SkMatrix* dst) const {
+    dst->setAll(fPost2x2[0][0], fPost2x2[0][1], 0,
+                fPost2x2[1][0], fPost2x2[1][1], 0,
+                0,              0,              SkScalarToPersp(SK_Scalar1));
+}
+
+void SkScalerContextRec::getLocalMatrix(SkMatrix* m) const {
+    SkPaint::SetTextMatrix(m, fTextSize, fPreScaleX, fPreSkewX);
+}
+
+void SkScalerContextRec::getSingleMatrix(SkMatrix* m) const {
+    this->getLocalMatrix(m);
+
+    //  now concat the device matrix
+    SkMatrix    deviceMatrix;
+    this->getMatrixFrom2x2(&deviceMatrix);
+    m->postConcat(deviceMatrix);
+}
+
+SkAxisAlignment SkComputeAxisAlignmentForHText(const SkMatrix& matrix) {
+    SkASSERT(!matrix.hasPerspective());
+
+    if (0 == matrix[SkMatrix::kMSkewY]) {
+        return kX_SkAxisAlignment;
+    }
+    if (0 == matrix[SkMatrix::kMScaleX]) {
+        return kY_SkAxisAlignment;
+    }
+    return kNone_SkAxisAlignment;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+#include "SkFontHost.h"
+
+class SkScalerContext_Empty : public SkScalerContext {
+public:
+    SkScalerContext_Empty(SkTypeface* face, const SkDescriptor* desc)
+        : SkScalerContext(face, desc) {}
+
+protected:
+    virtual unsigned generateGlyphCount() SK_OVERRIDE {
+        return 0;
+    }
+    virtual uint16_t generateCharToGlyph(SkUnichar uni) SK_OVERRIDE {
+        return 0;
+    }
+    virtual void generateAdvance(SkGlyph* glyph) SK_OVERRIDE {
+        glyph->zeroMetrics();
+    }
+    virtual void generateMetrics(SkGlyph* glyph) SK_OVERRIDE {
+        glyph->zeroMetrics();
+    }
+    virtual void generateImage(const SkGlyph& glyph) SK_OVERRIDE {}
+    virtual void generatePath(const SkGlyph& glyph, SkPath* path) SK_OVERRIDE {}
+    virtual void generateFontMetrics(SkPaint::FontMetrics* mx,
+                                     SkPaint::FontMetrics* my) SK_OVERRIDE {
+        if (mx) {
+            sk_bzero(mx, sizeof(*mx));
+        }
+        if (my) {
+            sk_bzero(my, sizeof(*my));
+        }
+    }
+};
+
+extern SkScalerContext* SkCreateColorScalerContext(const SkDescriptor* desc);
+
+SkScalerContext* SkTypeface::createScalerContext(const SkDescriptor* desc,
+                                                 bool allowFailure) const {
+    SkScalerContext* c = this->onCreateScalerContext(desc);
+
+    if (!c && !allowFailure) {
+        c = SkNEW_ARGS(SkScalerContext_Empty,
+                       (const_cast<SkTypeface*>(this), desc));
+    }
+    return c;
+}