/*
* 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 "SkTypes.h"
#if defined(SK_BUILD_FOR_WIN32)
#undef GetGlyphIndices
#include "SkDWrite.h"
#include "SkDWriteGeometrySink.h"
#include "SkEndian.h"
#include "SkGlyph.h"
#include "SkHRESULT.h"
#include "SkMaskGamma.h"
#include "SkMatrix22.h"
#include "SkMutex.h"
#include "SkOTTable_EBLC.h"
#include "SkOTTable_EBSC.h"
#include "SkOTTable_gasp.h"
#include "SkOTTable_maxp.h"
#include "SkPath.h"
#include "SkScalerContext.h"
#include "SkScalerContext_win_dw.h"
#include "SkSharedMutex.h"
#include "SkTScopedComPtr.h"
#include "SkTypeface_win_dw.h"
#include <dwrite.h>
#if SK_HAS_DWRITE_1_H
# include <dwrite_1.h>
#endif
/* Note:
* In versions 8 and 8.1 of Windows, some calls in DWrite are not thread safe.
* The DWriteFactoryMutex protects the calls that are problematic.
*/
static SkSharedMutex DWriteFactoryMutex;
typedef SkAutoTExclusive<SkSharedMutex> Exclusive;
typedef SkAutoSharedMutexShared Shared;
static bool isLCD(const SkScalerContext::Rec& rec) {
return SkMask::kLCD16_Format == rec.fMaskFormat;
}
static bool is_hinted_without_gasp(DWriteFontTypeface* typeface) {
Exclusive l(DWriteFactoryMutex);
AutoTDWriteTable<SkOTTableMaximumProfile> maxp(typeface->fDWriteFontFace.get());
if (!maxp.fExists) {
return false;
}
if (maxp.fSize < sizeof(SkOTTableMaximumProfile::Version::TT)) {
return false;
}
if (maxp->version.version != SkOTTableMaximumProfile::Version::TT::VERSION) {
return false;
}
if (0 == maxp->version.tt.maxSizeOfInstructions) {
// No hints.
return false;
}
AutoTDWriteTable<SkOTTableGridAndScanProcedure> gasp(typeface->fDWriteFontFace.get());
return !gasp.fExists;
}
/** A PPEMRange is inclusive, [min, max]. */
struct PPEMRange {
int min;
int max;
};
/** If the rendering mode for the specified 'size' is gridfit, then place
* the gridfit range into 'range'. Otherwise, leave 'range' alone.
*/
static void expand_range_if_gridfit_only(DWriteFontTypeface* typeface, int size, PPEMRange* range) {
AutoTDWriteTable<SkOTTableGridAndScanProcedure> gasp(typeface->fDWriteFontFace.get());
if (!gasp.fExists) {
return;
}
if (gasp.fSize < sizeof(SkOTTableGridAndScanProcedure)) {
return;
}
if (gasp->version != SkOTTableGridAndScanProcedure::version0 &&
gasp->version != SkOTTableGridAndScanProcedure::version1)
{
return;
}
uint16_t numRanges = SkEndianSwap16(gasp->numRanges);
if (numRanges > 1024 ||
gasp.fSize < sizeof(SkOTTableGridAndScanProcedure) +
sizeof(SkOTTableGridAndScanProcedure::GaspRange) * numRanges)
{
return;
}
const SkOTTableGridAndScanProcedure::GaspRange* rangeTable =
SkTAfter<const SkOTTableGridAndScanProcedure::GaspRange>(gasp.get());
int minPPEM = -1;
for (uint16_t i = 0; i < numRanges; ++i, ++rangeTable) {
int maxPPEM = SkEndianSwap16(rangeTable->maxPPEM);
// Test that the size is in range and the range is gridfit only.
if (minPPEM < size && size <= maxPPEM &&
rangeTable->flags.raw.value == SkOTTableGridAndScanProcedure::GaspRange::behavior::Raw::GridfitMask)
{
range->min = minPPEM + 1;
range->max = maxPPEM;
return;
}
minPPEM = maxPPEM;
}
}
static bool has_bitmap_strike(DWriteFontTypeface* typeface, PPEMRange range) {
Exclusive l(DWriteFactoryMutex);
{
AutoTDWriteTable<SkOTTableEmbeddedBitmapLocation> eblc(typeface->fDWriteFontFace.get());
if (!eblc.fExists) {
return false;
}
if (eblc.fSize < sizeof(SkOTTableEmbeddedBitmapLocation)) {
return false;
}
if (eblc->version != SkOTTableEmbeddedBitmapLocation::version_initial) {
return false;
}
uint32_t numSizes = SkEndianSwap32(eblc->numSizes);
if (numSizes > 1024 ||
eblc.fSize < sizeof(SkOTTableEmbeddedBitmapLocation) +
sizeof(SkOTTableEmbeddedBitmapLocation::BitmapSizeTable) * numSizes)
{
return false;
}
const SkOTTableEmbeddedBitmapLocation::BitmapSizeTable* sizeTable =
SkTAfter<const SkOTTableEmbeddedBitmapLocation::BitmapSizeTable>(eblc.get());
for (uint32_t i = 0; i < numSizes; ++i, ++sizeTable) {
if (sizeTable->ppemX == sizeTable->ppemY &&
range.min <= sizeTable->ppemX && sizeTable->ppemX <= range.max)
{
// TODO: determine if we should dig through IndexSubTableArray/IndexSubTable
// to determine the actual number of glyphs with bitmaps.
// TODO: Ensure that the bitmaps actually cover a significant portion of the strike.
// TODO: Ensure that the bitmaps are bi-level?
if (sizeTable->endGlyphIndex >= sizeTable->startGlyphIndex + 3) {
return true;
}
}
}
}
{
AutoTDWriteTable<SkOTTableEmbeddedBitmapScaling> ebsc(typeface->fDWriteFontFace.get());
if (!ebsc.fExists) {
return false;
}
if (ebsc.fSize < sizeof(SkOTTableEmbeddedBitmapScaling)) {
return false;
}
if (ebsc->version != SkOTTableEmbeddedBitmapScaling::version_initial) {
return false;
}
uint32_t numSizes = SkEndianSwap32(ebsc->numSizes);
if (numSizes > 1024 ||
ebsc.fSize < sizeof(SkOTTableEmbeddedBitmapScaling) +
sizeof(SkOTTableEmbeddedBitmapScaling::BitmapScaleTable) * numSizes)
{
return false;
}
const SkOTTableEmbeddedBitmapScaling::BitmapScaleTable* scaleTable =
SkTAfter<const SkOTTableEmbeddedBitmapScaling::BitmapScaleTable>(ebsc.get());
for (uint32_t i = 0; i < numSizes; ++i, ++scaleTable) {
if (scaleTable->ppemX == scaleTable->ppemY &&
range.min <= scaleTable->ppemX && scaleTable->ppemX <= range.max) {
// EBSC tables are normally only found in bitmap only fonts.
return true;
}
}
}
return false;
}
static bool both_zero(SkScalar a, SkScalar b) {
return 0 == a && 0 == b;
}
// returns false if there is any non-90-rotation or skew
static bool is_axis_aligned(const SkScalerContext::Rec& rec) {
return 0 == rec.fPreSkewX &&
(both_zero(rec.fPost2x2[0][1], rec.fPost2x2[1][0]) ||
both_zero(rec.fPost2x2[0][0], rec.fPost2x2[1][1]));
}
SkScalerContext_DW::SkScalerContext_DW(DWriteFontTypeface* typeface,
const SkDescriptor* desc)
: SkScalerContext(typeface, desc)
, fTypeface(SkRef(typeface))
, fGlyphCount(-1) {
// In general, all glyphs should use CLEARTYPE_NATURAL_SYMMETRIC
// except when bi-level rendering is requested or there are embedded
// bi-level bitmaps (and the embedded bitmap flag is set and no rotation).
//
// DirectWrite's IDWriteFontFace::GetRecommendedRenderingMode does not do
// this. As a result, determine the actual size of the text and then see if
// there are any embedded bi-level bitmaps of that size. If there are, then
// force bitmaps by requesting bi-level rendering.
//
// FreeType allows for separate ppemX and ppemY, but DirectWrite assumes
// square pixels and only uses ppemY. Therefore the transform must track any
// non-uniform x-scale.
//
// Also, rotated glyphs should have the same absolute advance widths as
// horizontal glyphs and the subpixel flag should not affect glyph shapes.
SkVector scale;
SkMatrix GsA;
fRec.computeMatrices(SkScalerContextRec::kVertical_PreMatrixScale,
&scale, &fSkXform, &GsA, &fG_inv);
fXform.m11 = SkScalarToFloat(fSkXform.getScaleX());
fXform.m12 = SkScalarToFloat(fSkXform.getSkewY());
fXform.m21 = SkScalarToFloat(fSkXform.getSkewX());
fXform.m22 = SkScalarToFloat(fSkXform.getScaleY());
fXform.dx = 0;
fXform.dy = 0;
fGsA.m11 = SkScalarToFloat(GsA.get(SkMatrix::kMScaleX));
fGsA.m12 = SkScalarToFloat(GsA.get(SkMatrix::kMSkewY)); // This should be ~0.
fGsA.m21 = SkScalarToFloat(GsA.get(SkMatrix::kMSkewX));
fGsA.m22 = SkScalarToFloat(GsA.get(SkMatrix::kMScaleY));
fGsA.dx = 0;
fGsA.dy = 0;
// realTextSize is the actual device size we want (as opposed to the size the user requested).
// gdiTextSize is the size we request when GDI compatible.
// If the scale is negative, this means the matrix will do the flip anyway.
const SkScalar realTextSize = scale.fY;
// Due to floating point math, the lower bits are suspect. Round carefully.
SkScalar gdiTextSize = SkScalarRoundToScalar(realTextSize * 64.0f) / 64.0f;
if (gdiTextSize == 0) {
gdiTextSize = SK_Scalar1;
}
bool bitmapRequested = SkToBool(fRec.fFlags & SkScalerContext::kEmbeddedBitmapText_Flag);
bool treatLikeBitmap = false;
bool axisAlignedBitmap = false;
if (bitmapRequested) {
// When embedded bitmaps are requested, treat the entire range like
// a bitmap strike if the range is gridfit only and contains a bitmap.
int bitmapPPEM = SkScalarTruncToInt(gdiTextSize);
PPEMRange range = { bitmapPPEM, bitmapPPEM };
expand_range_if_gridfit_only(typeface, bitmapPPEM, &range);
treatLikeBitmap = has_bitmap_strike(typeface, range);
axisAlignedBitmap = is_axis_aligned(fRec);
}
// If the user requested aliased, do so with aliased compatible metrics.
if (SkMask::kBW_Format == fRec.fMaskFormat) {
fTextSizeRender = gdiTextSize;
fRenderingMode = DWRITE_RENDERING_MODE_ALIASED;
fTextureType = DWRITE_TEXTURE_ALIASED_1x1;
fTextSizeMeasure = gdiTextSize;
fMeasuringMode = DWRITE_MEASURING_MODE_GDI_CLASSIC;
// If we can use a bitmap, use gdi classic rendering and measurement.
// This will not always provide a bitmap, but matches expected behavior.
} else if (treatLikeBitmap && axisAlignedBitmap) {
fTextSizeRender = gdiTextSize;
fRenderingMode = DWRITE_RENDERING_MODE_CLEARTYPE_GDI_CLASSIC;
fTextureType = DWRITE_TEXTURE_CLEARTYPE_3x1;
fTextSizeMeasure = gdiTextSize;
fMeasuringMode = DWRITE_MEASURING_MODE_GDI_CLASSIC;
// If rotated but the horizontal text could have used a bitmap,
// render high quality rotated glyphs but measure using bitmap metrics.
} else if (treatLikeBitmap) {
fTextSizeRender = gdiTextSize;
fRenderingMode = DWRITE_RENDERING_MODE_CLEARTYPE_NATURAL_SYMMETRIC;
fTextureType = DWRITE_TEXTURE_CLEARTYPE_3x1;
fTextSizeMeasure = gdiTextSize;
fMeasuringMode = DWRITE_MEASURING_MODE_GDI_CLASSIC;
// Fonts that have hints but no gasp table get non-symmetric rendering.
// Usually such fonts have low quality hints which were never tested
// with anything but GDI ClearType classic. Such fonts often rely on
// drop out control in the y direction in order to be legible.
} else if (is_hinted_without_gasp(typeface)) {
fTextSizeRender = gdiTextSize;
fRenderingMode = DWRITE_RENDERING_MODE_CLEARTYPE_NATURAL;
fTextureType = DWRITE_TEXTURE_CLEARTYPE_3x1;
fTextSizeMeasure = realTextSize;
fMeasuringMode = DWRITE_MEASURING_MODE_NATURAL;
// The normal case is to use natural symmetric rendering and linear metrics.
} else {
fTextSizeRender = realTextSize;
fRenderingMode = DWRITE_RENDERING_MODE_CLEARTYPE_NATURAL_SYMMETRIC;
fTextureType = DWRITE_TEXTURE_CLEARTYPE_3x1;
fTextSizeMeasure = realTextSize;
fMeasuringMode = DWRITE_MEASURING_MODE_NATURAL;
}
if (this->isSubpixel()) {
fTextSizeMeasure = realTextSize;
fMeasuringMode = DWRITE_MEASURING_MODE_NATURAL;
}
}
SkScalerContext_DW::~SkScalerContext_DW() {
}
unsigned SkScalerContext_DW::generateGlyphCount() {
if (fGlyphCount < 0) {
fGlyphCount = fTypeface->fDWriteFontFace->GetGlyphCount();
}
return fGlyphCount;
}
uint16_t SkScalerContext_DW::generateCharToGlyph(SkUnichar uni) {
uint16_t index = 0;
fTypeface->fDWriteFontFace->GetGlyphIndices(reinterpret_cast<UINT32*>(&uni), 1, &index);
return index;
}
void SkScalerContext_DW::generateAdvance(SkGlyph* glyph) {
//Delta is the difference between the right/left side bearing metric
//and where the right/left side bearing ends up after hinting.
//DirectWrite does not provide this information.
glyph->fRsbDelta = 0;
glyph->fLsbDelta = 0;
glyph->fAdvanceX = 0;
glyph->fAdvanceY = 0;
uint16_t glyphId = glyph->getGlyphID();
DWRITE_GLYPH_METRICS gm;
if (DWRITE_MEASURING_MODE_GDI_CLASSIC == fMeasuringMode ||
DWRITE_MEASURING_MODE_GDI_NATURAL == fMeasuringMode)
{
Exclusive l(DWriteFactoryMutex);
HRVM(fTypeface->fDWriteFontFace->GetGdiCompatibleGlyphMetrics(
fTextSizeMeasure,
1.0f, // pixelsPerDip
&fGsA,
DWRITE_MEASURING_MODE_GDI_NATURAL == fMeasuringMode,
&glyphId, 1,
&gm),
"Could not get gdi compatible glyph metrics.");
} else {
Exclusive l(DWriteFactoryMutex);
HRVM(fTypeface->fDWriteFontFace->GetDesignGlyphMetrics(&glyphId, 1, &gm),
"Could not get design metrics.");
}
DWRITE_FONT_METRICS dwfm;
{
Shared l(DWriteFactoryMutex);
fTypeface->fDWriteFontFace->GetMetrics(&dwfm);
}
SkScalar advanceX = SkScalarMulDiv(fTextSizeMeasure,
SkIntToScalar(gm.advanceWidth),
SkIntToScalar(dwfm.designUnitsPerEm));
SkVector vecs[1] = { { advanceX, 0 } };
if (DWRITE_MEASURING_MODE_GDI_CLASSIC == fMeasuringMode ||
DWRITE_MEASURING_MODE_GDI_NATURAL == fMeasuringMode)
{
// DirectWrite produced 'compatible' metrics, but while close,
// the end result is not always an integer as it would be with GDI.
vecs[0].fX = SkScalarRoundToScalar(advanceX);
fG_inv.mapVectors(vecs, SK_ARRAY_COUNT(vecs));
} else {
fSkXform.mapVectors(vecs, SK_ARRAY_COUNT(vecs));
}
glyph->fAdvanceX = SkScalarToFixed(vecs[0].fX);
glyph->fAdvanceY = SkScalarToFixed(vecs[0].fY);
}
HRESULT SkScalerContext_DW::getBoundingBox(SkGlyph* glyph,
DWRITE_RENDERING_MODE renderingMode,
DWRITE_TEXTURE_TYPE textureType,
RECT* bbox)
{
//Measure raster size.
fXform.dx = SkFixedToFloat(glyph->getSubXFixed());
fXform.dy = SkFixedToFloat(glyph->getSubYFixed());
FLOAT advance = 0;
UINT16 glyphId = glyph->getGlyphID();
DWRITE_GLYPH_OFFSET offset;
offset.advanceOffset = 0.0f;
offset.ascenderOffset = 0.0f;
DWRITE_GLYPH_RUN run;
run.glyphCount = 1;
run.glyphAdvances = &advance;
run.fontFace = fTypeface->fDWriteFontFace.get();
run.fontEmSize = SkScalarToFloat(fTextSizeRender);
run.bidiLevel = 0;
run.glyphIndices = &glyphId;
run.isSideways = FALSE;
run.glyphOffsets = &offset;
SkTScopedComPtr<IDWriteGlyphRunAnalysis> glyphRunAnalysis;
{
Exclusive l(DWriteFactoryMutex);
HRM(fTypeface->fFactory->CreateGlyphRunAnalysis(
&run,
1.0f, // pixelsPerDip,
&fXform,
renderingMode,
fMeasuringMode,
0.0f, // baselineOriginX,
0.0f, // baselineOriginY,
&glyphRunAnalysis),
"Could not create glyph run analysis.");
}
{
Shared l(DWriteFactoryMutex);
HRM(glyphRunAnalysis->GetAlphaTextureBounds(textureType, bbox),
"Could not get texture bounds.");
}
return S_OK;
}
/** GetAlphaTextureBounds succeeds but sometimes returns empty bounds like
* { 0x80000000, 0x80000000, 0x80000000, 0x80000000 }
* for small, but not quite zero, sized glyphs.
* Only set as non-empty if the returned bounds are non-empty.
*/
static bool glyph_check_and_set_bounds(SkGlyph* glyph, const RECT& bbox) {
if (bbox.left >= bbox.right || bbox.top >= bbox.bottom) {
return false;
}
glyph->fWidth = SkToU16(bbox.right - bbox.left);
glyph->fHeight = SkToU16(bbox.bottom - bbox.top);
glyph->fLeft = SkToS16(bbox.left);
glyph->fTop = SkToS16(bbox.top);
return true;
}
void SkScalerContext_DW::generateMetrics(SkGlyph* glyph) {
glyph->fWidth = 0;
glyph->fHeight = 0;
glyph->fLeft = 0;
glyph->fTop = 0;
this->generateAdvance(glyph);
RECT bbox;
HRVM(this->getBoundingBox(glyph, fRenderingMode, fTextureType, &bbox),
"Requested bounding box could not be determined.");
if (glyph_check_and_set_bounds(glyph, bbox)) {
return;
}
// GetAlphaTextureBounds succeeds but returns an empty RECT if there are no
// glyphs of the specified texture type. When this happens, try with the
// alternate texture type.
if (DWRITE_TEXTURE_CLEARTYPE_3x1 == fTextureType) {
HRVM(this->getBoundingBox(glyph,
DWRITE_RENDERING_MODE_ALIASED,
DWRITE_TEXTURE_ALIASED_1x1,
&bbox),
"Fallback bounding box could not be determined.");
if (glyph_check_and_set_bounds(glyph, bbox)) {
glyph->fForceBW = 1;
}
}
// TODO: handle the case where a request for DWRITE_TEXTURE_ALIASED_1x1
// fails, and try DWRITE_TEXTURE_CLEARTYPE_3x1.
}
void SkScalerContext_DW::generateFontMetrics(SkPaint::FontMetrics* metrics) {
if (nullptr == metrics) {
return;
}
sk_bzero(metrics, sizeof(*metrics));
DWRITE_FONT_METRICS dwfm;
if (DWRITE_MEASURING_MODE_GDI_CLASSIC == fMeasuringMode ||
DWRITE_MEASURING_MODE_GDI_NATURAL == fMeasuringMode)
{
fTypeface->fDWriteFontFace->GetGdiCompatibleMetrics(
fTextSizeRender,
1.0f, // pixelsPerDip
&fXform,
&dwfm);
} else {
fTypeface->fDWriteFontFace->GetMetrics(&dwfm);
}
SkScalar upem = SkIntToScalar(dwfm.designUnitsPerEm);
metrics->fAscent = -fTextSizeRender * SkIntToScalar(dwfm.ascent) / upem;
metrics->fDescent = fTextSizeRender * SkIntToScalar(dwfm.descent) / upem;
metrics->fLeading = fTextSizeRender * SkIntToScalar(dwfm.lineGap) / upem;
metrics->fXHeight = fTextSizeRender * SkIntToScalar(dwfm.xHeight) / upem;
metrics->fUnderlineThickness = fTextSizeRender * SkIntToScalar(dwfm.underlineThickness) / upem;
metrics->fUnderlinePosition = -(fTextSizeRender * SkIntToScalar(dwfm.underlinePosition) / upem);
metrics->fFlags |= SkPaint::FontMetrics::kUnderlineThinknessIsValid_Flag;
metrics->fFlags |= SkPaint::FontMetrics::kUnderlinePositionIsValid_Flag;
#if SK_HAS_DWRITE_1_H
if (fTypeface->fDWriteFontFace1.get()) {
DWRITE_FONT_METRICS1 dwfm1;
fTypeface->fDWriteFontFace1->GetMetrics(&dwfm1);
metrics->fTop = -fTextSizeRender * SkIntToScalar(dwfm1.glyphBoxTop) / upem;
metrics->fBottom = -fTextSizeRender * SkIntToScalar(dwfm1.glyphBoxBottom) / upem;
metrics->fXMin = fTextSizeRender * SkIntToScalar(dwfm1.glyphBoxLeft) / upem;
metrics->fXMax = fTextSizeRender * SkIntToScalar(dwfm1.glyphBoxRight) / upem;
metrics->fMaxCharWidth = metrics->fXMax - metrics->fXMin;
return;
}
#else
# pragma message("No dwrite_1.h is available, font metrics may be affected.")
#endif
AutoTDWriteTable<SkOTTableHead> head(fTypeface->fDWriteFontFace.get());
if (head.fExists &&
head.fSize >= sizeof(SkOTTableHead) &&
head->version == SkOTTableHead::version1)
{
metrics->fTop = -fTextSizeRender * (int16_t)SkEndian_SwapBE16(head->yMax) / upem;
metrics->fBottom = -fTextSizeRender * (int16_t)SkEndian_SwapBE16(head->yMin) / upem;
metrics->fXMin = fTextSizeRender * (int16_t)SkEndian_SwapBE16(head->xMin) / upem;
metrics->fXMax = fTextSizeRender * (int16_t)SkEndian_SwapBE16(head->xMax) / upem;
metrics->fMaxCharWidth = metrics->fXMax - metrics->fXMin;
return;
}
metrics->fTop = metrics->fAscent;
metrics->fBottom = metrics->fDescent;
}
///////////////////////////////////////////////////////////////////////////////
#include "SkColorPriv.h"
static void bilevel_to_bw(const uint8_t* SK_RESTRICT src, const SkGlyph& glyph) {
const int width = glyph.fWidth;
const size_t dstRB = (width + 7) >> 3;
uint8_t* SK_RESTRICT dst = static_cast<uint8_t*>(glyph.fImage);
int byteCount = width >> 3;
int bitCount = width & 7;
for (int y = 0; y < glyph.fHeight; ++y) {
if (byteCount > 0) {
for (int i = 0; i < byteCount; ++i) {
unsigned byte = 0;
byte |= src[0] & (1 << 7);
byte |= src[1] & (1 << 6);
byte |= src[2] & (1 << 5);
byte |= src[3] & (1 << 4);
byte |= src[4] & (1 << 3);
byte |= src[5] & (1 << 2);
byte |= src[6] & (1 << 1);
byte |= src[7] & (1 << 0);
dst[i] = byte;
src += 8;
}
}
if (bitCount > 0) {
unsigned byte = 0;
unsigned mask = 0x80;
for (int i = 0; i < bitCount; i++) {
byte |= (src[i]) & mask;
mask >>= 1;
}
dst[byteCount] = byte;
}
src += bitCount;
dst += dstRB;
}
}
template<bool APPLY_PREBLEND>
static void rgb_to_a8(const uint8_t* SK_RESTRICT src, const SkGlyph& glyph, const uint8_t* table8) {
const size_t dstRB = glyph.rowBytes();
const U16CPU width = glyph.fWidth;
uint8_t* SK_RESTRICT dst = static_cast<uint8_t*>(glyph.fImage);
for (U16CPU y = 0; y < glyph.fHeight; y++) {
for (U16CPU i = 0; i < width; i++) {
U8CPU r = *(src++);
U8CPU g = *(src++);
U8CPU b = *(src++);
dst[i] = sk_apply_lut_if<APPLY_PREBLEND>((r + g + b) / 3, table8);
}
dst = (uint8_t*)((char*)dst + dstRB);
}
}
template<bool APPLY_PREBLEND, bool RGB>
static void rgb_to_lcd16(const uint8_t* SK_RESTRICT src, const SkGlyph& glyph,
const uint8_t* tableR, const uint8_t* tableG, const uint8_t* tableB) {
const size_t dstRB = glyph.rowBytes();
const U16CPU width = glyph.fWidth;
uint16_t* SK_RESTRICT dst = static_cast<uint16_t*>(glyph.fImage);
for (U16CPU y = 0; y < glyph.fHeight; y++) {
for (U16CPU i = 0; i < width; i++) {
U8CPU r, g, b;
if (RGB) {
r = sk_apply_lut_if<APPLY_PREBLEND>(*(src++), tableR);
g = sk_apply_lut_if<APPLY_PREBLEND>(*(src++), tableG);
b = sk_apply_lut_if<APPLY_PREBLEND>(*(src++), tableB);
} else {
b = sk_apply_lut_if<APPLY_PREBLEND>(*(src++), tableB);
g = sk_apply_lut_if<APPLY_PREBLEND>(*(src++), tableG);
r = sk_apply_lut_if<APPLY_PREBLEND>(*(src++), tableR);
}
dst[i] = SkPack888ToRGB16(r, g, b);
}
dst = (uint16_t*)((char*)dst + dstRB);
}
}
const void* SkScalerContext_DW::drawDWMask(const SkGlyph& glyph,
DWRITE_RENDERING_MODE renderingMode,
DWRITE_TEXTURE_TYPE textureType)
{
int sizeNeeded = glyph.fWidth * glyph.fHeight;
if (DWRITE_RENDERING_MODE_ALIASED != renderingMode) {
sizeNeeded *= 3;
}
if (sizeNeeded > fBits.count()) {
fBits.setCount(sizeNeeded);
}
// erase
memset(fBits.begin(), 0, sizeNeeded);
fXform.dx = SkFixedToFloat(glyph.getSubXFixed());
fXform.dy = SkFixedToFloat(glyph.getSubYFixed());
FLOAT advance = 0.0f;
UINT16 index = glyph.getGlyphID();
DWRITE_GLYPH_OFFSET offset;
offset.advanceOffset = 0.0f;
offset.ascenderOffset = 0.0f;
DWRITE_GLYPH_RUN run;
run.glyphCount = 1;
run.glyphAdvances = &advance;
run.fontFace = fTypeface->fDWriteFontFace.get();
run.fontEmSize = SkScalarToFloat(fTextSizeRender);
run.bidiLevel = 0;
run.glyphIndices = &index;
run.isSideways = FALSE;
run.glyphOffsets = &offset;
{
SkTScopedComPtr<IDWriteGlyphRunAnalysis> glyphRunAnalysis;
{
Exclusive l(DWriteFactoryMutex);
HRNM(fTypeface->fFactory->CreateGlyphRunAnalysis(&run,
1.0f, // pixelsPerDip,
&fXform,
renderingMode,
fMeasuringMode,
0.0f, // baselineOriginX,
0.0f, // baselineOriginY,
&glyphRunAnalysis),
"Could not create glyph run analysis.");
}
//NOTE: this assumes that the glyph has already been measured
//with an exact same glyph run analysis.
RECT bbox;
bbox.left = glyph.fLeft;
bbox.top = glyph.fTop;
bbox.right = glyph.fLeft + glyph.fWidth;
bbox.bottom = glyph.fTop + glyph.fHeight;
{
Shared l(DWriteFactoryMutex);
HRNM(glyphRunAnalysis->CreateAlphaTexture(textureType,
&bbox,
fBits.begin(),
sizeNeeded),
"Could not draw mask.");
}
}
return fBits.begin();
}
void SkScalerContext_DW::generateImage(const SkGlyph& glyph) {
//Create the mask.
DWRITE_RENDERING_MODE renderingMode = fRenderingMode;
DWRITE_TEXTURE_TYPE textureType = fTextureType;
if (glyph.fForceBW) {
renderingMode = DWRITE_RENDERING_MODE_ALIASED;
textureType = DWRITE_TEXTURE_ALIASED_1x1;
}
const void* bits = this->drawDWMask(glyph, renderingMode, textureType);
if (!bits) {
sk_bzero(glyph.fImage, glyph.computeImageSize());
return;
}
//Copy the mask into the glyph.
const uint8_t* src = (const uint8_t*)bits;
if (DWRITE_RENDERING_MODE_ALIASED == renderingMode) {
bilevel_to_bw(src, glyph);
const_cast<SkGlyph&>(glyph).fMaskFormat = SkMask::kBW_Format;
} else if (!isLCD(fRec)) {
if (fPreBlend.isApplicable()) {
rgb_to_a8<true>(src, glyph, fPreBlend.fG);
} else {
rgb_to_a8<false>(src, glyph, fPreBlend.fG);
}
} else {
SkASSERT(SkMask::kLCD16_Format == glyph.fMaskFormat);
if (fPreBlend.isApplicable()) {
if (fRec.fFlags & SkScalerContext::kLCD_BGROrder_Flag) {
rgb_to_lcd16<true, false>(src, glyph, fPreBlend.fR, fPreBlend.fG, fPreBlend.fB);
} else {
rgb_to_lcd16<true, true>(src, glyph, fPreBlend.fR, fPreBlend.fG, fPreBlend.fB);
}
} else {
if (fRec.fFlags & SkScalerContext::kLCD_BGROrder_Flag) {
rgb_to_lcd16<false, false>(src, glyph, fPreBlend.fR, fPreBlend.fG, fPreBlend.fB);
} else {
rgb_to_lcd16<false, true>(src, glyph, fPreBlend.fR, fPreBlend.fG, fPreBlend.fB);
}
}
}
}
void SkScalerContext_DW::generatePath(const SkGlyph& glyph, SkPath* path) {
SkASSERT(path);
path->reset();
SkTScopedComPtr<IDWriteGeometrySink> geometryToPath;
HRVM(SkDWriteGeometrySink::Create(path, &geometryToPath),
"Could not create geometry to path converter.");
uint16_t glyphId = glyph.getGlyphID();
{
Exclusive l(DWriteFactoryMutex);
//TODO: convert to<->from DIUs? This would make a difference if hinting.
//It may not be needed, it appears that DirectWrite only hints at em size.
HRVM(fTypeface->fDWriteFontFace->GetGlyphRunOutline(SkScalarToFloat(fTextSizeRender),
&glyphId,
nullptr, //advances
nullptr, //offsets
1, //num glyphs
FALSE, //sideways
FALSE, //rtl
geometryToPath.get()),
"Could not create glyph outline.");
}
path->transform(fSkXform);
}
#endif//defined(SK_BUILD_FOR_WIN32)