src/gpu/GrTextContext.cpp - platform/external/skqp - Gitiles

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "GrTextContext.h"
 #include "GrBlurUtils.h"
 #include "GrContext.h"
 #include "GrDrawContext.h"
 #include "GrFontScaler.h"

 #include "SkAutoKern.h"
 #include "SkDrawFilter.h"
 #include "SkDrawProcs.h"
 #include "SkGlyphCache.h"
 #include "SkGpuDevice.h"
 #include "SkGrPriv.h"
 #include "SkTextBlobRunIterator.h"
 #include "SkTextMapStateProc.h"
 #include "SkTextToPathIter.h"

 GrTextContext::GrTextContext(GrContext* context, const SkSurfaceProps& surfaceProps)
     : fFallbackTextContext(nullptr)
     , fContext(context)
     , fSurfaceProps(surfaceProps) {
 }

 GrTextContext::~GrTextContext() {
     delete fFallbackTextContext;
 }

 void GrTextContext::drawText(GrDrawContext* dc, GrRenderTarget* rt,
                              const GrClip& clip, const GrPaint& paint,
                              const SkPaint& skPaint, const SkMatrix& viewMatrix,
                              const char text[], size_t byteLength,
                              SkScalar x, SkScalar y, const SkIRect& clipBounds) {
     if (fContext->abandoned()) {
         return;
     }

     GrTextContext* textContext = this;
     do {
         if (textContext->canDraw(rt, clip, paint, skPaint, viewMatrix)) {
             textContext->onDrawText(dc, rt, clip, paint, skPaint, viewMatrix,
                                     text, byteLength, x, y, clipBounds);
             return;
         }
         textContext = textContext->fFallbackTextContext;
     } while (textContext);

     // fall back to drawing as a path
     this->drawTextAsPath(dc, rt, clip, skPaint, viewMatrix,
                          text, byteLength, x, y, clipBounds);
 }

 void GrTextContext::drawPosText(GrDrawContext* dc, GrRenderTarget* rt,
                                 const GrClip& clip, const GrPaint& paint,
                                 const SkPaint& skPaint, const SkMatrix& viewMatrix,
                                 const char text[], size_t byteLength,
                                 const SkScalar pos[], int scalarsPerPosition,
                                 const SkPoint& offset, const SkIRect& clipBounds) {
     if (fContext->abandoned()) {
         return;
     }

     GrTextContext* textContext = this;
     do {
         if (textContext->canDraw(rt, clip, paint, skPaint, viewMatrix)) {
             textContext->onDrawPosText(dc, rt, clip, paint, skPaint, viewMatrix,
                                        text, byteLength, pos,
                                        scalarsPerPosition, offset, clipBounds);
             return;
         }
         textContext = textContext->fFallbackTextContext;
     } while (textContext);

     // fall back to drawing as a path
     this->drawPosTextAsPath(dc, rt, clip, skPaint, viewMatrix, text, byteLength, pos,
                             scalarsPerPosition, offset, clipBounds);
 }

 bool GrTextContext::ShouldDisableLCD(const SkPaint& paint) {
     if (!SkXfermode::AsMode(paint.getXfermode(), nullptr) ||
         paint.getMaskFilter() ||
         paint.getRasterizer() ||
         paint.getPathEffect() ||
         paint.isFakeBoldText() ||
         paint.getStyle() != SkPaint::kFill_Style)
     {
         return true;
     }
     return false;
 }

 uint32_t GrTextContext::FilterTextFlags(const SkSurfaceProps& surfaceProps, const SkPaint& paint) {
     uint32_t flags = paint.getFlags();

     if (!paint.isLCDRenderText() || !paint.isAntiAlias()) {
         return flags;
     }

     if (kUnknown_SkPixelGeometry == surfaceProps.pixelGeometry() || ShouldDisableLCD(paint)) {
         flags &= ~SkPaint::kLCDRenderText_Flag;
         flags |= SkPaint::kGenA8FromLCD_Flag;
     }

     return flags;
 }

 void GrTextContext::drawTextBlob(GrDrawContext* dc, GrRenderTarget* rt,
                                  const GrClip& clip, const SkPaint& skPaint,
                                  const SkMatrix& viewMatrix, const SkTextBlob* blob,
                                  SkScalar x, SkScalar y,
                                  SkDrawFilter* drawFilter, const SkIRect& clipBounds) {
     SkPaint runPaint = skPaint;

     SkTextBlobRunIterator it(blob);
     for (;!it.done(); it.next()) {
         size_t textLen = it.glyphCount() * sizeof(uint16_t);
         const SkPoint& offset = it.offset();
         // applyFontToPaint() always overwrites the exact same attributes,
         // so it is safe to not re-seed the paint for this reason.
         it.applyFontToPaint(&runPaint);

         if (drawFilter && !drawFilter->filter(&runPaint, SkDrawFilter::kText_Type)) {
             // A false return from filter() means we should abort the current draw.
             runPaint = skPaint;
             continue;
         }

         runPaint.setFlags(FilterTextFlags(fSurfaceProps, runPaint));

         GrPaint grPaint;
         if (!SkPaintToGrPaint(fContext, runPaint, viewMatrix, &grPaint)) {
             return;
         }

         switch (it.positioning()) {
         case SkTextBlob::kDefault_Positioning:
             this->drawText(dc, rt, clip, grPaint, runPaint, viewMatrix, (const char *)it.glyphs(),
                            textLen, x + offset.x(), y + offset.y(), clipBounds);
             break;
         case SkTextBlob::kHorizontal_Positioning:
             this->drawPosText(dc, rt, clip, grPaint, runPaint, viewMatrix, (const char*)it.glyphs(),
                               textLen, it.pos(), 1, SkPoint::Make(x, y + offset.y()), clipBounds);
             break;
         case SkTextBlob::kFull_Positioning:
             this->drawPosText(dc, rt, clip, grPaint, runPaint, viewMatrix, (const char*)it.glyphs(),
                               textLen, it.pos(), 2, SkPoint::Make(x, y), clipBounds);
             break;
         default:
             SkFAIL("unhandled positioning mode");
         }

         if (drawFilter) {
             // A draw filter may change the paint arbitrarily, so we must re-seed in this case.
             runPaint = skPaint;
         }
     }
 }

 void GrTextContext::drawTextAsPath(GrDrawContext* dc, GrRenderTarget* rt,
                                    const GrClip& clip,
                                    const SkPaint& skPaint, const SkMatrix& viewMatrix,
                                    const char text[], size_t byteLength, SkScalar x, SkScalar y,
                                    const SkIRect& clipBounds) {
     SkTextToPathIter iter(text, byteLength, skPaint, true);

     SkMatrix    matrix;
     matrix.setScale(iter.getPathScale(), iter.getPathScale());
     matrix.postTranslate(x, y);

     const SkPath* iterPath;
     SkScalar xpos, prevXPos = 0;

     while (iter.next(&iterPath, &xpos)) {
         matrix.postTranslate(xpos - prevXPos, 0);
         if (iterPath) {
             const SkPaint& pnt = iter.getPaint();
             GrBlurUtils::drawPathWithMaskFilter(fContext, dc, rt, clip, *iterPath,
                                                 pnt, viewMatrix, &matrix, clipBounds, false);
         }
         prevXPos = xpos;
     }
 }

 void GrTextContext::drawPosTextAsPath(GrDrawContext* dc, GrRenderTarget* rt,
                                       const GrClip& clip,
                                       const SkPaint& origPaint, const SkMatrix& viewMatrix,
                                       const char text[], size_t byteLength,
                                       const SkScalar pos[], int scalarsPerPosition,
                                       const SkPoint& offset, const SkIRect& clipBounds) {
     // setup our std paint, in hopes of getting hits in the cache
     SkPaint paint(origPaint);
     SkScalar matrixScale = paint.setupForAsPaths();

     SkMatrix matrix;
     matrix.setScale(matrixScale, matrixScale);

     // Temporarily jam in kFill, so we only ever ask for the raw outline from the cache.
     paint.setStyle(SkPaint::kFill_Style);
     paint.setPathEffect(nullptr);

     SkDrawCacheProc     glyphCacheProc = paint.getDrawCacheProc();
     SkAutoGlyphCache    autoCache(paint, &fSurfaceProps, nullptr);
     SkGlyphCache*       cache = autoCache.getCache();

     const char*        stop = text + byteLength;
     SkTextAlignProc    alignProc(paint.getTextAlign());
     SkTextMapStateProc tmsProc(SkMatrix::I(), offset, scalarsPerPosition);

     // Now restore the original settings, so we "draw" with whatever style/stroking.
     paint.setStyle(origPaint.getStyle());
     paint.setPathEffect(origPaint.getPathEffect());

     while (text < stop) {
         const SkGlyph& glyph = glyphCacheProc(cache, &text, 0, 0);
         if (glyph.fWidth) {
             const SkPath* path = cache->findPath(glyph);
             if (path) {
                 SkPoint tmsLoc;
                 tmsProc(pos, &tmsLoc);
                 SkPoint loc;
                 alignProc(tmsLoc, glyph, &loc);

                 matrix[SkMatrix::kMTransX] = loc.fX;
                 matrix[SkMatrix::kMTransY] = loc.fY;
                 GrBlurUtils::drawPathWithMaskFilter(fContext, dc, rt, clip, *path, paint,
                                                     viewMatrix, &matrix, clipBounds, false);
             }
         }
         pos += scalarsPerPosition;
     }
 }

 // *** change to output positions?
 int GrTextContext::MeasureText(SkGlyphCache* cache, SkDrawCacheProc glyphCacheProc,
                                 const char text[], size_t byteLength, SkVector* stopVector) {
     SkFixed     x = 0, y = 0;
     const char* stop = text + byteLength;

     SkAutoKern  autokern;

     int numGlyphs = 0;
     while (text < stop) {
         // don't need x, y here, since all subpixel variants will have the
         // same advance
         const SkGlyph& glyph = glyphCacheProc(cache, &text, 0, 0);

         x += autokern.adjust(glyph) + glyph.fAdvanceX;
         y += glyph.fAdvanceY;
         ++numGlyphs;
     }
     stopVector->set(SkFixedToScalar(x), SkFixedToScalar(y));

     SkASSERT(text == stop);

     return numGlyphs;
 }

 static void GlyphCacheAuxProc(void* data) {
     GrFontScaler* scaler = (GrFontScaler*)data;
     SkSafeUnref(scaler);
 }

 GrFontScaler* GrTextContext::GetGrFontScaler(SkGlyphCache* cache) {
     void* auxData;
     GrFontScaler* scaler = nullptr;

     if (cache->getAuxProcData(GlyphCacheAuxProc, &auxData)) {
         scaler = (GrFontScaler*)auxData;
     }
     if (nullptr == scaler) {
         scaler = new GrFontScaler(cache);
         cache->setAuxProc(GlyphCacheAuxProc, scaler);
     }

     return scaler;
 }
	/*
	* Copyright 2010 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "GrTextContext.h"
	#include "GrBlurUtils.h"
	#include "GrContext.h"
	#include "GrDrawContext.h"
	#include "GrFontScaler.h"

	#include "SkAutoKern.h"
	#include "SkDrawFilter.h"
	#include "SkDrawProcs.h"
	#include "SkGlyphCache.h"
	#include "SkGpuDevice.h"
	#include "SkGrPriv.h"
	#include "SkTextBlobRunIterator.h"
	#include "SkTextMapStateProc.h"
	#include "SkTextToPathIter.h"

	GrTextContext::GrTextContext(GrContext* context, const SkSurfaceProps& surfaceProps)
	: fFallbackTextContext(nullptr)
	, fContext(context)
	, fSurfaceProps(surfaceProps) {
	}

	GrTextContext::~GrTextContext() {
	delete fFallbackTextContext;
	}

	void GrTextContext::drawText(GrDrawContext* dc, GrRenderTarget* rt,
	const GrClip& clip, const GrPaint& paint,
	const SkPaint& skPaint, const SkMatrix& viewMatrix,
	const char text[], size_t byteLength,
	SkScalar x, SkScalar y, const SkIRect& clipBounds) {
	if (fContext->abandoned()) {
	return;
	}

	GrTextContext* textContext = this;
	do {
	if (textContext->canDraw(rt, clip, paint, skPaint, viewMatrix)) {
	textContext->onDrawText(dc, rt, clip, paint, skPaint, viewMatrix,
	text, byteLength, x, y, clipBounds);
	return;
	}
	textContext = textContext->fFallbackTextContext;
	} while (textContext);

	// fall back to drawing as a path
	this->drawTextAsPath(dc, rt, clip, skPaint, viewMatrix,
	text, byteLength, x, y, clipBounds);
	}

	void GrTextContext::drawPosText(GrDrawContext* dc, GrRenderTarget* rt,
	const GrClip& clip, const GrPaint& paint,
	const SkPaint& skPaint, const SkMatrix& viewMatrix,
	const char text[], size_t byteLength,
	const SkScalar pos[], int scalarsPerPosition,
	const SkPoint& offset, const SkIRect& clipBounds) {
	if (fContext->abandoned()) {
	return;
	}

	GrTextContext* textContext = this;
	do {
	if (textContext->canDraw(rt, clip, paint, skPaint, viewMatrix)) {
	textContext->onDrawPosText(dc, rt, clip, paint, skPaint, viewMatrix,
	text, byteLength, pos,
	scalarsPerPosition, offset, clipBounds);
	return;
	}
	textContext = textContext->fFallbackTextContext;
	} while (textContext);

	// fall back to drawing as a path
	this->drawPosTextAsPath(dc, rt, clip, skPaint, viewMatrix, text, byteLength, pos,
	scalarsPerPosition, offset, clipBounds);
	}

	bool GrTextContext::ShouldDisableLCD(const SkPaint& paint) {
	if (!SkXfermode::AsMode(paint.getXfermode(), nullptr) \|\|
	paint.getMaskFilter() \|\|
	paint.getRasterizer() \|\|
	paint.getPathEffect() \|\|
	paint.isFakeBoldText() \|\|
	paint.getStyle() != SkPaint::kFill_Style)
	{
	return true;
	}
	return false;
	}

	uint32_t GrTextContext::FilterTextFlags(const SkSurfaceProps& surfaceProps, const SkPaint& paint) {
	uint32_t flags = paint.getFlags();

	if (!paint.isLCDRenderText() \|\| !paint.isAntiAlias()) {
	return flags;
	}

	if (kUnknown_SkPixelGeometry == surfaceProps.pixelGeometry() \|\| ShouldDisableLCD(paint)) {
	flags &= ~SkPaint::kLCDRenderText_Flag;
	flags \|= SkPaint::kGenA8FromLCD_Flag;
	}

	return flags;
	}

	void GrTextContext::drawTextBlob(GrDrawContext* dc, GrRenderTarget* rt,
	const GrClip& clip, const SkPaint& skPaint,
	const SkMatrix& viewMatrix, const SkTextBlob* blob,
	SkScalar x, SkScalar y,
	SkDrawFilter* drawFilter, const SkIRect& clipBounds) {
	SkPaint runPaint = skPaint;

	SkTextBlobRunIterator it(blob);
	for (;!it.done(); it.next()) {
	size_t textLen = it.glyphCount() * sizeof(uint16_t);
	const SkPoint& offset = it.offset();
	// applyFontToPaint() always overwrites the exact same attributes,
	// so it is safe to not re-seed the paint for this reason.
	it.applyFontToPaint(&runPaint);

	if (drawFilter && !drawFilter->filter(&runPaint, SkDrawFilter::kText_Type)) {
	// A false return from filter() means we should abort the current draw.
	runPaint = skPaint;
	continue;
	}

	runPaint.setFlags(FilterTextFlags(fSurfaceProps, runPaint));

	GrPaint grPaint;
	if (!SkPaintToGrPaint(fContext, runPaint, viewMatrix, &grPaint)) {
	return;
	}

	switch (it.positioning()) {
	case SkTextBlob::kDefault_Positioning:
	this->drawText(dc, rt, clip, grPaint, runPaint, viewMatrix, (const char *)it.glyphs(),
	textLen, x + offset.x(), y + offset.y(), clipBounds);
	break;
	case SkTextBlob::kHorizontal_Positioning:
	this->drawPosText(dc, rt, clip, grPaint, runPaint, viewMatrix, (const char*)it.glyphs(),
	textLen, it.pos(), 1, SkPoint::Make(x, y + offset.y()), clipBounds);
	break;
	case SkTextBlob::kFull_Positioning:
	this->drawPosText(dc, rt, clip, grPaint, runPaint, viewMatrix, (const char*)it.glyphs(),
	textLen, it.pos(), 2, SkPoint::Make(x, y), clipBounds);
	break;
	default:
	SkFAIL("unhandled positioning mode");
	}

	if (drawFilter) {
	// A draw filter may change the paint arbitrarily, so we must re-seed in this case.
	runPaint = skPaint;
	}
	}
	}

	void GrTextContext::drawTextAsPath(GrDrawContext* dc, GrRenderTarget* rt,
	const GrClip& clip,
	const SkPaint& skPaint, const SkMatrix& viewMatrix,
	const char text[], size_t byteLength, SkScalar x, SkScalar y,
	const SkIRect& clipBounds) {
	SkTextToPathIter iter(text, byteLength, skPaint, true);

	SkMatrix matrix;
	matrix.setScale(iter.getPathScale(), iter.getPathScale());
	matrix.postTranslate(x, y);

	const SkPath* iterPath;
	SkScalar xpos, prevXPos = 0;

	while (iter.next(&iterPath, &xpos)) {
	matrix.postTranslate(xpos - prevXPos, 0);
	if (iterPath) {
	const SkPaint& pnt = iter.getPaint();
	GrBlurUtils::drawPathWithMaskFilter(fContext, dc, rt, clip, *iterPath,
	pnt, viewMatrix, &matrix, clipBounds, false);
	}
	prevXPos = xpos;
	}
	}

	void GrTextContext::drawPosTextAsPath(GrDrawContext* dc, GrRenderTarget* rt,
	const GrClip& clip,
	const SkPaint& origPaint, const SkMatrix& viewMatrix,
	const char text[], size_t byteLength,
	const SkScalar pos[], int scalarsPerPosition,
	const SkPoint& offset, const SkIRect& clipBounds) {
	// setup our std paint, in hopes of getting hits in the cache
	SkPaint paint(origPaint);
	SkScalar matrixScale = paint.setupForAsPaths();

	SkMatrix matrix;
	matrix.setScale(matrixScale, matrixScale);

	// Temporarily jam in kFill, so we only ever ask for the raw outline from the cache.
	paint.setStyle(SkPaint::kFill_Style);
	paint.setPathEffect(nullptr);

	SkDrawCacheProc glyphCacheProc = paint.getDrawCacheProc();
	SkAutoGlyphCache autoCache(paint, &fSurfaceProps, nullptr);
	SkGlyphCache* cache = autoCache.getCache();

	const char* stop = text + byteLength;
	SkTextAlignProc alignProc(paint.getTextAlign());
	SkTextMapStateProc tmsProc(SkMatrix::I(), offset, scalarsPerPosition);

	// Now restore the original settings, so we "draw" with whatever style/stroking.
	paint.setStyle(origPaint.getStyle());
	paint.setPathEffect(origPaint.getPathEffect());

	while (text < stop) {
	const SkGlyph& glyph = glyphCacheProc(cache, &text, 0, 0);
	if (glyph.fWidth) {
	const SkPath* path = cache->findPath(glyph);
	if (path) {
	SkPoint tmsLoc;
	tmsProc(pos, &tmsLoc);
	SkPoint loc;
	alignProc(tmsLoc, glyph, &loc);

	matrix[SkMatrix::kMTransX] = loc.fX;
	matrix[SkMatrix::kMTransY] = loc.fY;
	GrBlurUtils::drawPathWithMaskFilter(fContext, dc, rt, clip, *path, paint,
	viewMatrix, &matrix, clipBounds, false);
	}
	}
	pos += scalarsPerPosition;
	}
	}

	// *** change to output positions?
	int GrTextContext::MeasureText(SkGlyphCache* cache, SkDrawCacheProc glyphCacheProc,
	const char text[], size_t byteLength, SkVector* stopVector) {
	SkFixed x = 0, y = 0;
	const char* stop = text + byteLength;

	SkAutoKern autokern;

	int numGlyphs = 0;
	while (text < stop) {
	// don't need x, y here, since all subpixel variants will have the
	// same advance
	const SkGlyph& glyph = glyphCacheProc(cache, &text, 0, 0);

	x += autokern.adjust(glyph) + glyph.fAdvanceX;
	y += glyph.fAdvanceY;
	++numGlyphs;
	}
	stopVector->set(SkFixedToScalar(x), SkFixedToScalar(y));

	SkASSERT(text == stop);

	return numGlyphs;
	}

	static void GlyphCacheAuxProc(void* data) {
	GrFontScaler* scaler = (GrFontScaler*)data;
	SkSafeUnref(scaler);
	}

	GrFontScaler* GrTextContext::GetGrFontScaler(SkGlyphCache* cache) {
	void* auxData;
	GrFontScaler* scaler = nullptr;

	if (cache->getAuxProcData(GlyphCacheAuxProc, &auxData)) {
	scaler = (GrFontScaler*)auxData;
	}
	if (nullptr == scaler) {
	scaler = new GrFontScaler(cache);
	cache->setAuxProc(GlyphCacheAuxProc, scaler);
	}

	return scaler;
	}