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/*
* Copyright 2010 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrBatchedTextContext_DEFINED
#define GrBatchedTextContext_DEFINED
#include "GrPaint.h"
#include "GrTextContext.h"
class GrDrawTarget;
class GrTexture;
/**
* Base class for TextContexts that can batch multiple glyphs into single draw.
*
* Every glyph is encoded on a single texture.
* Every glyph is enclosed within a quad (formed by triangle fan) represented
* by 4 vertices.
*/
class GrBatchedTextContext: public GrTextContext {
public:
virtual ~GrBatchedTextContext();
protected:
enum {
kMinRequestedGlyphs = 1,
kDefaultRequestedGlyphs = 64,
kMinRequestedVerts = kMinRequestedGlyphs * 4,
kDefaultRequestedVerts = kDefaultRequestedGlyphs * 4,
kGlyphMaskStage = GrPaint::kTotalStages,
};
GrPaint fGrPaint;
GrDrawTarget* fDrawTarget;
int32_t fMaxVertices;
GrTexture* fCurrTexture;
int fCurrVertex;
GrBatchedTextContext();
virtual void init(GrContext* context, const GrPaint&,
const GrMatrix* extMatrix) SK_OVERRIDE;
virtual void finish() SK_OVERRIDE;
/**
* Prepare to add another glyph to buffer. The glyph is encoded on the
* texture provided. Make sure we are using the right texture (or switch
* to a new texture) and that our buffer is big enough.
*/
void prepareForGlyph(GrTexture*);
/**
* Flush the buffer. Called when switching textures.
* Must be called in finish() method of all derived classes.
*/
virtual void flush() = 0;
/**
* Set up a buffer to hold vertices of given layout.
* If NULL != *vertexBuff, don't do anything.
* Might cause flushing, if draw target suggests it.
*/
void setupVertexBuff(void** vertexBuff, GrVertexLayout vertexLayout);
/**
* Reset after flushing.
*/
void reset();
private:
typedef GrTextContext INHERITED;
};
#endif