skia2/include/gpu/GrTextContext.h
2012-05-10 12:40:40 +00:00

116 lines
2.8 KiB
C++

/*
* 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 GrTextContext_DEFINED
#define GrTextContext_DEFINED
#include "GrGlyph.h"
#include "GrMatrix.h"
#include "GrRefCnt.h"
class GrContext;
class GrFontScaler;
class GrPaint;
class SkGpuDevice;
class SkPaint;
/**
* Derived classes can use stages GrPaint::kTotalStages through
* GrDrawState::kNumStages-1. The stages before GrPaint::kTotalStages
* are reserved for setting up the draw (i.e., textures and filter masks).
*/
class GrTextContext: public GrRefCnt {
protected:
GrContext* fContext;
public:
/**
* To use a text context it must be wrapped in an AutoFinish. AutoFinish's
* destructor ensures all drawing is flushed to the GrContext.
*/
class AutoFinish {
public:
AutoFinish(GrTextContext* textContext, GrContext* context,
const GrPaint&, const GrMatrix* extMatrix);
~AutoFinish();
GrTextContext* getTextContext() const;
private:
GrTextContext* fTextContext;
};
virtual void drawPackedGlyph(GrGlyph::PackedID, GrFixed left, GrFixed top,
GrFontScaler*) = 0;
virtual ~GrTextContext() {}
protected:
GrTextContext() {
fContext = NULL;
}
bool isValid() const {
return (NULL != fContext);
}
/**
* Initialize the object.
*
* Before call to this method, the instance is considered to be in
* invalid state. I.e. call to any method other than isValid will result in
* undefined behaviour.
*
* @see finish
*/
virtual void init(GrContext* context, const GrPaint&,
const GrMatrix* extMatrix) {
fContext = context;
}
/**
* Reset the object to invalid state.
*
* After call to this method, the instance is considered to be in
* invalid state.
*
* It might be brought back to a valid state by calling init.
*
* @see init
*/
virtual void finish() {
fContext = NULL;
}
private:
typedef GrRefCnt INHERITED;
};
inline GrTextContext::AutoFinish::AutoFinish(GrTextContext* textContext,
GrContext* context,
const GrPaint& grPaint,
const GrMatrix* extMatrix) {
GrAssert(NULL != textContext);
fTextContext = textContext;
fTextContext->ref();
fTextContext->init(context, grPaint, extMatrix);
}
inline GrTextContext::AutoFinish::~AutoFinish() {
fTextContext->finish();
fTextContext->unref();
}
inline GrTextContext* GrTextContext::AutoFinish::getTextContext() const {
return fTextContext;
}
#endif