blob: d23a525e7a02e5446d4bb3e13671fdb860bf4776 [file] [log] [blame]
/*
* Copyright 2012 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrClipMaskManager_DEFINED
#define GrClipMaskManager_DEFINED
#include "GrContext.h"
#include "GrNoncopyable.h"
#include "GrRect.h"
#include "GrStencil.h"
#include "GrTexture.h"
#include "SkClipStack.h"
#include "SkDeque.h"
#include "SkPath.h"
#include "SkRefCnt.h"
#include "GrClipMaskCache.h"
class GrGpu;
class GrPathRenderer;
class GrPathRendererChain;
class SkPath;
class GrTexture;
class GrDrawState;
/**
* The clip mask creator handles the generation of the clip mask. If anti
* aliasing is requested it will (in the future) generate a single channel
* (8bit) mask. If no anti aliasing is requested it will generate a 1-bit
* mask in the stencil buffer. In the non anti-aliasing case, if the clip
* mask can be represented as a rectangle then scissoring is used. In all
* cases scissoring is used to bound the range of the clip mask.
*/
class GrClipMaskManager : public GrNoncopyable {
public:
GR_DECLARE_RESOURCE_CACHE_DOMAIN(GetAlphaMaskDomain)
GrClipMaskManager()
: fGpu(NULL)
, fCurrClipMaskType(kNone_ClipMaskType) {
}
/**
* Creates a clip mask if necessary as a stencil buffer or alpha texture
* and sets the GrGpu's scissor and stencil state. If the return is false
* then the draw can be skipped.
*/
bool setupClipping(const GrClipData* clipDataIn);
void releaseResources();
bool isClipInStencil() const {
return kStencil_ClipMaskType == fCurrClipMaskType;
}
bool isClipInAlpha() const {
return kAlpha_ClipMaskType == fCurrClipMaskType;
}
void invalidateStencilMask() {
if (kStencil_ClipMaskType == fCurrClipMaskType) {
fCurrClipMaskType = kNone_ClipMaskType;
}
}
void setContext(GrContext* context) {
fAACache.setContext(context);
}
GrContext* getContext() {
return fAACache.getContext();
}
void setGpu(GrGpu* gpu) {
fGpu = gpu;
}
private:
/**
* Informs the helper function adjustStencilParams() about how the stencil
* buffer clip is being used.
*/
enum StencilClipMode {
// Draw to the clip bit of the stencil buffer
kModifyClip_StencilClipMode,
// Clip against the existing representation of the clip in the high bit
// of the stencil buffer.
kRespectClip_StencilClipMode,
// Neither writing to nor clipping against the clip bit.
kIgnoreClip_StencilClipMode,
};
GrGpu* fGpu;
/**
* We may represent the clip as a mask in the stencil buffer or as an alpha
* texture. It may be neither because the scissor rect suffices or we
* haven't yet examined the clip.
*/
enum ClipMaskType {
kNone_ClipMaskType,
kStencil_ClipMaskType,
kAlpha_ClipMaskType,
} fCurrClipMaskType;
GrClipMaskCache fAACache; // cache for the AA path
bool createStencilClipMask(const GrClipData& clipDataIn,
const GrIRect& devClipBounds);
bool createAlphaClipMask(const GrClipData& clipDataIn,
GrTexture** result,
GrIRect *devResultBounds);
bool createSoftwareClipMask(const GrClipData& clipDataIn,
GrTexture** result,
GrIRect *devResultBounds);
bool clipMaskPreamble(const GrClipData& clipDataIn,
GrTexture** result,
GrIRect *devResultBounds);
bool useSWOnlyPath(const SkClipStack& clipIn);
bool drawClipShape(GrTexture* target,
const SkClipStack::Iter::Clip* clip,
const GrIRect& resultBounds);
void drawTexture(GrTexture* target,
GrTexture* texture);
void getTemp(const GrIRect& bounds, GrAutoScratchTexture* temp);
void setupCache(const SkClipStack& clip,
const GrIRect& bounds);
/**
* Called prior to return control back the GrGpu in setupClipping. It
* updates the GrGpu with stencil settings that account stencil-based
* clipping.
*/
void setGpuStencil();
/**
* Adjusts the stencil settings to account for interaction with stencil
* clipping.
*/
void adjustStencilParams(GrStencilSettings* settings,
StencilClipMode mode,
int stencilBitCnt);
typedef GrNoncopyable INHERITED;
};
#endif // GrClipMaskManager_DEFINED