skia2/include/gpu/GrRenderTarget.h
Robert Phillips cb2e235e6f Reduce stencil buffer clearing
TBR=bsalomon@google.com
Bug: skia:6953
Change-Id: I079f90711297ee290f2d4011cfcb18b764554deb
Reviewed-on: https://skia-review.googlesource.com/40691
Reviewed-by: Robert Phillips <robertphillips@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
2017-08-30 21:17:36 +00:00

143 lines
4.7 KiB
C++

/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrRenderTarget_DEFINED
#define GrRenderTarget_DEFINED
#include "GrSurface.h"
#include "SkRect.h"
class GrCaps;
class GrRenderTargetOpList;
class GrRenderTargetPriv;
class GrStencilAttachment;
/**
* GrRenderTarget represents a 2D buffer of pixels that can be rendered to.
* A context's render target is set by setRenderTarget(). Render targets are
* created by a createTexture with the kRenderTarget_SurfaceFlag flag.
* Additionally, GrContext provides methods for creating GrRenderTargets
* that wrap externally created render targets.
*/
class GrRenderTarget : virtual public GrSurface {
public:
virtual bool alwaysClearStencil() const { return false; }
// GrSurface overrides
GrRenderTarget* asRenderTarget() override { return this; }
const GrRenderTarget* asRenderTarget() const override { return this; }
// GrRenderTarget
bool isStencilBufferMultisampled() const { return fSampleCnt > 0; }
GrFSAAType fsaaType() const {
if (!fSampleCnt) {
SkASSERT(!(fFlags & GrRenderTargetFlags::kMixedSampled));
return GrFSAAType::kNone;
}
return (fFlags & GrRenderTargetFlags::kMixedSampled) ? GrFSAAType::kMixedSamples
: GrFSAAType::kUnifiedMSAA;
}
/**
* Returns the number of samples/pixel in the stencil buffer (Zero if non-MSAA).
*/
int numStencilSamples() const { return fSampleCnt; }
/**
* Returns the number of samples/pixel in the color buffer (Zero if non-MSAA or mixed sampled).
*/
int numColorSamples() const {
return GrFSAAType::kMixedSamples == this->fsaaType() ? 0 : fSampleCnt;
}
/**
* Call to indicate the multisample contents were modified such that the
* render target needs to be resolved before it can be used as texture. Gr
* tracks this for its own drawing and thus this only needs to be called
* when the render target has been modified outside of Gr. This has no
* effect on wrapped backend render targets.
*
* @param rect a rect bounding the area needing resolve. NULL indicates
* the whole RT needs resolving.
*/
void flagAsNeedingResolve(const SkIRect* rect = nullptr);
/**
* Call to override the region that needs to be resolved.
*/
void overrideResolveRect(const SkIRect rect);
/**
* Call to indicate that GrRenderTarget was externally resolved. This may
* allow Gr to skip a redundant resolve step.
*/
void flagAsResolved() { fResolveRect.setLargestInverted(); }
/**
* @return true if the GrRenderTarget requires MSAA resolving
*/
bool needsResolve() const { return !fResolveRect.isEmpty(); }
/**
* Returns a rect bounding the region needing resolving.
*/
const SkIRect& getResolveRect() const { return fResolveRect; }
// a MSAA RT may require explicit resolving , it may auto-resolve (e.g. FBO
// 0 in GL), or be unresolvable because the client didn't give us the
// resolve destination.
enum ResolveType {
kCanResolve_ResolveType,
kAutoResolves_ResolveType,
kCantResolve_ResolveType,
};
virtual ResolveType getResolveType() const = 0;
/**
* Return the native ID or handle to the rendertarget, depending on the
* platform. e.g. on OpenGL, return the FBO ID.
*/
virtual GrBackendObject getRenderTargetHandle() const = 0;
// Checked when this object is asked to attach a stencil buffer.
virtual bool canAttemptStencilAttachment() const = 0;
// Provides access to functions that aren't part of the public API.
GrRenderTargetPriv renderTargetPriv();
const GrRenderTargetPriv renderTargetPriv() const;
protected:
GrRenderTarget(GrGpu*, const GrSurfaceDesc&,
GrRenderTargetFlags = GrRenderTargetFlags::kNone,
GrStencilAttachment* = nullptr);
// override of GrResource
void onAbandon() override;
void onRelease() override;
private:
// Allows the backends to perform any additional work that is required for attaching a
// GrStencilAttachment. When this is called, the GrStencilAttachment has already been put onto
// the GrRenderTarget. This function must return false if any failures occur when completing the
// stencil attachment.
virtual bool completeStencilAttachment() = 0;
friend class GrRenderTargetPriv;
int fSampleCnt;
GrStencilAttachment* fStencilAttachment;
uint8_t fMultisampleSpecsID;
GrRenderTargetFlags fFlags;
SkIRect fResolveRect;
typedef GrSurface INHERITED;
};
#endif