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/*
* 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 GrDrawState_DEFINED
#define GrDrawState_DEFINED
#include "GrBackendEffectFactory.h"
#include "GrColor.h"
#include "GrEffectStage.h"
#include "GrPaint.h"
#include "GrRefCnt.h"
#include "GrRenderTarget.h"
#include "GrStencil.h"
#include "GrTemplates.h"
#include "GrTexture.h"
#include "GrTypesPriv.h"
#include "effects/GrSimpleTextureEffect.h"
#include "SkMatrix.h"
#include "SkXfermode.h"
class GrDrawState : public GrRefCnt {
public:
SK_DECLARE_INST_COUNT(GrDrawState)
/**
* Total number of effect stages. Each stage can host a GrEffect. A stage is enabled if it has a
* GrEffect. The effect produces an output color in the fragment shader. It's inputs are the
* output from the previous enabled stage and a position. The position is either derived from
* the interpolated vertex positions or explicit per-vertex coords, depending upon the
* GrAttribBindings used to draw.
*
* The stages are divided into two sets, color-computing and coverage-computing. The final color
* stage produces the final pixel color. The coverage-computing stages function exactly as the
* color-computing but the output of the final coverage stage is treated as a fractional pixel
* coverage rather than as input to the src/dst color blend step.
*
* The input color to the first enabled color-stage is either the constant color or interpolated
* per-vertex colors. The input to the first coverage stage is either a constant coverage
* (usually full-coverage) or interpolated per-vertex coverage.
*
* See the documentation of kCoverageDrawing_StateBit for information about disabling the
* the color / coverage distinction.
*
* Stages 0 through GrPaint::kTotalStages-1 are reserved for stages copied from the client's
* GrPaint. Stage GrPaint::kTotalStages is earmarked for use by GrTextContext, GrPathRenderer-
* derived classes, and the rect/oval helper classes. GrPaint::kTotalStages+1 is earmarked for
* clipping by GrClipMaskManager. TODO: replace fixed size array of stages with variable size
* arrays of color and coverage stages.
*/
enum {
kNumStages = GrPaint::kTotalStages + 2,
};
GrDrawState() {
this->reset();
}
GrDrawState(const GrDrawState& state) {
*this = state;
}
virtual ~GrDrawState() {
this->disableStages();
}
/**
* Resets to the default state.
* GrEffects will be removed from all stages.
*/
void reset() {
this->disableStages();
fRenderTarget.reset(NULL);
this->setDefaultVertexAttribs();
fCommon.fColor = 0xffffffff;
fCommon.fViewMatrix.reset();
fCommon.fSrcBlend = kOne_GrBlendCoeff;
fCommon.fDstBlend = kZero_GrBlendCoeff;
fCommon.fBlendConstant = 0x0;
fCommon.fFlagBits = 0x0;
fCommon.fStencilSettings.setDisabled();
fCommon.fFirstCoverageStage = kNumStages;
fCommon.fCoverage = 0xffffffff;
fCommon.fColorFilterMode = SkXfermode::kDst_Mode;
fCommon.fColorFilterColor = 0x0;
fCommon.fDrawFace = kBoth_DrawFace;
}
/**
* Initializes the GrDrawState based on a GrPaint. Note that GrDrawState
* encompasses more than GrPaint. Aspects of GrDrawState that have no
* GrPaint equivalents are not modified. GrPaint has fewer stages than
* GrDrawState. The extra GrDrawState stages are disabled.
*/
void setFromPaint(const GrPaint& paint);
///////////////////////////////////////////////////////////////////////////
/// @name Vertex Attributes
////
enum {
kMaxVertexAttribCnt = kLast_GrVertexAttribBinding + 4,
};
/**
* The format of vertices is represented as an array of GrVertexAttribs, with each representing
* the type of the attribute, its offset, and semantic binding (see GrVertexAttrib in
* GrTypesPriv.h).
*
* The mapping of attributes with kEffect bindings to GrEffect inputs is specified when
* setEffect is called.
*/
/**
* Sets vertex attributes for next draw.
*
* @param attribs the array of vertex attributes to set.
* @param count the number of attributes being set, limited to kMaxVertexAttribCnt.
*/
void setVertexAttribs(const GrVertexAttrib attribs[], int count);
const GrVertexAttrib* getVertexAttribs() const { return fCommon.fVertexAttribs.begin(); }
int getVertexAttribCount() const { return fCommon.fVertexAttribs.count(); }
size_t getVertexSize() const;
/**
* Sets default vertex attributes for next draw. The default is a single attribute:
* {kVec2f_GrVertexAttribType, 0, kPosition_GrVertexAttribType}
*/
void setDefaultVertexAttribs();
/**
* Getters for index into getVertexAttribs() for particular bindings. -1 is returned if the
* binding does not appear in the current attribs. These bindings should appear only once in
* the attrib array.
*/
int positionAttributeIndex() const {
return fCommon.fFixedFunctionVertexAttribIndices[kPosition_GrVertexAttribBinding];
}
int localCoordAttributeIndex() const {
return fCommon.fFixedFunctionVertexAttribIndices[kLocalCoord_GrVertexAttribBinding];
}
int colorVertexAttributeIndex() const {
return fCommon.fFixedFunctionVertexAttribIndices[kColor_GrVertexAttribBinding];
}
int coverageVertexAttributeIndex() const {
return fCommon.fFixedFunctionVertexAttribIndices[kCoverage_GrVertexAttribBinding];
}
bool hasLocalCoordAttribute() const {
return -1 != fCommon.fFixedFunctionVertexAttribIndices[kLocalCoord_GrVertexAttribBinding];
}
bool hasColorVertexAttribute() const {
return -1 != fCommon.fFixedFunctionVertexAttribIndices[kColor_GrVertexAttribBinding];
}
bool hasCoverageVertexAttribute() const {
return -1 != fCommon.fFixedFunctionVertexAttribIndices[kCoverage_GrVertexAttribBinding];
}
bool validateVertexAttribs() const;
/**
* Accessing positions, local coords, or colors, of a vertex within an array is a hassle
* involving casts and simple math. These helpers exist to keep GrDrawTarget clients' code a bit
* nicer looking.
*/
/**
* Gets a pointer to a GrPoint of a vertex's position or texture
* coordinate.
* @param vertices the vertex array
* @param vertexIndex the index of the vertex in the array
* @param vertexSize the size of each vertex in the array
* @param offset the offset in bytes of the vertex component.
* Defaults to zero (corresponding to vertex position)
* @return pointer to the vertex component as a GrPoint
*/
static GrPoint* GetVertexPoint(void* vertices,
int vertexIndex,
int vertexSize,
int offset = 0) {
intptr_t start = GrTCast<intptr_t>(vertices);
return GrTCast<GrPoint*>(start + offset +
vertexIndex * vertexSize);
}
static const GrPoint* GetVertexPoint(const void* vertices,
int vertexIndex,
int vertexSize,
int offset = 0) {
intptr_t start = GrTCast<intptr_t>(vertices);
return GrTCast<const GrPoint*>(start + offset +
vertexIndex * vertexSize);
}
/**
* Gets a pointer to a GrColor inside a vertex within a vertex array.
* @param vertices the vetex array
* @param vertexIndex the index of the vertex in the array
* @param vertexSize the size of each vertex in the array
* @param offset the offset in bytes of the vertex color
* @return pointer to the vertex component as a GrColor
*/
static GrColor* GetVertexColor(void* vertices,
int vertexIndex,
int vertexSize,
int offset) {
intptr_t start = GrTCast<intptr_t>(vertices);
return GrTCast<GrColor*>(start + offset +
vertexIndex * vertexSize);
}
static const GrColor* GetVertexColor(const void* vertices,
int vertexIndex,
int vertexSize,
int offset) {
const intptr_t start = GrTCast<intptr_t>(vertices);
return GrTCast<const GrColor*>(start + offset +
vertexIndex * vertexSize);
}
/// @}
/**
* Determines whether src alpha is guaranteed to be one for all src pixels
*/
bool srcAlphaWillBeOne() const;
/**
* Determines whether the output coverage is guaranteed to be one for all pixels hit by a draw.
*/
bool hasSolidCoverage() const;
/// @}
///////////////////////////////////////////////////////////////////////////
/// @name Color
////
/**
* Sets color for next draw to a premultiplied-alpha color.
*
* @param color the color to set.
*/
void setColor(GrColor color) { fCommon.fColor = color; }
GrColor getColor() const { return fCommon.fColor; }
/**
* Sets the color to be used for the next draw to be
* (r,g,b,a) = (alpha, alpha, alpha, alpha).
*
* @param alpha The alpha value to set as the color.
*/
void setAlpha(uint8_t a) {
this->setColor((a << 24) | (a << 16) | (a << 8) | a);
}
/**
* Add a color filter that can be represented by a color and a mode. Applied
* after color-computing effect stages.
*/
void setColorFilter(GrColor c, SkXfermode::Mode mode) {
fCommon.fColorFilterColor = c;
fCommon.fColorFilterMode = mode;
}
GrColor getColorFilterColor() const { return fCommon.fColorFilterColor; }
SkXfermode::Mode getColorFilterMode() const { return fCommon.fColorFilterMode; }
/**
* Constructor sets the color to be 'color' which is undone by the destructor.
*/
class AutoColorRestore : public ::GrNoncopyable {
public:
AutoColorRestore() : fDrawState(NULL), fOldColor(0) {}
AutoColorRestore(GrDrawState* drawState, GrColor color) {
fDrawState = NULL;
this->set(drawState, color);
}
void reset() {
if (NULL != fDrawState) {
fDrawState->setColor(fOldColor);
fDrawState = NULL;
}
}
void set(GrDrawState* drawState, GrColor color) {
this->reset();
fDrawState = drawState;
fOldColor = fDrawState->getColor();
fDrawState->setColor(color);
}
~AutoColorRestore() { this->reset(); }
private:
GrDrawState* fDrawState;
GrColor fOldColor;
};
/// @}
///////////////////////////////////////////////////////////////////////////
/// @name Coverage
////
/**
* Sets a constant fractional coverage to be applied to the draw. The
* initial value (after construction or reset()) is 0xff. The constant
* coverage is ignored when per-vertex coverage is provided.
*/
void setCoverage(uint8_t coverage) {
fCommon.fCoverage = GrColorPackRGBA(coverage, coverage, coverage, coverage);
}
/**
* Version of above that specifies 4 channel per-vertex color. The value
* should be premultiplied.
*/
void setCoverage4(GrColor coverage) {
fCommon.fCoverage = coverage;
}
GrColor getCoverage() const {
return fCommon.fCoverage;
}
/// @}
///////////////////////////////////////////////////////////////////////////
/// @name Effect Stages
////
const GrEffectRef* setEffect(int stageIdx, const GrEffectRef* effect) {
fStages[stageIdx].setEffect(effect);
return effect;
}
const GrEffectRef* setEffect(int stageIdx, const GrEffectRef* effect,
int attr0, int attr1 = -1) {
fStages[stageIdx].setEffect(effect, attr0, attr1);
return effect;
}
/**
* Creates a GrSimpleTextureEffect that uses local coords as texture coordinates.
*/
void createTextureEffect(int stageIdx, GrTexture* texture, const SkMatrix& matrix) {
GrAssert(!this->getStage(stageIdx).getEffect());
GrEffectRef* effect = GrSimpleTextureEffect::Create(texture, matrix);
this->setEffect(stageIdx, effect)->unref();
}
void createTextureEffect(int stageIdx,
GrTexture* texture,
const SkMatrix& matrix,
const GrTextureParams& params) {
GrAssert(!this->getStage(stageIdx).getEffect());
GrEffectRef* effect = GrSimpleTextureEffect::Create(texture, matrix, params);
this->setEffect(stageIdx, effect)->unref();
}
bool stagesDisabled() {
for (int i = 0; i < kNumStages; ++i) {
if (NULL != fStages[i].getEffect()) {
return false;
}
}
return true;
}
void disableStage(int stageIdx) {
this->setEffect(stageIdx, NULL);
}
/**
* Release all the GrEffects referred to by this draw state.
*/
void disableStages() {
for (int i = 0; i < kNumStages; ++i) {
this->disableStage(i);
}
}
class AutoStageDisable : public ::GrNoncopyable {
public:
AutoStageDisable(GrDrawState* ds) : fDrawState(ds) {}
~AutoStageDisable() {
if (NULL != fDrawState) {
fDrawState->disableStages();
}
}
private:
GrDrawState* fDrawState;
};
/**
* Returns the current stage by index.
*/
const GrEffectStage& getStage(int stageIdx) const {
GrAssert((unsigned)stageIdx < kNumStages);
return fStages[stageIdx];
}
/**
* Called when the source coord system is changing. This ensures that effects will see the
* correct local coordinates. oldToNew gives the transformation from the old coord system in
* which the geometry was specified to the new coordinate system from which it will be rendered.
*/
void localCoordChange(const SkMatrix& oldToNew) {
for (int i = 0; i < kNumStages; ++i) {
if (this->isStageEnabled(i)) {
fStages[i].localCoordChange(oldToNew);
}
}
}
/**
* Checks whether any of the effects will read the dst pixel color.
*/
bool willEffectReadDst() const {
for (int s = 0; s < kNumStages; ++s) {
if (this->isStageEnabled(s) && (*this->getStage(s).getEffect())->willReadDst()) {
return true;
}
}
return false;
}
/// @}
///////////////////////////////////////////////////////////////////////////
/// @name Coverage / Color Stages
////
/**
* A common pattern is to compute a color with the initial stages and then
* modulate that color by a coverage value in later stage(s) (AA, mask-
* filters, glyph mask, etc). Color-filters, xfermodes, etc should be
* computed based on the pre-coverage-modulated color. The division of
* stages between color-computing and coverage-computing is specified by
* this method. Initially this is kNumStages (all stages
* are color-computing).
*/
void setFirstCoverageStage(int firstCoverageStage) {
GrAssert((unsigned)firstCoverageStage <= kNumStages);
fCommon.fFirstCoverageStage = firstCoverageStage;
}
/**
* Gets the index of the first coverage-computing stage.
*/
int getFirstCoverageStage() const {
return fCommon.fFirstCoverageStage;
}
///@}
///////////////////////////////////////////////////////////////////////////
/// @name Blending
////
/**
* Sets the blending function coefficients.
*
* The blend function will be:
* D' = sat(S*srcCoef + D*dstCoef)
*
* where D is the existing destination color, S is the incoming source
* color, and D' is the new destination color that will be written. sat()
* is the saturation function.
*
* @param srcCoef coefficient applied to the src color.
* @param dstCoef coefficient applied to the dst color.
*/
void setBlendFunc(GrBlendCoeff srcCoeff, GrBlendCoeff dstCoeff) {
fCommon.fSrcBlend = srcCoeff;
fCommon.fDstBlend = dstCoeff;
#if GR_DEBUG
switch (dstCoeff) {
case kDC_GrBlendCoeff:
case kIDC_GrBlendCoeff:
case kDA_GrBlendCoeff:
case kIDA_GrBlendCoeff:
GrPrintf("Unexpected dst blend coeff. Won't work correctly with"
"coverage stages.\n");
break;
default:
break;
}
switch (srcCoeff) {
case kSC_GrBlendCoeff:
case kISC_GrBlendCoeff:
case kSA_GrBlendCoeff:
case kISA_GrBlendCoeff:
GrPrintf("Unexpected src blend coeff. Won't work correctly with"
"coverage stages.\n");
break;
default:
break;
}
#endif
}
GrBlendCoeff getSrcBlendCoeff() const { return fCommon.fSrcBlend; }
GrBlendCoeff getDstBlendCoeff() const { return fCommon.fDstBlend; }
void getDstBlendCoeff(GrBlendCoeff* srcBlendCoeff,
GrBlendCoeff* dstBlendCoeff) const {
*srcBlendCoeff = fCommon.fSrcBlend;
*dstBlendCoeff = fCommon.fDstBlend;
}
/**
* Sets the blending function constant referenced by the following blending
* coefficients:
* kConstC_GrBlendCoeff
* kIConstC_GrBlendCoeff
* kConstA_GrBlendCoeff
* kIConstA_GrBlendCoeff
*
* @param constant the constant to set
*/
void setBlendConstant(GrColor constant) { fCommon.fBlendConstant = constant; }
/**
* Retrieves the last value set by setBlendConstant()
* @return the blending constant value
*/
GrColor getBlendConstant() const { return fCommon.fBlendConstant; }
/**
* Determines whether multiplying the computed per-pixel color by the pixel's fractional
* coverage before the blend will give the correct final destination color. In general it
* will not as coverage is applied after blending.
*/
bool canTweakAlphaForCoverage() const;
/**
* Optimizations for blending / coverage to that can be applied based on the current state.
*/
enum BlendOptFlags {
/**
* No optimization
*/
kNone_BlendOpt = 0,
/**
* Don't draw at all
*/
kSkipDraw_BlendOptFlag = 0x1,
/**
* Emit the src color, disable HW blending (replace dst with src)
*/
kDisableBlend_BlendOptFlag = 0x2,
/**
* The coverage value does not have to be computed separately from alpha, the the output
* color can be the modulation of the two.
*/
kCoverageAsAlpha_BlendOptFlag = 0x4,
/**
* Instead of emitting a src color, emit coverage in the alpha channel and r,g,b are
* "don't cares".
*/
kEmitCoverage_BlendOptFlag = 0x8,
/**
* Emit transparent black instead of the src color, no need to compute coverage.
*/
kEmitTransBlack_BlendOptFlag = 0x10,
};
GR_DECL_BITFIELD_OPS_FRIENDS(BlendOptFlags);
/**
* Determines what optimizations can be applied based on the blend. The coefficients may have
* to be tweaked in order for the optimization to work. srcCoeff and dstCoeff are optional
* params that receive the tweaked coefficients. Normally the function looks at the current
* state to see if coverage is enabled. By setting forceCoverage the caller can speculatively
* determine the blend optimizations that would be used if there was partial pixel coverage.
*
* Subclasses of GrDrawTarget that actually draw (as opposed to those that just buffer for
* playback) must call this function and respect the flags that replace the output color.
*/
BlendOptFlags getBlendOpts(bool forceCoverage = false,
GrBlendCoeff* srcCoeff = NULL,
GrBlendCoeff* dstCoeff = NULL) const;
/// @}
///////////////////////////////////////////////////////////////////////////
/// @name View Matrix
////
/**
* Sets the matrix applied to vertex positions.
*
* In the post-view-matrix space the rectangle [0,w]x[0,h]
* fully covers the render target. (w and h are the width and height of the
* the render-target.)
*/
void setViewMatrix(const SkMatrix& m) { fCommon.fViewMatrix = m; }
/**
* Gets a writable pointer to the view matrix.
*/
SkMatrix* viewMatrix() { return &fCommon.fViewMatrix; }
/**
* Multiplies the current view matrix by a matrix
*
* After this call V' = V*m where V is the old view matrix,
* m is the parameter to this function, and V' is the new view matrix.
* (We consider positions to be column vectors so position vector p is
* transformed by matrix X as p' = X*p.)
*
* @param m the matrix used to modify the view matrix.
*/
void preConcatViewMatrix(const SkMatrix& m) { fCommon.fViewMatrix.preConcat(m); }
/**
* Multiplies the current view matrix by a matrix
*
* After this call V' = m*V where V is the old view matrix,
* m is the parameter to this function, and V' is the new view matrix.
* (We consider positions to be column vectors so position vector p is
* transformed by matrix X as p' = X*p.)
*
* @param m the matrix used to modify the view matrix.
*/
void postConcatViewMatrix(const SkMatrix& m) { fCommon.fViewMatrix.postConcat(m); }
/**
* Retrieves the current view matrix
* @return the current view matrix.
*/
const SkMatrix& getViewMatrix() const { return fCommon.fViewMatrix; }
/**
* Retrieves the inverse of the current view matrix.
*
* If the current view matrix is invertible, return true, and if matrix
* is non-null, copy the inverse into it. If the current view matrix is
* non-invertible, return false and ignore the matrix parameter.
*
* @param matrix if not null, will receive a copy of the current inverse.
*/
bool getViewInverse(SkMatrix* matrix) const {
// TODO: determine whether we really need to leave matrix unmodified
// at call sites when inversion fails.
SkMatrix inverse;
if (fCommon.fViewMatrix.invert(&inverse)) {
if (matrix) {
*matrix = inverse;
}
return true;
}
return false;
}
////////////////////////////////////////////////////////////////////////////
/**
* Preconcats the current view matrix and restores the previous view matrix in the destructor.
* Effect matrices are automatically adjusted to compensate.
*/
class AutoViewMatrixRestore : public ::GrNoncopyable {
public:
AutoViewMatrixRestore() : fDrawState(NULL) {}
AutoViewMatrixRestore(GrDrawState* ds, const SkMatrix& preconcatMatrix) {
fDrawState = NULL;
this->set(ds, preconcatMatrix);
}
~AutoViewMatrixRestore() { this->restore(); }
/**
* Can be called prior to destructor to restore the original matrix.
*/
void restore();
void set(GrDrawState* drawState, const SkMatrix& preconcatMatrix);
bool isSet() const { return NULL != fDrawState; }
private:
GrDrawState* fDrawState;
SkMatrix fViewMatrix;
GrEffectStage::SavedCoordChange fSavedCoordChanges[GrDrawState::kNumStages];
uint32_t fRestoreMask;
};
////////////////////////////////////////////////////////////////////////////
/**
* This sets the view matrix to identity and adjusts stage matrices to compensate. The
* destructor undoes the changes, restoring the view matrix that was set before the
* constructor. It is similar to passing the inverse of the current view matrix to
* AutoViewMatrixRestore, but lazily computes the inverse only if necessary.
*/
class AutoDeviceCoordDraw : ::GrNoncopyable {
public:
AutoDeviceCoordDraw() : fDrawState(NULL) {}
/**
* If a stage's texture matrix is applied to explicit per-vertex coords, rather than to
* positions, then we don't want to modify its matrix. The explicitCoordStageMask is used
* to specify such stages.
*/
AutoDeviceCoordDraw(GrDrawState* drawState) {
fDrawState = NULL;
this->set(drawState);
}
~AutoDeviceCoordDraw() { this->restore(); }
bool set(GrDrawState* drawState);
/**
* Returns true if this object was successfully initialized on to a GrDrawState. It may
* return false because a non-default constructor or set() were never called or because
* the view matrix was not invertible.
*/
bool succeeded() const { return NULL != fDrawState; }
/**
* Returns the matrix that was set previously set on the drawState. This is only valid
* if succeeded returns true.
*/
const SkMatrix& getOriginalMatrix() const {
GrAssert(this->succeeded());
return fViewMatrix;
}
/**
* Can be called prior to destructor to restore the original matrix.
*/
void restore();
private:
GrDrawState* fDrawState;
SkMatrix fViewMatrix;
GrEffectStage::SavedCoordChange fSavedCoordChanges[GrDrawState::kNumStages];
uint32_t fRestoreMask;
};
/// @}
///////////////////////////////////////////////////////////////////////////
/// @name Render Target
////
/**
* Sets the render-target used at the next drawing call
*
* @param target The render target to set.
*/
void setRenderTarget(GrRenderTarget* target) {
fRenderTarget.reset(SkSafeRef(target));
}
/**
* Retrieves the currently set render-target.
*
* @return The currently set render target.
*/
const GrRenderTarget* getRenderTarget() const { return fRenderTarget.get(); }
GrRenderTarget* getRenderTarget() { return fRenderTarget.get(); }
class AutoRenderTargetRestore : public ::GrNoncopyable {
public:
AutoRenderTargetRestore() : fDrawState(NULL), fSavedTarget(NULL) {}
AutoRenderTargetRestore(GrDrawState* ds, GrRenderTarget* newTarget) {
fDrawState = NULL;
fSavedTarget = NULL;
this->set(ds, newTarget);
}
~AutoRenderTargetRestore() { this->restore(); }
void restore() {
if (NULL != fDrawState) {
fDrawState->setRenderTarget(fSavedTarget);
fDrawState = NULL;
}
GrSafeSetNull(fSavedTarget);
}
void set(GrDrawState* ds, GrRenderTarget* newTarget) {
this->restore();
if (NULL != ds) {
GrAssert(NULL == fSavedTarget);
fSavedTarget = ds->getRenderTarget();
SkSafeRef(fSavedTarget);
ds->setRenderTarget(newTarget);
fDrawState = ds;
}
}
private:
GrDrawState* fDrawState;
GrRenderTarget* fSavedTarget;
};
/// @}
///////////////////////////////////////////////////////////////////////////
/// @name Stencil
////
/**
* Sets the stencil settings to use for the next draw.
* Changing the clip has the side-effect of possibly zeroing
* out the client settable stencil bits. So multipass algorithms
* using stencil should not change the clip between passes.
* @param settings the stencil settings to use.
*/
void setStencil(const GrStencilSettings& settings) {
fCommon.fStencilSettings = settings;
}
/**
* Shortcut to disable stencil testing and ops.
*/
void disableStencil() {
fCommon.fStencilSettings.setDisabled();
}
const GrStencilSettings& getStencil() const { return fCommon.fStencilSettings; }
GrStencilSettings* stencil() { return &fCommon.fStencilSettings; }
/// @}
///////////////////////////////////////////////////////////////////////////
/// @name State Flags
////
/**
* Flags that affect rendering. Controlled using enable/disableState(). All
* default to disabled.
*/
enum StateBits {
/**
* Perform dithering. TODO: Re-evaluate whether we need this bit
*/
kDither_StateBit = 0x01,
/**
* Perform HW anti-aliasing. This means either HW FSAA, if supported by the render target,
* or smooth-line rendering if a line primitive is drawn and line smoothing is supported by
* the 3D API.
*/
kHWAntialias_StateBit = 0x02,
/**
* Draws will respect the clip, otherwise the clip is ignored.
*/
kClip_StateBit = 0x04,
/**
* Disables writing to the color buffer. Useful when performing stencil
* operations.
*/
kNoColorWrites_StateBit = 0x08,
/**
* Usually coverage is applied after color blending. The color is blended using the coeffs
* specified by setBlendFunc(). The blended color is then combined with dst using coeffs
* of src_coverage, 1-src_coverage. Sometimes we are explicitly drawing a coverage mask. In
* this case there is no distinction between coverage and color and the caller needs direct
* control over the blend coeffs. When set, there will be a single blend step controlled by
* setBlendFunc() which will use coverage*color as the src color.
*/
kCoverageDrawing_StateBit = 0x10,
// Users of the class may add additional bits to the vector
kDummyStateBit,
kLastPublicStateBit = kDummyStateBit-1,
};
void resetStateFlags() {
fCommon.fFlagBits = 0;
}
/**
* Enable render state settings.
*
* @param stateBits bitfield of StateBits specifying the states to enable
*/
void enableState(uint32_t stateBits) {
fCommon.fFlagBits |= stateBits;
}
/**
* Disable render state settings.
*
* @param stateBits bitfield of StateBits specifying the states to disable
*/
void disableState(uint32_t stateBits) {
fCommon.fFlagBits &= ~(stateBits);
}
/**
* Enable or disable stateBits based on a boolean.
*
* @param stateBits bitfield of StateBits to enable or disable
* @param enable if true enable stateBits, otherwise disable
*/
void setState(uint32_t stateBits, bool enable) {
if (enable) {
this->enableState(stateBits);
} else {
this->disableState(stateBits);
}
}
bool isDitherState() const {
return 0 != (fCommon.fFlagBits & kDither_StateBit);
}
bool isHWAntialiasState() const {
return 0 != (fCommon.fFlagBits & kHWAntialias_StateBit);
}
bool isClipState() const {
return 0 != (fCommon.fFlagBits & kClip_StateBit);
}
bool isColorWriteDisabled() const {
return 0 != (fCommon.fFlagBits & kNoColorWrites_StateBit);
}
bool isCoverageDrawing() const {
return 0 != (fCommon.fFlagBits & kCoverageDrawing_StateBit);
}
bool isStateFlagEnabled(uint32_t stateBit) const {
return 0 != (stateBit & fCommon.fFlagBits);
}
/// @}
///////////////////////////////////////////////////////////////////////////
/// @name Face Culling
////
enum DrawFace {
kInvalid_DrawFace = -1,
kBoth_DrawFace,
kCCW_DrawFace,
kCW_DrawFace,
};
/**
* Controls whether clockwise, counterclockwise, or both faces are drawn.
* @param face the face(s) to draw.
*/
void setDrawFace(DrawFace face) {
GrAssert(kInvalid_DrawFace != face);
fCommon.fDrawFace = face;
}
/**
* Gets whether the target is drawing clockwise, counterclockwise,
* or both faces.
* @return the current draw face(s).
*/
DrawFace getDrawFace() const { return fCommon.fDrawFace; }
/// @}
///////////////////////////////////////////////////////////////////////////
bool isStageEnabled(int s) const {
GrAssert((unsigned)s < kNumStages);
return (NULL != fStages[s].getEffect());
}
bool operator ==(const GrDrawState& s) const {
if (fRenderTarget.get() != s.fRenderTarget.get() || fCommon != s.fCommon) {
return false;
}
for (int i = 0; i < kNumStages; i++) {
bool enabled = this->isStageEnabled(i);
if (enabled != s.isStageEnabled(i)) {
return false;
}
if (enabled && this->fStages[i] != s.fStages[i]) {
return false;
}
}
return true;
}
bool operator !=(const GrDrawState& s) const { return !(*this == s); }
GrDrawState& operator= (const GrDrawState& s) {
this->setRenderTarget(s.fRenderTarget.get());
fCommon = s.fCommon;
for (int i = 0; i < kNumStages; i++) {
if (s.isStageEnabled(i)) {
this->fStages[i] = s.fStages[i];
}
}
return *this;
}
private:
/** Fields that are identical in GrDrawState and GrDrawState::DeferredState. */
struct CommonState {
// These fields are roughly sorted by decreasing likelihood of being different in op==
GrColor fColor;
SkMatrix fViewMatrix;
GrBlendCoeff fSrcBlend;
GrBlendCoeff fDstBlend;
GrColor fBlendConstant;
uint32_t fFlagBits;
GrVertexAttribArray<kMaxVertexAttribCnt> fVertexAttribs;
GrStencilSettings fStencilSettings;
int fFirstCoverageStage;
GrColor fCoverage;
SkXfermode::Mode fColorFilterMode;
GrColor fColorFilterColor;
DrawFace fDrawFace;
// This is simply a different representation of info in fVertexAttribs and thus does
// not need to be compared in op==.
int fFixedFunctionVertexAttribIndices[kGrFixedFunctionVertexAttribBindingCnt];
GR_STATIC_ASSERT(kGrVertexAttribBindingCnt <= 8*sizeof(uint32_t));
bool operator== (const CommonState& other) const {
bool result = fColor == other.fColor &&
fViewMatrix.cheapEqualTo(other.fViewMatrix) &&
fSrcBlend == other.fSrcBlend &&
fDstBlend == other.fDstBlend &&
fBlendConstant == other.fBlendConstant &&
fFlagBits == other.fFlagBits &&
fVertexAttribs == other.fVertexAttribs &&
fStencilSettings == other.fStencilSettings &&
fFirstCoverageStage == other.fFirstCoverageStage &&
fCoverage == other.fCoverage &&
fColorFilterMode == other.fColorFilterMode &&
fColorFilterColor == other.fColorFilterColor &&
fDrawFace == other.fDrawFace;
GrAssert(!result || 0 == memcmp(fFixedFunctionVertexAttribIndices,
other.fFixedFunctionVertexAttribIndices,
sizeof(fFixedFunctionVertexAttribIndices)));
return result;
}
bool operator!= (const CommonState& other) const { return !(*this == other); }
};
/** GrDrawState uses GrEffectStages to hold stage state which holds a ref on GrEffectRef.
DeferredState must directly reference GrEffects, however. */
struct SavedEffectStage {
SavedEffectStage() : fEffect(NULL) {}
const GrEffect* fEffect;
GrEffectStage::SavedCoordChange fCoordChange;
};
public:
/**
* DeferredState contains all of the data of a GrDrawState but does not hold refs on GrResource
* objects. Resources are allowed to hit zero ref count while in DeferredStates. Their internal
* dispose mechanism returns them to the cache. This allows recycling resources through the
* the cache while they are in a deferred draw queue.
*/
class DeferredState {
public:
DeferredState() : fRenderTarget(NULL) {
GR_DEBUGCODE(fInitialized = false;)
}
// TODO: Remove this when DeferredState no longer holds a ref to the RT
~DeferredState() { SkSafeUnref(fRenderTarget); }
void saveFrom(const GrDrawState& drawState) {
fCommon = drawState.fCommon;
// TODO: Here we will copy the GrRenderTarget pointer without taking a ref.
fRenderTarget = drawState.fRenderTarget.get();
SkSafeRef(fRenderTarget);
// Here we ref the effects directly rather than the effect-refs. TODO: When the effect-
// ref gets fully unref'ed it will cause the underlying effect to unref its resources
// and recycle them to the cache (if no one else is holding a ref to the resources).
for (int i = 0; i < kNumStages; ++i) {
fStages[i].saveFrom(drawState.fStages[i]);
}
GR_DEBUGCODE(fInitialized = true;)
}
void restoreTo(GrDrawState* drawState) {
GrAssert(fInitialized);
drawState->fCommon = fCommon;
drawState->setRenderTarget(fRenderTarget);
for (int i = 0; i < kNumStages; ++i) {
fStages[i].restoreTo(&drawState->fStages[i]);
}
}
bool isEqual(const GrDrawState& state) const {
if (fRenderTarget != state.fRenderTarget.get() || fCommon != state.fCommon) {
return false;
}
for (int i = 0; i < kNumStages; ++i) {
if (!fStages[i].isEqual(state.fStages[i])) {
return false;
}
}
return true;
}
private:
GrRenderTarget* fRenderTarget;
CommonState fCommon;
GrEffectStage::DeferredStage fStages[kNumStages];
GR_DEBUGCODE(bool fInitialized;)
};
private:
SkAutoTUnref<GrRenderTarget> fRenderTarget;
CommonState fCommon;
GrEffectStage fStages[kNumStages];
typedef GrRefCnt INHERITED;
};
GR_MAKE_BITFIELD_OPS(GrDrawState::BlendOptFlags);
#endif