| /* |
| * Copyright 2014 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef GrRODrawState_DEFINED |
| #define GrRODrawState_DEFINED |
| |
| #include "GrProcessorStage.h" |
| #include "GrRenderTarget.h" |
| #include "GrStencil.h" |
| #include "SkMatrix.h" |
| |
| class GrDrawState; |
| class GrDrawTargetCaps; |
| class GrPaint; |
| class GrTexture; |
| |
| /** |
| * Read-only base class for GrDrawState. This class contains all the necessary data to represent a |
| * canonical DrawState. All methods in the class are const, thus once created the data in the class |
| * cannot be changed. |
| */ |
| class GrRODrawState : public SkRefCnt { |
| public: |
| SK_DECLARE_INST_COUNT(GrRODrawState) |
| |
| GrRODrawState() {} |
| |
| GrRODrawState& operator= (const GrRODrawState& that); |
| |
| /////////////////////////////////////////////////////////////////////////// |
| /// @name Vertex Attributes |
| //// |
| |
| enum { |
| kMaxVertexAttribCnt = kLast_GrVertexAttribBinding + 4, |
| }; |
| |
| const GrVertexAttrib* getVertexAttribs() const { return fVAPtr; } |
| int getVertexAttribCount() const { return fVACount; } |
| |
| size_t getVertexStride() const { return fVAStride; } |
| |
| /** |
| * 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 fFixedFunctionVertexAttribIndices[kPosition_GrVertexAttribBinding]; |
| } |
| int localCoordAttributeIndex() const { |
| return fFixedFunctionVertexAttribIndices[kLocalCoord_GrVertexAttribBinding]; |
| } |
| int colorVertexAttributeIndex() const { |
| return fFixedFunctionVertexAttribIndices[kColor_GrVertexAttribBinding]; |
| } |
| int coverageVertexAttributeIndex() const { |
| return fFixedFunctionVertexAttribIndices[kCoverage_GrVertexAttribBinding]; |
| } |
| |
| bool hasLocalCoordAttribute() const { |
| return -1 != fFixedFunctionVertexAttribIndices[kLocalCoord_GrVertexAttribBinding]; |
| } |
| bool hasColorVertexAttribute() const { |
| return -1 != fFixedFunctionVertexAttribIndices[kColor_GrVertexAttribBinding]; |
| } |
| bool hasCoverageVertexAttribute() const { |
| return -1 != fFixedFunctionVertexAttribIndices[kCoverage_GrVertexAttribBinding]; |
| } |
| |
| const int* getFixedFunctionVertexAttribIndices() const { |
| return fFixedFunctionVertexAttribIndices; |
| } |
| |
| bool validateVertexAttribs() const; |
| |
| /// @} |
| |
| /** |
| * Determines whether the output coverage is guaranteed to be one for all pixels hit by a draw. |
| */ |
| bool hasSolidCoverage() const; |
| |
| /// @} |
| |
| /////////////////////////////////////////////////////////////////////////// |
| /// @name Color |
| //// |
| |
| GrColor getColor() const { return fColor; } |
| |
| /// @} |
| |
| /////////////////////////////////////////////////////////////////////////// |
| /// @name Coverage |
| //// |
| |
| uint8_t getCoverage() const { return fCoverage; } |
| |
| GrColor getCoverageColor() const { |
| return GrColorPackRGBA(fCoverage, fCoverage, fCoverage, fCoverage); |
| } |
| |
| /// @} |
| |
| /////////////////////////////////////////////////////////////////////////// |
| /// @name Effect Stages |
| /// Each stage hosts a GrProcessor. The effect produces an output color or coverage in the |
| /// fragment shader. Its inputs are the output from the previous stage as well as some variables |
| /// available to it in the fragment and vertex shader (e.g. the vertex position, the dst color, |
| /// the fragment position, local coordinates). |
| /// |
| /// 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 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. |
| //// |
| |
| int numColorStages() const { return fColorStages.count(); } |
| int numCoverageStages() const { return fCoverageStages.count(); } |
| int numTotalStages() const { |
| return this->numColorStages() + this->numCoverageStages() + |
| (this->hasGeometryProcessor() ? 1 : 0); |
| } |
| |
| bool hasGeometryProcessor() const { return SkToBool(fGeometryProcessor.get()); } |
| const GrGeometryStage* getGeometryProcessor() const { return fGeometryProcessor.get(); } |
| const GrFragmentStage& getColorStage(int stageIdx) const { return fColorStages[stageIdx]; } |
| const GrFragmentStage& getCoverageStage(int stageIdx) const { return fCoverageStages[stageIdx]; } |
| |
| /** |
| * Checks whether any of the effects will read the dst pixel color. |
| */ |
| bool willEffectReadDstColor() const; |
| |
| /// @} |
| |
| /////////////////////////////////////////////////////////////////////////// |
| /// @name Blending |
| //// |
| |
| GrBlendCoeff getSrcBlendCoeff() const { return fSrcBlend; } |
| GrBlendCoeff getDstBlendCoeff() const { return fDstBlend; } |
| |
| void getDstBlendCoeff(GrBlendCoeff* srcBlendCoeff, |
| GrBlendCoeff* dstBlendCoeff) const { |
| *srcBlendCoeff = fSrcBlend; |
| *dstBlendCoeff = fDstBlend; |
| } |
| |
| /** |
| * Retrieves the last value set by setBlendConstant() |
| * @return the blending constant value |
| */ |
| GrColor getBlendConstant() const { return 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; |
| |
| /// @} |
| |
| /////////////////////////////////////////////////////////////////////////// |
| /// @name View Matrix |
| //// |
| |
| /** |
| * Retrieves the current view matrix |
| * @return the current view matrix. |
| */ |
| const SkMatrix& getViewMatrix() const { return 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 (fViewMatrix.invert(&inverse)) { |
| if (matrix) { |
| *matrix = inverse; |
| } |
| return true; |
| } |
| return false; |
| } |
| |
| /// @} |
| |
| /////////////////////////////////////////////////////////////////////////// |
| /// @name Render Target |
| //// |
| |
| /** |
| * Retrieves the currently set render-target. |
| * |
| * @return The currently set render target. |
| */ |
| GrRenderTarget* getRenderTarget() const { |
| return static_cast<GrRenderTarget*>(fRenderTarget.getResource()); |
| } |
| |
| /// @} |
| |
| /////////////////////////////////////////////////////////////////////////// |
| /// @name Stencil |
| //// |
| |
| const GrStencilSettings& getStencil() const { return 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, |
| }; |
| |
| uint32_t getFlagBits() const { return fFlagBits; } |
| |
| bool isStateFlagEnabled(uint32_t stateBit) const { return 0 != (stateBit & fFlagBits); } |
| |
| bool isDitherState() const { return 0 != (fFlagBits & kDither_StateBit); } |
| bool isHWAntialiasState() const { return 0 != (fFlagBits & kHWAntialias_StateBit); } |
| bool isClipState() const { return 0 != (fFlagBits & kClip_StateBit); } |
| bool isColorWriteDisabled() const { return 0 != (fFlagBits & kNoColorWrites_StateBit); } |
| bool isCoverageDrawing() const { return 0 != (fFlagBits & kCoverageDrawing_StateBit); } |
| |
| /// @} |
| |
| /////////////////////////////////////////////////////////////////////////// |
| /// @name Face Culling |
| //// |
| |
| enum DrawFace { |
| kInvalid_DrawFace = -1, |
| |
| kBoth_DrawFace, |
| kCCW_DrawFace, |
| kCW_DrawFace, |
| }; |
| |
| /** |
| * Gets whether the target is drawing clockwise, counterclockwise, |
| * or both faces. |
| * @return the current draw face(s). |
| */ |
| DrawFace getDrawFace() const { return fDrawFace; } |
| |
| /// @} |
| |
| /////////////////////////////////////////////////////////////////////////// |
| /// @name Hints |
| /// Hints that when provided can enable optimizations. |
| //// |
| |
| enum Hints { kVertexColorsAreOpaque_Hint = 0x1, }; |
| |
| bool vertexColorsAreOpaque() const { return kVertexColorsAreOpaque_Hint & fHints; } |
| |
| /// @} |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| /** Return type for CombineIfPossible. */ |
| enum CombinedState { |
| /** The GrDrawStates cannot be combined. */ |
| kIncompatible_CombinedState, |
| /** Either draw state can be used in place of the other. */ |
| kAOrB_CombinedState, |
| /** Use the first draw state. */ |
| kA_CombinedState, |
| /** Use the second draw state. */ |
| kB_CombinedState, |
| }; |
| |
| protected: |
| /** |
| * Converts refs on GrGpuResources owned directly or indirectly by this GrRODrawState into |
| * pending reads and writes. This should be called when a GrDrawState is recorded into |
| * a GrDrawTarget for later execution. Subclasses of GrRODrawState may add setters. However, |
| * once this call has been made the GrRODrawState is immutable. It is also no longer copyable. |
| * In the future this conversion will automatically happen when converting a GrDrawState into |
| * an optimized draw state. |
| */ |
| void convertToPendingExec(); |
| |
| friend class GrDrawTarget; |
| |
| explicit GrRODrawState(const GrRODrawState& drawState); |
| |
| bool isEqual(const GrRODrawState& that) 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, |
| /** |
| * 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 = 0x2, |
| /** |
| * Instead of emitting a src color, emit coverage in the alpha channel and r,g,b are |
| * "don't cares". |
| */ |
| kEmitCoverage_BlendOptFlag = 0x4, |
| /** |
| * Emit transparent black instead of the src color, no need to compute coverage. |
| */ |
| kEmitTransBlack_BlendOptFlag = 0x8, |
| }; |
| 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. |
| * |
| * If the cached BlendOptFlags does not have the invalidate bit set, then getBlendOpts will |
| * simply returned the cached flags and coefficients. Otherwise it will calculate the values. |
| */ |
| BlendOptFlags getBlendOpts(bool forceCoverage = false, |
| GrBlendCoeff* srcCoeff = NULL, |
| GrBlendCoeff* dstCoeff = NULL) const; |
| |
| typedef GrTGpuResourceRef<GrRenderTarget> ProgramRenderTarget; |
| // These fields are roughly sorted by decreasing likelihood of being different in op== |
| ProgramRenderTarget fRenderTarget; |
| GrColor fColor; |
| SkMatrix fViewMatrix; |
| GrColor fBlendConstant; |
| uint32_t fFlagBits; |
| const GrVertexAttrib* fVAPtr; |
| int fVACount; |
| size_t fVAStride; |
| GrStencilSettings fStencilSettings; |
| uint8_t fCoverage; |
| DrawFace fDrawFace; |
| GrBlendCoeff fSrcBlend; |
| GrBlendCoeff fDstBlend; |
| |
| typedef SkSTArray<4, GrFragmentStage> FragmentStageArray; |
| SkAutoTDelete<GrGeometryStage> fGeometryProcessor; |
| FragmentStageArray fColorStages; |
| FragmentStageArray fCoverageStages; |
| |
| uint32_t fHints; |
| |
| // This is simply a different representation of info in fVertexAttribs and thus does |
| // not need to be compared in op==. |
| int fFixedFunctionVertexAttribIndices[kGrFixedFunctionVertexAttribBindingCnt]; |
| |
| private: |
| /** |
| * Determines whether src alpha is guaranteed to be one for all src pixels |
| */ |
| bool srcAlphaWillBeOne() const; |
| |
| typedef SkRefCnt INHERITED; |
| }; |
| |
| GR_MAKE_BITFIELD_OPS(GrRODrawState::BlendOptFlags); |
| |
| #endif |