/* * 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 GrDrawTarget_DEFINED #define GrDrawTarget_DEFINED #include "GrClip.h" #include "GrColor.h" #include "GrDrawState.h" #include "GrIndexBuffer.h" #include "GrMatrix.h" #include "GrRefCnt.h" #include "GrSamplerState.h" #include "GrStencil.h" #include "GrTexture.h" #include "SkXfermode.h" #include "SkTLazy.h" class GrTexture; class GrClipIterator; class GrVertexBuffer; class GrIndexBuffer; class GrDrawTarget : public GrRefCnt { public: /** * Represents the draw target capabilities. */ struct Caps { Caps() { memset(this, 0, sizeof(Caps)); } Caps(const Caps& c) { *this = c; } Caps& operator= (const Caps& c) { memcpy(this, &c, sizeof(Caps)); return *this; } void print() const; bool f8BitPaletteSupport : 1; bool fNPOTTextureTileSupport : 1; bool fTwoSidedStencilSupport : 1; bool fStencilWrapOpsSupport : 1; bool fHWAALineSupport : 1; bool fShaderDerivativeSupport : 1; bool fGeometryShaderSupport : 1; bool fFSAASupport : 1; bool fDualSourceBlendingSupport : 1; bool fBufferLockSupport : 1; int fMaxRenderTargetSize; int fMaxTextureSize; }; // for convenience typedef GrDrawState::StageMask StageMask; /////////////////////////////////////////////////////////////////////////// GrDrawTarget(); virtual ~GrDrawTarget(); /** * Gets the capabilities of the draw target. */ const Caps& getCaps() const { return fCaps; } /** * Sets the current clip to the region specified by clip. All draws will be * clipped against this clip if kClip_StateBit is enabled. * * Setting the clip may (or may not) zero out the client's stencil bits. * * @param description of the clipping region */ void setClip(const GrClip& clip); /** * Gets the current clip. * * @return the clip. */ const GrClip& getClip() const; /** * Sets the draw state object for the draw target. Note that this does not * make a copy. The GrDrawTarget will take a reference to passed object. * Passing NULL will cause the GrDrawTarget to use its own internal draw * state object rather than an externally provided one. */ void setDrawState(GrDrawState* drawState); /** * Read-only access to the GrDrawTarget's current draw state. */ const GrDrawState& getDrawState() const { return *fDrawState; } /** * Read-write access to the GrDrawTarget's current draw state. Note that * this doesn't ref. */ GrDrawState* drawState() { return fDrawState; } /** * Shortcut for drawState()->preConcatSamplerMatrices() on all enabled * stages * * @param matrix the matrix to concat */ void preConcatEnabledSamplerMatrices(const GrMatrix& matrix) { StageMask stageMask = this->enabledStages(); this->drawState()->preConcatSamplerMatrices(stageMask, matrix); } /** * Color alpha and coverage are two inputs to the drawing pipeline. For some * blend modes it is safe to fold the coverage into constant or per-vertex * color alpha value. For other blend modes they must be handled separately. * Depending on features available in the underlying 3D API this may or may * not be possible. * * This function considers the current draw state and the draw target's * capabilities to determine whether coverage can be handled correctly. The * following assumptions are made: * 1. The caller intends to somehow specify coverage. This can be * specified either by enabling a coverage stage on the GrDrawState or * via the vertex layout. * 2. Other than enabling coverage stages, the current configuration of * the target's GrDrawState is as it will be at draw time. * 3. If a vertex source has not yet been specified then all stages with * non-NULL textures will be referenced by the vertex layout. */ bool canApplyCoverage() const; /** * Determines whether incorporating partial pixel coverage into the constant * color specified by setColor or per-vertex colors will give the right * blending result. If a vertex source has not yet been specified then * the function assumes that all stages with non-NULL textures will be * referenced by the vertex layout. */ bool canTweakAlphaForCoverage() const; /** * Given the current draw state and hw support, will HW AA lines be used * (if line primitive type is drawn)? If a vertex source has not yet been * specified then the function assumes that all stages with non-NULL * textures will be referenced by the vertex layout. */ bool willUseHWAALines() const; /** * The format of vertices is represented as a bitfield of flags. * Flags that indicate the layout of vertex data. Vertices always contain * positions and may also contain up to GrDrawState::kMaxTexCoords sets * of 2D texture * coordinates, per-vertex colors, and per-vertex coverage. * Each stage can * use any of the texture coordinates as its input texture coordinates or it * may use the positions as texture coordinates. * * If no texture coordinates are specified for a stage then the stage is * disabled. * * Only one type of texture coord can be specified per stage. For * example StageTexCoordVertexLayoutBit(0, 2) and * StagePosAsTexCoordVertexLayoutBit(0) cannot both be specified. * * The order in memory is always (position, texture coord 0, ..., color, * coverage) with any unused fields omitted. Note that this means that if * only texture coordinates 1 is referenced then there is no texture * coordinates 0 and the order would be (position, texture coordinate 1 * [, color][, coverage]). */ /** * Generates a bit indicating that a texture stage uses texture coordinates * * @param stage the stage that will use texture coordinates. * @param texCoordIdx the index of the texture coordinates to use * * @return the bit to add to a GrVertexLayout bitfield. */ static int StageTexCoordVertexLayoutBit(int stage, int texCoordIdx) { GrAssert(stage < GrDrawState::kNumStages); GrAssert(texCoordIdx < GrDrawState::kMaxTexCoords); return 1 << (stage + (texCoordIdx * GrDrawState::kNumStages)); } virtual void postClipPush() {}; virtual void preClipPop() {}; private: static const int TEX_COORD_BIT_CNT = GrDrawState::kNumStages * GrDrawState::kMaxTexCoords; public: /** * Generates a bit indicating that a texture stage uses the position * as its texture coordinate. * * @param stage the stage that will use position as texture * coordinates. * * @return the bit to add to a GrVertexLayout bitfield. */ static int StagePosAsTexCoordVertexLayoutBit(int stage) { GrAssert(stage < GrDrawState::kNumStages); return (1 << (TEX_COORD_BIT_CNT + stage)); } /** * Modify the existing vertex layout. Realistically the only thing that * can be added w/o recomputing the vertex layout is one of the * StagePosAsTexCoordVertexLayoutBit flags */ void addToVertexLayout(int flag) { GrAssert((1 << TEX_COORD_BIT_CNT) == flag || (1 << (TEX_COORD_BIT_CNT + 1)) == flag || (1 << (TEX_COORD_BIT_CNT + 2)) == flag || (1 << (TEX_COORD_BIT_CNT + 3)) == flag); fGeoSrcStateStack.back().fVertexLayout |= flag; } private: static const int STAGE_BIT_CNT = TEX_COORD_BIT_CNT + GrDrawState::kNumStages; public: /** * Additional Bits that can be specified in GrVertexLayout. */ enum VertexLayoutBits { /* vertices have colors (GrColor) */ kColor_VertexLayoutBit = 1 << (STAGE_BIT_CNT + 0), /* vertices have coverage (GrColor) */ kCoverage_VertexLayoutBit = 1 << (STAGE_BIT_CNT + 1), /* Use text vertices. (Pos and tex coords may be a different type for * text [GrGpuTextVertex vs GrPoint].) */ kTextFormat_VertexLayoutBit = 1 << (STAGE_BIT_CNT + 2), /* Each vertex specificies an edge. Distance to the edge is used to * compute a coverage. See GrDrawState::setVertexEdgeType(). */ kEdge_VertexLayoutBit = 1 << (STAGE_BIT_CNT + 3), // for below assert kDummyVertexLayoutBit, kHighVertexLayoutBit = kDummyVertexLayoutBit - 1 }; // make sure we haven't exceeded the number of bits in GrVertexLayout. GR_STATIC_ASSERT(kHighVertexLayoutBit < ((uint64_t)1 << 8*sizeof(GrVertexLayout))); /** * There are three types of "sources" of geometry (vertices and indices) for * draw calls made on the target. When performing an indexed draw, the * indices and vertices can use different source types. Once a source is * specified it can be used for multiple draws. However, the time at which * the geometry data is no longer editable depends on the source type. * * Sometimes it is necessary to perform a draw while upstack code has * already specified geometry that it isn't finished with. So there are push * and pop methods. This allows the client to push the sources, draw * something using alternate sources, and then pop to restore the original * sources. * * Aside from pushes and pops, a source remains valid until another source * is set or resetVertexSource / resetIndexSource is called. Drawing from * a reset source is an error. * * The three types of sources are: * * 1. A cpu array (set*SourceToArray). This is useful when the caller * already provided vertex data in a format compatible with a * GrVertexLayout. The data in the array is consumed at the time that * set*SourceToArray is called and subsequent edits to the array will not * be reflected in draws. * * 2. Reserve. This is most useful when the caller has data it must * transform before drawing and is not long-lived. The caller requests * that the draw target make room for some amount of vertex and/or index * data. The target provides ptrs to hold the vertex and/or index data. * * The data is writable up until the next drawIndexed, drawNonIndexed, * drawIndexedInstances, or pushGeometrySource. At this point the data is * frozen and the ptrs are no longer valid. * * Where the space is allocated and how it is uploaded to the GPU is * subclass-dependent. * * 3. Vertex and Index Buffers. This is most useful for geometry that will * is long-lived. When the data in the buffer is consumed depends on the * GrDrawTarget subclass. For deferred subclasses the caller has to * guarantee that the data is still available in the buffers at playback. * (TODO: Make this more automatic as we have done for read/write pixels) */ /** * Reserves space for vertices and/or indices. Zero can be specifed as * either the vertex or index count if the caller desires to only reserve * space for only indices or only vertices. If zero is specifed for * vertexCount then the vertex source will be unmodified and likewise for * indexCount. * * If the function returns true then the reserve suceeded and the vertices * and indices pointers will point to the space created. * * If the target cannot make space for the request then this function will * return false. If vertexCount was non-zero then upon failure the vertex * source is reset and likewise for indexCount. * * The pointers to the space allocated for vertices and indices remain valid * until a drawIndexed, drawNonIndexed, drawIndexedInstances, or push/ * popGeomtrySource is called. At that point logically a snapshot of the * data is made and the pointers are invalid. * * @param vertexLayout the format of vertices (ignored if vertexCount == 0). * @param vertexCount the number of vertices to reserve space for. Can be * 0. * @param indexCount the number of indices to reserve space for. Can be 0. * @param vertices will point to reserved vertex space if vertexCount is * non-zero. Illegal to pass NULL if vertexCount > 0. * @param indices will point to reserved index space if indexCount is * non-zero. Illegal to pass NULL if indexCount > 0. */ bool reserveVertexAndIndexSpace(GrVertexLayout vertexLayout, int vertexCount, int indexCount, void** vertices, void** indices); /** * Provides hints to caller about the number of vertices and indices * that can be allocated cheaply. This can be useful if caller is reserving * space but doesn't know exactly how much geometry is needed. * * Also may hint whether the draw target should be flushed first. This is * useful for deferred targets. * * @param vertexLayout layout of vertices caller would like to reserve * @param vertexCount in: hint about how many vertices the caller would * like to allocate. * out: a hint about the number of vertices that can be * allocated cheaply. Negative means no hint. * Ignored if NULL. * @param indexCount in: hint about how many indices the caller would * like to allocate. * out: a hint about the number of indices that can be * allocated cheaply. Negative means no hint. * Ignored if NULL. * * @return true if target should be flushed based on the input values. */ virtual bool geometryHints(GrVertexLayout vertexLayout, int* vertexCount, int* indexCount) const; /** * Sets source of vertex data for the next draw. Array must contain * the vertex data when this is called. * * @param array cpu array containing vertex data. * @param size size of the vertex data. * @param vertexCount the number of vertices in the array. */ void setVertexSourceToArray(GrVertexLayout vertexLayout, const void* vertexArray, int vertexCount); /** * Sets source of index data for the next indexed draw. Array must contain * the indices when this is called. * * @param array cpu array containing index data. * @param indexCount the number of indices in the array. */ void setIndexSourceToArray(const void* indexArray, int indexCount); /** * Sets source of vertex data for the next draw. Data does not have to be * in the buffer until drawIndexed, drawNonIndexed, or drawIndexedInstances. * * @param buffer vertex buffer containing vertex data. Must be * unlocked before draw call. * @param vertexLayout layout of the vertex data in the buffer. */ void setVertexSourceToBuffer(GrVertexLayout vertexLayout, const GrVertexBuffer* buffer); /** * Sets source of index data for the next indexed draw. Data does not have * to be in the buffer until drawIndexed. * * @param buffer index buffer containing indices. Must be unlocked * before indexed draw call. */ void setIndexSourceToBuffer(const GrIndexBuffer* buffer); /** * Resets vertex source. Drawing from reset vertices is illegal. Set vertex * source to reserved, array, or buffer before next draw. May be able to free * up temporary storage allocated by setVertexSourceToArray or * reserveVertexSpace. */ void resetVertexSource(); /** * Resets index source. Indexed Drawing from reset indices is illegal. Set * index source to reserved, array, or buffer before next indexed draw. May * be able to free up temporary storage allocated by setIndexSourceToArray * or reserveIndexSpace. */ void resetIndexSource(); /** * Query to find out if the vertex or index source is reserved. */ bool hasReservedVerticesOrIndices() const { return kReserved_GeometrySrcType == this->getGeomSrc().fVertexSrc || kReserved_GeometrySrcType == this->getGeomSrc().fIndexSrc; } /** * Pushes and resets the vertex/index sources. Any reserved vertex / index * data is finalized (i.e. cannot be updated after the matching pop but can * be drawn from). Must be balanced by a pop. */ void pushGeometrySource(); /** * Pops the vertex / index sources from the matching push. */ void popGeometrySource(); /** * Draws indexed geometry using the current state and current vertex / index * sources. * * @param type The type of primitives to draw. * @param startVertex the vertex in the vertex array/buffer corresponding * to index 0 * @param startIndex first index to read from index src. * @param vertexCount one greater than the max index. * @param indexCount the number of index elements to read. The index count * is effectively trimmed to the last completely * specified primitive. */ void drawIndexed(GrPrimitiveType type, int startVertex, int startIndex, int vertexCount, int indexCount); /** * Draws non-indexed geometry using the current state and current vertex * sources. * * @param type The type of primitives to draw. * @param startVertex the vertex in the vertex array/buffer corresponding * to index 0 * @param vertexCount one greater than the max index. */ void drawNonIndexed(GrPrimitiveType type, int startVertex, int vertexCount); /** * Helper function for drawing rects. This does not use the current index * and vertex sources. After returning, the vertex and index sources may * have changed. They should be reestablished before the next drawIndexed * or drawNonIndexed. This cannot be called between reserving and releasing * geometry. The GrDrawTarget subclass may be able to perform additional * optimizations if drawRect is used rather than drawIndexed or * drawNonIndexed. * @param rect the rect to draw * @param matrix optional matrix applied to rect (before viewMatrix) * @param stageMask bitmask indicating which stages are enabled. * Bit i indicates whether stage i is enabled. * @param srcRects specifies rects for stages enabled by stageEnableMask. * if stageEnableMask bit i is 1, srcRects is not NULL, * and srcRects[i] is not NULL, then srcRects[i] will be * used as coordinates for stage i. Otherwise, if stage i * is enabled then rect is used as the coordinates. * @param srcMatrices optional matrices applied to srcRects. If * srcRect[i] is non-NULL and srcMatrices[i] is * non-NULL then srcRect[i] will be transformed by * srcMatrix[i]. srcMatrices can be NULL when no * srcMatrices are desired. */ virtual void drawRect(const GrRect& rect, const GrMatrix* matrix, StageMask stageMask, const GrRect* srcRects[], const GrMatrix* srcMatrices[]); /** * This call is used to draw multiple instances of some geometry with a * given number of vertices (V) and indices (I) per-instance. The indices in * the index source must have the form i[k+I] == i[k] + V. Also, all indices * i[kI] ... i[(k+1)I-1] must be elements of the range kV ... (k+1)V-1. As a * concrete example, the following index buffer for drawing a series of * quads each as two triangles each satisfies these conditions with V=4 and * I=6: * (0,1,2,0,2,3, 4,5,6,4,6,7, 8,9,10,8,10,11, ...) * * The call assumes that the pattern of indices fills the entire index * source. The size of the index buffer limits the number of instances that * can be drawn by the GPU in a single draw. However, the caller may specify * any (positive) number for instanceCount and if necessary multiple GPU * draws will be issued. Morever, when drawIndexedInstances is called * multiple times it may be possible for GrDrawTarget to group them into a * single GPU draw. * * @param type the type of primitives to draw * @param instanceCount the number of instances to draw. Each instance * consists of verticesPerInstance vertices indexed by * indicesPerInstance indices drawn as the primitive * type specified by type. * @param verticesPerInstance The number of vertices in each instance (V * in the above description). * @param indicesPerInstance The number of indices in each instance (I * in the above description). */ virtual void drawIndexedInstances(GrPrimitiveType type, int instanceCount, int verticesPerInstance, int indicesPerInstance); /** * Helper for drawRect when the caller doesn't need separate src rects or * matrices. */ void drawSimpleRect(const GrRect& rect, const GrMatrix* matrix, StageMask stageEnableBitfield) { drawRect(rect, matrix, stageEnableBitfield, NULL, NULL); } /** * Clear the render target. Ignores the clip and all other draw state * (blend mode, stages, etc). Clears the whole thing if rect is NULL, * otherwise just the rect. */ virtual void clear(const GrIRect* rect, GrColor color) = 0; /** * Release any resources that are cached but not currently in use. This * is intended to give an application some recourse when resources are low. */ virtual void purgeResources() {}; //////////////////////////////////////////////////////////////////////////// /** * See AutoStateRestore below. */ enum ASRInit { kPreserve_ASRInit, kReset_ASRInit }; /** * Saves off the current state and restores it in the destructor. It will * install a new GrDrawState object on the target (setDrawState) and restore * the previous one in the destructor. The caller should call drawState() to * get the new draw state after the ASR is installed. * * GrDrawState* state = target->drawState(); * AutoStateRestore asr(target, GrDrawTarget::kReset_ASRInit). * state->setRenderTarget(rt); // state refers to the GrDrawState set on * // target before asr was initialized. * // Therefore, rt is set on the GrDrawState * // that will be restored after asr's * // destructor rather than target's current * // GrDrawState. */ class AutoStateRestore : ::GrNoncopyable { public: /** * Default ASR will have no effect unless set() is subsequently called. */ AutoStateRestore(); /** * Saves the state on target. The state will be restored when the ASR * is destroyed. If this constructor is used do not call set(). * * @param init Should the newly installed GrDrawState be a copy of the * previous state or a default-initialized GrDrawState. */ AutoStateRestore(GrDrawTarget* target, ASRInit init); ~AutoStateRestore(); /** * Saves the state on target. The state will be restored when the ASR * is destroyed. This should only be called once per ASR object and only * when the default constructor was used. For nested saves use multiple * ASR objects. * * @param init Should the newly installed GrDrawState be a copy of the * previous state or a default-initialized GrDrawState. */ void set(GrDrawTarget* target, ASRInit init); private: GrDrawTarget* fDrawTarget; SkTLazy fTempState; GrDrawState* fSavedState; }; //////////////////////////////////////////////////////////////////////////// /** * Sets the view matrix to I and preconcats all stage matrices enabled in * mask by the view inverse. Destructor undoes these changes. */ class AutoDeviceCoordDraw : ::GrNoncopyable { public: AutoDeviceCoordDraw(GrDrawTarget* target, StageMask stageMask); ~AutoDeviceCoordDraw(); private: GrDrawTarget* fDrawTarget; GrMatrix fViewMatrix; GrMatrix fSamplerMatrices[GrDrawState::kNumStages]; int fStageMask; }; //////////////////////////////////////////////////////////////////////////// class AutoReleaseGeometry : ::GrNoncopyable { public: AutoReleaseGeometry(GrDrawTarget* target, GrVertexLayout vertexLayout, int vertexCount, int indexCount); AutoReleaseGeometry(); ~AutoReleaseGeometry(); bool set(GrDrawTarget* target, GrVertexLayout vertexLayout, int vertexCount, int indexCount); bool succeeded() const { return NULL != fTarget; } void* vertices() const { GrAssert(this->succeeded()); return fVertices; } void* indices() const { GrAssert(this->succeeded()); return fIndices; } GrPoint* positions() const { return static_cast(this->vertices()); } private: void reset(); GrDrawTarget* fTarget; void* fVertices; void* fIndices; }; //////////////////////////////////////////////////////////////////////////// class AutoClipRestore : ::GrNoncopyable { public: AutoClipRestore(GrDrawTarget* target) { fTarget = target; fClip = fTarget->getClip(); } ~AutoClipRestore() { fTarget->setClip(fClip); } private: GrDrawTarget* fTarget; GrClip fClip; }; //////////////////////////////////////////////////////////////////////////// class AutoGeometryPush : ::GrNoncopyable { public: AutoGeometryPush(GrDrawTarget* target) { GrAssert(NULL != target); fTarget = target; target->pushGeometrySource(); } ~AutoGeometryPush() { fTarget->popGeometrySource(); } private: GrDrawTarget* fTarget; }; //////////////////////////////////////////////////////////////////////////// // Helpers for picking apart vertex layouts /** * Helper function to compute the size of a vertex from a vertex layout * @return size of a single vertex. */ static size_t VertexSize(GrVertexLayout vertexLayout); /** * Helper function for determining the index of texture coordinates that * is input for a texture stage. Note that a stage may instead use positions * as texture coordinates, in which case the result of the function is * indistinguishable from the case when the stage is disabled. * * @param stage the stage to query * @param vertexLayout layout to query * * @return the texture coordinate index or -1 if the stage doesn't use * separate (non-position) texture coordinates. */ static int VertexTexCoordsForStage(int stage, GrVertexLayout vertexLayout); /** * Helper function to compute the offset of texture coordinates in a vertex * @return offset of texture coordinates in vertex layout or -1 if the * layout has no texture coordinates. Will be 0 if positions are * used as texture coordinates for the stage. */ static int VertexStageCoordOffset(int stage, GrVertexLayout vertexLayout); /** * Helper function to compute the offset of the color in a vertex * @return offset of color in vertex layout or -1 if the * layout has no color. */ static int VertexColorOffset(GrVertexLayout vertexLayout); /** * Helper function to compute the offset of the coverage in a vertex * @return offset of coverage in vertex layout or -1 if the * layout has no coverage. */ static int VertexCoverageOffset(GrVertexLayout vertexLayout); /** * Helper function to compute the offset of the edge pts in a vertex * @return offset of edge in vertex layout or -1 if the * layout has no edge. */ static int VertexEdgeOffset(GrVertexLayout vertexLayout); /** * Helper function to determine if vertex layout contains explicit texture * coordinates of some index. * * @param coordIndex the tex coord index to query * @param vertexLayout layout to query * * @return true if vertex specifies texture coordinates for the index, * false otherwise. */ static bool VertexUsesTexCoordIdx(int coordIndex, GrVertexLayout vertexLayout); /** * Helper function to determine if vertex layout contains either explicit or * implicit texture coordinates for a stage. * * @param stage the stage to query * @param vertexLayout layout to query * * @return true if vertex specifies texture coordinates for the stage, * false otherwise. */ static bool VertexUsesStage(int stage, GrVertexLayout vertexLayout); /** * Helper function to compute the size of each vertex and the offsets of * texture coordinates and color. Determines tex coord offsets by tex coord * index rather than by stage. (Each stage can be mapped to any t.c. index * by StageTexCoordVertexLayoutBit.) * * @param vertexLayout the layout to query * @param texCoordOffsetsByIdx after return it is the offset of each * tex coord index in the vertex or -1 if * index isn't used. (optional) * @param colorOffset after return it is the offset of the * color field in each vertex, or -1 if * there aren't per-vertex colors. (optional) * @param coverageOffset after return it is the offset of the * coverage field in each vertex, or -1 if * there aren't per-vertex coeverages. * (optional) * @param edgeOffset after return it is the offset of the * edge eq field in each vertex, or -1 if * there aren't per-vertex edge equations. * (optional) * @return size of a single vertex */ static int VertexSizeAndOffsetsByIdx(GrVertexLayout vertexLayout, int texCoordOffsetsByIdx[GrDrawState::kMaxTexCoords], int *colorOffset, int *coverageOffset, int* edgeOffset); /** * Helper function to compute the size of each vertex and the offsets of * texture coordinates and color. Determines tex coord offsets by stage * rather than by index. (Each stage can be mapped to any t.c. index * by StageTexCoordVertexLayoutBit.) If a stage uses positions for * tex coords then that stage's offset will be 0 (positions are always at 0). * * @param vertexLayout the layout to query * @param texCoordOffsetsByStage after return it is the offset of each * tex coord index in the vertex or -1 if * index isn't used. (optional) * @param colorOffset after return it is the offset of the * color field in each vertex, or -1 if * there aren't per-vertex colors. * (optional) * @param coverageOffset after return it is the offset of the * coverage field in each vertex, or -1 if * there aren't per-vertex coeverages. * (optional) * @param edgeOffset after return it is the offset of the * edge eq field in each vertex, or -1 if * there aren't per-vertex edge equations. * (optional) * @return size of a single vertex */ static int VertexSizeAndOffsetsByStage(GrVertexLayout vertexLayout, int texCoordOffsetsByStage[GrDrawState::kNumStages], int* colorOffset, int* coverageOffset, int* edgeOffset); /** * Accessing positions, texture 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 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 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(vertices); return GrTCast(start + offset + vertexIndex * vertexSize); } static const GrPoint* GetVertexPoint(const void* vertices, int vertexIndex, int vertexSize, int offset = 0) { intptr_t start = GrTCast(vertices); return GrTCast(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(vertices); return GrTCast(start + offset + vertexIndex * vertexSize); } static const GrColor* GetVertexColor(const void* vertices, int vertexIndex, int vertexSize, int offset) { const intptr_t start = GrTCast(vertices); return GrTCast(start + offset + vertexIndex * vertexSize); } static void VertexLayoutUnitTest(); protected: /** * Optimizations for blending / coverage to be applied based on the current * state. * Subclasses that actually draw (as opposed to those that just buffer for * playback) must implement the flags that replace the output color. */ enum BlendOptFlags { /** * No optimization */ kNone_BlendOpt = 0, /** * Don't draw at all */ kSkipDraw_BlendOptFlag = 0x2, /** * Emit the src color, disable HW blending (replace dst with src) */ kDisableBlend_BlendOptFlag = 0x4, /** * 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 = 0x1, /** * Instead of emitting a src color, emit coverage in the alpha channel * and r,g,b are "don't cares". */ kEmitCoverage_BlendOptFlag = 0x10, /** * 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 coeffecients may have to be tweaked in order for the optimization // to work. srcCoeff and dstCoeff are optional params that receive the // tweaked coeffecients. // 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 BlendOptFlags getBlendOpts(bool forceCoverage = false, GrBlendCoeff* srcCoeff = NULL, GrBlendCoeff* dstCoeff = NULL) const; // determine if src alpha is guaranteed to be one for all src pixels bool srcAlphaWillBeOne(GrVertexLayout vertexLayout) const; enum GeometrySrcType { kNone_GeometrySrcType, //getGeomSrc(); switch (src.fIndexSrc) { case kNone_GeometrySrcType: return 0; case kReserved_GeometrySrcType: case kArray_GeometrySrcType: return src.fIndexCount; case kBuffer_GeometrySrcType: return src.fIndexBuffer->sizeInBytes() / sizeof(uint16_t); default: GrCrash("Unexpected Index Source."); return 0; } } // given a vertex layout and a draw state, will a stage be used? static bool StageWillBeUsed(int stage, GrVertexLayout layout, const GrDrawState& state) { return NULL != state.getTexture(stage) && VertexUsesStage(stage, layout); } bool isStageEnabled(int stage) const { return StageWillBeUsed(stage, this->getVertexLayout(), this->getDrawState()); } StageMask enabledStages() const { StageMask mask = 0; for (int s = 0; s < GrDrawState::kNumStages; ++s) { mask |= this->isStageEnabled(s) ? 1 : 0; } return mask; } // A sublcass can optionally overload this function to be notified before // vertex and index space is reserved. virtual void willReserveVertexAndIndexSpace(GrVertexLayout vertexLayout, int vertexCount, int indexCount) {} // implemented by subclass to allocate space for reserved geom virtual bool onReserveVertexSpace(GrVertexLayout vertexLayout, int vertexCount, void** vertices) = 0; virtual bool onReserveIndexSpace(int indexCount, void** indices) = 0; // implemented by subclass to handle release of reserved geom space virtual void releaseReservedVertexSpace() = 0; virtual void releaseReservedIndexSpace() = 0; // subclass must consume array contents when set virtual void onSetVertexSourceToArray(const void* vertexArray, int vertexCount) = 0; virtual void onSetIndexSourceToArray(const void* indexArray, int indexCount) = 0; // subclass is notified that geom source will be set away from an array virtual void releaseVertexArray() = 0; virtual void releaseIndexArray() = 0; // subclass overrides to be notified just before geo src state // is pushed/popped. virtual void geometrySourceWillPush() = 0; virtual void geometrySourceWillPop(const GeometrySrcState& restoredState) = 0; // subclass called to perform drawing virtual void onDrawIndexed(GrPrimitiveType type, int startVertex, int startIndex, int vertexCount, int indexCount) = 0; virtual void onDrawNonIndexed(GrPrimitiveType type, int startVertex, int vertexCount) = 0; // subclass overrides to be notified when clip is set. Must call // INHERITED::clipwillBeSet virtual void clipWillBeSet(const GrClip& clip) {} // Helpers for drawRect, protected so subclasses that override drawRect // can use them. static GrVertexLayout GetRectVertexLayout(StageMask stageEnableBitfield, const GrRect* srcRects[]); static void SetRectVertices(const GrRect& rect, const GrMatrix* matrix, const GrRect* srcRects[], const GrMatrix* srcMatrices[], GrVertexLayout layout, void* vertices); // accessors for derived classes const GeometrySrcState& getGeomSrc() const { return fGeoSrcStateStack.back(); } // it is prefereable to call this rather than getGeomSrc()->fVertexLayout // because of the assert. GrVertexLayout getVertexLayout() const { // the vertex layout is only valid if a vertex source has been // specified. GrAssert(this->getGeomSrc().fVertexSrc != kNone_GeometrySrcType); return this->getGeomSrc().fVertexLayout; } GrClip fClip; GrDrawState* fDrawState; GrDrawState fDefaultDrawState; Caps fCaps; // subclasses must call this in their destructors to ensure all vertex // and index sources have been released (including those held by // pushGeometrySource()) void releaseGeometry(); private: // helpers for reserving vertex and index space. bool reserveVertexSpace(GrVertexLayout vertexLayout, int vertexCount, void** vertices); bool reserveIndexSpace(int indexCount, void** indices); // called by drawIndexed and drawNonIndexed. Use a negative indexCount to // indicate non-indexed drawing. bool checkDraw(GrPrimitiveType type, int startVertex, int startIndex, int vertexCount, int indexCount) const; // called when setting a new vert/idx source to unref prev vb/ib void releasePreviousVertexSource(); void releasePreviousIndexSource(); enum { kPreallocGeoSrcStateStackCnt = 4, }; SkSTArray fGeoSrcStateStack; }; GR_MAKE_BITFIELD_OPS(GrDrawTarget::BlendOptFlags); #endif