| |
| /* |
| * 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 "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; |
| |
| const GrDrawState& getDrawState() const { return fCurrDrawState; } |
| GrDrawState* drawState() { return &fCurrDrawState; } |
| |
| /** |
| * 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); |
| } |
| |
| /** |
| * Determines if blending will require a read of a dst given the current |
| * state set on the draw target |
| * |
| * @return true if the dst surface will be read at each pixel hit by the |
| * a draw operation. |
| */ |
| bool drawWillReadDst() const; |
| |
| /** |
| * 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 looks at the current blend on the draw target and the draw |
| * target's capabilities to determine whether coverage can be handled |
| * correctly. |
| */ |
| 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. |
| */ |
| bool canTweakAlphaForCoverage() const; |
| |
| /** |
| * Given the current draw state, vertex layout, and hw support, will HW AA |
| * lines be used (if line primitive type is drawn)? (Note that lines are |
| * always 1 pixel wide) |
| */ |
| bool willUseHWAALines() const; |
| |
| /** |
| * Used to save and restore the GrGpu's drawing state |
| */ |
| struct SavedDrawState { |
| private: |
| SkTLazy<GrDrawState> fState; |
| friend class GrDrawTarget; |
| }; |
| |
| /** |
| * Saves the current draw state. The state can be restored at a later time |
| * with restoreDrawState. |
| * |
| * See also AutoStateRestore class. |
| * |
| * @param state will hold the state after the function returns. |
| */ |
| void saveCurrentDrawState(SavedDrawState* state) const; |
| |
| /** |
| * Restores previously saved draw state. The client guarantees that state |
| * was previously passed to saveCurrentDrawState and that the rendertarget |
| * and texture set at save are still valid. |
| * |
| * See also AutoStateRestore class. |
| * |
| * @param state the previously saved state to restore. |
| */ |
| void restoreDrawState(const SavedDrawState& state); |
| |
| /** |
| * Copies the draw state from another target to this target. |
| * |
| * @param srcTarget draw target used as src of the draw state. |
| */ |
| void copyDrawState(const GrDrawTarget& srcTarget); |
| |
| /** |
| * 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)); |
| } |
| |
| 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)); |
| } |
| |
| 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 methods for specifying geometry (vertices and optionally |
| * indices) to the draw target. When indexed drawing the indices and vertices |
| * can use a different method. Once geometry is specified it can be used for |
| * multiple drawIndexed and drawNonIndexed calls. |
| * |
| * Sometimes it is necessary to perform a draw while upstack code has |
| * already specified geometry that it isn't finished with. There are push |
| * pop methods |
| * |
| * 1. Provide a cpu array (set*SourceToArray). This is useful when the |
| * caller's client has already provided vertex data in a format |
| * the time compatible with a GrVertexLayout. The array must contain the |
| * data at set*SourceToArray is called. The source stays in effect for |
| * drawIndexed & drawNonIndexed calls until set*SourceToArray is called |
| * again or one of the other two paths is chosen. |
| * |
| * 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, |
| * or pushGeometrySource At this point the data is frozen and the ptrs |
| * are no longer valid. |
| * |
| * 3. Vertex and Index Buffers. This is most useful for geometry that will |
| * is long-lived. SetVertexSourceToBuffer and SetIndexSourceToBuffer are |
| * used to set the buffer and subsequent drawIndexed and drawNonIndexed |
| * calls use this source until another source is set. |
| */ |
| |
| /** |
| * Reserves space for vertices. Draw target will use reserved vertices at |
| * at the next draw. |
| * |
| * If succeeds: |
| * if vertexCount > 0, *vertices will be the array |
| * of vertices to be filled by caller. The next draw will read |
| * these vertices. |
| * |
| * If a client does not already have a vertex buffer then this is the |
| * preferred way to allocate vertex data. It allows the subclass of |
| * GrDrawTarget to decide whether to put data in buffers, to group vertex |
| * data that uses the same state (e.g. for deferred rendering), etc. |
| * |
| * After the next draw or pushGeometrySource the vertices ptr is no longer |
| * valid and the geometry data cannot be further modified. The contents |
| * that were put in the reserved space can be drawn by multiple draws, |
| * however. |
| * |
| * @param vertexLayout the format of vertices (ignored if vertexCount == 0). |
| * @param vertexCount the number of vertices 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. |
| * |
| * @return true if succeeded in allocating space for the vertices and false |
| * if not. |
| */ |
| bool reserveVertexSpace(GrVertexLayout vertexLayout, |
| int vertexCount, |
| void** vertices); |
| /** |
| * Reserves space for indices. Draw target will use the reserved indices at |
| * the next indexed draw. |
| * |
| * If succeeds: |
| * if indexCount > 0, *indices will be the array |
| * of indices to be filled by caller. The next draw will read |
| * these indices. |
| * |
| * If a client does not already have a index buffer then this is the |
| * preferred way to allocate index data. It allows the subclass of |
| * GrDrawTarget to decide whether to put data in buffers, to group index |
| * data that uses the same state (e.g. for deferred rendering), etc. |
| * |
| * After the next indexed draw or pushGeometrySource the indices ptr is no |
| * longer valid and the geometry data cannot be further modified. The |
| * contents that were put in the reserved space can be drawn by multiple |
| * draws, however. |
| * |
| * @param indexCount the number of indices to reserve space for. Can be 0. |
| * @param indices will point to reserved index space if indexCount is |
| * non-zero. Illegal to pass NULL if indexCount > 0. |
| */ |
| |
| bool reserveIndexSpace(int indexCount, 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 or drawNonIndexed. |
| * |
| * @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 or drawNonIndexed. |
| * |
| * @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(); |
| |
| /** |
| * 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[]); |
| |
| /** |
| * 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; |
| |
| /** |
| * Returns the maximum number of edges that may be specified in a single |
| * draw call when performing edge antialiasing. This is usually limited |
| * by the number of fragment uniforms which may be uploaded. Must be a |
| * minimum of six, since a triangle's vertices each belong to two boundary |
| * edges which may be distinct. |
| */ |
| virtual int getMaxEdges() const { return 6; } |
| |
| //////////////////////////////////////////////////////////////////////////// |
| |
| class AutoStateRestore : ::GrNoncopyable { |
| public: |
| AutoStateRestore(); |
| AutoStateRestore(GrDrawTarget* target); |
| ~AutoStateRestore(); |
| |
| /** |
| * if this object is already saving state for param target then |
| * this does nothing. Otherise, it restores previously saved state on |
| * previous target (if any) and saves current state on param target. |
| */ |
| void set(GrDrawTarget* target); |
| |
| private: |
| GrDrawTarget* fDrawTarget; |
| SavedDrawState fDrawState; |
| }; |
| |
| //////////////////////////////////////////////////////////////////////////// |
| |
| /** |
| * 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<GrPoint*>(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<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); |
| } |
| |
| 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() const; |
| |
| enum GeometrySrcType { |
| kNone_GeometrySrcType, //<! src has not been specified |
| kReserved_GeometrySrcType, //<! src was set using reserve*Space |
| kArray_GeometrySrcType, //<! src was set using set*SourceToArray |
| kBuffer_GeometrySrcType //<! src was set using set*SourceToBuffer |
| }; |
| |
| struct GeometrySrcState { |
| GeometrySrcType fVertexSrc; |
| union { |
| // valid if src type is buffer |
| const GrVertexBuffer* fVertexBuffer; |
| // valid if src type is reserved or array |
| int fVertexCount; |
| }; |
| |
| GeometrySrcType fIndexSrc; |
| union { |
| // valid if src type is buffer |
| const GrIndexBuffer* fIndexBuffer; |
| // valid if src type is reserved or array |
| int fIndexCount; |
| }; |
| |
| GrVertexLayout fVertexLayout; |
| }; |
| |
| // 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->getGeomSrc().fVertexLayout, |
| fCurrDrawState); |
| } |
| |
| StageMask enabledStages() const { |
| StageMask mask = 0; |
| for (int s = 0; s < GrDrawState::kNumStages; ++s) { |
| mask |= this->isStageEnabled(s) ? 1 : 0; |
| } |
| return mask; |
| } |
| |
| // Helpers for GrDrawTarget subclasses that won't have private access to |
| // SavedDrawState but need to peek at the state values. |
| static GrDrawState& accessSavedDrawState(SavedDrawState& sds) { |
| return *sds.fState.get(); |
| } |
| static const GrDrawState& accessSavedDrawState(const SavedDrawState& sds){ |
| return *sds.fState.get(); |
| } |
| |
| // 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); |
| |
| // accessor for derived classes |
| const GeometrySrcState& getGeomSrc() const { |
| return fGeoSrcStateStack.back(); |
| } |
| |
| GrClip fClip; |
| |
| GrDrawState fCurrDrawState; |
| |
| 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: |
| // 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<kPreallocGeoSrcStateStackCnt, |
| GeometrySrcState, true> fGeoSrcStateStack; |
| |
| }; |
| |
| GR_MAKE_BITFIELD_OPS(GrDrawTarget::BlendOptFlags); |
| |
| #endif |
