skia2/gpu/include/GrDrawTarget.h
2011-08-01 15:51:05 +00:00

1261 lines
48 KiB
C++

/*
* 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 "GrMatrix.h"
#include "GrRefCnt.h"
#include "GrRenderTarget.h"
#include "GrSamplerState.h"
#include "GrStencil.h"
#include "GrTexture.h"
#include "SkXfermode.h"
class GrTexture;
class GrClipIterator;
class GrVertexBuffer;
class GrIndexBuffer;
class GrDrawTarget : public GrRefCnt {
public:
/**
* Number of texture stages. Each stage takes as input a color and
* 2D texture coordinates. The color input to the first enabled stage is the
* per-vertex color or the constant color (setColor/setAlpha) if there are
* no per-vertex colors. For subsequent stages the input color is the output
* color from the previous enabled stage. The output color of each stage is
* the input color modulated with the result of a texture lookup. Texture
* lookups are specified by a texture a sampler (setSamplerState). Texture
* coordinates for each stage come from the vertices based on a
* GrVertexLayout bitfield. The output fragment color is the output color of
* the last enabled stage. The presence or absence of texture coordinates
* for each stage in the vertex layout indicates whether a stage is enabled
* or not.
*/
enum {
kNumStages = 3,
kMaxTexCoords = kNumStages
};
/**
* The absolute maximum number of edges that may be specified for
* a single draw call when performing edge antialiasing. This is used for
* the size of several static buffers, so implementations of getMaxEdges()
* (below) should clamp to this value.
*/
enum {
kMaxEdges = 32
};
/**
* Bitfield used to indicate which stages are in use.
*/
typedef int StageBitfield;
GR_STATIC_ASSERT(sizeof(StageBitfield)*8 >= kNumStages);
/**
* Flags that affect rendering. Controlled using enable/disableState(). All
* default to disabled.
*/
enum StateBits {
kDither_StateBit = 0x01, //<! Perform color dithering
kAntialias_StateBit = 0x02, //<! Perform anti-aliasing. The render-
// target must support some form of AA
// (msaa, coverage sampling, etc). For
// GrGpu-created rendertarget/textures
// this is controlled by parameters
// passed to createTexture.
kClip_StateBit = 0x04, //<! Controls whether drawing is clipped
// against the region specified by
// setClip.
kNoColorWrites_StateBit = 0x08, //<! If set it disables writing colors.
// Useful while performing stencil
// ops.
kEdgeAAConcave_StateBit = 0x10,//<! If set, edge AA will test edge
// pairs for convexity while
// rasterizing. Set this if the
// source polygon is non-convex.
// subclass may use additional bits internally
kDummyStateBit,
kLastPublicStateBit = kDummyStateBit-1
};
enum DrawFace {
kBoth_DrawFace,
kCCW_DrawFace,
kCW_DrawFace,
};
/**
* 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) {
fCurrDrawState.fStencilSettings = settings;
}
/**
* Shortcut to disable stencil testing and ops.
*/
void disableStencil() {
fCurrDrawState.fStencilSettings.setDisabled();
}
class Edge {
public:
Edge() {}
Edge(float x, float y, float z) : fX(x), fY(y), fZ(z) {}
GrPoint intersect(const Edge& other) {
return GrPoint::Make(
(fY * other.fZ - other.fY * fZ) /
(fX * other.fY - other.fX * fY),
(fX * other.fZ - other.fX * fZ) /
(other.fX * fY - fX * other.fY));
}
float fX, fY, fZ;
};
protected:
struct DrState {
DrState() {
// make sure any pad is zero for memcmp
// all DrState members should default to something
// valid by the memset
memset(this, 0, sizeof(DrState));
// memset exceptions
fColorFilterXfermode = SkXfermode::kDstIn_Mode;
fFirstCoverageStage = kNumStages;
// pedantic assertion that our ptrs will
// be NULL (0 ptr is mem addr 0)
GrAssert((intptr_t)(void*)NULL == 0LL);
// default stencil setting should be disabled
GrAssert(fStencilSettings.isDisabled());
fFirstCoverageStage = kNumStages;
}
uint32_t fFlagBits;
GrBlendCoeff fSrcBlend;
GrBlendCoeff fDstBlend;
GrColor fBlendConstant;
GrTexture* fTextures[kNumStages];
GrSamplerState fSamplerStates[kNumStages];
int fFirstCoverageStage;
GrRenderTarget* fRenderTarget;
GrColor fColor;
DrawFace fDrawFace;
GrColor fColorFilterColor;
SkXfermode::Mode fColorFilterXfermode;
GrStencilSettings fStencilSettings;
GrMatrix fViewMatrix;
Edge fEdgeAAEdges[kMaxEdges];
int fEdgeAANumEdges;
bool operator ==(const DrState& s) const {
return 0 == memcmp(this, &s, sizeof(DrState));
}
bool operator !=(const DrState& s) const { return !(*this == s); }
};
public:
///////////////////////////////////////////////////////////////////////////
GrDrawTarget();
virtual ~GrDrawTarget();
/**
* 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 texture used at the next drawing call
*
* @param stage The texture stage for which the texture will be set
*
* @param texture The texture to set. Can be NULL though there is no advantage
* to settings a NULL texture if doing non-textured drawing
*/
void setTexture(int stage, GrTexture* texture);
/**
* Retrieves the currently set texture.
*
* @return The currently set texture. The return value will be NULL if no
* texture has been set, NULL was most recently passed to
* setTexture, or the last setTexture was destroyed.
*/
const GrTexture* getTexture(int stage) const;
GrTexture* getTexture(int stage);
/**
* Sets the rendertarget used at the next drawing call
*
* @param target The render target to set.
*/
void setRenderTarget(GrRenderTarget* target);
/**
* Retrieves the currently set rendertarget.
*
* @return The currently set render target.
*/
const GrRenderTarget* getRenderTarget() const;
GrRenderTarget* getRenderTarget();
/**
* Sets the sampler state for a stage used in subsequent draws.
*
* The sampler state determines how texture coordinates are
* intepretted and used to sample the texture.
*
* @param stage the stage of the sampler to set
* @param samplerState Specifies the sampler state.
*/
void setSamplerState(int stage, const GrSamplerState& samplerState);
/**
* Concats the matrix of a stage's sampler.
*
* @param stage the stage of the sampler to set
* @param matrix the matrix to concat
*/
void preConcatSamplerMatrix(int stage, const GrMatrix& matrix) {
GrAssert(stage >= 0 && stage < kNumStages);
fCurrDrawState.fSamplerStates[stage].preConcatMatrix(matrix);
}
/**
* Shortcut for preConcatSamplerMatrix on all stages in mask with same
* matrix
*/
void preConcatSamplerMatrices(int stageMask, const GrMatrix& matrix) {
for (int i = 0; i < kNumStages; ++i) {
if ((1 << i) & stageMask) {
this->preConcatSamplerMatrix(i, matrix);
}
}
}
/**
* Gets the matrix of a stage's sampler
*
* @param stage the stage to of sampler to get
* @return the sampler state's matrix
*/
const GrMatrix& getSamplerMatrix(int stage) const {
return fCurrDrawState.fSamplerStates[stage].getMatrix();
}
/**
* Sets the matrix of a stage's sampler
*
* @param stage the stage of sampler set
* @param matrix the matrix to set
*/
void setSamplerMatrix(int stage, const GrMatrix& matrix) {
fCurrDrawState.fSamplerStates[stage].setMatrix(matrix);
}
/**
* Sets the matrix applied to veretx 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 rendertarget.)
*
* @param m the matrix used to transform the vertex positions.
*/
void setViewMatrix(const GrMatrix& m);
/**
* 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 GrMatrix& 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 GrMatrix& m);
/**
* Retrieves the current view matrix
* @return the current view matrix.
*/
const GrMatrix& getViewMatrix() const;
/**
* 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(GrMatrix* matrix) const;
/**
* Sets color for next draw to a premultiplied-alpha color.
*
* @param the color to set.
*/
void setColor(GrColor);
/**
* Add a color filter that can be represented by a color and a mode.
*/
void setColorFilter(GrColor, SkXfermode::Mode);
/**
* 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 alpha);
/**
* Controls whether clockwise, counterclockwise, or both faces are drawn.
* @param face the face(s) to draw.
*/
void setDrawFace(DrawFace face) { fCurrDrawState.fDrawFace = face; }
/**
* 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) {
fCurrDrawState.fFirstCoverageStage = firstCoverageStage;
}
/**
* Gets the index of the first coverage-computing stage.
*/
int getFirstCoverageStage() const {
return fCurrDrawState.fFirstCoverageStage;
}
/**
* Gets whether the target is drawing clockwise, counterclockwise,
* or both faces.
* @return the current draw face(s).
*/
DrawFace getDrawFace() const { return fCurrDrawState.fDrawFace; }
/**
* Enable render state settings.
*
* @param flags bitfield of StateBits specifing the states to enable
*/
void enableState(uint32_t stateBits);
/**
* Disable render state settings.
*
* @param flags bitfield of StateBits specifing the states to disable
*/
void disableState(uint32_t stateBits);
bool isDitherState() const {
return 0 != (fCurrDrawState.fFlagBits & kDither_StateBit);
}
bool isAntialiasState() const {
return 0 != (fCurrDrawState.fFlagBits & kAntialias_StateBit);
}
bool isClipState() const {
return 0 != (fCurrDrawState.fFlagBits & kClip_StateBit);
}
bool isColorWriteDisabled() const {
return 0 != (fCurrDrawState.fFlagBits & kNoColorWrites_StateBit);
}
/**
* Sets the blending function coeffecients.
*
* 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 coeffecient applied to the src color.
* @param dstCoef coeffecient applied to the dst color.
*/
void setBlendFunc(GrBlendCoeff srcCoeff, GrBlendCoeff dstCoeff);
/**
* Sets the blending function constant referenced by the following blending
* coeffecients:
* kConstC_BlendCoeff
* kIConstC_BlendCoeff
* kConstA_BlendCoeff
* kIConstA_BlendCoeff
*
* @param constant the constant to set
*/
void setBlendConstant(GrColor constant) { fCurrDrawState.fBlendConstant = constant; }
/**
* Retrieves the last value set by setBlendConstant()
* @return the blending constant value
*/
GrColor getBlendConstant() const { return fCurrDrawState.fBlendConstant; }
/**
* Used to save and restore the GrGpu's drawing state
*/
struct SavedDrawState {
private:
DrState 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 kMaxTexCoords sets of 2D texture
* coordinates and per-vertex colors. Each stage can use any of the texture
* coordinates as its input texture coordinates or it may use the positions.
*
* 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)
* 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]).
*/
/**
* 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 < kNumStages);
GrAssert(texCoordIdx < kMaxTexCoords);
return 1 << (stage + (texCoordIdx * kNumStages));
}
/**
* Determines if blend is effectively disabled.
*
* @return true if blend can be disabled without changing the rendering
* result given the current state including the vertex layout specified
* with the vertex source.
*/
bool canDisableBlend() const;
/**
* Sets the edge data required for edge antialiasing.
*
* @param edges 3 * 6 float values, representing the edge
* equations in Ax + By + C form
*/
void setEdgeAAData(const Edge* edges, int numEdges);
private:
static const int TEX_COORD_BIT_CNT = kNumStages*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 < kNumStages);
return (1 << (TEX_COORD_BIT_CNT + stage));
}
private:
static const int STAGE_BIT_CNT = TEX_COORD_BIT_CNT + kNumStages;
public:
/**
* Additional Bits that can be specified in GrVertexLayout.
*/
enum VertexLayoutBits {
kColor_VertexLayoutBit = 1 << (STAGE_BIT_CNT + 0),
//<! vertices have colors
kTextFormat_VertexLayoutBit = 1 << (STAGE_BIT_CNT + 1),
//<! use text vertices. (Pos
// and tex coords may be
// a different type for
// text [GrGpuTextVertex vs
// GrPoint].)
// 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 stageEnableBitfield 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,
StageBitfield stageEnableBitfield,
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,
StageBitfield 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;
};
////////////////////////////////////////////////////////////////////////////
class AutoViewMatrixRestore : ::GrNoncopyable {
public:
AutoViewMatrixRestore() {
fDrawTarget = NULL;
}
AutoViewMatrixRestore(GrDrawTarget* target)
: fDrawTarget(target), fMatrix(fDrawTarget->getViewMatrix()) {
GrAssert(NULL != target);
}
void set(GrDrawTarget* target) {
GrAssert(NULL != target);
if (NULL != fDrawTarget) {
fDrawTarget->setViewMatrix(fMatrix);
}
fDrawTarget = target;
fMatrix = target->getViewMatrix();
}
~AutoViewMatrixRestore() {
if (NULL != fDrawTarget) {
fDrawTarget->setViewMatrix(fMatrix);
}
}
private:
GrDrawTarget* fDrawTarget;
GrMatrix fMatrix;
};
////////////////////////////////////////////////////////////////////////////
/**
* 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, int stageMask);
~AutoDeviceCoordDraw();
private:
GrDrawTarget* fDrawTarget;
GrMatrix fViewMatrix;
GrMatrix fSamplerMatrices[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 { return fVertices; }
void* indices() const { return fIndices; }
GrPoint* positions() const {
return static_cast<GrPoint*>(fVertices);
}
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 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.
* @return size of a single vertex
*/
static int VertexSizeAndOffsetsByIdx(GrVertexLayout vertexLayout,
int texCoordOffsetsByIdx[kMaxTexCoords],
int *colorOffset);
/**
* 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.
* @return size of a single vertex
*/
static int VertexSizeAndOffsetsByStage(GrVertexLayout vertexLayout,
int texCoordOffsetsByStage[kNumStages],
int *colorOffset);
/**
* 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:
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 DrState& state) {
return NULL != state.fTextures[stage] && VertexUsesStage(stage, layout);
}
bool isStageEnabled(int stage) const {
return StageWillBeUsed(stage, this->getGeomSrc().fVertexLayout,
fCurrDrawState);
}
// Helpers for GrDrawTarget subclasses that won't have private access to
// SavedDrawState but need to peek at the state values.
static DrState& accessSavedDrawState(SavedDrawState& sds)
{ return sds.fState; }
static const DrState& accessSavedDrawState(const SavedDrawState& sds)
{ return sds.fState; }
// 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(StageBitfield 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;
DrState fCurrDrawState;
private:
// called when setting a new vert/idx source to unref prev vb/ib
void releasePreviousVertexSource();
void releasePreviousIndexSource();
enum {
kPreallocGeoSrcStateStackCnt = 4,
};
GrAlignedSTStorage<kPreallocGeoSrcStateStackCnt,
GeometrySrcState>
fGeoSrcStateStackStorage;
GrTArray<GeometrySrcState, true> fGeoSrcStateStack;
};
#endif