Vertex processing

Functions related to vertex processing and post-VS cache. More...

Collaboration diagram for Vertex processing:

Files
file	vertex_processing.c
file	vertex_processing.h

Classes
struct	VertexCacheEntry
typedef struct VertexCacheEntry	VertexCacheEntry
typedef struct VertexCache	VertexCache
static void	computeMinMaxVI (const SRPIndexBuffer *ib, size_t startIndex, size_t vertexCount, size_t *outMinVI, size_t *outMaxVI)
void	allocateVertexCache (VertexCache *cache, const SRPIndexBuffer *ib, size_t startIndex, size_t vertexCount, size_t varyingSize)
SRPVertexShaderOut *	vertexCacheFetch (VertexCache *cache, size_t vertexIndex, const SRPVertexBuffer *vb, const SRPShaderProgram *sp)
void	processVertex (size_t vertexIndex, void *varyingBlock, size_t varyingIndex, const SRPVertexBuffer *vb, const SRPShaderProgram *sp, SRPVertexShaderOut *outV)
void	applyPerspectiveDivide (SRPVertexShaderOut *output, float *outInvW)

Detailed Description

Functions related to vertex processing and post-VS cache.

Typedef Documentation

VertexCache

typedef struct VertexCache VertexCache

Post-VS cache

VertexCacheEntry

typedef struct VertexCacheEntry VertexCacheEntry

Represents an entry in VertexCache

Function Documentation

allocateVertexCache()

void allocateVertexCache	(	VertexCache *	cache,
		const SRPIndexBuffer *	ib,
		size_t	startIndex,
		size_t	vertexCount,
		size_t	varyingSize
	)

Initialize / allocate vertex cache

Parameters

[in]	cache	Pointer to the cache
[in]	ib	The SRPIndexBuffer being used
[in]	startIndex	First stream index
[in]	vertexCount	How many vertices from the ib you want to process
[in]	varyingSize	The size of varying vertex parameters, in bytes

applyPerspectiveDivide()

void applyPerspectiveDivide	(	SRPVertexShaderOut *	output,
		float *	outInvW
	)

Apply perspective divide to the output of the vertex shader, optionally saving the 1 / W_clip value

Parameters

[in]	output	Output of the vertex shader
[out]	outInvW	Pointer where 1/W value will be stored. May be NULL

computeMinMaxVI()

static void computeMinMaxVI ( const SRPIndexBuffer *  ib, size_t  startIndex, size_t  vertexCount, size_t *  outMinVI, size_t *  outMaxVI  )

static

Compute minimal and maximal vertex indices given stream indices

processVertex()

void processVertex	(	size_t	vertexIndex,
		void *	varyingBlock,
		size_t	varyingIndex,
		const SRPVertexBuffer *	vb,
		const SRPShaderProgram *	sp,
		SRPVertexShaderOut *	outV
	)

Run vertex shader

Parameters

[in]	vertexIndex	The index of the vertex to process (not its stream index!)
[in]	varyingBlock	Pointer to the block where vertex varyings are stored
[in]	varyingIndex	Index into the varyingBlock
[in]	vb	The SRPVertexBuffer being used
[in]	sp	The SRPShaderProgram being used
[out]	outV	Where to store the processed vertex

vertexCacheFetch()

SRPVertexShaderOut * vertexCacheFetch	(	VertexCache *	cache,
		size_t	vertexIndex,
		const SRPVertexBuffer *	vb,
		const SRPShaderProgram *	sp
	)

Fetch vertex shader output from post-VS cache. If not found, compute and store it. Returns clip-space positions (does not perform perspective divide)

Parameters

[in]	cache	The vertex cache
[in]	vertexIndex	The index of the vertex to fetch (not its stream index!)
[in]	vb	The SRPVertexBuffer being used
[in]	sp	The SRPShaderProgram being used

Returns

The processed, post-VS vertex