Clipping

Functions related to primitive clipping. More...

Collaboration diagram for Clipping:

Files
file	clipping.c
file	clipping.h
enum	ClipPlane {   PLANE_LEFT , PLANE_RIGHT , PLANE_BOTTOM , PLANE_TOP ,   PLANE_NEAR , PLANE_FAR , PLANE_COUNT }
static uint8_t	computeClipCode (const SRPVertexShaderOut *v)
static size_t	clipAgainstPlane (SRPVertexShaderOut *in, size_t inCount, ClipPlane plane, const SRPShaderProgram *sp, SRPVertexShaderOut *out)
static void	interpolateVertex (const SRPVertexShaderOut *a, const SRPVertexShaderOut *b, float t, const SRPShaderProgram *sp, SRPVertexShaderOut *out)
static float	planeDistance (const SRPVertexShaderOut *v, ClipPlane p)
bool	clipLine (SRPLine *line, const SRPShaderProgram *sp)
bool	clipPoint (SRPPoint *p)
size_t	clipTriangle (const SRPTriangle *in, const SRPShaderProgram *sp, SRPTriangle *out)

Detailed Description

Functions related to primitive clipping.

Enumeration Type Documentation

ClipPlane

enum ClipPlane

Represents all possible clip planes

Function Documentation

clipAgainstPlane()

static size_t clipAgainstPlane ( SRPVertexShaderOut *  in, size_t  inCount, ClipPlane  plane, const SRPShaderProgram *  sp, SRPVertexShaderOut *  out  )

static

Clip a polygon against specified plane (Sutherland-Hodgman)

Parameters

[in]	in	Vertices of an input polygon
[in]	inCount	Amount of vertices the input polygon has
[in]	plane	The plane to clip against
[in]	sp	The shader program being used
[out]	out	Vertices of a clipped polygon

Returns

Amount of vertices the clipped polygon has

clipLine()

bool clipLine	(	SRPLine *	line,
		const SRPShaderProgram *	sp
	)

Clip the line in-place using Liang-Barsky algorithm

Parameters

[in]	line	The line to clip
[in]	sp	The shader program being used

Returns

true if clipped fully (nothing left), false if clipped partially

clipPoint()

bool clipPoint

(

SRPPoint *

p

)

Determine whether or not a point should be clipped

Parameters

[in]

p

Point to test

Returns

true if point is clipped, false otherwise

clipTriangle()

size_t clipTriangle	(	const SRPTriangle *	in,
		const SRPShaderProgram *	sp,
		SRPTriangle *	out
	)

Clip the triangle using Sutherland-Hodgman algorithm

Parameters

[in]	in	The triangle to clip
[in]	sp	The shader program being used
[out]	out	The returned array of triangles

Returns

Amount of outputted triangles

computeClipCode()

static uint8_t computeClipCode ( const SRPVertexShaderOut *  v )

inlinestatic

Compute the clip code for a vertex. 0 if inside all 6 clip planes, else 1 in a specific bit.

Parameters

[in]

v

Vertex

Returns

Clip code

interpolateVertex()

static void interpolateVertex ( const SRPVertexShaderOut *  a, const SRPVertexShaderOut *  b, float  t, const SRPShaderProgram *  sp, SRPVertexShaderOut *  out  )

static

Create new vertex via interpolating between two existing ones

Parameters

[in]	a	First vertex
[in]	b	Second vertex
[in]	t	Interpolation parameter: 0 -> first vertex, 1 -> second vertex
[in]	sp	The shader program being used
[in]	out	Interpolated vertex

Todo:

this is disgusting

planeDistance()

static float planeDistance ( const SRPVertexShaderOut *  v, ClipPlane  p  )

inlinestatic

Calculate the distance from the vertex to the specified clip plane

Parameters

[in]	v	Vertex
[in]	p	Clip plane

Returns

The distance from the vertex to the specified clip plane