collision.c File Reference

Deals with 2d collisions. More...

#include "collision.h"
#include "array.h"
#include "log.h"
#include "physics.h"

Include dependency graph for collision.c:

Go to the source code of this file.

Macros
#define	FX(A, B, C, x)
#define	FY(A, B, C, y)

Functions
static int	PointInPolygon (const CollPolyView *at, const vec2 *ap, float x, float y)
	Checks whether or not a point is inside a polygon.
static int	LineOnPolygon (const CollPolyView *at, const vec2 *ap, float x1, float y1, float x2, float y2, vec2 *crash)
	Checks whether or not a line intersects a polygon.
void	poly_load (CollPoly *polygon, xmlNodePtr base, const char *name)
	Loads a polygon from an xml node.
void	poly_free (CollPoly *poly)
int	CollideSprite (const glTexture *at, const int asx, const int asy, const vec2 *ap, const glTexture *bt, const int bsx, const int bsy, const vec2 *bp, vec2 *crash)
	Checks whether or not two sprites collide.
int	CollideSpritePolygon (const CollPolyView *at, const vec2 *ap, const glTexture *bt, int bsx, int bsy, const vec2 *bp, vec2 *crash)
	Checks whether or not a sprite collides with a polygon.
int	CollidePolygon (const CollPolyView *at, const vec2 *ap, const CollPolyView *bt, const vec2 *bp, vec2 *crash)
	Checks whether or not two polygons collide. /!\ The function is not symmetric: the points of polygon 2 are tested against the polygon 1. Consequently, it works better if polygon 2 is small.
void	poly_rotate (CollPolyView *rpolygon, const CollPolyView *ipolygon, float theta)
	Rotates a polygon.
const CollPolyView *	poly_view (const CollPoly *poly, double dir)
int	CollideLineLine (double s1x, double s1y, double e1x, double e1y, double s2x, double s2y, double e2x, double e2y, vec2 *crash)
	Checks to see if two lines collide.
int	CollideLineSprite (const vec2 *ap, double ad, double al, const glTexture *bt, const int bsx, const int bsy, const vec2 *bp, vec2 crash[2])
	Checks to see if a line collides with a sprite.
int	CollideLinePolygon (const vec2 *ap, double ad, double al, const CollPolyView *bt, const vec2 *bp, vec2 crash[2])
	Checks to see if a line collides with a polygon.
int	CollideCirclePolygon (const vec2 *ap, double ar, const CollPolyView *bt, const vec2 *bp, vec2 crash[2])
	Checks to see if a circle collides with a polygon.
int	CollideCircleSprite (const vec2 *ap, double ar, const glTexture *bt, const int bsx, const int bsy, const vec2 *bp, vec2 *crash)
	Checks whether or not a sprite collides with a polygon.
static int	linePointOnSegment (double d1, double x1, double y1, double x2, double y2, double x, double y)
int	CollideLineCircle (const vec2 *p1, const vec2 *p2, const vec2 *cc, double cr, vec2 crash[2])
	Checks to see if a line collides with a circle.
int	CollideCircleCircle (const vec2 *p1, double r1, const vec2 *p2, double r2, vec2 crash[2])
	Computes the collision between two circles.
double	CollideCircleIntersection (const vec2 *p1, double r1, const vec2 *p2, double r2)
	Calculates the area of intersection between two circles.

Detailed Description

Deals with 2d collisions.

Definition in file collision.c.

Macro Definition Documentation

FX

#define FX	(		A,
			B,
			C,
			x )

Value:

( -( A * x + C ) / B )

Definition at line 1018 of file collision.c.

FY

#define FY	(		A,
			B,
			C,
			y )

Value:

( -( B * y + C ) / A )

Definition at line 1019 of file collision.c.

Function Documentation

CollideCircleCircle()

int CollideCircleCircle	(	const vec2 *	p1,
		double	r1,
		const vec2 *	p2,
		double	r2,
		vec2	crash[2] )

Computes the collision between two circles.

Definition at line 1142 of file collision.c.

CollideCircleIntersection()

double CollideCircleIntersection	(	const vec2 *	p1,
		double	r1,
		const vec2 *	p2,
		double	r2 )

Calculates the area of intersection between two circles.

Definition at line 1159 of file collision.c.

CollideCirclePolygon()

int CollideCirclePolygon	(	const vec2 *	ap,
		double	ar,
		const CollPolyView *	bt,
		const vec2 *	bp,
		vec2	crash[2] )

Checks to see if a circle collides with a polygon.

First collisions are detected on all the walls of the polygon's rectangle. Then the collisions are tested on every line of the polygon.

Parameters

[in]	ap	Origin of the circle.
[in]	ar	Radius of the circle.
[in]	bt	Polygon b.
[in]	bp	Position in space of polygon b.
[out]	crash	Position of the collision.

Returns

1 on collision, 0 else.

See also

CollideCirclePolygon

Definition at line 862 of file collision.c.

CollideCircleSprite()

int CollideCircleSprite	(	const vec2 *	ap,
		double	ar,
		const glTexture *	bt,
		const int	bsx,
		const int	bsy,
		const vec2 *	bp,
		vec2 *	crash )

Checks whether or not a sprite collides with a polygon.

Parameters

[in]	ap	Position in space of circle a.
[in]	ar	Radius of circle a.
[in]	bt	Texture b.
[in]	bsx	Position of x of sprite b.
[in]	bsy	Position of y of sprite b.
[in]	bp	Position in space of sprite b.
[out]	crash	Actual position of the collision (only set on collision).

Returns

1 on collision, 0 else.

Definition at line 941 of file collision.c.

CollideLineCircle()

int CollideLineCircle	(	const vec2 *	p1,
		const vec2 *	p2,
		const vec2 *	cc,
		double	cr,
		vec2	crash[2] )

Checks to see if a line collides with a circle.

Parameters

[in]	p1	Point 1 of the line segment.
[in]	p2	Point 2 of the line segment.
[in]	cc	Center of the circle.
[in]	cr	Radius of the circle.
[out]	crash	Position of the collision.

Returns

1 on collision, 0 else.

Definition at line 1030 of file collision.c.

CollideLineLine()

int CollideLineLine	(	double	s1x,
		double	s1y,
		double	e1x,
		double	e1y,
		double	s2x,
		double	s2y,
		double	e2x,
		double	e2y,
		vec2 *	crash )

Checks to see if two lines collide.

Parameters

[in]	s1x	X start point of line 1.
[in]	s1y	Y start point of line 1.
[in]	e1x	X end point of line 1.
[in]	e1y	Y end point of line 1.
[in]	s2x	X start point of line 2.
[in]	s2y	Y start point of line 2.
[in]	e2x	X end point of line 2.
[in]	e2y	Y end point of line 2.
[out]	crash	Position of the collision.

Returns

3 if lines are coincident, 2 if lines are parallel, 1 if lines just collide on a point, or 0 if they don't.

Definition at line 526 of file collision.c.

CollideLinePolygon()

int CollideLinePolygon	(	const vec2 *	ap,
		double	ad,
		double	al,
		const CollPolyView *	bt,
		const vec2 *	bp,
		vec2	crash[2] )

Checks to see if a line collides with a polygon.

First collisions are detected on all the walls of the polygon's rectangle. Then the collisions are tested on every line of the polygon.

Parameters

[in]	ap	Origin of the line.
[in]	ad	Direction of the line.
[in]	al	Length of the line.
[in]	bt	Polygon b.
[in]	bp	Position in space of polygon b.
[out]	crash	Position of the collision.

Returns

1 on collision, 0 else.

See also

CollideLinePolygon

Definition at line 729 of file collision.c.

CollideLineSprite()

int CollideLineSprite	(	const vec2 *	ap,
		double	ad,
		double	al,
		const glTexture *	bt,
		const int	bsx,
		const int	bsy,
		const vec2 *	bp,
		vec2	crash[2] )

Checks to see if a line collides with a sprite.

First collisions are detected on all the walls of the sprite's rectangle. Then the collisions are tested by pixel perfectness until collisions are actually found with the ship itself.

Parameters

[in]	ap	Origin of the line.
[in]	ad	Direction of the line.
[in]	al	Length of the line.
[in]	bt	Texture b.
[in]	bsx	Position of x of sprite b.
[in]	bsy	Position of y of sprite b.
[in]	bp	Position in space of sprite b.
[out]	crash	Position of the collision.

Returns

1 on collision, 0 else.

See also

CollideSprite

Definition at line 578 of file collision.c.

CollidePolygon()

int CollidePolygon	(	const CollPolyView *	at,
		const vec2 *	ap,
		const CollPolyView *	bt,
		const vec2 *	bp,
		vec2 *	crash )

Checks whether or not two polygons collide. /!\ The function is not symmetric: the points of polygon 2 are tested against the polygon 1. Consequently, it works better if polygon 2 is small.

Parameters

[in]	at	Polygon a.
[in]	ap	Position in space of polygon a.
[in]	bt	Polygon b.
[in]	bp	Position in space of polygon b.
[out]	crash	Actual position of the collision (only set on collision).

Returns

1 on collision, 0 else.

Definition at line 311 of file collision.c.

CollideSprite()

int CollideSprite	(	const glTexture *	at,
		const int	asx,
		const int	asy,
		const vec2 *	ap,
		const glTexture *	bt,
		const int	bsx,
		const int	bsy,
		const vec2 *	bp,
		vec2 *	crash )

Checks whether or not two sprites collide.

This function does pixel perfect checks. If the collision actually occurs, crash is set to store the real position of the collision.

Parameters

[in]	at	Texture a.
[in]	asx	Position of x of sprite a.
[in]	asy	Position of y of sprite a.
[in]	ap	Position in space of sprite a.
[in]	bt	Texture b.
[in]	bsx	Position of x of sprite b.
[in]	bsy	Position of y of sprite b.
[in]	bp	Position in space of sprite b.
[out]	crash	Actual position of the collision (only set on collision).

Returns

1 on collision, 0 else.

Definition at line 148 of file collision.c.

CollideSpritePolygon()

int CollideSpritePolygon	(	const CollPolyView *	at,
		const vec2 *	ap,
		const glTexture *	bt,
		int	bsx,
		int	bsy,
		const vec2 *	bp,
		vec2 *	crash )

Checks whether or not a sprite collides with a polygon.

Parameters

[in]	at	Polygon a.
[in]	ap	Position in space of polygon a.
[in]	bt	Texture b.
[in]	bsx	Position of x of sprite b.
[in]	bsy	Position of y of sprite b.
[in]	bp	Position in space of sprite b.
[out]	crash	Actual position of the collision (only set on collision).

Returns

1 on collision, 0 else.

Definition at line 233 of file collision.c.

LineOnPolygon()

int LineOnPolygon ( const CollPolyView * at, const vec2 * ap, float x1, float y1, float x2, float y2, vec2 * crash )

static

Checks whether or not a line intersects a polygon.

Parameters

[in]	at	Polygon a.
[in]	ap	Position in space of polygon a.
[in]	x1	Coordinate of point 1.
[in]	y1	Coordinate of point 1.
[in]	x2	Coordinate of point 2.
[in]	y2	Coordinate of point 2.
[out]	crash	coordinates of the intersection.

Returns

1 on collision, 0 else.

Definition at line 486 of file collision.c.

linePointOnSegment()

int linePointOnSegment ( double d1, double x1, double y1, double x2, double y2, double x, double y )

static

Definition at line 1008 of file collision.c.

PointInPolygon()

int PointInPolygon ( const CollPolyView * at, const vec2 * ap, float x, float y )

static

Checks whether or not a point is inside a polygon.

Parameters

[in]	at	Polygon a.
[in]	ap	Position in space of polygon a.
[in]	x	Coordinate of point.
[in]	y	Coordinate of point.

Returns

1 on collision, 0 else.

Definition at line 440 of file collision.c.

poly_free()

void poly_free

(

CollPoly *

poly

)

Definition at line 120 of file collision.c.

poly_load()

void poly_load	(	CollPoly *	polygon,
		xmlNodePtr	base,
		const char *	name )

Loads a polygon from an xml node.

Parameters

[out]	polygon	Polygon.
[in]	base	XML node to parse.
[in]	name	Name to give the polygon for debugging purposes.

Definition at line 37 of file collision.c.

poly_rotate()

void poly_rotate	(	CollPolyView *	rpolygon,
		const CollPolyView *	ipolygon,
		float	theta )

Rotates a polygon.

Parameters

[out]	rpolygon	Rotated polygon.
[in]	ipolygon	Input polygon.
[in]	theta	Rotation angle (radian).

Definition at line 385 of file collision.c.

poly_view()

const CollPolyView * poly_view	(	const CollPoly *	poly,
		double	dir )

Definition at line 414 of file collision.c.