Parallax scrolling world with camera. More...

Data Structures
struct	SGELAYER
	information about a layer More...
struct	SGESTAGE
	information about the stage More...
Defines
#define	ABSOLUTE 0
#define	RELATIVE 1
#define	sgeStageGetSpriteGroup(stage, group) sgeArrayGet(stage->spriteGroups, group)
	get a sprite group from the stage
Functions
SGELAYER *	sgeLayerNew (SGESPRITE *sprite)
	create a new layer from a sprite
void	sgeLayerDestroy (SGELAYER *l)
	destroy a layer and free the resources
SGESTAGE *	sgeStageNew (int width, int height)
	create a new stage
void	sgeStageDestroy (SGESTAGE *s)
	destroy a stage and free resources
int	sgeStageAddLayer (SGESTAGE s, SGESPRITE sprite, int x, int y)
	add a sprite as new layer to the stage
void	sgeStageSetLayerHeight (SGESTAGE *s, int layer, int height)
	change the height of a layer in the stage
void	sgeStageSetLayerWidth (SGESTAGE *s, int layer, int width)
	change the width of a layer in the stage
void	sgeStageDrawLayer (SGESTAGE s, SDL_Surface dest, int layer)
	draw a layer
int	sgeStageAddSpriteGroup (SGESTAGE s, SGESPRITEGROUP g)
	add a sprite group to the stage
int	sgeStageAddSprite (SGESTAGE s, int spriteGroup, SGESPRITE sprite)
	add a sprite to the stage
void	sgeStageDrawSpriteGroup (SGESTAGE *s, int spriteGroup)
	draw a sprite group to the screen
void	sgeStageDrawSpriteGroups (SGESTAGE *s)
	draw all sprite groups on the screen
int	sgeStageSpriteGroupCollideSprite (SGESTAGE s, int b, SGESPRITE a, int orientation)
	test if a sprite collides a sprite group
int	sgeStageSpriteGroupCollideSpriteGroup (SGESTAGE *s, int a, int b, int orientationa)
	test if two sprite groups within a scene have a collision
SGEPOSITION *	sgeStageScreenToReal (SGESTAGE *s, int x, int y)
	calculate thie position of a coordinate on screen within the stage
Variables
int	SGELAYER::y
	the y position of the layer
int	SGELAYER::w
	the width of the layer
int	SGELAYER::h
	the height of the layer
SGESPRITE *	SGELAYER::sprite
	the sprite (image) of the layer
int	SGESTAGE::cameraY
	the y position of the camera
int	SGESTAGE::w
	the width of the stage
int	SGESTAGE::h
	the height of the stage
SGEARRAY *	SGESTAGE::layers
	a SGEARRAY holding all layers of the stage
SGEARRAY *	SGESTAGE::spriteGroups
	a SGEARRAY holding all sprite groups of the stage

Detailed Description

Parallax scrolling world with camera.

Define Documentation

#define ABSOLUTE 0

ABSOLUTE

Interpret coordinates without camera position in mind

Definition at line 32 of file sgestage.h.

#define RELATIVE 1

RELATIVE

Interpret coordinates relative to the camera position

Definition at line 39 of file sgestage.h.

#define sgeStageGetSpriteGroup	(	stage,
		group
	)	sgeArrayGet(stage->spriteGroups, group)

get a sprite group from the stage

Parameters:

stage	a pointer to SGESTAGE
group	the index of the sprite group

Returns:: a pointer to SGESPRITEGROUP

example:

get the first sprite group in the current scene

 SGESPRITEGROUP *g=sgeStageGetSpriteGroup(myStage, 0);

Definition at line 55 of file sgestage.h.

Function Documentation

void sgeLayerDestroy ( SGELAYER * l )

destroy a layer and free the resources

Parameters:

l	a pointer to SGELAYER

Definition at line 23 of file sgestage.c.

SGELAYER* sgeLayerNew ( SGESPRITE * sprite )

create a new layer from a sprite

Parameters:

sprite a pointer to SGESPRITE

Returns:: a pointer to a new SGELAYER

a layer is a background image layer which moves depending on its with.

For example on a side scroller you would have a layer for the sky, which is less wide then a layer over it of the hills, which is less wide then a layer of nearer objects like houses and street lamps.

Definition at line 11 of file sgestage.c.

int sgeStageAddLayer	(	SGESTAGE *	s,
		SGESPRITE *	sprite,
		int	x,
		int	y
	)

add a sprite as new layer to the stage

Parameters:

s	a pointer to SGESTAGE
sprite	a pointer to the SGESPRITE to use as layer
x	the x position of the layer in the stage
y	the y position of the layer in the stage

Returns:: the position in the SGEARRAY of s->layers

Definition at line 58 of file sgestage.c.

int sgeStageAddSprite	(	SGESTAGE *	s,
		int	spriteGroup,
		SGESPRITE *	sprite
	)

add a sprite to the stage

Parameters:

s	a pointer to SGESTAGE
spriteGroup	the index of the SGESPRITEGROUP in s->spriteGroup
sprite	a pointer to SGESPRITE

Definition at line 107 of file sgestage.c.

int sgeStageAddSpriteGroup	(	SGESTAGE *	s,
		SGESPRITEGROUP *	g
	)

add a sprite group to the stage

Parameters:

s	a pointer to SGESTAGE
g	a pointer to SGESPRITEGROUP

Returns:: the position in the SGEARRAY of s->spriteGroups

Definition at line 102 of file sgestage.c.

void sgeStageDestroy ( SGESTAGE * s )

destroy a stage and free resources

Parameters:

s	a pointer to SGESTAGE

Definition at line 50 of file sgestage.c.

void sgeStageDrawLayer	(	SGESTAGE *	s,
		SDL_Surface *	dest,
		int	layer
	)

draw a layer

Parameters:

s	a pointer to SGESTAGE
dest	a SDL_Surface to draw on (e.g. screen)
layer	the index of the layer in s->layers

Definition at line 77 of file sgestage.c.

void sgeStageDrawSpriteGroup	(	SGESTAGE *	s,
		int	spriteGroup
	)

draw a sprite group to the screen

Parameters:

s	a pointer to SGESTAGE
spriteGroup	the index of the SGESPRITEGROUP in s->spriteGroup

Definition at line 113 of file sgestage.c.

void sgeStageDrawSpriteGroups ( SGESTAGE * s )

draw all sprite groups on the screen

Parameters:

s	a pointer to SGESTAGE

Definition at line 118 of file sgestage.c.

SGESTAGE* sgeStageNew	(	int	width,
		int	height
	)

create a new stage

Parameters:

width	the width of the stage
height	the height of the stage

Returns:: a pointer to SGESTAGE

If you use layers, you usually want to be the stage the same width as the largest foreground layer (or height if you go for a vertical scrolling game)

Definition at line 28 of file sgestage.c.

SGEPOSITION* sgeStageScreenToReal	(	SGESTAGE *	s,
		int	x,
		int	y
	)

calculate thie position of a coordinate on screen within the stage

Parameters:

s	a pointer to SGESTAGE
x	the x position on the screen
y	the y position on the screen

Returns:: a pointer to SGEPOSITION

See also:: SGEPOSITION

example:

test where the mouseclick would end up in the stage

 SGEPOSITION *pos=sgeStageScreenToReal(myStage, mouseX, mouseY);
 printf("you clicked on stage position %d,%d\n",pos->x, pos->y);
 sgePositionDestroy(pos);

Definition at line 174 of file sgestage.c.

void sgeStageSetLayerHeight	(	SGESTAGE *	s,
		int	layer,
		int	height
	)

change the height of a layer in the stage

Parameters:

s	a pointer to SGESTAGE
layer	the index of the layer in s->layers
height	the new height of the layer

Definition at line 67 of file sgestage.c.

void sgeStageSetLayerWidth	(	SGESTAGE *	s,
		int	layer,
		int	width
	)

change the width of a layer in the stage

Parameters:

s	a pointer to SGESTAGE
layer	the index of the layer in s->layers
width	the new width of the layer

Definition at line 72 of file sgestage.c.

int sgeStageSpriteGroupCollideSprite	(	SGESTAGE *	s,
		int	b,
		SGESPRITE *	a,
		int	orientation
	)

test if a sprite collides a sprite group

Parameters:

s	a pointer to SGESTAGE
b	the index of the SGESPRITEGROUP in s->spriteGroup
a	a pointer to SGESPRITE
orientation	RELATIVE/ABSOLUTE if the sprite coordinates should be treated as relative to the camera position or not

Returns:: YES/NO if there is a collision

Normally you want to use RELATIVE as orientation, which takes the camera coordinations in account.

 #define ENEMY_GROUP 2
 if (sgeStageSpriteGroupCollideSprite(myStage, ENEMY_GROUP, player, RELATIVE)) {
     // player hits enemy, start player die animation
 }

Definition at line 127 of file sgestage.c.

int sgeStageSpriteGroupCollideSpriteGroup	(	SGESTAGE *	s,
		int	a,
		int	b,
		int	orientationa
	)

test if two sprite groups within a scene have a collision

Parameters:

s	a pointer to SGESTAGE
a	the index of the first SGESPRITEGROUP in s->spriteGroup
b	the index of the second SGESPRITEGROUP in s->spriteGroup
orientation	RELATIVE/ABSOLUTE if the sprite coordinates should be treated as relative to the camera position or not

Returns:: YES/NO if there is a collision

See also:: sgeStageSpriteGroupCollideSprite

Definition at line 154 of file sgestage.c.

SgeStage

Data Structures

Defines

Functions

Variables

Detailed Description

Define Documentation

Function Documentation