SXPointSpriteGroup.h

gistfile1.txt

#import <Foundation/Foundation.h>
#import "Sparrow.h"


typedef struct{
    float x;
    float y;
	float size;
} SXPSData;

@interface SXPointSpriteGroup : SPSprite{
	SPTexture *texture;
	BOOL processing;
	int numPointSprites;
	SXPSData *pointSprites;
	BOOL initialized;
}

@property (nonatomic, retain) SPTexture *texture;

- (id)initWithTexture:(SPTexture*)t andNumSprites:(int)amount;
- (void)start;
- (void)stop;
- (void)reset;
- (void)update:(SPEnterFrameEvent*)event;

@end

SXPointSpriteGroup.m

#import "SXPointSpriteGroup.h"

@implementation SXPointSpriteGroup
@synthesize texture;

- (id)initWithTexture:(SPTexture*)t andNumSprites:(int)amount{
	self = [super init];
	numPointSprites = amount;
	self.texture = t;
	[self reset];
	return self;
}

- (void)start{
	if(!processing){
		[self addEventListener:@selector(update:) atObject:self forType:SP_EVENT_TYPE_ENTER_FRAME];
		processing = YES;
	}
}

- (void)stop{
	if(processing){
		[self removeEventListener:@selector(update:) atObject:self forType:SP_EVENT_TYPE_ENTER_FRAME];
		processing = NO;
	}
}

- (void)reset{
	if(pointSprites != NULL){
		free(pointSprites);
	}
	pointSprites = malloc(numPointSprites * sizeof(SXPSData));
	for(int i=0; i<numPointSprites; i++){
		SXPSData *ps = &pointSprites[i];
		ps->x = 0;
		ps->y = 0;
		ps->size = 10; // TODO: NEED TO FIGURE THIS OUT
	}
	initialized = YES;
	// override when resets to do things like set start position
}

- (void)update:(SPEnterFrameEvent*)event{
	// override and process your pointSprites before they get rendered
	// event.passedTime can be very hand here for accuracy. 
}

- (void)render:(SPRenderSupport *)support{
	[super render:support];
	if(!processing) return;
	if(!texture) return;
	if(!initialized) [self reset];
	
	[support bindTexture:texture]; // the class has a texture
	
    glEnable(GL_POINT_SPRITE_OES);
    glTexEnvi(GL_POINT_SPRITE_OES, GL_COORD_REPLACE_OES, GL_TRUE);
	
    GLubyte alpha = self.alpha * 255;
    if (support.usingPremultipliedAlpha) glColor4ub(alpha, alpha, alpha, alpha);
    else                                 glColor4ub(255, 255, 255, alpha);
	
    glEnableClientState(GL_VERTEX_ARRAY);
    glVertexPointer(2, GL_FLOAT, sizeof(SXPSData), pointSprites);
	
    glEnableClientState(GL_POINT_SIZE_ARRAY_OES);
    glPointSizePointerOES(GL_FLOAT, sizeof(SXPSData), (void*)pointSprites +
                          offsetof(SXPSData, size));    
	
    glDrawArrays(GL_POINTS, 0, numPointSprites);    
	
    glDisableClientState(GL_POINT_SIZE_ARRAY_OES);
    glDisableClientState(GL_VERTEX_ARRAY);
	
    glDisable(GL_POINT_SPRITE_OES);
}

- (void)dealloc{
	[self stop];
	self.texture = nil;
	if(pointSprites != NULL){
		free(pointSprites);
	}
	[super dealloc];
}


@end