--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/XCodeiPhoneOS/Demos/src/fireworks.c	Fri Jul 18 20:51:34 2008 +0000
@@ -0,0 +1,438 @@
+/*
+ *	fireworks.c
+ *	written by Holmes Futrell
+ *	use however you want
+ */
+
+#include "SDL.h"
+#include "math.h"
+#include "common.h"
+#include <math.h>
+#include <time.h>
+#include <OpenGLES/ES1/gl.h>
+
+#define MILLESECONDS_PER_FRAME 16	/* about 60 frames per second */
+#define ACCEL 0.0001f
+#define WIND_RESISTANCE 0.00005f
+#define MAX_PARTICLES 2000
+#define VEL_BEFORE_EXPLODE 0.0f
+
+SDL_TextureID flashTextureID;
+
+
+enum particleType {
+	emitter = 0,
+	trail,
+	dust
+};
+
+struct glformat {
+	int SDL_GL_RED_SIZE;
+	int SDL_GL_GREEN_SIZE;
+	int SDL_GL_BLUE_SIZE;
+	int SDL_GL_ALPHA_SIZE;
+	int SDL_GL_BUFFER_SIZE;
+	int SDL_GL_DOUBLEBUFFER;
+	int SDL_GL_DEPTH_SIZE;
+	int SDL_GL_STENCIL_SIZE;
+	int SDL_GL_ACCUM_RED_SIZE;
+	int SDL_GL_ACCUM_GREEN_SIZE;
+	int SDL_GL_ACCUM_BLUE_SIZE;
+	int SDL_GL_ACCUM_ALPHA_SIZE;
+	int SDL_GL_STEREO;
+	int SDL_GL_MULTISAMPLEBUFFERS;
+	int SDL_GL_MULTISAMPLESAMPLES;
+	int SDL_GL_ACCELERATED_VISUAL;
+	int SDL_GL_RETAINED_BACKING;
+};
+
+struct particle {
+
+	GLfloat x;
+	GLfloat y;
+	GLubyte color[4];
+	GLfloat size;
+	GLfloat xvel;
+	GLfloat yvel;
+	int isActive;
+	enum particleType type;
+	int framesSinceEmission;
+} particles[MAX_PARTICLES];
+
+void spawnParticleFromEmitter(struct particle *emitter);
+void explodeEmitter(struct particle *emitter);
+
+static int num_active_particles;
+
+static void getError(const char *prefix)
+{
+    const char *error;
+	
+	GLenum result = glGetError();
+	if (result == GL_NO_ERROR)
+		return;
+	
+    switch (result) {
+		case GL_NO_ERROR:
+			error = "GL_NO_ERROR";
+			break;
+		case GL_INVALID_ENUM:
+			error = "GL_INVALID_ENUM";
+			break;
+		case GL_INVALID_VALUE:
+			error = "GL_INVALID_VALUE";
+			break;
+		case GL_INVALID_OPERATION:
+			error = "GL_INVALID_OPERATION";
+			break;
+		case GL_STACK_OVERFLOW:
+			error = "GL_STACK_OVERFLOW";
+			break;
+		case GL_STACK_UNDERFLOW:
+			error = "GL_STACK_UNDERFLOW";
+			break;
+		case GL_OUT_OF_MEMORY:
+			error = "GL_OUT_OF_MEMORY";
+			break;
+		default:
+			error = "UNKNOWN";
+			break;
+    }
+    printf("%s: %s\n", prefix, error);
+}
+
+void render(void) {
+		
+	/* draw the background */
+	glClear(GL_COLOR_BUFFER_BIT);
+	
+	struct particle *slot = particles;
+	struct particle *curr = particles;
+	int i;
+	for (i=0; i<num_active_particles; i++) {
+		if (curr->isActive) {
+			
+			if (curr->y > SCREEN_HEIGHT) curr->isActive = 0;
+			if (curr->y < 0) curr->isActive = 0;
+			if (curr->x > SCREEN_WIDTH) curr->isActive = 0;
+			if (curr->x < 0) curr->isActive = 0;
+
+			curr->yvel += ACCEL * MILLESECONDS_PER_FRAME;
+			curr->xvel += 0.0f;
+			curr->y += curr->yvel * MILLESECONDS_PER_FRAME;
+			curr->x += curr->xvel * MILLESECONDS_PER_FRAME;
+			
+			if (curr->type == emitter) {
+				spawnParticleFromEmitter(curr);
+				curr->framesSinceEmission = 0;
+				if (curr->yvel > -VEL_BEFORE_EXPLODE) {
+					explodeEmitter(curr);
+				}
+				curr->framesSinceEmission++;
+			}
+			else {
+				
+				float speed = sqrt(curr->xvel*curr->xvel + curr->yvel*curr->yvel);
+				
+				if (WIND_RESISTANCE * MILLESECONDS_PER_FRAME < speed) {
+					float normx = curr->xvel / speed;
+					float normy = curr->yvel / speed;
+					curr->xvel -= normx * WIND_RESISTANCE * MILLESECONDS_PER_FRAME;
+					curr->yvel -= normy * WIND_RESISTANCE * MILLESECONDS_PER_FRAME;
+				}
+				else {
+					curr->xvel = 0;
+					curr->yvel = 0;
+				}
+				
+				if (curr->color[3] <= MILLESECONDS_PER_FRAME * 0.0005f * 255) {
+					curr->isActive = 0;
+
+				}
+				else {
+					curr->color[3] -= MILLESECONDS_PER_FRAME * 0.0005f * 255;
+				}
+				
+				if (curr->type == dust)
+					curr->size -= MILLESECONDS_PER_FRAME * 0.010f;
+				
+			}
+			
+			*(slot++) = *curr;
+		}
+		curr++;
+	}
+	num_active_particles = slot - particles;
+	
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	glTexEnvi(GL_POINT_SPRITE_OES, GL_COORD_REPLACE_OES, 1);
+
+	glEnableClientState(GL_VERTEX_ARRAY);
+	glVertexPointer(2, GL_FLOAT, sizeof(struct particle), particles + 0);
+	getError("vertices");
+	
+	glEnableClientState(GL_COLOR_ARRAY);
+	glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(struct particle), particles[0].color);
+	getError("colors");
+
+	glEnableClientState(GL_POINT_SIZE_ARRAY_OES);
+	getError("enable client state");
+	glPointSizePointerOES(GL_FLOAT, sizeof(struct particle), &(particles[0].size));	
+	getError("point size");
+
+	glEnable(GL_POINT_SPRITE_OES);
+	glDrawArrays(GL_POINTS, 0, num_active_particles);	
+	getError("glDrawArrays");
+
+		
+	/* update screen */
+	SDL_RenderPresent();
+	
+}
+
+void printOpenGLAttributes(struct glformat *format) {
+	printf("\tSDL_GL_RED_SIZE = %d\n", format->SDL_GL_RED_SIZE);
+	printf("\tSDL_GL_GREEN_SIZE = %d\n", format->SDL_GL_GREEN_SIZE);
+	printf("\tSDL_GL_BLUE_SIZE = %d\n", format->SDL_GL_BLUE_SIZE);
+	printf("\tSDL_GL_ALPHA_SIZE = %d\n", format->SDL_GL_ALPHA_SIZE);
+	printf("\tSDL_GL_BUFFER_SIZE = %d\n", format->SDL_GL_BUFFER_SIZE);
+	printf("\tSDL_GL_DOUBLEBUFFER = %d\n", format->SDL_GL_DOUBLEBUFFER);
+	printf("\tSDL_GL_DEPTH_SIZE = %d\n", format->SDL_GL_DEPTH_SIZE);
+	printf("\tSDL_GL_STENCIL_SIZE = %d\n", format->SDL_GL_STENCIL_SIZE);
+	printf("\tSDL_GL_ACCUM_RED_SIZE = %d\n", format->SDL_GL_ACCUM_RED_SIZE);
+	printf("\tSDL_GL_ACCUM_GREEN_SIZE = %d\n", format->SDL_GL_ACCUM_GREEN_SIZE);
+	printf("\tSDL_GL_ACCUM_BLUE_SIZE = %d\n", format->SDL_GL_ACCUM_BLUE_SIZE);
+	printf("\tSDL_GL_ACCUM_ALPHA_SIZE = %d\n", format->SDL_GL_ACCUM_ALPHA_SIZE);
+	printf("\tSDL_GL_STEREO = %d\n", format->SDL_GL_STEREO);
+	printf("\tSDL_GL_MULTISAMPLEBUFFERS = %d\n", format->SDL_GL_MULTISAMPLEBUFFERS);
+	printf("\tSDL_GL_MULTISAMPLESAMPLES = %d\n", format->SDL_GL_MULTISAMPLESAMPLES);
+	printf("\tSDL_GL_ACCELERATED_VISUAL = %d\n", format->SDL_GL_ACCELERATED_VISUAL);
+	printf("\tSDL_GL_RETAINED_BACKING = %d\n", format->SDL_GL_RETAINED_BACKING);	
+}
+
+void setOpenGLAttributes(struct glformat *format) {
+	SDL_GL_SetAttribute(SDL_GL_RED_SIZE, format->SDL_GL_RED_SIZE);
+	SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, format->SDL_GL_GREEN_SIZE);
+	SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, format->SDL_GL_BLUE_SIZE);
+	SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, format->SDL_GL_ALPHA_SIZE);
+	SDL_GL_SetAttribute(SDL_GL_BUFFER_SIZE, format->SDL_GL_BUFFER_SIZE);
+	SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, format->SDL_GL_DOUBLEBUFFER);
+	SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, format->SDL_GL_DEPTH_SIZE);
+	SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, format->SDL_GL_STENCIL_SIZE);
+	SDL_GL_SetAttribute(SDL_GL_ACCUM_RED_SIZE, format->SDL_GL_ACCUM_RED_SIZE);
+	SDL_GL_SetAttribute(SDL_GL_ACCUM_GREEN_SIZE, format->SDL_GL_ACCUM_GREEN_SIZE);
+	SDL_GL_SetAttribute(SDL_GL_ACCUM_BLUE_SIZE, format->SDL_GL_ACCUM_BLUE_SIZE);
+	SDL_GL_SetAttribute(SDL_GL_ACCUM_ALPHA_SIZE, format->SDL_GL_ACCUM_ALPHA_SIZE);
+	SDL_GL_SetAttribute(SDL_GL_STEREO, format->SDL_GL_STEREO);
+	SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, format->SDL_GL_MULTISAMPLEBUFFERS);
+	SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, format->SDL_GL_MULTISAMPLESAMPLES);
+	SDL_GL_SetAttribute(SDL_GL_ACCELERATED_VISUAL, format->SDL_GL_ACCELERATED_VISUAL);
+	SDL_GL_SetAttribute(SDL_GL_RETAINED_BACKING, format->SDL_GL_RETAINED_BACKING);
+}
+
+void getOpenGLAttributes(struct glformat *format) {
+		
+	SDL_GL_GetAttribute(SDL_GL_RED_SIZE, &(format->SDL_GL_RED_SIZE));
+	SDL_GL_GetAttribute(SDL_GL_GREEN_SIZE, &(format->SDL_GL_GREEN_SIZE));
+	SDL_GL_GetAttribute(SDL_GL_BLUE_SIZE, &(format->SDL_GL_BLUE_SIZE));
+	SDL_GL_GetAttribute(SDL_GL_ALPHA_SIZE, &(format->SDL_GL_ALPHA_SIZE));
+	SDL_GL_GetAttribute(SDL_GL_BUFFER_SIZE, &(format->SDL_GL_BUFFER_SIZE));
+	SDL_GL_GetAttribute(SDL_GL_DOUBLEBUFFER, &(format->SDL_GL_DOUBLEBUFFER));
+	SDL_GL_GetAttribute(SDL_GL_DEPTH_SIZE, &(format->SDL_GL_DEPTH_SIZE));
+	SDL_GL_GetAttribute(SDL_GL_STENCIL_SIZE, &(format->SDL_GL_STENCIL_SIZE));
+	SDL_GL_GetAttribute(SDL_GL_ACCUM_RED_SIZE, &(format->SDL_GL_ACCUM_RED_SIZE));
+	SDL_GL_GetAttribute(SDL_GL_ACCUM_GREEN_SIZE, &(format->SDL_GL_ACCUM_GREEN_SIZE));
+	SDL_GL_GetAttribute(SDL_GL_ACCUM_BLUE_SIZE, &(format->SDL_GL_ACCUM_BLUE_SIZE));
+	SDL_GL_GetAttribute(SDL_GL_ACCUM_ALPHA_SIZE, &(format->SDL_GL_ACCUM_ALPHA_SIZE));
+	SDL_GL_GetAttribute(SDL_GL_STEREO, &(format->SDL_GL_STEREO));
+	SDL_GL_GetAttribute(SDL_GL_MULTISAMPLEBUFFERS, &(format->SDL_GL_MULTISAMPLEBUFFERS));
+	SDL_GL_GetAttribute(SDL_GL_MULTISAMPLESAMPLES, &(format->SDL_GL_MULTISAMPLESAMPLES));
+	SDL_GL_GetAttribute(SDL_GL_ACCELERATED_VISUAL, &(format->SDL_GL_ACCELERATED_VISUAL));
+	SDL_GL_GetAttribute(SDL_GL_RETAINED_BACKING, &(format->SDL_GL_RETAINED_BACKING));
+}
+
+void explodeEmitter(struct particle *emitter) {
+
+	emitter->isActive = 0;
+	
+	int i;
+	for (i=0; i<200; i++) {
+		
+		if (num_active_particles >= MAX_PARTICLES) return;
+		
+		float theta = randomFloat(0, 2.0f * 3.141592);
+		float max = 3.0f;
+		float speed = randomFloat(0.00, powf(0.17, max));
+		speed = powf(speed, 1.0f / max);
+		
+		struct particle *p = &particles[num_active_particles];
+		p->xvel = speed * cos(theta);
+		p->yvel = speed * sin(theta);
+		p->x = emitter->x + emitter->xvel;
+		p->y = emitter->y + emitter->yvel;
+		p->isActive = 1;
+		p->type = dust;
+		p->color[0] = emitter->color[0];
+		p->color[1] = emitter->color[1];
+		p->color[2] = emitter->color[2];
+		p->color[3] = 255;
+
+		p->size = 15;
+		
+		num_active_particles++;
+		
+	}
+	
+}
+
+void spawnParticleFromEmitter(struct particle *emitter) {
+	
+	if (num_active_particles >= MAX_PARTICLES) return;
+	
+	struct particle *p = &particles[num_active_particles];
+	p->x = emitter->x + randomFloat(-3.0, 3.0);
+	p->y = emitter->y + emitter->size / 2.0f;
+	p->xvel = emitter->xvel + randomFloat(-0.005, 0.005);
+	p->yvel = emitter->yvel + 0.1;
+	p->color[0] = (0.8f + randomFloat(-0.1, 0.0)) * 255;
+	p->color[1] = (0.4f + randomFloat(-0.1, 0.1)) * 255;
+	p->color[2] = (0.0f + randomFloat(0.0, 0.2)) * 255;
+	p->color[3] = (0.7f) * 255;
+	p->size = 10;
+	p->type = trail;
+	p->isActive = 1;
+	num_active_particles++;
+	
+}
+	
+void spawnEmitterParticle(int x, int y) {
+
+	if (num_active_particles >= MAX_PARTICLES) return;
+	
+	struct particle *p = &particles[num_active_particles];
+	p->x = x;
+	p->y = SCREEN_HEIGHT;
+	p->xvel = 0;
+	p->yvel = -sqrt(2*ACCEL*(SCREEN_HEIGHT-y) + VEL_BEFORE_EXPLODE * VEL_BEFORE_EXPLODE);
+	p->color[0] = 1.0 * 255;
+	p->color[1] = 0.4 * 255;
+	p->color[2] = 0.4 * 255;
+	p->color[3] = 1.0f * 255;
+	p->size = 10;
+	p->type = emitter;
+	p->framesSinceEmission = 0;
+	p->isActive = 1;
+	num_active_particles++;
+}
+
+void initializeParticles(void) {
+	
+	num_active_particles = 0;
+	
+}
+
+/*
+ loads the brush texture
+ */
+void initializeTexture() {
+	SDL_Surface *bmp_surface;
+	bmp_surface = SDL_LoadBMP("stroke.bmp");
+	if (bmp_surface == NULL) {
+		fatalError("could not load stroke.bmp");
+	}
+	flashTextureID = SDL_CreateTextureFromSurface(SDL_PIXELFORMAT_ABGR8888, bmp_surface);
+	SDL_FreeSurface(bmp_surface);
+	if (flashTextureID == 0) {
+		fatalError("could not create brush texture");
+	}
+	glEnable(GL_TEXTURE_2D);
+	glEnable(GL_BLEND);
+	glBlendFunc(GL_SRC_ALPHA, GL_ONE);
+}
+
+int main(int argc, char *argv[]) {
+	
+	SDL_WindowID windowID;	/* ID of main window */
+	Uint32 startFrame;		/* time frame began to process */
+	Uint32 endFrame;		/* time frame ended processing */
+	Uint32 delay;			/* time to pause waiting to draw next frame */
+	int done;				/* should we clean up and exit? */
+	
+	struct glformat requested, obtained;
+	
+	/* initialize SDL */
+	if (SDL_Init(SDL_INIT_VIDEO) < 0) {
+		fatalError("Could not initialize SDL");
+	}
+	
+	srand(time(NULL));
+	
+	SDL_GL_LoadLibrary(NULL);
+		
+	SDL_memset(&requested, 0, sizeof(requested));
+	requested.SDL_GL_RED_SIZE = 5;
+	requested.SDL_GL_GREEN_SIZE = 6; 
+	requested.SDL_GL_BLUE_SIZE = 5;
+	requested.SDL_GL_ALPHA_SIZE = 0;
+	requested.SDL_GL_DEPTH_SIZE = 0;
+	requested.SDL_GL_RETAINED_BACKING = 0;
+	requested.SDL_GL_ACCELERATED_VISUAL = 1;	
+	
+	setOpenGLAttributes(&requested);
+	
+	/* create main window and renderer */
+	windowID = SDL_CreateWindow(NULL, 0, 0, SCREEN_WIDTH, SCREEN_HEIGHT,\
+								SDL_WINDOW_OPENGL|SDL_WINDOW_SHOWN|SDL_WINDOW_BORDERLESS);
+	SDL_CreateRenderer(windowID, 0, 0);		
+	
+	printf("Requested:\n");
+	printOpenGLAttributes(&requested);
+	
+	printf("obtained:\n");
+	getOpenGLAttributes(&obtained);
+	printOpenGLAttributes(&obtained);	
+	
+	initializeTexture();
+
+	done = 0;
+	/* enter main loop */
+	while(!done) {
+		startFrame = SDL_GetTicks();
+		SDL_Event event;
+        while (SDL_PollEvent(&event)) {
+            if (event.type == SDL_QUIT) {
+				done = 1;
+            }
+			if (event.type == SDL_MOUSEBUTTONDOWN) {
+				printf("mouse down\n");
+				int which = event.button.which;
+				int x, y;
+				SDL_SelectMouse(which);
+				SDL_GetMouseState(&x, &y);
+				spawnEmitterParticle(x, y);
+			}
+        }
+		render();
+		endFrame = SDL_GetTicks();
+		
+		/* figure out how much time we have left, and then sleep */
+		delay = MILLESECONDS_PER_FRAME - (endFrame - startFrame);
+		if (delay > MILLESECONDS_PER_FRAME) {
+			delay = MILLESECONDS_PER_FRAME;
+		}
+		if (delay > 0) {
+			SDL_Delay(delay);
+		}
+			
+		//SDL_Delay(delay);
+	}
+	
+	/* delete textures */
+	
+	/* shutdown SDL */
+	SDL_Quit();
+	
+	return 0;
+	
+}
\ No newline at end of file