void ParticleManager::step(float dtime)
{
stepParticles (dtime);
stepSpawners (dtime);
}
int
main(int argc, char *argv[])
{
SDL_Window *window; /* main window */
SDL_GLContext context;
//int w, h;
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? */
/* initialize SDL */
if (SDL_Init(SDL_INIT_VIDEO) < 0) {
fatalError("Could not initialize SDL");
}
/* seed the random number generator */
srand(time(NULL));
/*
request some OpenGL parameters
that may speed drawing
*/
SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 5);
SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 6);
SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 5);
SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 0);
SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 0);
SDL_GL_SetAttribute(SDL_GL_RETAINED_BACKING, 0);
SDL_GL_SetAttribute(SDL_GL_ACCELERATED_VISUAL, 1);
//SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2);
/* create main window and renderer */
window = SDL_CreateWindow(NULL, 0, 0, SCREEN_WIDTH, SCREEN_HEIGHT,
SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN |
SDL_WINDOW_BORDERLESS);
context = SDL_GL_CreateContext(window);
/* load the particle texture */
initializeTexture();
/* check if GL_POINT_SIZE_ARRAY_OES is supported
this is used to give each particle its own size
*/
pointSizeExtensionSupported = SDL_GL_ExtensionSupported("GL_OES_point_size_array");
/* set up some OpenGL state */
glDisable(GL_DEPTH_TEST);
glDisable(GL_CULL_FACE);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
SDL_GetWindowSize(window, &screen_w, &screen_h);
glViewport(0, 0, screen_w, screen_h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrthof((GLfloat) 0,
(GLfloat) screen_w,
(GLfloat) screen_h,
(GLfloat) 0, 0.0, 1.0);
glEnable(GL_TEXTURE_2D);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE);
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_COLOR_ARRAY);
glEnable(GL_POINT_SPRITE_OES);
glTexEnvi(GL_POINT_SPRITE_OES, GL_COORD_REPLACE_OES, 1);
if (pointSizeExtensionSupported) {
/* we use this to set the sizes of all the particles */
glEnableClientState(GL_POINT_SIZE_ARRAY_OES);
} else {
/* if extension not available then all particles have size 10 */
glPointSize(10);
}
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) {
int x, y;
SDL_GetMouseState(&x, &y);
spawnEmitterParticle(x, y);
}
}
stepParticles();
drawParticles();
SDL_GL_SwapWindow(window);
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);
}
}
/* delete textures */
glDeleteTextures(1, &particleTextureID);
/* shutdown SDL */
SDL_Quit();
return 0;
}