diff options
Diffstat (limited to 'Xcode-iOS/Demos/src/fireworks.c')
| -rw-r--r-- | Xcode-iOS/Demos/src/fireworks.c | 474 |
1 files changed, 0 insertions, 474 deletions
diff --git a/Xcode-iOS/Demos/src/fireworks.c b/Xcode-iOS/Demos/src/fireworks.c deleted file mode 100644 index 2c4f621f1..000000000 --- a/Xcode-iOS/Demos/src/fireworks.c +++ /dev/null @@ -1,474 +0,0 @@ -/* - * fireworks.c - * written by Holmes Futrell - * use however you want - */ - -#include "SDL.h" -#include "SDL_opengles.h" -#include "common.h" -#include <math.h> -#include <time.h> - -#define ACCEL 0.0001f /* acceleration due to gravity, units in pixels per millesecond squared */ -#define WIND_RESISTANCE 0.00005f /* acceleration per unit velocity due to wind resistance */ -#define MAX_PARTICLES 2000 /* maximum number of particles displayed at once */ - -static GLuint particleTextureID; /* OpenGL particle texture id */ -static SDL_bool pointSizeExtensionSupported; /* is GL_OES_point_size_array supported ? */ -static float pointSizeScale; -/* - used to describe what type of particle a given struct particle is. - emitter - this particle flies up, shooting off trail particles, then finally explodes into dust particles. - trail - shoots off, following emitter particle - dust - radiates outwards from emitter explosion -*/ -enum particleType -{ - emitter = 0, - trail, - dust -}; -/* - struct particle is used to describe each particle displayed on screen -*/ -struct particle -{ - GLfloat x; /* x position of particle */ - GLfloat y; /* y position of particle */ - GLubyte color[4]; /* rgba color of particle */ - GLfloat size; /* size of particle in pixels */ - GLfloat xvel; /* x velocity of particle in pixels per milesecond */ - GLfloat yvel; /* y velocity of particle in pixels per millescond */ - int isActive; /* if not active, then particle is overwritten */ - enum particleType type; /* see enum particleType */ -} particles[MAX_PARTICLES]; /* this array holds all our particles */ - -static int num_active_particles; /* how many members of the particle array are actually being drawn / animated? */ -static int screen_w, screen_h; - -/* function declarations */ -void spawnTrailFromEmitter(struct particle *emitter); -void spawnEmitterParticle(GLfloat x, GLfloat y); -void explodeEmitter(struct particle *emitter); -void initializeParticles(void); -void initializeTexture(); -int nextPowerOfTwo(int x); -void drawParticles(); -void stepParticles(double deltaTime); - -/* helper function (used in texture loading) - returns next power of two greater than or equal to x -*/ -int -nextPowerOfTwo(int x) -{ - int val = 1; - while (val < x) { - val *= 2; - } - return val; -} - -/* - steps each active particle by timestep deltaTime -*/ -void -stepParticles(double deltaTime) -{ - float deltaMilliseconds = deltaTime * 1000; - int i; - struct particle *slot = particles; - struct particle *curr = particles; - for (i = 0; i < num_active_particles; i++) { - /* is the particle actually active, or is it marked for deletion? */ - if (curr->isActive) { - /* is the particle off the screen? */ - if (curr->y > screen_h) - curr->isActive = 0; - else if (curr->y < 0) - curr->isActive = 0; - if (curr->x > screen_w) - curr->isActive = 0; - else if (curr->x < 0) - curr->isActive = 0; - - /* step velocity, then step position */ - curr->yvel += ACCEL * deltaMilliseconds; - curr->xvel += 0.0f; - curr->y += curr->yvel * deltaMilliseconds; - curr->x += curr->xvel * deltaMilliseconds; - - /* particle behavior */ - if (curr->type == emitter) { - /* if we're an emitter, spawn a trail */ - spawnTrailFromEmitter(curr); - /* if we've reached our peak, explode */ - if (curr->yvel > 0.0) { - explodeEmitter(curr); - } - } else { - float speed = - sqrt(curr->xvel * curr->xvel + curr->yvel * curr->yvel); - /* if wind resistance is not powerful enough to stop us completely, - then apply winde resistance, otherwise just stop us completely */ - if (WIND_RESISTANCE * deltaMilliseconds < speed) { - float normx = curr->xvel / speed; - float normy = curr->yvel / speed; - curr->xvel -= - normx * WIND_RESISTANCE * deltaMilliseconds; - curr->yvel -= - normy * WIND_RESISTANCE * deltaMilliseconds; - } else { - curr->xvel = curr->yvel = 0; /* stop particle */ - } - - if (curr->color[3] <= deltaMilliseconds * 0.1275f) { - /* if this next step will cause us to fade out completely - then just mark for deletion */ - curr->isActive = 0; - } else { - /* otherwise, let's fade a bit more */ - curr->color[3] -= deltaMilliseconds * 0.1275f; - } - - /* if we're a dust particle, shrink our size */ - if (curr->type == dust) - curr->size -= deltaMilliseconds * 0.010f; - - } - - /* if we're still active, pack ourselves in the array next - to the last active guy (pack the array tightly) */ - if (curr->isActive) - *(slot++) = *curr; - } /* endif (curr->isActive) */ - curr++; - } - /* the number of active particles is computed as the difference between - old number of active particles, where slot points, and the - new size of the array, where particles points */ - num_active_particles = (int) (slot - particles); -} - -/* - This draws all the particles shown on screen -*/ -void -drawParticles() -{ - - /* draw the background */ - glClear(GL_COLOR_BUFFER_BIT); - - /* set up the position and color pointers */ - glVertexPointer(2, GL_FLOAT, sizeof(struct particle), particles); - glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(struct particle), - particles[0].color); - - if (pointSizeExtensionSupported) { - /* pass in our array of point sizes */ - glPointSizePointerOES(GL_FLOAT, sizeof(struct particle), - &(particles[0].size)); - } - - /* draw our particles! */ - glDrawArrays(GL_POINTS, 0, num_active_particles); - -} - -/* - This causes an emitter to explode in a circular bloom of dust particles -*/ -void -explodeEmitter(struct particle *emitter) -{ - /* first off, we're done with this particle, so turn active off */ - emitter->isActive = 0; - int i; - for (i = 0; i < 200; i++) { - - if (num_active_particles >= MAX_PARTICLES) - return; - - /* come up with a random angle and speed for new particle */ - float theta = randomFloat(0, 2.0f * 3.141592); - float exponent = 3.0f; - float speed = randomFloat(0.00, powf(0.17, exponent)); - speed = powf(speed, 1.0f / exponent); - - /* select the particle at the end of our array */ - struct particle *p = &particles[num_active_particles]; - - /* set the particles properties */ - 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->size = 15 * pointSizeScale; - /* inherit emitter's color */ - p->color[0] = emitter->color[0]; - p->color[1] = emitter->color[1]; - p->color[2] = emitter->color[2]; - p->color[3] = 255; - /* our array has expanded at the end */ - num_active_particles++; - } - -} - -/* - This spawns a trail particle from an emitter -*/ -void -spawnTrailFromEmitter(struct particle *emitter) -{ - - if (num_active_particles >= MAX_PARTICLES) - return; - - /* select the particle at the slot at the end of our array */ - struct particle *p = &particles[num_active_particles]; - - /* set position and velocity to roughly that of the emitter */ - 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; - - /* set the color to a random-ish orangy type color */ - 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; - - /* set other attributes */ - p->size = 10 * pointSizeScale; - p->type = trail; - p->isActive = 1; - - /* our array has expanded at the end */ - num_active_particles++; - -} - -/* - spawns a new emitter particle at the bottom of the screen - destined for the point (x,y). -*/ -void -spawnEmitterParticle(GLfloat x, GLfloat y) -{ - - if (num_active_particles >= MAX_PARTICLES) - return; - - /* find particle at endpoint of array */ - struct particle *p = &particles[num_active_particles]; - - /* set the color randomly */ - switch (rand() % 4) { - case 0: - p->color[0] = 255; - p->color[1] = 100; - p->color[2] = 100; - break; - case 1: - p->color[0] = 100; - p->color[1] = 255; - p->color[2] = 100; - break; - case 2: - p->color[0] = 100; - p->color[1] = 100; - p->color[2] = 255; - break; - case 3: - p->color[0] = 255; - p->color[1] = 150; - p->color[2] = 50; - break; - } - p->color[3] = 255; - /* set position to (x, screen_h) */ - p->x = x; - p->y = screen_h; - /* set velocity so that terminal point is (x,y) */ - p->xvel = 0; - p->yvel = -sqrt(2 * ACCEL * (screen_h - y)); - /* set other attributes */ - p->size = 10 * pointSizeScale; - p->type = emitter; - p->isActive = 1; - /* our array has expanded at the end */ - num_active_particles++; -} - -/* just sets the endpoint of the particle array to element zero */ -void -initializeParticles(void) -{ - num_active_particles = 0; -} - -/* - loads the particle texture - */ -void -initializeTexture() -{ - - int bpp; /* texture bits per pixel */ - Uint32 Rmask, Gmask, Bmask, Amask; /* masks for pixel format passed into OpenGL */ - SDL_Surface *bmp_surface; /* the bmp is loaded here */ - SDL_Surface *bmp_surface_rgba8888; /* this serves as a destination to convert the BMP - to format passed into OpenGL */ - - bmp_surface = SDL_LoadBMP("stroke.bmp"); - if (bmp_surface == NULL) { - fatalError("could not load stroke.bmp"); - } - - /* Grab info about format that will be passed into OpenGL */ - SDL_PixelFormatEnumToMasks(SDL_PIXELFORMAT_ABGR8888, &bpp, &Rmask, &Gmask, - &Bmask, &Amask); - /* Create surface that will hold pixels passed into OpenGL */ - bmp_surface_rgba8888 = - SDL_CreateRGBSurface(0, bmp_surface->w, bmp_surface->h, bpp, Rmask, - Gmask, Bmask, Amask); - /* Blit to this surface, effectively converting the format */ - SDL_BlitSurface(bmp_surface, NULL, bmp_surface_rgba8888, NULL); - - glGenTextures(1, &particleTextureID); - glBindTexture(GL_TEXTURE_2D, particleTextureID); - glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, - nextPowerOfTwo(bmp_surface->w), - nextPowerOfTwo(bmp_surface->h), - 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL); - glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); - glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); - /* this is where we actually pass in the pixel data */ - glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, bmp_surface->w, bmp_surface->h, 0, - GL_RGBA, GL_UNSIGNED_BYTE, bmp_surface_rgba8888->pixels); - - /* free bmp surface and converted bmp surface */ - SDL_FreeSurface(bmp_surface); - SDL_FreeSurface(bmp_surface_rgba8888); - -} - -int -main(int argc, char *argv[]) -{ - SDL_Window *window; /* main window */ - SDL_GLContext context; - int drawableW, drawableH; - 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, 1); - SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 1); - - /* create main window and renderer */ - window = SDL_CreateWindow(NULL, 0, 0, 320, 480, - SDL_WINDOW_OPENGL | SDL_WINDOW_BORDERLESS | SDL_WINDOW_ALLOW_HIGHDPI); - context = SDL_GL_CreateContext(window); - - /* The window size and drawable size may be different when highdpi is enabled, - * due to the increased pixel density of the drawable. */ - SDL_GetWindowSize(window, &screen_w, &screen_h); - SDL_GL_GetDrawableSize(window, &drawableW, &drawableH); - - /* In OpenGL, point sizes are always in pixels. We don't want them looking - * tiny on a retina screen. */ - pointSizeScale = (float) drawableH / (float) screen_h; - - /* 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(); - - glViewport(0, 0, drawableW, drawableH); - - 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 * pointSizeScale); - } - - done = 0; - /* enter main loop */ - while (!done) { - SDL_Event event; - double deltaTime = updateDeltaTime(); - 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(deltaTime); - drawParticles(); - SDL_GL_SwapWindow(window); - SDL_Delay(1); - } - - /* delete textures */ - glDeleteTextures(1, &particleTextureID); - /* shutdown SDL */ - SDL_Quit(); - - return 0; -} |