Astrophysics/sdl/projectile.c

#include <stdio.h>
#include <SDL2/SDL.h>
#include <time.h>
#include <sys/time.h>
#include "projectile.h"

/* State of projectile */
int isLaunch;

/*
 * This function initialize our Projectile
 */
static void initProjectile(struct window *s_w, struct projectile *s_p){
	s_w->r = SDL_CreateRenderer(s_w->win, -1, 0);
	if(s_w->r == NULL){
		printf("Failed to create renderer\n");
		destroyWindow(s_w->win, s_w->r, s_w->font);
		exit(1);
	}
	s_p->s = loadImage("sdl/imgs/projectile.png");
	if(s_p->s == NULL){
		destroyWindow(s_w->win, s_w->r, s_w->font);
		exit(1);
	}
	s_p->t = SDL_CreateTextureFromSurface(s_w->r, s_p->s);
}
/*
 * This function init our rect for drawing Informations on the projectile
 */
static void initInfos(TTF_Font *font, SDL_Rect *r, const SDL_Surface *s, int x, int y){
	r->w = s->w;
	r->h = s->h;
	r->x = x;
	r->y = y;
}
/*
 * This function draw an celestial object, for instance a planet
 */
static void drawCelestialObject(const struct window window, const SDL_Rect rectObject){
	// Draw celestial object
	SDL_SetRenderDrawColor(window.r, 55, 27, 7, 255);
	SDL_RenderFillRect(window.r, &rectObject);
}
/*
 * This function draw a text from SDL_Surface *surface in window
 */
static void drawText(const struct window window, const SDL_Rect rect, SDL_Surface *surface){
	SDL_Texture *tFont = SDL_CreateTextureFromSurface(window.r, surface);

	SDL_RenderCopy(window.r, tFont, NULL, &rect);

	SDL_DestroyTexture(tFont);
}
/*
 * This function draw all objects in our screen
 */
static void drawObjects(const struct window window, const struct projectile *s_projectile, const SDL_Rect rectObject, const SDL_Rect *rectInfos, SDL_Surface **sInfos){
	/* Draw screen */
	SDL_SetRenderDrawColor(window.r, 0, 0, 0, 255);
	SDL_RenderClear(window.r);

	/* Draw grid */
	drawGrid(window);

	// Draw celestial object
	drawCelestialObject(window, rectObject);
	drawText(window, *rectInfos, *sInfos);

	// Draw infos
	drawText(window, *(rectInfos + 1), *(sInfos + 1));
	drawText(window, *(rectInfos + 2), *(sInfos + 2));
	drawText(window, *(rectInfos + 3), *(sInfos + 3));

	// Draw balle
	SDL_RenderCopy(window.r, s_projectile->t, NULL, &s_projectile->rect);
	SDL_RenderPresent(window.r);
}
/*
 * This function draw a grid in window
 */
 static void drawGrid(const struct window window){
	 int i;
	 int scale = SCALE * 5;
	 SDL_SetRenderDrawColor(window.r, 83, 83, 83, 255);

	 // Draw vertical lines
	 for (i = 0; i < window.w; i = i + scale)
		 SDL_RenderDrawLine(window.r, i, 0, i, window.h);

	 // Draw horizontal lines
	 for (i = 0; i < window.h; i = i + scale)
		 SDL_RenderDrawLine(window.r, 0, i, window.w, i);
 }
 /*
  * This function execute the thread
	*/
static int run(void *args){
	int i = 0;
	struct thread_projectile_args *arg = (struct thread_projectile_args*)args;
	double v0x = arg->projectile->v0x * SCALE;
	double v0y = arg->projectile->v0y * SCALE;
	double x0 = arg->projectile->x;
	double y0;
	SDL_Rect rectObject = arg->rectObject;
	SDL_Rect *rectInfos = arg->rectInfos;
	SDL_Surface **sInfos = arg->sInfos;

	/* Position projectile in altitude */
	arg->projectile->rect.y = rectObject.y + (-arg->projectile->y) - arg->projectile->width;
	y0 = arg->projectile->rect.y;
	arg->projectile->rect.x = arg->projectile->x - (arg->projectile->width / 2);
	x0 = arg->projectile->rect.x;

	/* Draw projectile */
	drawObjects(arg->window, arg->projectile, rectObject, rectInfos, sInfos);

	while(1){
		while(isLaunch != LANDING && isLaunch != STOP) {
			int res = y0 - ((v0y * i) - arg->planet->grav * (i * i));

			if((res + arg->projectile->height) > rectObject.y){
				arg->projectile->rect.y = rectObject.y - arg->projectile->height;
				isLaunch = LANDING;
			}
			else{
				arg->projectile->rect.x = x0 + v0x * i;
				arg->projectile->rect.y = res;
			}

			drawObjects(arg->window, arg->projectile, rectObject, rectInfos, sInfos);

			SDL_Delay(50);
			if(arg->debug == TRUE)
				printf("x: %d y:%d\n", arg->projectile->rect.x, arg->projectile->rect.y);
			i++;
		}
	}

	return 0;
}
/*
 * This is main function, init our objects and create a thread
 */
void handleProjectile(struct projectile *s_projectile, const struct object *s_planet, int debug){
	SDL_Event event;
	SDL_Thread *sthread;
	static struct thread_projectile_args args;
	SDL_Rect rectObject;
	SDL_Rect rectInfos[4];
	SDL_Surface *sInfos[4];
	SDL_Color colorFont = {255, 255, 255};
	char buf[BUF_SIZE];
	int done = 1;
	struct window s_window;
	s_window.h = WIN_PROJECTILE_HEIGHT;
	s_window.w = WIN_PROJECTILE_WIDTH;

	args.projectile = s_projectile;
	args.planet = s_planet;
	args.debug = debug;

	// Init celestial object
	rectObject.x = 0;
	rectObject.y = WIN_PROJECTILE_HEIGHT - (WIN_PROJECTILE_HEIGHT / 5);
	rectObject.h = WIN_PROJECTILE_HEIGHT - 200;
	rectObject.w = WIN_PROJECTILE_WIDTH;
	args.rectObject = rectObject;

	// Init Video
	initWindow(&s_window.win, &s_window.font, "Projectile simulator", s_window.h, s_window.w);

	// Init projectile
	initProjectile(&s_window, s_projectile);
	args.window = s_window;

	/* Init celestial object */
	*sInfos = TTF_RenderText_Blended(s_window.font, "Earth", colorFont);
	initInfos(s_window.font, &rectInfos[0], sInfos[0], (WIN_PROJECTILE_WIDTH / 2) - sInfos[0]->w, rectObject.y + 15);

	/* Get distance and time */
	sprintf(buf, "Distance: %f m", s_projectile->distance);
	*(sInfos + 1) = TTF_RenderText_Blended(s_window.font, buf, colorFont);
	initInfos(s_window.font, &rectInfos[1], sInfos[1], 10, rectInfos[0].y + 20);

	memset(buf, 0, BUF_SIZE);
	sprintf(buf, "Time: %f s", s_projectile->deltat);
	*(sInfos + 2) = TTF_RenderText_Blended(s_window.font, buf, colorFont);
	initInfos(s_window.font, &rectInfos[2], sInfos[2], 10, rectInfos[1].y + 30);

	memset(buf, 0, BUF_SIZE);
	sprintf(buf, "Height max: %f m", s_projectile->hmax);
	*(sInfos + 3) = TTF_RenderText_Blended(s_window.font, buf, colorFont);
	initInfos(s_window.font, &rectInfos[3], sInfos[3], 10, rectInfos[2].y + 30);

	args.rectInfos = rectInfos;
	args.sInfos = sInfos;

	// Create our thread
	isLaunch = STOP;
	sthread = SDL_CreateThread(run, "Projectile", (void*)&args);

	if(sthread == NULL){
		printf("SDL_CreateThread failed: %s\n", SDL_GetError());
		exit(1);
	}

	while(done){
		SDL_WaitEvent(&event);
		switch(event.type){
				case SDL_KEYDOWN:
					switch(event.key.keysym.sym){
						case SDLK_ESCAPE:
							done = 0;
							break;
						case SDLK_RETURN:
							// launch the projectile
							isLaunch = LAUNCH;
							break;
			}
			break;
		}
	}

	SDL_FreeSurface(sInfos[0]);
	SDL_FreeSurface(sInfos[1]);
	SDL_FreeSurface(sInfos[2]);
	SDL_FreeSurface(sInfos[3]);

	cleanProjectile(&s_window, s_projectile);
}
/*
 * This function clean our projectile object
 */
static void cleanProjectile(struct window *s_window, struct projectile *p){
    if(p->t != NULL)
        SDL_DestroyTexture(p->t);
    if(p->s != NULL)
        SDL_FreeSurface(p->s);

	destroyWindow(s_window->win, s_window->r, s_window->font);
}