sdl_rect.c

#include "SDL.h"
#include <stdio.h>
#include <stdlib.h>
#include <time.h>


SDL_Window* create_window(){
	int posX = 100;
	int posY = 100;
	int width = 500;
	int height = 500;

	return SDL_CreateWindow(
		"SDL Window",
		posX,
		posY,
		width,
		height,
		SDL_WINDOW_OPENGL
	);
}

SDL_Renderer* create_renderer(SDL_Window *window){
	return SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
	// SDL_RENDERER_ACCELERATED
	// SDL_RENDERER_SOFTWARE
}

void destroy_and_quit(SDL_Window *window, SDL_Renderer *renderer){
	SDL_DestroyRenderer(renderer);
	SDL_DestroyWindow(window);
	SDL_Quit();
}

int input_quit(SDL_Event *event){
	SDL_PollEvent(event);
	if (event->type == SDL_QUIT){
		printf("quiting\n");
		return 1;
	}
	return 0;
}

void draw(SDL_Renderer *renderer, SDL_Rect *rect1, SDL_Texture *texture){
    // SDL_SetRenderTarget(renderer, texture);

	SDL_SetRenderDrawColor(renderer, 0x22, 0x22, 0x22, 0x00);
	SDL_RenderClear(renderer);

    SDL_RenderDrawRect(renderer, rect1);
	SDL_SetRenderDrawColor(renderer, 0xbb, 0x00, 0x00, 0x00);
	SDL_RenderFillRect(renderer, rect1);

    // SDL_SetRenderTarget(renderer, NULL);
    // SDL_RenderCopy(renderer, texture, NULL, NULL);

	SDL_RenderPresent(renderer);
}

struct Rectangle {
	double x;
	double y;
	SDL_Rect rect;
};

struct Rectangle* rectangle(double x, double y){
	static struct Rectangle r;
    static SDL_Rect rect;

	// printf("%0.10f\n", x);
    r.x = x;
    r.y = y;


    rect.w = 100;
    rect.h = 100;
    rect.x = r.x;
    rect.y = r.y;

	// printf("%i\n\n", rect.x);
    r.rect = rect;
    return &r;
}

SDL_Rect* rectangle_update(struct Rectangle *r, double seconds_elapsed){
	// int x = rand() % 400;
	// int y = rand() % 400;
	double x = r->x + (500 * seconds_elapsed);
	double y = r->y;
	// printf("%0.10f\n\n", x);
	return &rectangle(x, y)->rect;
}

double get_time_elapsed(clock_t t_start, clock_t t_now){
	double time_diff = (double)(t_now - t_start) / CLOCKS_PER_SEC;
	return time_diff;
}

void body(SDL_Renderer *renderer){
	SDL_Event event;
	SDL_Texture *texture;
	struct Rectangle *rect1;
    // SDL_Rect *rect1;

    texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_RGBA8888, SDL_TEXTUREACCESS_TARGET, 500, 500);

    rect1 = rectangle(0, 0);

    clock_t time;
    clock_t time_now;
    time = clock();
	while (1) {
		time_now = clock();
		double seconds_elapsed = get_time_elapsed(time, time_now);
		time = time_now;
		if (input_quit(&event)){break;}
		// printf("%f\n", seconds_elapsed);

		rectangle_update(rect1, seconds_elapsed);
		draw(renderer, &rect1->rect, texture);
	}
}

int main(int argc, char const *argv[])
{
	SDL_Window *window;
	SDL_Renderer *renderer;

	// SDL_GLContext glcontext = SDL_GL_CreateContext(window);

	SDL_Init(SDL_INIT_VIDEO);

	window = create_window();
	renderer = create_renderer(window);

	body(renderer);

	// SDL_GL_DeleteContext(glcontext);
	destroy_and_quit(window, renderer);
	return 0;
}