/*

	plasma.c - Dotted Plasma

	Author Jani Kniivilä

	compile with: gcc -o plasma plasma.c -lSDL -lpthread -ltSGGL

*/

#include <stdio.h>
#include <math.h>

#include <SDL/SDL.h>
#include <tSGGL/SGGL.h>

#define	WIDTH	640
#define	HEIGHT	480

SDL_Surface	*surface;
gfx_image_t	*output;
gfx_image_t	*dot;

const float	my_pi = 3.141593;

int	fx_init()
{
	gfx_color_t	color;

	if (SDL_Init(SDL_INIT_VIDEO) < 0) return -1;
	atexit(SDL_Quit);

	surface = SDL_SetVideoMode(WIDTH, HEIGHT, 16, SDL_SWSURFACE);
	if (!surface) return -2;

	output = gfx_create_null_image(WIDTH, HEIGHT);	/* create an image without pixel-data */
	if (!output) return -3;
	output->data = (Uint16 *) surface->pixels;	/* redirect the pixels to "screen" */

	/*
	 * Generate "dot"
	 */

	dot = gfx_create_image(63, 63);
	if (!dot) return -1;

	gfx_clear(dot);

	gfx_set_color(&color, 75, 75, 192);
	gfx_fcircle(31, 31, 30, &color, dot);

	gfx_set_color(&color, 92, 92, 224);
	gfx_fcircle(31, 31, 23, &color, dot);

	return 0;
}

void	fx_shutdown()
{
	gfx_dispose_image(dot);
	free(output);
}

int	fx_draw_frame()
{
	float		dH, dV;
	static float	angle = 0;
	int		xx, yy, size;

	if (SDL_MUSTLOCK(surface))
		SDL_LockSurface(surface);

	gfx_clear(output);

	dV = cos(angle/2.5)*(my_pi/2.0+sin(angle/5.0)*my_pi/2.0)+my_pi;

	for (yy = 0; yy < 15; yy++)
	{
		dH = sin(angle/2.5) * cos(angle/2) * my_pi + my_pi;

		for (xx = 0; xx < 20; xx++)
		{
			size = 16+(int)(cos(dH + xx*my_pi/20.0)*sin(dV + yy*my_pi/14.0)*15); 

			gfx_put_scaled_image(	16 + xx*32 - (size>>1), 
						16 + yy*32 - (size>>1), dot, size, size, output);
		}
	}

	if (SDL_MUSTLOCK(surface))
		SDL_UnlockSurface(surface);

	SDL_Flip(surface);

	angle += my_pi/40.0;

	return 0;
}

int	main()
{
	SDL_Event	event;
	int		done = 0;

	if (fx_init()) return -1;

	while (!done)
	{
		fx_draw_frame();

		while (SDL_PollEvent(&event))
		{
			switch (event.type)
			{
				case SDL_QUIT:
				case SDL_KEYDOWN:
				case SDL_MOUSEBUTTONDOWN:
					done = 1;
			}
		}
	}

	fx_shutdown();

	return 0;
}