#include <SDL/SDL.h>

#include <GL/gl.h>
#include <GL/glu.h>

#include <math.h>

#include <time.h>

float WIDTH = 1024;
float HEIGHT = 768;

float RWIDTH = 1024;
float RHEIGHT = 768;

#define GWIDTH 1024
#define GHEIGHT 768

SDL_Event event;

int glSetupView();

double rot = 0;

int sinwave[GWIDTH];
int coswave[GWIDTH];
int tanwave[GWIDTH];

int interpol(double a);

int radius = 0;

int buildarrays()
{
	int x;
	for(x=0;x!=GWIDTH;x++) {
		sinwave[x] = interpol(sin((x/57.3)));
		coswave[x] = interpol(cos((x/57.3)));
		tanwave[x] = interpol(tan((x/57.3)));	
	}
}

int glPutPixel(int xpos,int ypos,int r,int g,int b)
{
	glBegin(GL_QUADS);
		glColor3f(	r /255,
				 	g / 255,
					b / 255);
		glVertex2i(xpos,ypos);
		glVertex2i(xpos+10,ypos);
		glVertex2i(xpos+10,ypos+10);
		glVertex2i(xpos,ypos+10);
	glEnd();	
	
	/*
	glBegin(GL_POINTS);
		glColor3f(r / 255,g / 255,b / 255);
		glVertex2i(xpos,ypos);
	glEnd();
	*/
}

double sin1(int a) {
	return(sin(a));
}

float rand1(int seed) {
	int i;
	srand(seed);
	i = rand() % 10;
//	printf("%f\n",(float)i/10.0f);
	return (float)i/10.0;
}

int interpol(double a)
{
	return(((a+1) /2) * 255);
}

int getItem(int* array,int index)
{
	int i;
	if(index < GWIDTH) return array[index];
	for(i=1;i*GWIDTH < index;i++);
	return array[(i*(GWIDTH-1))-index];
}

int loop()
{
	static int a = 0;
	static int x =0;

	while(1) 
	{
		while(SDL_PollEvent(&event)) 
		{
			if(event.type == SDL_QUIT) return 0;
			if(event.type == SDL_VIDEORESIZE) {
				a = 1;
				WIDTH = event.resize.w;
				HEIGHT = event.resize.h;
				RWIDTH = event.resize.w;
				RHEIGHT = event.resize.w*.75;
			}else if(a == 1) {
				a = 0;
				glSetupView();
			}
			if(event.type == SDL_KEYDOWN) {
				if(event.key.keysym.sym == SDLK_UP) 
					radius+=40;
				else if (event.key.keysym.sym == SDLK_DOWN) 
					radius-=40;
			}	
		}

		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
		glClearColor(0.0f,0.0f,0.0f,0.0f);
		glLoadIdentity();

		for(int i=-GWIDTH/2;i<=0;i++)
	   	{
			glRotatef(rot,1.0f,1.0f,1.0f);
			glPutPixel(i,
				interpol(
					sin( (i-x)/57.3) + 
					rand1(i)
			//		rand1(time(NULL))
					
 				) + radius
				,
				255,255,255
			);
		}
		x++;
		rot+=.01;
		SDL_GL_SwapBuffers();

	}
	return 0;
}

int 
glSetupView()
{
	SDL_GL_SetAttribute( SDL_GL_RED_SIZE, 5 );
	SDL_GL_SetAttribute( SDL_GL_GREEN_SIZE, 5 );
	SDL_GL_SetAttribute( SDL_GL_BLUE_SIZE, 5 );
	SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, 16 );
	SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 );

	SDL_SetVideoMode(WIDTH,HEIGHT,32,SDL_OPENGL | SDL_RESIZABLE);

	glViewport(0,0,WIDTH,HEIGHT);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrtho(-GWIDTH/2,GWIDTH/2,-GHEIGHT/2,GHEIGHT/2,
		-100000.0f,100000.0f);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();

	glPointSize(1.0f);

	return 0;
}

int main(int argc,char * argv[])
{
	buildarrays();
	SDL_Init(SDL_INIT_VIDEO);
	glSetupView();
/* main loop */
	loop();

	SDL_Quit();
}