#include <SDL/SDL.h>

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

#include <math.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 glPutPixel(int xpos,int ypos,int r,int g,int b)
{
	glRotatef(rot,0.0f,0.0f,1.0f);
	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();
	*/
}

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

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();
		}
	}

	{
		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!=GWIDTH/2;i++) {
			glPutPixel(i,interpol(sin((i-x)/57.3)),255,255,255);
		}
		x++;
		rot+=.001;
		SDL_GL_SwapBuffers();
	}
	}
	return 0;
}

int 
glSetupView()
{
	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[])
{
	SDL_Init(SDL_INIT_VIDEO);
	glSetupView();
/* main loop */
	loop();

	SDL_Quit();
}