set to ignore *.o files

[physics.git] / src / graphics.cpp

#include "graphics.h"

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

#include <iostream>
using std::cerr;
using std::cout;
using std::endl;


static const float PI = 3.1415926535897;

/// ***** Private Method Headers *****
void sdlInit();
void glInit();

/// ***** Public Methods *****

void graphicsInit()
{
    sdlInit();
    glInit();
}

void graphicsCleanUp()
{

}

void glDrawCircle()
{
    int num = 32;

    glBegin(GL_POLYGON);
        for(int n = 0; n < num; n++)
        {
            float angle = 2 * PI * n / num;
            float x = cos(angle);
            float y = sin(angle);

            glVertex3f(x, y, -1);
        }
    glEnd();
}

/// ***** Private Methods *****
void sdlInit()
{
    if(SDL_Init(SDL_INIT_VIDEO) < 0)
    {
        cerr << "SDL_Init failed: " << SDL_GetError() << endl;
        exit(1);
    }

    // In order to use SDL_OPENGLBLIT we have to
    // set GL attributes first
    SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);

    if(SDL_SetVideoMode(800, 600, 16, SDL_OPENGL) < 0)
    {
        cerr << "SDL_SetVideoMode failed: " << SDL_GetError() << endl;
        exit(1);
    }
}

void glInit()
{
    glClearColor(0.0, 0.0, 0.0, 0.0);

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();

    glOrtho(-20.0, 20.0, -15.0, 15.0, -0.01, 1.01);

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    glEnable(GL_DEPTH_TEST);
}