made a ball move

[physics.git] / src / graphics / graphics.cpp

#include "graphics.h"

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

#include "../debug.h"

static const float PI = 3.1415926535897;

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

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

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

void graphicsCleanUp()
{

}

void glDrawCircle(float radius, const Vector2& vec, const float* color)
{
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glTranslatef(vec.x, vec.y, -1);
    glScalef(radius, radius, radius);

    if(color != NULL)
        glColor3fv(color);

    drawCircle(32);
}

/// ***** Private Methods *****

void drawCircle(int pieces)
{
    glBegin(GL_POLYGON);
        for(int n = 0; n < pieces; n++)
        {
            float angle = 2 * PI * n / pieces;
            float ix = cos(angle);
            float iy = sin(angle);

            glVertex3f(ix, iy, 0);
        }
    glEnd();
}

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(0, 800.0, 600.0, 0.0, -0.01, 1.01);

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    glEnable(GL_DEPTH_TEST);
}