STARWARS.cpp

// The OpenGL libraries, make sure to include the GLUT and OpenGL frameworks
#include <OpenGL/gl.h>
#include <OpenGL/glu.h>
#include <SDL2/SDL.h>
#include <math.h>   
// This is just an example using basic glut functionality.
// If you want specific Apple functionality, look up AGL

float PI = 3.1415;

int main(int argc, char **argv)
{
   SDL_Window *window = SDL_CreateWindow(
       "SDL2/OpenGL Demo", 0, 0, 720, 720, 
       SDL_WINDOW_OPENGL|SDL_WINDOW_RESIZABLE);
     
   // Create an OpenGL context associated with the window.
   SDL_GLContext glcontext = SDL_GL_CreateContext(window);

   // now you can make GL calls.
   int quit = 0;
   int color = 0;
   float spin = -0.5f;
   float beginRadians = 0.0f;
   int growShrink = 1;
   float growRate = .25f;
   float length = .5f;
   float x = 0;
   float y = 0;
   float y_speed = .7;
   float x_speed = .3f;
   SDL_Event event;
   float startingTick = SDL_GetTicks();
   while(!quit){

    while(SDL_PollEvent(&event))
    {
        /* If a quit event has been sent */
        if (event.type == SDL_QUIT)
        {
            /* Quit the application */
            quit = 1;
        }
    }
    glClearColor(0,0,color,0);
    glClear(GL_COLOR_BUFFER_BIT);
    
    float rad = 1.25664f;
    float start = 1.5708f + beginRadians;
    

    for(int point = 0; point < 5; point++){
      float next = start + (2*rad);
      glBegin(GL_LINES);
        glVertex3f(cos(start)*length+x, sin(start)*length+y, 0.0f);
        glVertex3f(cos(next)*length+x, sin(next)*length+y, 0.0f);
      glEnd();
      start += rad;
    }
    float now = SDL_GetTicks();
    float delta = (now - startingTick)/1000;
    beginRadians += spin * (delta);
    beginRadians = fmod(beginRadians, 2.0f * PI);
    length += (growShrink * growRate) * delta;
    x += x_speed * delta;
    y += y_speed * delta;

    if(y >= 1 || y <= -1){
      y_speed *= -1;
    }
    if(x>= 1|| x <= -1){
      x_speed *= -1;
    }
    if(length >= 1.0f){
      growShrink = -1;
    }
    if(length <= .25f){
      growShrink = 1;
    }
    SDL_GL_SwapWindow(window);
    // if(color == 1){
    //   color = 0;
    // }
    // else{
    //   color = 1;
    // }
    startingTick = now;
   }

   // Once finished with OpenGL functions, the SDL_GLContext can be deleted.
   SDL_GL_DeleteContext(glcontext);  
   return 0;

}