Re: Simple Cube

THIS IS HOW TO DO IT!!!

 

Code:
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>

#include <SDL2/SDL.h>
#include <SDL2/SDL_opengl.h>

/* Undefine this if you want a flat cube instead of a rainbow cube */
#define SHADED_CUBE

static SDL_GLContext ctx;
static SDL_Window* window;
/* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
static void
quit(int rc)
{
    if (ctx) {
        /* SDL_GL_MakeCurrent(0, NULL); *//* doesn't do anything */
        SDL_GL_DeleteContext(ctx);
    }
    SDL_DestroyWindow( window );
    SDL_Quit();
    exit(rc);
}

static void
Render()
{
    static float color[8][3] = {
        {1.0, 1.0, 0.0},
        {1.0, 0.0, 0.0},
        {0.0, 0.0, 0.0},
        {0.0, 1.0, 0.0},
        {0.0, 1.0, 1.0},
        {1.0, 1.0, 1.0},
        {1.0, 0.0, 1.0},
        {0.0, 0.0, 1.0}
    };
    static float cube[8][3] = {
        {0.5, 0.5, -0.5},
        {0.5, -0.5, -0.5},
        {-0.5, -0.5, -0.5},
        {-0.5, 0.5, -0.5},
        {-0.5, 0.5, 0.5},
        {0.5, 0.5, 0.5},
        {0.5, -0.5, 0.5},
        {-0.5, -0.5, 0.5}
    };
    
    /* Do our drawing, too. */
    glClearColor(0.0, 0.0, 0.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    
    glBegin(GL_QUADS);
    
#ifdef SHADED_CUBE
    glColor3fv(color[0]);
    glVertex3fv(cube[0]);
    glColor3fv(color[1]);
    glVertex3fv(cube[1]);
    glColor3fv(color[2]);
    glVertex3fv(cube[2]);
    glColor3fv(color[3]);
    glVertex3fv(cube[3]);
    
    glColor3fv(color[3]);
    glVertex3fv(cube[3]);
    glColor3fv(color[4]);
    glVertex3fv(cube[4]);
    glColor3fv(color[7]);
    glVertex3fv(cube[7]);
    glColor3fv(color[2]);
    glVertex3fv(cube[2]);
    
    glColor3fv(color[0]);
    glVertex3fv(cube[0]);
    glColor3fv(color[5]);
    glVertex3fv(cube[5]);
    glColor3fv(color[6]);
    glVertex3fv(cube[6]);
    glColor3fv(color[1]);
    glVertex3fv(cube[1]);
    
    glColor3fv(color[5]);
    glVertex3fv(cube[5]);
    glColor3fv(color[4]);
    glVertex3fv(cube[4]);
    glColor3fv(color[7]);
    glVertex3fv(cube[7]);
    glColor3fv(color[6]);
    glVertex3fv(cube[6]);
    
    glColor3fv(color[5]);
    glVertex3fv(cube[5]);
    glColor3fv(color[0]);
    glVertex3fv(cube[0]);
    glColor3fv(color[3]);
    glVertex3fv(cube[3]);
    glColor3fv(color[4]);
    glVertex3fv(cube[4]);
    
    glColor3fv(color[6]);
    glVertex3fv(cube[6]);
    glColor3fv(color[1]);
    glVertex3fv(cube[1]);
    glColor3fv(color[2]);
    glVertex3fv(cube[2]);
    glColor3fv(color[7]);
    glVertex3fv(cube[7]);
#else /* flat cube */
    glColor3f(1.0, 0.0, 0.0);
    glVertex3fv(cube[0]);
    glVertex3fv(cube[1]);
    glVertex3fv(cube[2]);
    glVertex3fv(cube[3]);
    
    glColor3f(0.0, 1.0, 0.0);
    glVertex3fv(cube[3]);
    glVertex3fv(cube[4]);
    glVertex3fv(cube[7]);
    glVertex3fv(cube[2]);
    
    glColor3f(0.0, 0.0, 1.0);
    glVertex3fv(cube[0]);
    glVertex3fv(cube[5]);
    glVertex3fv(cube[6]);
    glVertex3fv(cube[1]);
    
    glColor3f(0.0, 1.0, 1.0);
    glVertex3fv(cube[5]);
    glVertex3fv(cube[4]);
    glVertex3fv(cube[7]);
    glVertex3fv(cube[6]);
    
    glColor3f(1.0, 1.0, 0.0);
    glVertex3fv(cube[5]);
    glVertex3fv(cube[0]);
    glVertex3fv(cube[3]);
    glVertex3fv(cube[4]);
    
    glColor3f(1.0, 0.0, 1.0);
    glVertex3fv(cube[6]);
    glVertex3fv(cube[1]);
    glVertex3fv(cube[2]);
    glVertex3fv(cube[7]);
#endif /* SHADED_CUBE */
    
    glEnd();
    
    glMatrixMode(GL_MODELVIEW);
    glRotatef(5.0, 1.0, 1.0, 1.0);
}

int
main(int argc, char *argv[])
{
    int value;
    int i, done;
    SDL_DisplayMode mode;
    SDL_Event event;
    Uint32 then, now, frames;
    int status;

    //Initialize SDL
    if( SDL_Init( SDL_INIT_VIDEO ) < 0 )
    {
        printf( "SDL could not initialize! SDL_Error: %s\n", SDL_GetError() );
        return 1;
    }
    
    //Create window
    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
    window = SDL_CreateWindow
    (
     "SDL AR Example",
     SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
     640, 480,
     SDL_WINDOW_OPENGL
     );
    
    if( window == NULL )
    {
        printf( "Window could not be created! SDL_Error: %s\n", SDL_GetError() );
        return 1;
    }
    
    //creating new context
    ctx = SDL_GL_CreateContext(window);
    SDL_GL_SetSwapInterval(1);
    
    
    /* Set rendering settings */
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(-2.0, 2.0, -2.0, 2.0, -20.0, 20.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS);
    glShadeModel(GL_SMOOTH);
    
    /* Main render loop */
    frames = 0;
    then = SDL_GetTicks();
    done = 0;
    while (!done) {
        /* Check for events */
        ++frames;
        SDL_Event ev;
        while( SDL_PollEvent( &ev ) )
        {
            if( ( SDL_QUIT == ev.type ) ||
               ( SDL_KEYDOWN == ev.type && SDLK_ESCAPE == ev.key.keysym.sym ) )
            {
                break;
            }
        }
        int w, h;
        SDL_GL_MakeCurrent(window, ctx);
        SDL_GetWindowSize(window, &w, &h);
        glViewport(0, 0, w, h);
        Render();
        SDL_GL_SwapWindow(window);
    
    }
    
    /* Print out some timing information */
    now = SDL_GetTicks();
    if (now > then) {
        printf("%2.2f frames per second\n",
               ((double) frames * 1000) / (now - then));
    }
    quit(0);
    return 0;
}

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