cube_rotate_thing.cpp

#if 0 /* (sh-mode) 
set -e

LPATH=/Users/cro/Documents/PersonalProjects/Graphics/

tu_name=cube_rotate_thing

# -Ofast
[ ! ]&& time clang++ -g  --std=c++11 -fPIC -Wall \
  -D "RELOADABLE_CODE=\"$LPATH${tu_name}_reloadable.cpp.so\"" \
  $LPATH/${tu_name}.cpp \
  -Wno-writable-strings \
  -Wno-unused-function \
  -Wno-deprecated-declarations \
  -framework Cocoa -framework AppKit -framework OpenGL \
  -F /Library/Frameworks/ -framework SDL2 \
  -o $LPATH/${tu_name}.cpp.elf

[ ! ]&&{
 cd $RPATH
 ulimit -c unlimited
 rm -fv core
 pwd
 time $LPATH/${tu_name}.cpp.elf
}

true
exit # (c++-mode) */
#endif


// inspiration http://3.bp.blogspot.com/-aehqua-FgkQ/VmeNFzYXkuI/AAAAAAABQcU/Mi4OSTi-DUs/s640/doze_studio_151207.gif
// result https://www.dropbox.com/s/vspgm61jn1hcatr/cube_rotate_thing.mov?dl=0

#if defined __APPLE__
#include <SDL2/SDL.h>
#include <SDL2/SDL_opengl.h>
#else
#include <SDL.h>
#include <SDL_opengl.h>
#endif


struct Memory {
    float rotate_amount;
} m;

void render_frame(int window_width, int window_height) {

    glEnable (GL_DEPTH_TEST);
    glClearColor(0, 0,0, 1);
    glClear(GL_COLOR_BUFFER_BIT);
    glClear(GL_DEPTH_BUFFER_BIT);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(0, window_width, window_height, 0, 1000, -1000);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    glPushMatrix();

    glColor4f(1, 1, 1, 1);
    glLineWidth(5);
    
    glPopMatrix();

    int size = 100;
    float oyh = 166;

    
    for (int x=-2; x<10; x++) {
        for (int y=-2; y<20; y++) {

            float this_rot_amount = 0;
            if (x == 1 && y == 2) this_rot_amount = m.rotate_amount;


            
            glPushMatrix();
            glTranslatef(100 + 144.9*x, oyh*y - (oyh * this_rot_amount / 90) , 0);
            // glRotatef(10, 0, 0, 1);
            glRotatef(35, 1, 0, 0);
    
            glTranslatef(size/2, size/2, size/2);
            glRotatef(45 + this_rot_amount, 0, 1, 0);
            glTranslatef(-size/2, -size/2, -size/2);
            
#define _v glVertex3f
#define _s size
    glColor4f(0, 0, 0, 1);
            
            glBegin(GL_QUADS);
           _v( 0, _s,  0); _v(_s, _s,  0); _v(_s,  0, 0 ); _v( 0,  0,  0);
           _v( 0, _s, _s); _v(_s, _s, _s); _v(_s,  0, _s); _v( 0,  0, _s);            
//           // _v( 0, _s,  0); _v( 0, _s, _s); _v( 0,  0, _s); _v( 0,  0,  0);
           _v(_s, _s,  0); _v(_s, _s, _s); _v(_s,  0, _s); _v(_s,  0,  0);
           
           _v( 0,  0,  0); _v( 0,  0, _s); _v(_s,  0, _s); _v(_s,  0,  0);
            glEnd();
#undef _v
#undef _s
    glColor4f(1, 1, 1, 1);
        
            glBegin(GL_LINES);
            glVertex3f(0,    size, 0);       glVertex3f(size, size, 0);
            glVertex3f(size, size, 0);       glVertex3f(size, 0,    0);
            glVertex3f(size, 0,    0);       glVertex3f(0,    0,    0);
            glVertex3f(0,    0,    0);       glVertex3f(0,    size, 0);

            glVertex3f(0,    size, size);    glVertex3f(size, size, size);
            glVertex3f(size, size, size);    glVertex3f(size, 0,    size);
            glVertex3f(size, 0,    size);    glVertex3f(0,    0,    size);
            glVertex3f(0,    0,    size);    glVertex3f(0,    size, size);
    
            glVertex3f(0,    size, 0);       glVertex3f(0,    size, size);
            glVertex3f(size, size, 0);       glVertex3f(size, size, size);
            glVertex3f(size, 0,    0);       glVertex3f(size, 0,    size);
            glVertex3f(0,    0,    0);       glVertex3f(0,    0,    size);
    
            glEnd();
    
            glPopMatrix();
        
        }
    }
    
    if (m.rotate_amount++ > 90) m.rotate_amount = 0;

    glEnable (GL_BLEND);

}


int main() {
    
	int render_width = 100;
	int render_height = 100;

	//Create window
	SDL_Window * window = SDL_CreateWindow(
	 "Untitled Window", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
	 render_width, render_height,
	 SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE | SDL_WINDOW_OPENGL);

	if(!window) {
		SDL_LogCritical(SDL_LOG_CATEGORY_SYSTEM, "Window could not be created! SDL_Error: %s\n", SDL_GetError() );
		return -1;
	}

	SDL_GLContext context = SDL_GL_CreateContext( window );
	if( context == NULL ) {
		SDL_LogCritical(SDL_LOG_CATEGORY_SYSTEM, "OpenGL context could not be created! SDL Error: %s\n", SDL_GetError() );
		return -3;
	}

	if( SDL_GL_SetSwapInterval( 1 ) < 0 ) {
		SDL_LogCritical(SDL_LOG_CATEGORY_SYSTEM, "Warning: Unable to set VSync! SDL Error: %s\n", SDL_GetError() );
	}

    glEnable (GL_BLEND); glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	bool running = true;

	while(running) {

        int window_width, window_height;
        SDL_GetWindowSize(window, &window_width, &window_height);
        
		SDL_Event e;
		while(SDL_PollEvent( &e )) {
			switch (e.type) {
				case SDL_QUIT:
					running = false;
					break;
				default:
					break;
			}
		}



        glViewport(0, 0, window_width, window_height);

        render_frame(window_width, window_height);
        
        SDL_GL_SwapWindow(window);

	}
	return 0;

    

}