#if ( (defined(__MACH__)) && (defined(__APPLE__)) )   
#include <stdlib.h>
#include <OpenGL/gl.h>
#include <GLUT/glut.h>
#include <OpenGL/glext.h>
#else
#include <stdlib.h>
#include <GL/glew.h>
#include <GL/gl.h>
#include <GL/glut.h>
#include <GL/glext.h>
#endif

#include "shader.h"

Shader shader;

GLuint texture;

GLfloat angle = 0.0; //set the angle of rotation

GLuint LoadTexture( const char * filename, int width, int height )
{
	GLuint texture;
	unsigned char * data;
	FILE * file;
    
	//The following code will read in our RAW file
	file = fopen( filename, "rb" );
	if ( file == NULL ) return 0;
	data = (unsigned char *)malloc( width * height * 3 );
	fread( data, width * height * 3, 1, file );
	fclose( file );
    
	glGenTextures( 1, &texture ); //generate the texture with the loaded data
	glBindTexture( GL_TEXTURE_2D, texture ); //bind the texture to it's array
	glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE ); //set texture environment parameters
    
	//And if you go and use extensions, you can use Anisotropic filtering textures which are of an
	//even better quality, but this will do for now.
	glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
	glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
    
	//Here we are setting the parameter to repeat the texture instead of clamping the texture
	//to the edge of our shape. 
	glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
	glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
    
	//Generate the texture
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
	free( data ); //free the texture
    
	return texture; //return whether it was successfull
}

void FreeTexture( GLuint texture )
{
    glDeleteTextures( 1, &texture ); 
}

void init(void) {
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS);
    
    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    
    shader.init("shader.vert", "shader.frag");
    texture = LoadTexture("texture.raw", 256, 256);
}

void cube (void) {
	glRotatef(angle, 1.0, 0.0, 0.0); //rotate on the x axis
	glRotatef(angle, 0.0, 1.0, 0.0); //rotate on the y axis
	glRotatef(angle, 0.0, 0.0, 1.0); //rotate on the z axis

    glActiveTexture(GL_TEXTURE0);
    int texture_location = glGetUniformLocation(shader.id(), "texture_color");
    glUniform1i(texture_location, 0);
    glBindTexture(GL_TEXTURE_2D, texture);
	
    glutSolidTeapot(2.0);
}

void display (void) {
	glClearColor (0.0,0.0,0.0,1.0);
    glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glLoadIdentity();  
	gluLookAt (0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
    
    shader.bind();
	cube();
    shader.unbind();
	
    glutSwapBuffers();
	angle += 0.01f;
}

void reshape (int w, int h) {
	glViewport (0, 0, (GLsizei)w, (GLsizei)h);
	glMatrixMode (GL_PROJECTION);
	glLoadIdentity ();
	gluPerspective (60, (GLfloat)w / (GLfloat)h, 1.0, 100.0);
	glMatrixMode (GL_MODELVIEW);
}

int main (int argc, char **argv) {
    glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH); //set up the double buffering
	glutInitWindowSize(500, 500);
	glutInitWindowPosition(100, 100);
    glutCreateWindow("A basic OpenGL Window");
    
    glutDisplayFunc(display);
	glutIdleFunc(display);
	
    glutReshapeFunc(reshape);
    
    init();
    
    glutMainLoop();
    
    return 0;
}