#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#include "SDL.h"
#include "SDL_opengl.h"
#include "SDL_image.h"

#include "glpong3d.h"

int main(int argc, char * argv[]) {
	if (argc) {
		if (argv) {}
	}
	
	GLPong_Init();
	
	while ( !GLPong.done ) {
		GLPong_HandleEvents();
	/*	GLPong_Move();*/
		GLPong_Draw();
		SDL_Delay(10);
	}
	GLPong_CleanUp();
	
	return 0;
}

void GLPong_Init() {
	SDL_Surface * temp = NULL;
	
	GLPong.done = 0;
	
	GLPong.w = 800;
	GLPong.h = 600;
	
	GLPong.Ball.w = 1.0f;
	GLPong.Ball.h = 1.0f;
	GLPong.Ball.x = -0.5f;
	GLPong.Ball.y = -0.5f;
	GLPong.Ball.z = -3.0f;
	GLPong.Ball.xv = 0.0f;
	GLPong.Ball.yv = 0.0f;
	GLPong.Ball.zv = -0.05f;
	
	SDL_Init(SDL_INIT_VIDEO | SDL_INIT_NOPARACHUTE);
	atexit(SDL_Quit);
	
	SDL_WM_SetCaption("glpong3d", "glpong3d");
	temp = IMG_Load("ball.png");
	SDL_WM_SetIcon(temp, NULL);
	SDL_FreeSurface(temp);
	SDL_ShowCursor(SDL_DISABLE);
	
	SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 8);
	SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 8);
    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
	
	GLPong.Surface = SDL_SetVideoMode(GLPong.w, GLPong.h, 32, SDL_OPENGL);
	glViewport(0, 0, GLPong.w, GLPong.h);
	
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(45.0f, GLPong.w / GLPong.h, 0.1f, 50.0f);
	
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    
    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
    glShadeModel(GL_SMOOTH);
	glEnable(GL_BLEND);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glDepthFunc(GL_LEQUAL);
    glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
	
	GLPong.Event.type = SDL_NOEVENT;
	
	printf("OpenGL Vendor:     %s\n", glGetString(GL_VENDOR));
	printf("OpenGL Renderer:   %s\n", glGetString(GL_RENDERER));
	printf("OpenGL Version:    %s\n", glGetString(GL_VERSION));
	printf("OpenGL Extensions: %s\n", glGetString(GL_EXTENSIONS));
	
	temp = IMG_Load("128x128.png");
	ball_texture = SDL_GL_SurfaceToTexture(temp);
	SDL_FreeSurface(temp);	
}

void GLPong_HandleEvents() {
	if (SDL_PollEvent(&GLPong.Event) != 0) {
		if (GLPong.Event.type == SDL_QUIT) {
			GLPong.done = 1;
			return;
		}
		if (GLPong.Event.type == SDL_KEYDOWN) {
			if (GLPong.Event.key.keysym.sym == SDLK_ESCAPE) {
				GLPong.done = 1;
				return;
			} else if (GLPong.Event.key.keysym.sym == SDLK_p) {
				for (;;) {
					SDL_Delay(10);
					if (SDL_PollEvent(&GLPong.Event) != 0) {
						if (GLPong.Event.type == SDL_QUIT) {
							GLPong.done = 1;
							return;
						} else if (GLPong.Event.type == SDL_KEYDOWN){
							if (GLPong.Event.key.keysym.sym == SDLK_ESCAPE) {
								GLPong.done = 1;
								return;
							} else if (GLPong.Event.key.keysym.sym == SDLK_p) {
								break;
							}
						}
					}
				}
			}
		}
	}
}

void GLPong_Draw() {
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	
	glBindTexture(GL_TEXTURE_2D, ball_texture);
	glEnable(GL_TEXTURE_2D);
	glLoadIdentity();
	glTranslatef(GLPong.Ball.x, GLPong.Ball.y, GLPong.Ball.z);
	glBegin(GL_QUADS);
		glTexCoord2f(0.0f, 1.0f); glVertex2f(GLPong.Ball.w, GLPong.Ball.h);	/* Lower Left */
		glTexCoord2f(1.0f, 1.0f); glVertex2f(0.0f, GLPong.Ball.h);			/* Lower Right */
		glTexCoord2f(1.0f, 0.0f); glVertex2f(0.0f, 0.0f);					/* Upper Right */
		glTexCoord2f(0.0f, 0.0f); glVertex2f(GLPong.Ball.w, 0.0f);			/* Upper Left */
	glEnd();
	glDisable(GL_TEXTURE_2D);
	
	SDL_GL_SwapBuffers();
}

void GLPong_CleanUp() {

}

void GLPong_Move() {
	GLPong.Ball.x += GLPong.Ball.xv;
	GLPong.Ball.y += GLPong.Ball.yv;
	GLPong.Ball.z += GLPong.Ball.zv;
	if (GLPong.Ball.z < -12.0f) {
		GLPong.Ball.zv = -GLPong.Ball.zv;
	} else if (GLPong.Ball.z > -3.0f) {
		GLPong.Ball.zv = -GLPong.Ball.zv;
	}
}

__inline__ unsigned int NextPow2(unsigned int value) {   
	unsigned int x;
	__asm("dec %1\n\t"
		"movl $2,%0\n\t"
		"bsr %1,%1\n\t"
		"shl %b1,%0\n\t"
		: "=r" (x)
		: "c" (value)
	);
	return x;
}

GLuint SDL_GL_SurfaceToTexture(SDL_Surface * surface) {
	Uint32 rmask, gmask, bmask, amask;
	GLuint texture;
	GLenum format = GL_RGB;

#if SDL_BYTEORDER == SDL_BIG_ENDIAN
	rmask = 0xff000000;
	gmask = 0x00ff0000;
	bmask = 0x0000ff00;
	amask = 0x000000ff;
#else
	rmask = 0x000000ff;
	gmask = 0x0000ff00;
	bmask = 0x00ff0000;
	amask = 0xff000000;
#endif
	
	if (surface->format->Rmask & rmask) {
		format = GL_RGB;
		printf("GL_RGB");
		if (surface->format->BitsPerPixel == 32) {
			format = GL_RGBA;
			printf("A");
		}
	} else if (surface->format->Rmask & bmask) {
		format = GL_BGR;
		printf("GL_BGR");
		if (surface->format->BitsPerPixel == 32) {
			format = GL_BGRA;
			printf("A");
		}
	}
	printf("\n");
	
	glGenTextures(1, &texture);
	glBindTexture(GL_TEXTURE_2D, texture);
	
	SDL_LockSurface(surface);
	glTexImage2D(GL_TEXTURE_2D, 0, surface->format->BytesPerPixel, surface->w, surface->h, 0, format, GL_UNSIGNED_BYTE, surface->pixels);
	SDL_UnlockSurface(surface);
	
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	
	return texture;
}
/*
GLuint SDL_GL_NPOTSurfaceToTexture(SDL_Surface * surface, GLfloat * wratio, GLfloat * hratio) {
	SDL_Surface * pow2 = NULL;
	unsigned int w = NextPow2(surface->w);
	unsigned int h = NextPow2(surface->h);
	if (wratio) {
		*wratio = (GLfloat)surface->w / (GLfloat)h;
	}
	if (hratio) {
		*hratio = (GLfloat)surface->h/(GLfloat)h;
	}
	
	pow2 = SDL_CreateRGBSurface(SDL_SWSURFACE, w, h, surface->format->BitsPerPixel, surface->format->Rmask, surface->format->Gmask, surface->format->Bmask, surface->format->Amask);
	SDL_BlitSurface(surface, NULL, pow2, NULL);
	SDL_FreeSurface(surface);
	
	return SDL_GL_SurfaceToTexture(pow2);
}*/