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

#include "SDL.h"
#include "SDL_opengl.h"
#include "SDL_image.h"
#include "SDL_net.h"
#include <GL/glc.h>

#include "glpong3d.h"
#include "text.h"
#include "fps.h"

static int  GLPong_Init(GLPong_t * GLPong);
static int  GLPong_HandleEvents(void);
static void GLPong_Draw(void);
static void GLPong_CleanUp(void);
static void GLPong_Move(void);
static void SDL_GL_GetMouseState(Paddle_t * paddle);

GLuint box;

int main(int argc, char * argv[]) {
	unsigned int frames = 0;
	int done = 0;
	int action;

	if (argc) {
		if (argv) {}
	}
	
	if (GLPong_Init(&GLPong) < 0) {
		fprintf(stderr, "Bailing out.\n");
		return -1;
	}

	GLPong_FPSInit();
	
	while (!done) {
		action = GLPong_HandleEvents();
		switch (action) {
			case GLPONG_EXIT:	/* exit */
				done = 1;
				break;
		}

		SDL_GL_GetMouseState(&GLPong.Front);
		GLPong_Move();

		/* begin drawing */
		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

		GLPong_Draw();

		frames++;
		if (frames == 30) {
			frames = 0;
		}

		GLPong_TextDrawFPS(GLPong_FPSCount());

		SDL_GL_SwapBuffers();
		/* end drawing */

		SDL_Delay(10);
	}
	GLPong_CleanUp();
	
	return 0;
}

static int
GLPong_Init(GLPong_t * GLPong) {
	SDL_Surface * temp = NULL;
	
	GLPong->Ball.w = 0.5f;
	GLPong->Ball.h = 0.5f;
	GLPong->Ball.coord.x = -(GLPong->Ball.w / 2);
	GLPong->Ball.coord.y = -(GLPong->Ball.h / 2);
	GLPong->Ball.coord.z = GLPONG_FRONT_Z;
	GLPong->Ball.r = 1.0f;
	GLPong->Ball.g = 0.0f;
	GLPong->Ball.b = 0.0f;
	GLPong->Ball.xv = 0.02f;
	GLPong->Ball.yv = 0.01f;
	GLPong->Ball.zv = -0.05f;
	
	GLPong->Front.w = 0.66f;
	GLPong->Front.h = 0.5f;
	GLPong->Front.coord.x = -1.0f;
	GLPong->Front.coord.y = -1.0f;
	GLPong->Front.coord.z = GLPONG_FRONT_Z;
	GLPong->Front.r = 1.0f;
	GLPong->Front.g = 1.0f;
	GLPong->Front.b = 1.0f;
	
	GLPong->Back.w = 0.66f;
	GLPong->Back.h = 0.5f;
	GLPong->Back.coord.x = -(GLPong->Front.w / 2);
	GLPong->Back.coord.y = -(GLPong->Front.h / 2);
	GLPong->Back.coord.z = GLPONG_BACK_Z;
	GLPong->Back.r = 1.0f;
	GLPong->Back.g = 1.0f;
	GLPong->Back.b = 1.0f;

	if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_NOPARACHUTE) < 0) {
		fprintf(stderr, "Unable to init SDL: %s\n", SDL_GetError());
		return -1;
	}
	atexit(SDL_Quit);

	SDL_WM_SetCaption("glpong3d", "glpong3d");
/*	SDL_ShowCursor(SDL_DISABLE);*/
	
	temp = IMG_Load("ball.png");
	if (!temp) {
		fprintf(stderr, "Unable to open ball.png\n");
		return -1;
	}
	
	SDL_WM_SetIcon(temp, NULL);

	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);
	
	if (GLPong_TextInit() < 0) {
		fprintf(stderr, "Cannot initialize GLC context: %d\n", glcGetError());
		return -1;
	}
	atexit(GLPong_TextDeinit);
	
	if (SDLNet_Init() < 0) {
		fprintf(stderr, "Cannot initialize SDL_net: %s\n", SDL_GetError());
		return -1;
	}
	atexit(SDLNet_Quit);
	
	GLPong->Surface = SDL_SetVideoMode(GLPONG_WIDTH, GLPONG_HEIGHT, 32, SDL_OPENGL);
	glViewport(0, 0, GLPONG_WIDTH, GLPONG_HEIGHT);
	
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(45.0f, GLPONG_WIDTH / GLPONG_HEIGHT, 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);*/ /* disabled since it causes drawing corruption, but necessary to enable transparency */
	glDepthFunc(GL_LEQUAL);
	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
	
	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("ball.png");*/ /* disabled since it's already loaded for the icon */
	ball_texture = SDL_GL_SurfaceToTexture(temp);
	SDL_FreeSurface(temp);	
	temp = IMG_Load("paddle-skyos.png");
	paddle_texture = SDL_GL_SurfaceToTexture(temp);
	SDL_FreeSurface(temp);
	temp = IMG_Load("paddle-skyos.png");
	paddle_texture_hit = SDL_GL_SurfaceToTexture(temp);
	SDL_FreeSurface(temp);

	box = glGenLists(1);
	glNewList(box, GL_COMPILE);
		glBegin(GL_LINE_LOOP);
			glVertex3f(-1.5f, -1.0f, 0.0f); /* Lower Left */
			glVertex3f( 1.5f, -1.0f, 0.0f); /* Lower Right */
			glVertex3f( 1.5f,  1.0f, 0.0f); /* Upper Right */
			glVertex3f(-1.5f,  1.0f, 0.0f); /* Upper Left */
		glEnd();
	glEndList();
	glPointSize(10.0f);

	return 0;
}

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

	return GLPONG_NOACTION;
}

void GLPong_Move(void) {
	GLPong.Ball.coord.x += GLPong.Ball.xv;
	if (GLPong.Ball.coord.x > 1.0f) {
		GLPong.Ball.coord.x = 1.0f;
		GLPong.Ball.xv = -GLPong.Ball.xv;
	} else if (GLPong.Ball.coord.x  + GLPong.Ball.w < -1.0f) {
		GLPong.Ball.coord.x = -1.0f - GLPong.Ball.w;
		GLPong.Ball.xv = -GLPong.Ball.xv;
	}

	GLPong.Ball.coord.y += GLPong.Ball.yv;
	if (GLPong.Ball.coord.y > 0.5f) {
		GLPong.Ball.coord.y = 0.5f;
		GLPong.Ball.yv = -GLPong.Ball.yv;
	} else if (GLPong.Ball.coord.y + GLPong.Ball.h < -0.5f) {
		GLPong.Ball.coord.y = -0.5f - GLPong.Ball.h;
		GLPong.Ball.yv = -GLPong.Ball.yv;
	}

	GLPong.Ball.coord.z += GLPong.Ball.zv;
	if (GLPong.Ball.coord.z < GLPONG_BACK_Z) {
		GLPong.Ball.coord.z = GLPONG_BACK_Z;
		GLPong.Ball.zv = -GLPong.Ball.zv;
	} else if (GLPong.Ball.coord.z > GLPONG_FRONT_Z) {
		GLPong.Ball.coord.z = GLPONG_FRONT_Z;
		GLPong.Ball.zv = -GLPong.Ball.zv;
	}
	GLPong.Back.coord.x = GLPong.Ball.coord.x;
	GLPong.Back.coord.y = GLPong.Ball.coord.y;
	GLPong_Collide(&GLPong.Ball, &GLPong.Front);
}

void GLPong_Draw(void) {
	float count;

	glLoadIdentity();
	glColor3f(0.0f, 0.0f, 0.0f);
	glTranslatef(0.0f, 0.0f, GLPONG_BACK_Z);
	glBegin(GL_QUADS);	
		glTexCoord2f(0.875f, 0.0f); glVertex2f( 1.5f,  1.0f);	/* Upper Right */
		glTexCoord2f(0.125f, 0.0f); glVertex2f(-1.5f,  1.0f);	/* Upper Left  */
		glTexCoord2f(0.125f, 1.0f); glVertex2f(-1.5f, -1.0f);	/* Lower Left */
		glTexCoord2f(0.875f, 1.0f); glVertex2f( 1.5f, -1.0f);	/* Lower Right */	
	glEnd();
	glDisable(GL_TEXTURE_2D);
	
	glColor3f(0.0f, 1.0f, 0.0f);
	for (count = GLPONG_FRONT_Z; count >= GLPONG_BACK_Z; count -= 1.0f) {
		glLoadIdentity();
		glTranslatef(0.0f, 0.0f, count);
		glCallList(box);
	}
	
	glLoadIdentity();
	glTranslatef(0.0f, 0.0f, 0.0f);
	glBegin(GL_LINES);
		glVertex3f(-1.5f, -1.0f, GLPONG_FRONT_Z); /* Lower Left */
		glVertex3f(-1.5f, -1.0f, GLPONG_BACK_Z);
	glEnd();

	glBegin(GL_LINES);
		glVertex3f( 1.5f, -1.0f, GLPONG_FRONT_Z); /* Lower Right */
		glVertex3f( 1.5f, -1.0f, GLPONG_BACK_Z);
	glEnd();

	glBegin(GL_LINES);
		glVertex3f( 1.5f,  1.0f, GLPONG_FRONT_Z); /* Upper Right */
		glVertex3f( 1.5f,  1.0f, GLPONG_BACK_Z);
	glEnd();
	
	glBegin(GL_LINES);
		glVertex3f(-1.5f,  1.0f, GLPONG_FRONT_Z); /* Upper Left */
		glVertex3f(-1.5f,  1.0f, GLPONG_BACK_Z);
	glEnd();
	
	glLoadIdentity();
	glBindTexture(GL_TEXTURE_2D, paddle_texture);
	glEnable(GL_TEXTURE_2D);
	glColor3f(GLPong.Back.r, GLPong.Back.g, GLPong.Back.b);
	glTranslatef(GLPong.Back.coord.x, GLPong.Back.coord.y, GLPong.Back.coord.z);
	glBegin(GL_QUADS);
		glTexCoord2f(0.832f, 1.0f); glVertex2f(GLPong.Back.w / 2, GLPong.Back.h / 2);	/* Upper Right */
		glTexCoord2f(0.168f, 1.0f); glVertex2f(-GLPong.Back.w / 2, GLPong.Back.h / 2);	/* Upper Left  */
		glTexCoord2f(0.168f, 0.0f); glVertex2f(-GLPong.Back.w / 2, -GLPong.Back.h / 2);	/* Lower Left */
		glTexCoord2f(0.832f, 0.0f); glVertex2f(GLPong.Back.w / 2, -GLPong.Back.h / 2);	/* Lower Right */	
	glEnd();
	glDisable(GL_TEXTURE_2D);

	glLoadIdentity();
	glColor3f(1.0f, 0.0f, 0.0f);
	glTranslatef(GLPong.Back.coord.x, GLPong.Back.coord.y, GLPong.Back.coord.z);
	glBegin(GL_POINTS);
		glVertex3f(0.0f, 0.0f, 0.0f);
	glEnd();

	glLoadIdentity();
	glBindTexture(GL_TEXTURE_2D, ball_texture);
	glEnable(GL_TEXTURE_2D);
	glColor3f(GLPong.Ball.r, GLPong.Ball.g, GLPong.Ball.b);
	glTranslatef(GLPong.Ball.coord.x, GLPong.Ball.coord.y, GLPong.Ball.coord.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);

	/* Lower Left */
	glLoadIdentity();
	glColor3f(1.0f, 0.0f, 0.0f);
	glTranslatef(GLPong.Ball.coord.x, GLPong.Ball.coord.y, GLPong.Ball.coord.z);
	glBegin(GL_POINTS);
		glVertex3f(0.0f, 0.0f, 0.0f);
	glEnd();

	/* Lower Right */
	glLoadIdentity();
	glTranslatef(GLPong.Ball.coord.x + GLPong.Ball.w, GLPong.Ball.coord.y, GLPong.Ball.coord.z);
	glBegin(GL_POINTS);
		glVertex3f(0.0f, 0.0f, 0.0f);
	glEnd();
	
	/* Top Right */
	glLoadIdentity();
	glTranslatef(GLPong.Ball.coord.x + GLPong.Ball.w, GLPong.Ball.coord.y + GLPong.Ball.h, GLPong.Ball.coord.z);
	glBegin(GL_POINTS);
		glVertex3f(0.0f, 0.0f, 0.0f);
	glEnd();
	/* Top Left */
	glLoadIdentity();
	glTranslatef(GLPong.Ball.coord.x, GLPong.Ball.coord.y + GLPong.Ball.h, GLPong.Ball.coord.z);
	glBegin(GL_POINTS);
		glVertex3f(0.0f, 0.0f, 0.0f);
	glEnd();
	
	glLoadIdentity();
	glTranslatef(0.0f, 0.0f, GLPong.Ball.coord.z);
	glCallList(box);
	
	glLoadIdentity();
	glBindTexture(GL_TEXTURE_2D, paddle_texture);
	glEnable(GL_TEXTURE_2D);
	glColor3f(GLPong.Front.r, GLPong.Front.g, GLPong.Front.b);
	glTranslatef(GLPong.Front.coord.x + (GLPong.Front.w / 2), GLPong.Front.coord.y + (GLPong.Front.h / 2), GLPong.Front.coord.z);
	glBegin(GL_QUADS);
		glTexCoord2f(0.168f, 1.0f); glVertex2f(GLPong.Front.w / 2, GLPong.Front.h / 2);		/* Upper Right */
		glTexCoord2f(0.832f, 1.0f); glVertex2f(-GLPong.Front.w / 2, GLPong.Front.h / 2);	/* Upper Left  */
		glTexCoord2f(0.832f, 0.0f); glVertex2f(-GLPong.Front.w / 2, -GLPong.Front.h / 2);	/* Lower Left */
		glTexCoord2f(0.168f, 0.0f); glVertex2f(GLPong.Front.w / 2, -GLPong.Front.h / 2);	/* Lower Right */
	glEnd();
	glDisable(GL_TEXTURE_2D);

	/* Lower Left */
	glLoadIdentity();
	glColor3f(1.0f, 0.0f, 0.0f);
	glTranslatef(GLPong.Front.coord.x, GLPong.Front.coord.y, GLPong.Front.coord.z);
	glBegin(GL_POINTS);
		glVertex3f(0.0f, 0.0f, 0.0f);
	glEnd();

	/* Lower Right */
	glLoadIdentity();
	glTranslatef(GLPong.Front.coord.x + GLPong.Front.w, GLPong.Front.coord.y, GLPong.Front.coord.z);
	glBegin(GL_POINTS);
		glVertex3f(0.0f, 0.0f, 0.0f);
	glEnd();
	
	/* Top Right */
	glLoadIdentity();
	glTranslatef(GLPong.Front.coord.x + GLPong.Front.w, GLPong.Front.coord.y + GLPong.Front.h, GLPong.Front.coord.z);
	glBegin(GL_POINTS);
		glVertex3f(0.0f, 0.0f, 0.0f);
	glEnd();
	/* Top Left */
	glLoadIdentity();
	glTranslatef(GLPong.Front.coord.x, GLPong.Front.coord.y + GLPong.Front.h, GLPong.Front.coord.z);
	glBegin(GL_POINTS);
		glVertex3f(0.0f, 0.0f, 0.0f);
	glEnd();
}

void GLPong_Collide(Ball_t * ball, const Paddle_t * paddle) {
	if (ball->coord.z == paddle->coord.z) {
		if (ball->coord.x + ball->w < paddle->coord.x) return; 				/* if ball is left of paddle */
		if (ball->coord.x > paddle->coord.x + paddle->w) return;				/* if ball is right of paddle */
		if (ball->coord.y > paddle->coord.y + paddle->h) return;				/* if ball is above paddle */
		if (ball->coord.y + ball->h < paddle->coord.y) return;				/* if ball is below paddle */
		if (ball->zv < 0) {
			ball->zv -= 0.005f;
		} else {
			ball->zv += 0.005f;
		}
		printf("x: %.3f, y: %.2f, z: %.2f\n", ball->coord.x, ball->coord.y, ball->coord.z);
	}
}

void GLPong_CleanUp(void) {

}

static __inline__ unsigned int
NextPow2(unsigned int value) {   
#if (defined __i386__ || defined __amd64__ || defined __x86_64__) \
 && (defined __GNUC__)
	unsigned int x;
	__asm(
		"dec    %1      \n\t" /* so that if the number is a power of 
                                       * two we don't change it
                                       */
		"movl   $2,%0   \n\t"
		"bsr    %1,%1   \n\t"
		"shl    %b1,%0  \n\t"
		: "=r" (x)
		: "c" (value)
	);
#else
	unsigned int x = 2;
	while (x < value) {
		x *= 2;
	}
#endif
	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;
		if (surface->format->BitsPerPixel == 32) {
			format = GL_RGBA;
		}
	} else if (surface->format->Rmask & bmask) {
		format = GL_BGR;
		if (surface->format->BitsPerPixel == 32) {
			format = GL_BGRA;
		}
	}
	
	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;
}

static void
SDL_GL_GetMouseState(Paddle_t * paddle) {
	int x, y;
	float temp_x, temp_y;
	Uint8 * key;

	key = SDL_GetKeyState(NULL);
	SDL_GetMouseState(&x, &y);

	temp_x = ((float) x / GLPONG_WIDTH) * 3.3f - 1.65f;

	if (temp_x <= -1.5 + (paddle->w / 2)) {
		temp_x = -1.5 + (paddle->w / 2);
	} else if (temp_x >= 1.5 - (paddle->w / 2)) {
		temp_x = 1.5 - (paddle->w / 2);
	}

	temp_y = ((float) y / GLPONG_HEIGHT) * 2.5f - 1.25f;

	if (temp_y <= -1.0 + (paddle->h / 2)) {
		temp_y = -1.0 + (paddle->h / 2);
	} else if (temp_y >= 1.0 - (paddle->h / 2)) {
		temp_y = 1.0 - (paddle->h / 2);
	}

	paddle->coord.x = temp_x - paddle->w / 2;
	paddle->coord.y = -(temp_y + paddle->h / 2);

#ifdef DEBUG
	printf("SDL (x, y): (%d, %d)\tGL (x, y, z): (%.3f, %.3f)\n", x, y, paddle->coord.x, paddle->coord.y);
#endif
}