/* $Id: sdlgl.c,v 1.1.1.1 2006/03/17 19:53:36 zicodxx Exp $ */
/*
 *
 * Graphics functions for SDL-GL.
 *
 *
 */

#ifdef HAVE_CONFIG_H
#include <conf.h>
#endif

#include <SDL.h>
#ifdef SDL_IMAGE
#include <SDL_image.h>
#endif

#include "internal.h"
#include "vers_id.h"
#include "error.h"
#include "u_mem.h"
#include "args.h"

static int curx=-1,cury=-1,curfull=0;

void ogl_do_fullscreen_internal(void){
	ogl_init_window(curx,cury);
}

static Uint16 gammaramp[512];

static void init_gammaramp(void)
{
	int i;

	for (i = 0; i < 256; ++i)
		gammaramp[i] = i * 256;
	for (i = 256; i < 512; ++i)
		gammaramp[i] = 0xffff;
}

int ogl_setbrightness_internal(void)
{
	return SDL_SetGammaRamp(gammaramp + ogl_brightness_r * 4,
	                        gammaramp + ogl_brightness_g * 4,
	                        gammaramp + ogl_brightness_b * 4
							);
}

void ogl_swap_buffers_internal(void)
{
	SDL_GL_SwapBuffers();
}

int ogl_check_mode(int x, int y)
{
	return !SDL_VideoModeOK(x, y, 16, SDL_OPENGL | (ogl_fullscreen?SDL_FULLSCREEN:0)); // ZICO - use bpp instead of 16
}


int ogl_init_window(int x, int y)
{
	int bpp = FindArg("-gl_16bpp") ? 16 : 32;
	
	if (gl_initialized){
		if (x==curx && y==cury && curfull==ogl_fullscreen)
			return 0;
#ifdef __linux__ // Windows, at least, seems to need to reload every time.
		if (ogl_fullscreen || curfull)
#endif
			ogl_smash_texture_list_internal();//if we are or were fullscreen, changing vid mode will invalidate current textures
	}
	SDL_WM_SetCaption(DESCENT_VERSION, "Descent II");

#ifdef SDL_IMAGE
	{
#include "descent.xpm"
		SDL_WM_SetIcon(IMG_ReadXPMFromArray(pixmap), NULL);
	}
#endif

	if (!SDL_SetVideoMode(x, y, bpp, SDL_OPENGL | (ogl_fullscreen ? SDL_FULLSCREEN : 0)))
	{
		Error("Could not set %dx%dx%d opengl video mode\n", x, y, bpp);
	}
	SDL_ShowCursor(0);

	curx=x;cury=y;curfull=ogl_fullscreen;
	gl_initialized=1;

	return 0;
}

void ogl_destroy_window(void){
	if (gl_initialized){
		ogl_smash_texture_list_internal();
		SDL_ShowCursor(1);
		//gl_initialized=0;
		//well..SDL doesn't really let you kill the window.. so we just need to wait for sdl_quit
	}
	return;
}

void ogl_init(void){
	int t;
	if ((t=FindArg("-gl_red")))
		SDL_GL_SetAttribute( SDL_GL_RED_SIZE, atoi(Args[t+1]) );
	if ((t=FindArg("-gl_green")))
		SDL_GL_SetAttribute( SDL_GL_GREEN_SIZE, atoi(Args[t+1]) );
	if ((t=FindArg("-gl_blue")))
		SDL_GL_SetAttribute( SDL_GL_BLUE_SIZE, atoi(Args[t+1]) );
	if ((t=FindArg("-gl_alpha")))
		SDL_GL_SetAttribute( SDL_GL_ALPHA_SIZE, atoi(Args[t+1]) );
	if ((t=FindArg("-gl_buffer")))
		SDL_GL_SetAttribute( SDL_GL_BUFFER_SIZE, atoi(Args[t+1]) );

//	SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE,0); // ZICO - provisoric for INV-WALLS-effect
	SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 16);
	SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE,0);
	SDL_GL_SetAttribute(SDL_GL_ACCUM_RED_SIZE,0);
	SDL_GL_SetAttribute(SDL_GL_ACCUM_GREEN_SIZE,0);
	SDL_GL_SetAttribute(SDL_GL_ACCUM_BLUE_SIZE,0);
	SDL_GL_SetAttribute(SDL_GL_ACCUM_ALPHA_SIZE,0);
	SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER,1);
	
	init_gammaramp();
}

void ogl_close(void){
#if 0  // shouldn't really be necessary...
	if (ogl_fullscreen){
		ogl_fullscreen=0;
		ogl_do_fullscreen_internal();
	}
#endif
	ogl_destroy_window();
}