/*
	vid_3dfxsvga.c

	OpenGL device driver for 3Dfx chipsets running Linux

	Copyright (C) 1996-1997  Id Software, Inc.
	Copyright (C) 1999,2000  contributors of the QuakeForge project
	Please see the file "AUTHORS" for a list of contributors

	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License
	as published by the Free Software Foundation; either version 2
	of the License, or (at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

	See the GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to:

		Free Software Foundation, Inc.
		59 Temple Place - Suite 330
		Boston, MA  02111-1307, USA

*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#ifdef HAVE_STRING_H
# include <string.h>
#endif
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif
#ifdef HAVE_DLOPEN
# include <dlfcn.h>
#endif

#include <setjmp.h>

#include "QF/cvar.h"
#include "QF/console.h"
#include "QF/qargs.h"
#include "QF/qendian.h"
#include "QF/sys.h"
#include "QF/va.h"
#include "QF/vid.h"
#include "QF/GL/extensions.h"
#include "QF/GL/funcs.h"
#include "QF/GL/qf_vid.h"

#include "compat.h"
#include "sbar.h"
#include "r_cvar.h"

#define WARP_WIDTH				320
#define WARP_HEIGHT				200

#define GLAPI extern
#define GLAPIENTRY

#define FXMESA_NONE				0		// to terminate attribList
#define FXMESA_DOUBLEBUFFER     10
#define FXMESA_ALPHA_SIZE       11		// followed by an integer
#define FXMESA_DEPTH_SIZE		12		// followed by an integer

#define GL_DITHER				0x0BD0

typedef struct tfxMesaContext *fxMesaContext;

#define GR_REFRESH_75Hz			0x3

#define GR_DITHER_2x2			0x1
#define GR_DITHER_4x4			0x2
#define GR_RESOLUTION_320x200	0x0
#define GR_RESOLUTION_320x240	0x1
#define GR_RESOLUTION_400x256	0x2
#define GR_RESOLUTION_512x384	0x3
#define GR_RESOLUTION_640x200	0x4
#define GR_RESOLUTION_640x350	0x5
#define GR_RESOLUTION_640x400	0x6
#define GR_RESOLUTION_640x480	0x7
#define GR_RESOLUTION_800x600	0x8
#define GR_RESOLUTION_960x720	0x9
#define GR_RESOLUTION_512x256	0xb
#define GR_RESOLUTION_856x480	0xa
#define GR_RESOLUTION_400x300	0xF

void (* qf_fxMesaDestroyContext) (fxMesaContext ctx);
void (* qf_fxMesaSwapBuffers) (void);
fxMesaContext (* qf_fxMesaCreateContext) (GLuint win, GrScreenResolution_t, GrScreenRefresh_t, const GLint attribList[]);
void (* qf_fxMesaMakeCurrent) (fxMesaContext ctx);

static fxMesaContext fc = NULL;

int			VID_options_items = 0;


#if defined(HAVE_DLOPEN)

void * (* glGetProcAddress) (const char *symbol)= NULL;

void *
QFGL_GetProcAddress (void *handle, const char *name)
{
	void       *glfunc = NULL;

	if (glGetProcAddress)
		glfunc = glGetProcAddress (name);
	if (!glfunc)
		glfunc = dlsym (handle, name);
	return glfunc;
}

void *
QFGL_LoadLibrary (void)
{
	void   *handle;

	if (!(handle = dlopen (gl_driver, RTLD_NOW))) {
		Sys_Error ("Couldn't load OpenGL library %s: %s", gl_driver,
				   dlerror ());
	}
	glGetProcAddress = dlsym (handle, "glXGetProcAddress");
	if (!glGetProcAddress)
		glGetProcAddress = dlsym (handle, "glXGetProcAddressARB");
	return handle;
}

#else

# error "Cannot load libraries: %s was not configured with DSO support"

// the following is to avoid other compiler errors
void *
QFGL_GetProcAddress (void *handle, const char *name)
{
	return 0;
}

void *
QFGL_LoadLibrary (void)
{
	return 0;
}
#endif  // HAVE_DLOPEN


static void
VID_shutdown (void)
{
	if (!fc)
		return;

	qf_fxMesaDestroyContext (fc);
}

static void
GL_Init (void)
{
	QF_3DfxSetDitherModeEXT dither_select = NULL;
	int p;

	GL_Init_Common ();

	if (!(QFGL_ExtensionPresent ("3DFX_set_dither_mode")))
		return;

	if (!(dither_select = QFGL_ExtensionAddress ("gl3DfxSetDitherModeEXT")))
		return;

	Sys_MaskPrintf (SYS_vid, "Dithering: ");

	if ((p = COM_CheckParm ("-dither")) && p < com_argc) {
		if (strequal (com_argv[p+1], "2x2")) {
			dither_select (GR_DITHER_2x2);
			Sys_MaskPrintf (SYS_vid, "2x2.\n");
		}
		if (strequal (com_argv[p+1], "4x4")) {
			dither_select (GR_DITHER_4x4);
			Sys_MaskPrintf (SYS_vid, "4x4.\n");
		}
	} else {
		qfglDisable (GL_DITHER);
		Sys_MaskPrintf (SYS_vid, "disabled.\n");
	}
}

VISIBLE void
GL_EndRendering (void)
{
	qfglFinish ();
	qf_fxMesaSwapBuffers ();
}

static unsigned int  resolutions[][3] = {
	{320, 200, GR_RESOLUTION_320x200},
	{320, 240, GR_RESOLUTION_320x240},
	{400, 256, GR_RESOLUTION_400x256},
	{400, 300, GR_RESOLUTION_400x300},
	{512, 256, GR_RESOLUTION_512x256},
	{512, 384, GR_RESOLUTION_512x384},
	{640, 200, GR_RESOLUTION_640x200},
	{640, 350, GR_RESOLUTION_640x350},
	{640, 400, GR_RESOLUTION_640x400},
	{640, 480, GR_RESOLUTION_640x480},
	{800, 600, GR_RESOLUTION_800x600},
	{856, 480, GR_RESOLUTION_856x480},
	{960, 720, GR_RESOLUTION_960x720},
#ifdef GR_RESOLUTION_1024x768
	{1024, 768, GR_RESOLUTION_1024x768},
#endif
#ifdef GR_RESOLUTION_1152x864
	{1152, 864, GR_RESOLUTION_1152x864},
#endif
#ifdef GR_RESOLUTION_1280x960
	{1280, 960, GR_RESOLUTION_1280x960},
#endif
#ifdef GR_RESOLUTION_1280x1024
	{1280, 1024, GR_RESOLUTION_1280x1024},
#endif
#ifdef GR_RESOLUTION_1600x1024
	{1600, 1024, GR_RESOLUTION_1600x1024},
#endif
#ifdef GR_RESOLUTION_1600x1200
	{1600, 1200, GR_RESOLUTION_1600x1200},
#endif
#ifdef GR_RESOLUTION_1792x1344
	{1792, 1344, GR_RESOLUTION_1792x1344},
#endif
#ifdef GR_RESOLUTION_1856x1392
	{1856, 1392, GR_RESOLUTION_1856x1392},
#endif
#ifdef GR_RESOLUTION_1920x1440
	{1920, 1440, GR_RESOLUTION_1920x1440},
#endif
#ifdef GR_RESOLUTION_2048x1536
	{2048, 1536, GR_RESOLUTION_2048x1536},
#endif
#ifdef GR_RESOLUTION_2048x2048
	{2048, 2048, GR_RESOLUTION_2048x2048}
#endif
};

#define NUM_RESOLUTIONS		(sizeof (resolutions) / (sizeof (int) * 3))

static int
findres (unsigned int *width, unsigned int *height)
{
	unsigned int i;

	for (i = 0; i < NUM_RESOLUTIONS; i++) {
		if ((*width <= resolutions[i][0]) && (*height <= resolutions[i][1])) {
			*width = resolutions[i][0];
			*height = resolutions[i][1];
			return resolutions[i][2];
		}
	}

	*width = 640;
	*height = 480;
	return GR_RESOLUTION_640x480;
}

void
VID_Init (byte *palette, byte *colormap)
{
	GLint       attribs[32];

	Sys_RegisterShutdown (VID_shutdown);

	GLF_Init ();

	qf_fxMesaCreateContext = QFGL_ProcAddress (libgl_handle,
											"fxMesaCreateContext", true);
	qf_fxMesaDestroyContext = QFGL_ProcAddress (libgl_handle,
											 "fxMesaDestroyContext", true);
	qf_fxMesaMakeCurrent = QFGL_ProcAddress (libgl_handle,
										  "fxMesaMakeCurrent", true);
	qf_fxMesaSwapBuffers = QFGL_ProcAddress (libgl_handle,
										  "fxMesaSwapBuffers", true);

	VID_GetWindowSize (640, 480);

	vid.maxwarpwidth = WARP_WIDTH;
	vid.maxwarpheight = WARP_HEIGHT;
	vid.colormap8 = vid_colormap = colormap;
	vid.fullbright = 256 - vid.colormap8[256 * VID_GRADES];

	// interpret command-line params

	// set vid parameters
	attribs[0] = FXMESA_DOUBLEBUFFER;
	attribs[1] = FXMESA_ALPHA_SIZE;
	attribs[2] = 1;
	attribs[3] = FXMESA_DEPTH_SIZE;
	attribs[4] = 1;
	attribs[5] = FXMESA_NONE;

	fc = qf_fxMesaCreateContext (0, findres (&vid.width, &vid.height),
							  GR_REFRESH_75Hz, attribs);
	if (!fc)
		Sys_Error ("Unable to create 3DFX context.");

	qf_fxMesaMakeCurrent (fc);

	vid.numpages = 2;

	vid_gamma_avail = 1;

	GL_Init ();

	VID_InitGamma (palette);
	VID_SetPalette (vid.palette);

	// Check for 3DFX Extensions and initialize them.
	VID_Init8bitPalette ();

	vid.initialized = true;

	Sys_MaskPrintf (SYS_vid, "Video mode %dx%d initialized.\n",
					vid.width, vid.height);

	vid.recalc_refdef = 1;				// force a surface cache flush
}

void
VID_Init_Cvars (void)
{
	Cvar_Register (&vid_system_gamma_cvar, 0, 0);
}

void
VID_SetCaption (const char *text)
{
}

qboolean
VID_SetGamma (double gamma)
{
	return true;
}
