/*
Copyright (C) 1996-2001 Id Software, Inc.
Copyright (C) 2002-2009 John Fitzgibbons and others
Copyright (C) 2007-2008 Kristian Duske

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

//gl_texmgr.c -- fitzquake's texture manager. manages opengl texture images

#include "quakedef.h"

extern qboolean	gl_anisotropy_able;

cvar_t		gl_texture_anisotropy = {"gl_texture_anisotropy", "1", true};
cvar_t		gl_max_size = {"gl_max_size", "0"};
cvar_t		gl_picmip = {"gl_picmip", "0"};
GLint			gl_hardware_maxsize;
const int	gl_solid_format = 3;
const int	gl_alpha_format = 4;

#define	MAX_GLTEXTURES	2048
gltexture_t	*active_gltextures, *free_gltextures;
int numgltextures;

/*
================================================================================

	COMMANDS

================================================================================
*/

typedef struct
{
	int	magfilter;
	int minfilter;
	char *name;
} glmode_t;
glmode_t modes[] = {
	{GL_NEAREST, GL_NEAREST,				"GL_NEAREST"},
	{GL_NEAREST, GL_NEAREST_MIPMAP_NEAREST,	"GL_NEAREST_MIPMAP_NEAREST"},
	{GL_NEAREST, GL_NEAREST_MIPMAP_LINEAR,	"GL_NEAREST_MIPMAP_LINEAR"},
	{GL_LINEAR,  GL_LINEAR,					"GL_LINEAR"},
	{GL_LINEAR,  GL_LINEAR_MIPMAP_NEAREST,	"GL_LINEAR_MIPMAP_NEAREST"},
	{GL_LINEAR,  GL_LINEAR_MIPMAP_LINEAR,	"GL_LINEAR_MIPMAP_LINEAR"},
};
#define NUM_GLMODES 6
int gl_texturemode = 5; // bilinear

/*
===============
TexMgr_DescribeTextureModes_f -- report available texturemodes
===============
*/
void TexMgr_DescribeTextureModes_f (void)
{
	int i;

	for (i=0; i<NUM_GLMODES; i++)
		Con_SafePrintf ("   %2i: %s\n", i + 1, modes[i].name);

	Con_Printf ("%i modes\n", i);
}

/*
===============
TexMgr_SetFilterModes
===============
*/
void TexMgr_SetFilterModes (gltexture_t *glt)
{
	GL_Bind (glt);

	if (glt->flags & TEXPREF_NEAREST)
	{
		glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
		glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	}
	else if (glt->flags & TEXPREF_LINEAR)
	{
		glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
		glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	}
	else if (glt->flags & TEXPREF_MIPMAP)
	{
		glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, modes[gl_texturemode].magfilter);
		glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, modes[gl_texturemode].minfilter);
	}
	else
	{
		glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, modes[gl_texturemode].magfilter);
		glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, modes[gl_texturemode].magfilter);
	}

	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, gl_texture_anisotropy.value);
}

/*
===============
TexMgr_TextureMode_f
===============
*/
void TexMgr_TextureMode_f (void)
{
	gltexture_t	*glt;
	char *arg;
	int i;

	switch (Cmd_Argc())
	{
	case 1:
		Con_Printf ("\"gl_texturemode\" is \"%s\"\n", modes[gl_texturemode].name);
		break;
	case 2:
		arg = Cmd_Argv(1);
		if (arg[0] == 'G' || arg[0] == 'g')
		{
			for (i=0; i<NUM_GLMODES; i++)
				if (!Q_strcasecmp (modes[i].name, arg))
				{
					gl_texturemode = i;
					goto stuff;
				}
			Con_Printf ("\"%s\" is not a valid texturemode\n", arg);
			return;
		}
		else if (arg[0] >= '0' && arg[0] <= '9')
		{
			i = atoi(arg);
			if (i > NUM_GLMODES || i < 1)
			{
				Con_Printf ("\"%s\" is not a valid texturemode\n", arg);
				return;
			}
			gl_texturemode = i - 1;
		}
		else
			Con_Printf ("\"%s\" is not a valid texturemode\n", arg);

stuff:
		for (glt=active_gltextures; glt; glt=glt->next)
			TexMgr_SetFilterModes (glt);

		Sbar_Changed (); //sbar graphics need to be redrawn with new filter mode

		//FIXME: warpimages need to be redrawn, too.

		break;
	default:
		Con_SafePrintf ("usage: gl_texturemode <mode>\n");
		break;
	}
}

/*
===============
TexMgr_Anisotropy_f -- called when gl_texture_anisotropy changes

FIXME: this is getting called twice (becuase of the recursive Cvar_SetValue call)
===============
*/
void TexMgr_Anisotropy_f (void)
{
	extern float gl_max_anisotropy;
	gltexture_t	*glt;

	Cvar_SetValue ("gl_texture_anisotropy", CLAMP (1.0f, gl_texture_anisotropy.value, gl_max_anisotropy));

	for (glt=active_gltextures; glt; glt=glt->next)
		TexMgr_SetFilterModes (glt);
}

/*
===============
TexMgr_Imagelist_f -- report loaded textures
===============
*/
void TexMgr_Imagelist_f (void)
{
	float mb;
	float texels = 0;
	gltexture_t	*glt;
	extern cvar_t vid_bpp;

	for (glt=active_gltextures; glt; glt=glt->next)
	{
		Con_SafePrintf ("   %4i x%4i %s\n", glt->width, glt->height, glt->name);
		if (glt->flags & TEXPREF_MIPMAP)
			texels += glt->width * glt->height * 4.0f / 3.0f;
		else
			texels += (glt->width * glt->height);
	}

	mb = texels * (vid_bpp.value / 8.0f) / 0x100000;
	Con_Printf ("%i textures %i pixels %1.1f megabytes\n", numgltextures, (int)texels, mb);
}

/*
===============
TexMgr_Imagedump_f -- dump all current textures to TGA files
===============
*/
void TexMgr_Imagedump_f (void)
{
	char tganame[MAX_OSPATH], tempname[MAX_OSPATH], dirname[MAX_OSPATH];
	gltexture_t	*glt;
	byte *buffer;
	char *c;

	//create directory
	sprintf(dirname, "%s/imagedump", com_gamedir);
	Sys_mkdir (dirname);

	//loop through textures
	for (glt=active_gltextures; glt; glt=glt->next)
	{
		Q_strcpy(tempname, glt->name);
		while ( (c = strchr(tempname, ':')) ) *c = '_';
		while ( (c = strchr(tempname, '/')) ) *c = '_';
		while ( (c = strchr(tempname, '*')) ) *c = '_';
		sprintf(tganame, "imagedump/%s.tga", tempname);

		GL_Bind (glt);
		if (glt->flags & TEXPREF_ALPHA)
		{
			buffer = malloc(glt->width*glt->height*4);
			glGetTexImage(GL_TEXTURE_2D, 0, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
			Image_WriteTGA (tganame, buffer, glt->width, glt->height, 32, true);
		}
		else
		{
			buffer = malloc(glt->width*glt->height*3);
			glGetTexImage(GL_TEXTURE_2D, 0, GL_RGB, GL_UNSIGNED_BYTE, buffer);
			Image_WriteTGA (tganame, buffer, glt->width, glt->height, 24, true);
		}
		free (buffer);
	}

	Con_Printf ("dumped %i textures to %s\n", numgltextures, dirname);
}

/*
===============
TexMgr_FrameUsage -- report texture memory usage for this frame
===============
*/
float TexMgr_FrameUsage (void)
{
	float mb;
	float texels = 0;
	gltexture_t	*glt;
	extern cvar_t vid_bpp;

	for (glt=active_gltextures; glt; glt=glt->next)
		if (glt->visframe == r_framecount)
		{
			if (glt->flags & TEXPREF_MIPMAP)
				texels += glt->width * glt->height * 4.0f / 3.0f;
			else
				texels += (glt->width * glt->height);
		}

	mb = texels * (vid_bpp.value / 8.0f) / 0x100000;
	return mb;
}

/*
================================================================================

	TEXTURE MANAGER

================================================================================
*/

/*
================
TexMgr_FindTexture
================
*/
gltexture_t *TexMgr_FindTexture (model_t *owner, char *name)
{
	gltexture_t	*glt;

	if (name)
	{
		for (glt=active_gltextures; glt; glt=glt->next)
			if (glt->owner == owner && !strcmp (glt->name, name))
				return glt;
	}

	return NULL;
}

/*
================
TexMgr_NewTexture
================
*/
gltexture_t *TexMgr_NewTexture (void)
{
	gltexture_t *glt;

	if (numgltextures == MAX_GLTEXTURES)
		Sys_Error("numgltextures == MAX_GLTEXTURES\n");

	glt = free_gltextures;
	free_gltextures = glt->next;
	glt->next = active_gltextures;
	active_gltextures = glt;

	glGenTextures(1, (GLuint *)&glt->texnum);
	numgltextures++;
	return glt;
}

/*
================
TexMgr_FreeTexture
================
*/
void TexMgr_FreeTexture (gltexture_t *kill)
{
	gltexture_t *glt;

	if (kill == NULL)
	{
		Con_Printf ("TexMgr_FreeTexture: NULL texture\n");
		return;
	}

	if (active_gltextures == kill)
	{
		active_gltextures = kill->next;
		kill->next = free_gltextures;
		free_gltextures = kill;

		glDeleteTextures(1, (const GLuint *)&kill->texnum);
		numgltextures--;
		return;
	}

	for (glt = active_gltextures; glt; glt = glt->next)
		if (glt->next == kill)
		{
			glt->next = kill->next;
			kill->next = free_gltextures;
			free_gltextures = kill;

			glDeleteTextures(1, (const GLuint *)&kill->texnum);
			numgltextures--;
			return;
		}

	Con_Printf ("TexMgr_FreeTexture: not found\n");
}

/*
================
TexMgr_FreeTextures

compares each bit in "flags" to the one in glt->flags only if that bit is active in "mask"
================
*/
void TexMgr_FreeTextures (int flags, int mask)
{
	gltexture_t *glt, *next;

	for (glt = active_gltextures; glt; glt = next)
	{
		next = glt->next;
		if ((glt->flags & mask) == (flags & mask))
			TexMgr_FreeTexture (glt);
	}
}

/*
================
TexMgr_FreeTexturesForOwner
================
*/
void TexMgr_FreeTexturesForOwner (model_t *owner)
{
	gltexture_t *glt, *next;

	for (glt = active_gltextures; glt; glt = next)
	{
		next = glt->next;
		if (glt && glt->owner == owner)
			TexMgr_FreeTexture (glt);
	}
}

/*
================================================================================

	INIT

================================================================================
*/

/*
=================
TexMgr_LoadPalette -- johnfitz -- was VID_SetPalette, moved here, renamed, rewritten
=================
*/
void TexMgr_LoadPalette (void)
{
	byte mask[] = {255,255,255,0};
	byte black[] = {0,0,0,255};
	byte *pal, *src, *dst;
	int i, mark;
	FILE *f;

	COM_FOpenFile ("gfx/palette.lmp", &f);
	if (!f)
		Sys_Error ("Couldn't load gfx/palette.lmp");

	mark = Hunk_LowMark ();
	pal = Hunk_Alloc (768);
	fread (pal, 1, 768, f);
	fclose(f);

	//standard palette, 255 is transparent
	dst = (byte *)d_8to24table;
	src = pal;
	for (i=0; i<256; i++)
	{
		*dst++ = *src++;
		*dst++ = *src++;
		*dst++ = *src++;
		*dst++ = 255;
	}
	d_8to24table[255] &= *(int *)mask;

	//fullbright palette, 0-223 are black (for additive blending)
	src = pal + 224*3;
	dst = (byte *)(d_8to24table_fbright) + 224*4;
	for (i=224; i<256; i++)
	{
		*dst++ = *src++;
		*dst++ = *src++;
		*dst++ = *src++;
		*dst++ = 255;
	}
	for (i=0; i<224; i++)
		d_8to24table_fbright[i] = *(int *)black;

	//nobright palette, 224-255 are black (for additive blending)
	dst = (byte *)d_8to24table_nobright;
	src = pal;
	for (i=0; i<256; i++)
	{
		*dst++ = *src++;
		*dst++ = *src++;
		*dst++ = *src++;
		*dst++ = 255;
	}
	for (i=224; i<256; i++)
		d_8to24table_nobright[i] = *(int *)black;

	//conchars palette, 0 and 255 are transparent
	memcpy(d_8to24table_conchars, d_8to24table, 256*4);
	d_8to24table_conchars[0] &= *(int *)mask;

	Hunk_FreeToLowMark (mark);
}

/*
================
TexMgr_NewGame
================
*/
void TexMgr_NewGame (void)
{
	TexMgr_FreeTextures (0, TEXPREF_PERSIST); //deletes all textures where TEXPREF_PERSIST is unset
	TexMgr_LoadPalette ();
}

/*
=============
TexMgr_RecalcWarpImageSize -- called during init, and after a vid_restart

choose safe warpimage size and resize existing warpimage textures
=============
*/
void TexMgr_RecalcWarpImageSize (void)
{
	int	mark, oldsize;
	gltexture_t *glt;
	byte *dummy;

	//
	// find the new correct size
	//
	oldsize = gl_warpimagesize;

	gl_warpimagesize = TexMgr_SafeTextureSize (512);

	while (gl_warpimagesize > vid.width)
		gl_warpimagesize >>= 1;
	while (gl_warpimagesize > vid.height)
		gl_warpimagesize >>= 1;

	if (gl_warpimagesize == oldsize)
		return;

	//
	// resize the textures in opengl
	//
	mark = Hunk_LowMark();
	dummy = Hunk_Alloc (gl_warpimagesize*gl_warpimagesize*4);

	for (glt=active_gltextures; glt; glt=glt->next)
	{
		if (glt->flags & TEXPREF_WARPIMAGE)
		{
			GL_Bind (glt);
			glTexImage2D (GL_TEXTURE_2D, 0, gl_solid_format, gl_warpimagesize, gl_warpimagesize, 0, GL_RGBA, GL_UNSIGNED_BYTE, dummy);
			glt->width = glt->height = gl_warpimagesize;
		}
	}

	Hunk_FreeToLowMark (mark);
}

/*
================
TexMgr_Init

must be called before any texture loading
================
*/
void TexMgr_Init (void)
{
	int i;
	static byte notexture_data[16] = {159,91,83,255,0,0,0,255,0,0,0,255,159,91,83,255}; //black and pink checker
	static byte nulltexture_data[16] = {127,191,255,255,0,0,0,255,0,0,0,255,127,191,255,255}; //black and blue checker
	extern texture_t *r_notexture_mip, *r_notexture_mip2;

	// init texture list
	free_gltextures = (gltexture_t *) Hunk_AllocName (MAX_GLTEXTURES * sizeof(gltexture_t), "gltextures");
	active_gltextures = NULL;
	for (i=0; i<MAX_GLTEXTURES-1; i++)
		free_gltextures[i].next = &free_gltextures[i+1];
	free_gltextures[i].next = NULL;
	numgltextures = 0;

	// palette
	TexMgr_LoadPalette ();

	Cvar_RegisterVariable (&gl_max_size, NULL);
	Cvar_RegisterVariable (&gl_picmip, NULL);
	Cvar_RegisterVariable (&gl_texture_anisotropy, &TexMgr_Anisotropy_f);
	Cmd_AddCommand ("gl_texturemode", &TexMgr_TextureMode_f);
	Cmd_AddCommand ("gl_describetexturemodes", &TexMgr_DescribeTextureModes_f);
	Cmd_AddCommand ("imagelist", &TexMgr_Imagelist_f);
	Cmd_AddCommand ("imagedump", &TexMgr_Imagedump_f);

	// poll max size from hardware
	glGetIntegerv (GL_MAX_TEXTURE_SIZE, &gl_hardware_maxsize);

	// load notexture images
	notexture = TexMgr_LoadImage (NULL, "notexture", 2, 2, SRC_RGBA, notexture_data, "", (src_offset_t)notexture_data, TEXPREF_NEAREST | TEXPREF_PERSIST | TEXPREF_NOPICMIP);
	nulltexture = TexMgr_LoadImage (NULL, "nulltexture", 2, 2, SRC_RGBA, nulltexture_data, "", (src_offset_t)nulltexture_data, TEXPREF_NEAREST | TEXPREF_PERSIST | TEXPREF_NOPICMIP);

	//have to assign these here becuase Mod_Init is called before TexMgr_Init
	r_notexture_mip->gltexture = r_notexture_mip2->gltexture = notexture;

	//set safe size for warpimages
	gl_warpimagesize = 0;
	TexMgr_RecalcWarpImageSize ();
}

/*
================================================================================

	IMAGE LOADING

================================================================================
*/

/*
================
TexMgr_Pad -- return smallest power of two greater than or equal to s
================
*/
int TexMgr_Pad (int s)
{
	int i;
	for (i = 1; i < s; i<<=1);
	return i;
}

/*
===============
TexMgr_SafeTextureSize -- return a size with hardware and user prefs in mind
===============
*/
int TexMgr_SafeTextureSize (int s)
{
	s = TexMgr_Pad(s);
	if ((int)gl_max_size.value > 0)
		s = min(TexMgr_Pad((int)gl_max_size.value), s);
	s = min(gl_hardware_maxsize, s);
	return s;
}

/*
================
TexMgr_PadConditional -- only pad if a texture of that size would be padded. (used for tex coords)
================
*/
int TexMgr_PadConditional (int s)
{
	if (s < TexMgr_SafeTextureSize(s))
		return TexMgr_Pad(s);
	else
		return s;
}

/*
================
TexMgr_MipMapW
================
*/
unsigned *TexMgr_MipMapW (unsigned *data, int width, int height)
{
	int		i, size;
	byte	*out, *in;

	out = in = (byte *)data;
	size = (width*height)>>1;

	for (i=0; i<size; i++, out+=4, in+=8)
	{
		out[0] = (in[0] + in[4])>>1;
		out[1] = (in[1] + in[5])>>1;
		out[2] = (in[2] + in[6])>>1;
		out[3] = (in[3] + in[7])>>1;
	}

	return data;
}

/*
================
TexMgr_MipMapH
================
*/
unsigned *TexMgr_MipMapH (unsigned *data, int width, int height)
{
	int		i, j;
	byte	*out, *in;

	out = in = (byte *)data;
	height>>=1;
	width<<=2;

	for (i=0; i<height; i++, in+=width)
		for (j=0; j<width; j+=4, out+=4, in+=4)
		{
			out[0] = (in[0] + in[width+0])>>1;
			out[1] = (in[1] + in[width+1])>>1;
			out[2] = (in[2] + in[width+2])>>1;
			out[3] = (in[3] + in[width+3])>>1;
		}

	return data;
}

/*
================
TexMgr_ResampleTexture -- bilinear resample
================
*/
unsigned *TexMgr_ResampleTexture (unsigned *in, int inwidth, int inheight, qboolean alpha)
{
	byte *nwpx, *nepx, *swpx, *sepx, *dest;
	unsigned xfrac, yfrac, x, y, modx, mody, imodx, imody, injump, outjump;
	unsigned *out;
	int i, j, outwidth, outheight;

	if (inwidth == TexMgr_Pad(inwidth) && inheight == TexMgr_Pad(inheight))
		return in;

	outwidth = TexMgr_Pad(inwidth);
	outheight = TexMgr_Pad(inheight);
	out = Hunk_Alloc(outwidth*outheight*4);

	xfrac = ((inwidth-1) << 16) / (outwidth-1);
	yfrac = ((inheight-1) << 16) / (outheight-1);
	y = outjump = 0;

	for (i=0; i<outheight; i++)
	{
		mody = (y>>8) & 0xFF;
		imody = 256 - mody;
		injump = (y>>16) * inwidth;
		x = 0;

		for (j=0; j<outwidth; j++)
		{
			modx = (x>>8) & 0xFF;
			imodx = 256 - modx;

			nwpx = (byte *)(in + (x>>16) + injump);
			nepx = nwpx + 4;
			swpx = nwpx + inwidth*4;
			sepx = swpx + 4;

			dest = (byte *)(out + outjump + j);

			dest[0] = (nwpx[0]*imodx*imody + nepx[0]*modx*imody + swpx[0]*imodx*mody + sepx[0]*modx*mody)>>16;
			dest[1] = (nwpx[1]*imodx*imody + nepx[1]*modx*imody + swpx[1]*imodx*mody + sepx[1]*modx*mody)>>16;
			dest[2] = (nwpx[2]*imodx*imody + nepx[2]*modx*imody + swpx[2]*imodx*mody + sepx[2]*modx*mody)>>16;
			if (alpha)
				dest[3] = (nwpx[3]*imodx*imody + nepx[3]*modx*imody + swpx[3]*imodx*mody + sepx[3]*modx*mody)>>16;
			else
				dest[3] = 255;

			x += xfrac;
		}
		outjump += outwidth;
		y += yfrac;
	}

	return out;
}

/*
===============
TexMgr_AlphaEdgeFix

eliminate pink edges on sprites, etc.
operates in place on 32bit data
===============
*/
void TexMgr_AlphaEdgeFix (byte *data, int width, int height)
{
	int i,j,n=0,b,c[3]={0,0,0},lastrow,thisrow,nextrow,lastpix,thispix,nextpix;
	byte *dest = data;

	for (i=0; i<height; i++)
	{
		lastrow = width * 4 * ((i == 0) ? height-1 : i-1);
		thisrow = width * 4 * i;
		nextrow = width * 4 * ((i == height-1) ? 0 : i+1);

		for (j=0; j<width; j++, dest+=4)
		{
			if (dest[3]) //not transparent
				continue;

			lastpix = 4 * ((j == 0) ? width-1 : j-1);
			thispix = 4 * j;
			nextpix = 4 * ((j == width-1) ? 0 : j+1);

			b = lastrow + lastpix; if (data[b+3]) {c[0] += data[b]; c[1] += data[b+1]; c[2] += data[b+2]; n++;}
			b = thisrow + lastpix; if (data[b+3]) {c[0] += data[b]; c[1] += data[b+1]; c[2] += data[b+2]; n++;}
			b = nextrow + lastpix; if (data[b+3]) {c[0] += data[b]; c[1] += data[b+1]; c[2] += data[b+2]; n++;}
			b = lastrow + thispix; if (data[b+3]) {c[0] += data[b]; c[1] += data[b+1]; c[2] += data[b+2]; n++;}
			b = nextrow + thispix; if (data[b+3]) {c[0] += data[b]; c[1] += data[b+1]; c[2] += data[b+2]; n++;}
			b = lastrow + nextpix; if (data[b+3]) {c[0] += data[b]; c[1] += data[b+1]; c[2] += data[b+2]; n++;}
			b = thisrow + nextpix; if (data[b+3]) {c[0] += data[b]; c[1] += data[b+1]; c[2] += data[b+2]; n++;}
			b = nextrow + nextpix; if (data[b+3]) {c[0] += data[b]; c[1] += data[b+1]; c[2] += data[b+2]; n++;}

			//average all non-transparent neighbors
			if (n)
			{
				dest[0] = (byte)(c[0]/n);
				dest[1] = (byte)(c[1]/n);
				dest[2] = (byte)(c[2]/n);

				n = c[0] = c[1] = c[2] = 0;
			}
		}
	}
}

/*
===============
TexMgr_PadEdgeFixW -- special case of AlphaEdgeFix for textures that only need it because they were padded

operates in place on 32bit data, and expects unpadded height and width values
===============
*/
void TexMgr_PadEdgeFixW (byte *data, int width, int height)
{
	byte *src, *dst;
	int i, padw, padh;

	padw = TexMgr_PadConditional(width);
	padh = TexMgr_PadConditional(height);

	//copy last full column to first empty column, leaving alpha byte at zero
	src = data + (width - 1) * 4;
	for (i=0; i<padh; i++)
	{
		src[4] = src[0];
		src[5] = src[1];
		src[6] = src[2];
		src += padw * 4;
	}

	//copy first full column to last empty column, leaving alpha byte at zero
	src = data;
	dst = data + (padw - 1) * 4;
	for (i=0; i<padh; i++)
	{
		dst[0] = src[0];
		dst[1] = src[1];
		dst[2] = src[2];
		src += padw * 4;
		dst += padw * 4;
	}
}

/*
===============
TexMgr_PadEdgeFixH -- special case of AlphaEdgeFix for textures that only need it because they were padded

operates in place on 32bit data, and expects unpadded height and width values
===============
*/
void TexMgr_PadEdgeFixH (byte *data, int width, int height)
{
	byte *src, *dst;
	int i, padw, padh;

	padw = TexMgr_PadConditional(width);
	padh = TexMgr_PadConditional(height);

	//copy last full row to first empty row, leaving alpha byte at zero
	dst = data + height * padw * 4;
	src = dst - padw * 4;
	for (i=0; i<padw; i++)
	{
		dst[0] = src[0];
		dst[1] = src[1];
		dst[2] = src[2];
		src += 4;
		dst += 4;
	}

	//copy first full row to last empty row, leaving alpha byte at zero
	dst = data + (padh - 1) * padw * 4;
	src = data;
	for (i=0; i<padw; i++)
	{
		dst[0] = src[0];
		dst[1] = src[1];
		dst[2] = src[2];
		src += 4;
		dst += 4;
	}
}

/*
================
TexMgr_8to32
================
*/
unsigned *TexMgr_8to32 (byte *in, int pixels, unsigned int *usepal)
{
	int i;
	unsigned *out, *data;

	out = data = Hunk_Alloc(pixels*4);

	for (i=0 ; i<pixels ; i++)
		*out++ = usepal[*in++];

	return data;
}

/*
================
TexMgr_PadImageW -- return image with width padded up to power-of-two dimentions
================
*/
byte *TexMgr_PadImageW (byte *in, int width, int height, byte padbyte)
{
	int i, j, outwidth;
	byte *out, *data;

	if (width == TexMgr_Pad(width))
		return in;

	outwidth = TexMgr_Pad(width);

	out = data = Hunk_Alloc(outwidth*height);

	for (i=0; i<height; i++)
	{
		for (j=0; j<width; j++)
			*out++ = *in++;
		for (   ; j<outwidth; j++)
			*out++ = padbyte;
	}

	return data;
}

/*
================
TexMgr_PadImageH -- return image with height padded up to power-of-two dimentions
================
*/
byte *TexMgr_PadImageH (byte *in, int width, int height, byte padbyte)
{
	int i, srcpix, dstpix;
	byte *data, *out;

	if (height == TexMgr_Pad(height))
		return in;

	srcpix = width * height;
	dstpix = width * TexMgr_Pad(height);

	out = data = Hunk_Alloc(dstpix);

	for (i=0; i<srcpix; i++)
		*out++ = *in++;
	for (   ; i<dstpix; i++)
		*out++ = padbyte;

	return data;
}

/*
================
TexMgr_LoadImage32 -- handles 32bit source data
================
*/
void TexMgr_LoadImage32 (gltexture_t *glt, unsigned *data)
{
	int	internalformat,	miplevel, mipwidth, mipheight, picmip;

	// resample up
	data = TexMgr_ResampleTexture (data, glt->width, glt->height, glt->flags & TEXPREF_ALPHA);
	glt->width = TexMgr_Pad(glt->width);
	glt->height = TexMgr_Pad(glt->height);

	// mipmap down
	picmip = (glt->flags & TEXPREF_NOPICMIP) ? 0 : max ((int)gl_picmip.value, 0);
	mipwidth = TexMgr_SafeTextureSize (glt->width >> picmip);
	mipheight = TexMgr_SafeTextureSize (glt->height >> picmip);
	while (glt->width > mipwidth)
	{
		TexMgr_MipMapW (data, glt->width, glt->height);
		glt->width >>= 1;
		if (glt->flags & TEXPREF_ALPHA)
			TexMgr_AlphaEdgeFix ((byte *)data, glt->width, glt->height);
	}
	while (glt->height > mipheight)
	{
		TexMgr_MipMapH (data, glt->width, glt->height);
		glt->height >>= 1;
		if (glt->flags & TEXPREF_ALPHA)
			TexMgr_AlphaEdgeFix ((byte *)data, glt->width, glt->height);
	}

	// upload
	GL_Bind (glt);
	internalformat = (glt->flags & TEXPREF_ALPHA) ? gl_alpha_format : gl_solid_format;
	glTexImage2D (GL_TEXTURE_2D, 0, internalformat, glt->width, glt->height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);

	// upload mipmaps
	if (glt->flags & TEXPREF_MIPMAP)
	{
		mipwidth = glt->width;
		mipheight = glt->height;

		for (miplevel=1; mipwidth > 1 || mipheight > 1; miplevel++)
		{
			if (mipwidth > 1)
			{
				TexMgr_MipMapW (data, mipwidth, mipheight);
				mipwidth >>= 1;
			}
			if (mipheight > 1)
			{
				TexMgr_MipMapH (data, mipwidth, mipheight);
				mipheight >>= 1;
			}
			glTexImage2D (GL_TEXTURE_2D, miplevel, internalformat, mipwidth, mipheight, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);
		}
	}

	// set filter modes
	TexMgr_SetFilterModes (glt);
}

/*
================
TexMgr_LoadImage8 -- handles 8bit source data, then passes it to LoadImage32
================
*/
void TexMgr_LoadImage8 (gltexture_t *glt, byte *data)
{
	extern cvar_t gl_fullbrights;
	qboolean padw = false, padh = false;
	byte padbyte;
	unsigned int *usepal;
	int i;

	// HACK HACK HACK -- taken from tomazquake
	if (strstr(glt->name, "shot1sid") && glt->width==32 && glt->height==32 && CRC_Block(data, 1024) == 65393)
	{
		// This texture in b_shell1.bsp has some of the first 32 pixels painted white.
		// They are invisible in software, but look really ugly in GL. So we just copy
		// 32 pixels from the bottom to make it look nice.
		memcpy (data, data + 32*31, 32);
	}

	// detect false alpha cases
	if (glt->flags & TEXPREF_ALPHA && !(glt->flags & TEXPREF_CONCHARS))
	{
		for (i = 0; i < glt->width*glt->height; i++)
			if (data[i] == 255) //transparent index
				break;
		if (i == glt->width*glt->height)
			glt->flags -= TEXPREF_ALPHA;
	}

	// choose palette and padbyte
	if (glt->flags & TEXPREF_FULLBRIGHT)
	{
		usepal = d_8to24table_fbright;
		padbyte = 0;
	}
	else if (glt->flags & TEXPREF_NOBRIGHT && gl_fullbrights.value)
	{
		usepal = d_8to24table_nobright;
		padbyte = 0;
	}
	else if (glt->flags & TEXPREF_CONCHARS)
	{
		usepal = d_8to24table_conchars;
		padbyte = 0;
	}
	else
	{
		usepal = d_8to24table;
		padbyte = 255;
	}

	// pad each dimention, but only if it's not going to be downsampled later
	if (glt->flags & TEXPREF_PAD)
	{
		if (glt->width < TexMgr_SafeTextureSize(glt->width))
		{
			data = TexMgr_PadImageW (data, glt->width, glt->height, padbyte);
			glt->width = TexMgr_Pad(glt->width);
			padw = true;
		}
		if (glt->height < TexMgr_SafeTextureSize(glt->height))
		{
			data = TexMgr_PadImageH (data, glt->width, glt->height, padbyte);
			glt->height = TexMgr_Pad(glt->height);
			padh = true;
		}
	}

	// convert to 32bit
	data = (byte *)TexMgr_8to32(data, glt->width * glt->height, usepal);

	// fix edges
	if (glt->flags & TEXPREF_ALPHA)
		TexMgr_AlphaEdgeFix (data, glt->width, glt->height);
	else
	{
		if (padw)
			TexMgr_PadEdgeFixW (data, glt->source_width, glt->source_height);
		if (padh)
			TexMgr_PadEdgeFixH (data, glt->source_width, glt->source_height);
	}

	// upload it
	TexMgr_LoadImage32 (glt, (unsigned *)data);
}

/*
================
TexMgr_LoadLightmap -- handles lightmap data
================
*/
void TexMgr_LoadLightmap (gltexture_t *glt, byte *data)
{
	extern int gl_lightmap_format, lightmap_bytes;

	// upload it
	GL_Bind (glt);
	glTexImage2D (GL_TEXTURE_2D, 0, lightmap_bytes, glt->width, glt->height, 0, gl_lightmap_format, GL_UNSIGNED_BYTE, data);

	// set filter modes
	TexMgr_SetFilterModes (glt);
}

/*
================
TexMgr_LoadImage -- the one entry point for loading all textures
================
*/
gltexture_t *TexMgr_LoadImage (model_t *owner, char *name, int width, int height, enum srcformat format,
			       byte *data, char *source_file, src_offset_t source_offset, unsigned flags)
{
	extern int lightmap_bytes;
	unsigned short crc;
	gltexture_t *glt;
	int mark;

	if (isDedicated)
		return NULL;

	// cache check
	switch (format)
	{
		case SRC_INDEXED:
			crc = CRC_Block(data, width * height);
			break;
		case SRC_LIGHTMAP:
			crc = CRC_Block(data, width * height * lightmap_bytes);
			break;
		case SRC_RGBA:
			crc = CRC_Block(data, width * height * 4);
			break;
	}
	if ((flags & TEXPREF_OVERWRITE) && (glt = TexMgr_FindTexture (owner, name)))
	{
		if (glt->source_crc == crc)
			return glt;
	}
	else
		glt = TexMgr_NewTexture ();

	// copy data
	glt->owner = owner;
	strncpy (glt->name, name, sizeof(glt->name));
	glt->width = width;
	glt->height = height;
	glt->flags = flags;
	glt->shirt = -1;
	glt->pants = -1;
	strncpy (glt->source_file, source_file, sizeof(glt->source_file));
	glt->source_offset = source_offset;
	glt->source_format = format;
	glt->source_width = width;
	glt->source_height = height;
	glt->source_crc = crc;

	//upload it
	mark = Hunk_LowMark();

	switch (glt->source_format)
	{
		case SRC_INDEXED:
			TexMgr_LoadImage8 (glt, data);
			break;
		case SRC_LIGHTMAP:
			TexMgr_LoadLightmap (glt, data);
			break;
		case SRC_RGBA:
			TexMgr_LoadImage32 (glt, (unsigned *)data);
			break;
	}

	Hunk_FreeToLowMark(mark);

	return glt;
}

/*
================================================================================

	COLORMAPPING AND TEXTURE RELOADING

================================================================================
*/

/*
================
TexMgr_ReloadImage -- reloads a texture, and colormaps it if needed
================
*/
void TexMgr_ReloadImage (gltexture_t *glt, int shirt, int pants)
{
	byte	translation[256];
	byte	*src, *dst, *data = NULL, *translated;
	int		mark, size, i;
//
// get source data
//
	mark = Hunk_LowMark ();

	if (glt->source_file[0] && glt->source_offset)
	{
		//lump inside file
		data = COM_LoadHunkFile (glt->source_file);
		if (!data)
			goto invalid;
		data += glt->source_offset;
	}
	else if (glt->source_file[0] && !glt->source_offset)
		data = Image_LoadImage (glt->source_file, (int *)&glt->source_width, (int *)&glt->source_height); //simple file
	else if (!glt->source_file[0] && glt->source_offset)
		data = (byte *) glt->source_offset; //image in memory

	if (!data)
	{
invalid:
		Con_Printf ("TexMgr_ReloadImage: invalid source for %s\n", glt->name);
		Hunk_FreeToLowMark(mark);
		return;
	}

	glt->width = glt->source_width;
	glt->height = glt->source_height;
//
// apply shirt and pants colors
//
// if shirt and pants are -1,-1, use existing shirt and pants colors
// if existing shirt and pants colors are -1,-1, don't bother colormapping
	if (shirt > -1 && pants > -1)
	{
		if (glt->source_format == SRC_INDEXED)
		{
			glt->shirt = shirt;
			glt->pants = pants;
		}
		else
			Con_Printf ("TexMgr_ReloadImage: can't colormap a non SRC_INDEXED texture: %s\n", glt->name);
	}
	if (glt->shirt > -1 && glt->pants > -1)
	{
		//create new translation table
		for (i=0 ; i<256 ; i++)
			translation[i] = i;

		shirt = glt->shirt * 16;
		if (shirt < 128)
			for (i=0 ; i<16 ; i++)
				translation[TOP_RANGE+i] = shirt+i;
		else
			for (i=0 ; i<16 ; i++)
				translation[TOP_RANGE+i] = shirt+15-i;

		pants = glt->pants * 16;
		if (pants < 128)
			for (i=0 ; i<16 ; i++)
				translation[BOTTOM_RANGE+i] = pants+i;
		else
			for (i=0 ; i<16 ; i++)
				translation[BOTTOM_RANGE+i] = pants+15-i;

		//translate texture
		size = glt->width * glt->height;
		dst = translated = Hunk_Alloc (size);
		src = data;

		for (i=0; i<size; i++)
			*dst++ = translation[*src++];

		data = translated;
	}
//
// upload it
//
	switch (glt->source_format)
	{
		case SRC_INDEXED:
			TexMgr_LoadImage8 (glt, data);
			break;
		case SRC_LIGHTMAP:
			TexMgr_LoadLightmap (glt, data);
			break;
		case SRC_RGBA:
			TexMgr_LoadImage32 (glt, (unsigned *)data);
			break;
	}

	Hunk_FreeToLowMark(mark);
}

/*
================
TexMgr_ReloadImages -- reloads all texture images. called only by vid_restart
================
*/
void TexMgr_ReloadImages (void)
{
	gltexture_t *glt;

	for (glt=active_gltextures; glt; glt=glt->next)
	{
		glGenTextures(1, (GLuint *)&glt->texnum);
		TexMgr_ReloadImage (glt, -1, -1);
	}
}

/*
================
TexMgr_ReloadNobrightImages -- reloads all texture that were loaded with the nobright palette.  called when gl_fullbrights changes
================
*/
void TexMgr_ReloadNobrightImages (void)
{
	gltexture_t *glt;

	for (glt=active_gltextures; glt; glt=glt->next)
		if (glt->flags & TEXPREF_NOBRIGHT)
			TexMgr_ReloadImage(glt, -1, -1);
}

/*
================================================================================

	TEXTURE BINDING / TEXTURE UNIT SWITCHING

================================================================================
*/

int	currenttexture = -1; // to avoid unnecessary texture sets
GLenum TEXTURE0, TEXTURE1; //johnfitz
qboolean mtexenabled = false;

/*
================
GL_SelectTexture -- johnfitz -- rewritten
================
*/
void GL_SelectTexture (GLenum target)
{
	static GLenum currenttarget;
	static int ct0, ct1;

	if (target == currenttarget)
		return;

	GL_SelectTextureFunc(target);

	if (target == TEXTURE0)
	{
		ct1 = currenttexture;
		currenttexture = ct0;
	}
	else //target == TEXTURE1
	{
		ct0 = currenttexture;
		currenttexture = ct1;
	}

	currenttarget = target;
}

/*
================
GL_DisableMultitexture -- selects texture unit 0
================
*/
void GL_DisableMultitexture(void)
{
	if (mtexenabled)
	{
		glDisable(GL_TEXTURE_2D);
		GL_SelectTexture(TEXTURE0); //johnfitz -- no longer SGIS specific
		mtexenabled = false;
	}
}

/*
================
GL_EnableMultitexture -- selects texture unit 1
================
*/
void GL_EnableMultitexture(void)
{
	if (gl_mtexable)
	{
		GL_SelectTexture(TEXTURE1); //johnfitz -- no longer SGIS specific
		glEnable(GL_TEXTURE_2D);
		mtexenabled = true;
	}
}

/*
================
GL_Bind -- johnfitz -- heavy revision
================
*/
void GL_Bind (gltexture_t *texture)
{
	if (!texture)
		texture = nulltexture;

	if (texture->texnum != currenttexture)
	{
		currenttexture = texture->texnum;
		glBindTexture (GL_TEXTURE_2D, currenttexture);
		texture->visframe = r_framecount;
	}
}