/*
Copyright (C) 1996-1997 Id Software, Inc.

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.

*/
// r_main.c

#include "quakedef.h"

entity_t	r_worldentity;

qboolean	r_cache_thrash;		// compatability

vec3_t		modelorg, r_entorigin;
entity_t	*currententity;

int			r_visframecount;	// bumped when going to a new PVS
int			r_framecount;		// used for dlight push checking

mplane_t	frustum[4];

int			c_brush_polys, c_alias_polys;

qboolean	envmap;				// true during envmap command capture

int			currenttexture = -1;		// to avoid unnecessary texture sets

int			cnttextures[2] = {-1, -1};     // cached

int			particletexture;	// little dot for particles
int			playertextures;		// up to 16 color translated skins

int			mirrortexturenum;	// quake texturenum, not gltexturenum
qboolean	mirror;
mplane_t	*mirror_plane;

//
// view origin
//
vec3_t	vup;
vec3_t	vpn;
vec3_t	vright;
vec3_t	r_origin;

float	r_world_matrix[16];
float	r_base_world_matrix[16];

//
// screen size info
//
refdef_t	r_refdef;

mleaf_t		*r_viewleaf, *r_oldviewleaf;

texture_t	*r_notexture_mip;

int		d_lightstylevalue[256];	// 8.8 fraction of base light value


void R_MarkLeaves (void);

cvar_t	r_norefresh = CVAR2("r_norefresh","0");
cvar_t	r_drawentities = CVAR2("r_drawentities","1");
cvar_t	r_drawviewmodel = CVAR2("r_drawviewmodel","1");
cvar_t	r_speeds = CVAR2("r_speeds","0");
cvar_t	r_fullbright = CVAR2("r_fullbright","0");
cvar_t	r_lightmap = CVAR2("r_lightmap","0");
cvar_t	r_shadows = CVAR2("r_shadows","0");
cvar_t	r_mirroralpha = CVAR2("r_mirroralpha","1");
cvar_t	r_wateralpha = CVAR2("r_wateralpha","1");
cvar_t	r_dynamic = CVAR2("r_dynamic","1");
cvar_t	r_novis = CVAR2("r_novis","0");

cvar_t	gl_finish = CVAR2("gl_finish","0");
cvar_t	gl_clear = CVAR2("gl_clear","0");
cvar_t	gl_cull = CVAR2("gl_cull","1");
cvar_t	gl_texsort = CVAR2("gl_texsort","1");
cvar_t	gl_smoothmodels = CVAR2("gl_smoothmodels","1");
cvar_t	gl_affinemodels = CVAR2("gl_affinemodels","1");
cvar_t	gl_polyblend = CVAR2("gl_polyblend","1");
cvar_t	gl_flashblend = CVAR2("gl_flashblend","1");
cvar_t	gl_playermip = CVAR2("gl_playermip","0");
cvar_t	gl_nocolors = CVAR2("gl_nocolors","0");
cvar_t	gl_keeptjunctions = CVAR2("gl_keeptjunctions","1");
cvar_t	gl_reporttjunctions = CVAR2("gl_reporttjunctions","0");
cvar_t	gl_doubleeyes = CVAR2("gl_doubleeys", "1");

extern	cvar_t	gl_ztrick;

/*
=================
R_CullBox

Returns true if the box is completely outside the frustom
=================
*/
qboolean R_CullBox (vec3_t mins, vec3_t maxs)
{
	int		i;

	for (i=0 ; i<4 ; i++)
		if (BoxOnPlaneSide (mins, maxs, &frustum[i]) == 2)
			return true;
	return false;
}


void R_RotateForEntity (entity_t *e)
{
    glTranslatef (e->origin[0],  e->origin[1],  e->origin[2]);

    glRotatef (e->angles[1],  0, 0, 1);
    glRotatef (-e->angles[0],  0, 1, 0);
    glRotatef (e->angles[2],  1, 0, 0);
}

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

  SPRITE MODELS

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

/*
================
R_GetSpriteFrame
================
*/
mspriteframe_t *R_GetSpriteFrame (entity_t *currententity)
{
	msprite_t		*psprite;
	mspritegroup_t	*pspritegroup;
	mspriteframe_t	*pspriteframe;
	int				i, numframes, frame;
	float			*pintervals, fullinterval, targettime, time;

	psprite = (msprite_t*) currententity->model->cache.data;
	frame = currententity->frame;

	if ((frame >= psprite->numframes) || (frame < 0))
	{
		Con_Printf ("R_DrawSprite: no such frame %d\n", frame);
		frame = 0;
	}

	if (psprite->frames[frame].type == SPR_SINGLE)
	{
		pspriteframe = psprite->frames[frame].frameptr;
	}
	else
	{
		pspritegroup = (mspritegroup_t *)psprite->frames[frame].frameptr;
		pintervals = pspritegroup->intervals;
		numframes = pspritegroup->numframes;
		fullinterval = pintervals[numframes-1];

		time = cl.time + currententity->syncbase;

	// when loading in Mod_LoadSpriteGroup, we guaranteed all interval values
	// are positive, so we don't have to worry about division by 0
		targettime = time - ((int)(time / fullinterval)) * fullinterval;

		for (i=0 ; i<(numframes-1) ; i++)
		{
			if (pintervals[i] > targettime)
				break;
		}

		pspriteframe = pspritegroup->frames[i];
	}

	return pspriteframe;
}


/*
=================
R_DrawSpriteModel

=================
*/
void R_DrawSpriteModel (entity_t *e)
{
	vec3_t	point;
	mspriteframe_t	*frame;
	float		*up, *right;
	vec3_t		v_forward, v_right, v_up;
	msprite_t		*psprite;

	// don't even bother culling, because it's just a single
	// polygon without a surface cache
	frame = R_GetSpriteFrame (e);
	psprite = (msprite_t*) currententity->model->cache.data;

	if (psprite->type == SPR_ORIENTED)
	{	// bullet marks on walls
		AngleVectors (currententity->angles, v_forward, v_right, v_up);
		up = v_up;
		right = v_right;
	}
	else
	{	// normal sprite
		up = vup;
		right = vright;
	}

	glColor3f (1,1,1);

	GL_DisableMultitexture();

    GL_Bind(frame->gl_texturenum);

	glEnable (GL_ALPHA_TEST);

#ifdef USE_OPENGLES

	{
	    float* pPoint = gVertexBuffer;
	    float texCoords[] = {
			0, 1,
			0, 0,
			1, 0,
			1, 1
		};

		VectorMA (e->origin, frame->down, up, point);
		VectorMA (point, frame->left, right, pPoint);
		pPoint += 3;

		VectorMA (e->origin, frame->up, up, point);
		VectorMA (point, frame->left, right, pPoint);
		pPoint += 3;

		VectorMA (e->origin, frame->up, up, point);
		VectorMA (point, frame->right, right, pPoint);
		pPoint += 3;

		VectorMA (e->origin, frame->down, up, point);
		VectorMA (point, frame->right, right, pPoint);

		glVertexPointer(3, GL_FLOAT, 0, gVertexBuffer);
		glTexCoordPointer(2, GL_FLOAT, 0, texCoords);
		glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
	}

#else
	glBegin (GL_QUADS);

	glTexCoord2f (0, 1);
	VectorMA (e->origin, frame->down, up, point);
	VectorMA (point, frame->left, right, point);
	glVertex3fv (point);

	glTexCoord2f (0, 0);
	VectorMA (e->origin, frame->up, up, point);
	VectorMA (point, frame->left, right, point);
	glVertex3fv (point);

	glTexCoord2f (1, 0);
	VectorMA (e->origin, frame->up, up, point);
	VectorMA (point, frame->right, right, point);
	glVertex3fv (point);

	glTexCoord2f (1, 1);
	VectorMA (e->origin, frame->down, up, point);
	VectorMA (point, frame->right, right, point);
	glVertex3fv (point);

	glEnd ();
#endif

	glDisable (GL_ALPHA_TEST);
}

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

  ALIAS MODELS

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


#define NUMVERTEXNORMALS	162

float	r_avertexnormals[NUMVERTEXNORMALS][3] = {
#include "anorms.h"
};

vec3_t	shadevector;
float	shadelight, ambientlight;

// precalculated dot products for quantized angles
#define SHADEDOT_QUANT 16
float	r_avertexnormal_dots[SHADEDOT_QUANT][256] =
#include "anorm_dots.h"
;

float	*shadedots = r_avertexnormal_dots[0];

int	lastposenum;

/*
=============
GL_DrawAliasFrame
=============
*/
void GL_DrawAliasFrame (aliashdr_t *paliashdr, int posenum)
{
	float	s, t;
	float 	l;
	int		i, j;
	int		index;
	trivertx_t	*v, *verts;
	int		list;
	int		*order;
	vec3_t	point;
	float	*normal;
	int		count;

#ifdef USE_OPENGLES
	glEnableClientState(GL_COLOR_ARRAY);
#endif

lastposenum = posenum;

	verts = (trivertx_t *)((byte *)paliashdr + paliashdr->posedata);
	verts += posenum * paliashdr->poseverts;
	order = (int *)((byte *)paliashdr + paliashdr->commands);

	while (1)
	{
		// get the vertex count and primitive type
		count = *order++;
		if (!count)
			break;		// done

#ifdef USE_OPENGLES
		{
			int primType;
			int c;
			float* pColor;
			float* pTexCoord;
			float* pPos;

			if (count < 0)
			{
				count = -count;
				primType = GL_TRIANGLE_FAN;
			}
			else
				primType = GL_TRIANGLE_STRIP;

			// texture coordinates come from the draw list
			glTexCoordPointer(2, GL_FLOAT, 0, gTexCoordBuffer);
			glVertexPointer(3, GL_FLOAT, 0, gVertexBuffer);
			glColorPointer(4, GL_FLOAT, 0, gColorBuffer);

			pColor = gColorBuffer;
			pPos = gVertexBuffer;
			pTexCoord = gTexCoordBuffer;
			c = count;
			do
			{
				// texture coordinates come from the draw list
				*pTexCoord++ = ((float *)order)[0];
				*pTexCoord++ = ((float *)order)[1];
				order += 2;

				// normals and vertexes come from the frame list
				l = shadedots[verts->lightnormalindex] * shadelight;
				*pColor++ = l;
				*pColor++ = l;
				*pColor++ = l;
				*pColor++ = 1.0f;
				*pPos++ = verts->v[0];
				*pPos++ = verts->v[1];
				*pPos++ = verts->v[2];
				verts++;
		    } while (--c);

			glDrawArrays(primType, 0, count);
		}

#else
		if (count < 0)
		{
			count = -count;
			glBegin (GL_TRIANGLE_FAN);
		}
		else
			glBegin (GL_TRIANGLE_STRIP);

		do
		{
			// texture coordinates come from the draw list
			glTexCoord2f (((float *)order)[0], ((float *)order)[1]);
			order += 2;

			// normals and vertexes come from the frame list
			l = shadedots[verts->lightnormalindex] * shadelight;
			glColor3f (l, l, l);
			glVertex3f (verts->v[0], verts->v[1], verts->v[2]);
			verts++;
		} while (--count);

		glEnd ();
#endif
	}

#ifdef USE_OPENGLES
	glDisableClientState(GL_COLOR_ARRAY);
#endif

}


/*
=============
GL_DrawAliasShadow
=============
*/
extern	vec3_t			lightspot;

void GL_DrawAliasShadow (aliashdr_t *paliashdr, int posenum)
{
	float	s, t, l;
	int		i, j;
	int		index;
	trivertx_t	*v, *verts;
	int		list;
	int		*order;
	vec3_t	point;
	float	*normal;
	float	height, lheight;
	int		count;

	lheight = currententity->origin[2] - lightspot[2];

	height = 0;
	verts = (trivertx_t *)((byte *)paliashdr + paliashdr->posedata);
	verts += posenum * paliashdr->poseverts;
	order = (int *)((byte *)paliashdr + paliashdr->commands);

	height = -lheight + 1.0;

	while (1)
	{
		// get the vertex count and primitive type
		count = *order++;
		if (!count)
			break;		// done

#ifdef USE_OPENGLES

		{
			int primType;
			int c;
			float* pVertex;

			if (count < 0)
			{
				count = -count;
				primType = GL_TRIANGLE_FAN;
			}
			else
				primType = GL_TRIANGLE_STRIP;

			pVertex = gVertexBuffer;
			for(c = 0; c < count; c++)
			{
				// texture coordinates come from the draw list
				// (skipped for shadows) glTexCoord2fv ((float *)order);
				order += 2;

				// normals and vertexes come from the frame list
				pVertex[0] = verts->v[0] * paliashdr->scale[0] + paliashdr->scale_origin[0];
				pVertex[1] = verts->v[1] * paliashdr->scale[1] + paliashdr->scale_origin[1];
				pVertex[2] = verts->v[2] * paliashdr->scale[2] + paliashdr->scale_origin[2];

				pVertex[0] -= shadevector[0]*(pVertex[2]+lheight);
				pVertex[1] -= shadevector[1]*(pVertex[2]+lheight);
				pVertex[2] = height;
	//			height -= 0.001;

				pVertex += 3;
				verts++;
			}

			glVertexPointer(3, GL_FLOAT, 0, gVertexBuffer);
			glDisableClientState(GL_TEXTURE_COORD_ARRAY);
			glDrawArrays(primType, 0, count);
			glEnableClientState(GL_TEXTURE_COORD_ARRAY);
		}

#else

		if (count < 0)
		{
			count = -count;
			glBegin (GL_TRIANGLE_FAN);
		}
		else
			glBegin (GL_TRIANGLE_STRIP);

		do
		{
			// texture coordinates come from the draw list
			// (skipped for shadows) glTexCoord2fv ((float *)order);
			order += 2;

			// normals and vertexes come from the frame list
			point[0] = verts->v[0] * paliashdr->scale[0] + paliashdr->scale_origin[0];
			point[1] = verts->v[1] * paliashdr->scale[1] + paliashdr->scale_origin[1];
			point[2] = verts->v[2] * paliashdr->scale[2] + paliashdr->scale_origin[2];

			point[0] -= shadevector[0]*(point[2]+lheight);
			point[1] -= shadevector[1]*(point[2]+lheight);
			point[2] = height;
//			height -= 0.001;
			glVertex3fv (point);

			verts++;
		} while (--count);

		glEnd ();

#endif

	}
}


/*
=================
R_SetupAliasFrame

=================
*/
void R_SetupAliasFrame (int frame, aliashdr_t *paliashdr)
{
	int				pose, numposes;
	float			interval;

	if ((frame >= paliashdr->numframes) || (frame < 0))
	{
		Con_DPrintf ("R_AliasSetupFrame: no such frame %d\n", frame);
		frame = 0;
	}

	pose = paliashdr->frames[frame].firstpose;
	numposes = paliashdr->frames[frame].numposes;

	if (numposes > 1)
	{
		interval = paliashdr->frames[frame].interval;
		pose += (int)(cl.time / interval) % numposes;
	}

	GL_DrawAliasFrame (paliashdr, pose);
}


/*
=================
R_DrawAliasModel

=================
*/
void R_DrawAliasModel (entity_t *e)
{
	int			i, j;
	int			lnum;
	vec3_t		dist;
	float		add;
	model_t		*clmodel;
	vec3_t		mins, maxs;
	aliashdr_t	*paliashdr;
	trivertx_t	*verts, *v;
	int			index;
	float		s, t, an;
	int			anim;

	clmodel = currententity->model;

	VectorAdd (currententity->origin, clmodel->mins, mins);
	VectorAdd (currententity->origin, clmodel->maxs, maxs);

	if (R_CullBox (mins, maxs))
		return;


	VectorCopy (currententity->origin, r_entorigin);
	VectorSubtract (r_origin, r_entorigin, modelorg);

	//
	// get lighting information
	//

	ambientlight = shadelight = R_LightPoint (currententity->origin);

	// allways give the gun some light
	if (e == &cl.viewent && ambientlight < 24)
		ambientlight = shadelight = 24;

	for (lnum=0 ; lnum<MAX_DLIGHTS ; lnum++)
	{
		if (cl_dlights[lnum].die >= cl.time)
		{
			VectorSubtract (currententity->origin,
							cl_dlights[lnum].origin,
							dist);
			add = cl_dlights[lnum].radius - Length(dist);

			if (add > 0) {
				ambientlight += add;
				//ZOID models should be affected by dlights as well
				shadelight += add;
			}
		}
	}

	// clamp lighting so it doesn't overbright as much
	if (ambientlight > 128)
		ambientlight = 128;
	if (ambientlight + shadelight > 192)
		shadelight = 192 - ambientlight;

	// ZOID: never allow players to go totally black
	i = currententity - cl_entities;
	if (i >= 1 && i<=cl.maxclients /* && !strcmp (currententity->model->name, "progs/player.mdl") */)
		if (ambientlight < 8)
			ambientlight = shadelight = 8;

	// HACK HACK HACK -- no fullbright colors, so make torches full light
	if (!strcmp (clmodel->name, "progs/flame2.mdl")
		|| !strcmp (clmodel->name, "progs/flame.mdl") )
		ambientlight = shadelight = 256;

	shadedots = r_avertexnormal_dots[((int)(e->angles[1] * (SHADEDOT_QUANT / 360.0))) & (SHADEDOT_QUANT - 1)];
	shadelight = shadelight / 200.0;

	an = e->angles[1]/180*M_PI;
	shadevector[0] = cos(-an);
	shadevector[1] = sin(-an);
	shadevector[2] = 1;
	VectorNormalize (shadevector);

	//
	// locate the proper data
	//
	paliashdr = (aliashdr_t *)Mod_Extradata (currententity->model);

	c_alias_polys += paliashdr->numtris;

	//
	// draw all the triangles
	//

	GL_DisableMultitexture();

    glPushMatrix ();
	R_RotateForEntity (e);

	if (!strcmp (clmodel->name, "progs/eyes.mdl") && gl_doubleeyes.value) {
		glTranslatef (paliashdr->scale_origin[0], paliashdr->scale_origin[1], paliashdr->scale_origin[2] - (22 + 8));
// double size of eyes, since they are really hard to see in gl
		glScalef (paliashdr->scale[0]*2, paliashdr->scale[1]*2, paliashdr->scale[2]*2);
	} else {
		glTranslatef (paliashdr->scale_origin[0], paliashdr->scale_origin[1], paliashdr->scale_origin[2]);
		glScalef (paliashdr->scale[0], paliashdr->scale[1], paliashdr->scale[2]);
	}

	anim = (int)(cl.time*10) & 3;
    GL_Bind(paliashdr->gl_texturenum[currententity->skinnum][anim]);

	// we can't dynamically colormap textures, so they are cached
	// seperately for the players.  Heads are just uncolored.
	if (currententity->colormap != vid.colormap && !gl_nocolors.value)
	{
		i = currententity - cl_entities;
		if (i >= 1 && i<=cl.maxclients /* && !strcmp (currententity->model->name, "progs/player.mdl") */)
		    GL_Bind(playertextures - 1 + i);
	}

	if (gl_smoothmodels.value)
		glShadeModel (GL_SMOOTH);
	glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

	if (gl_affinemodels.value)
		glHint (GL_PERSPECTIVE_CORRECTION_HINT, GL_FASTEST);

	R_SetupAliasFrame (currententity->frame, paliashdr);

	glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);

	glShadeModel (GL_FLAT);
	if (gl_affinemodels.value)
		glHint (GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);

	glPopMatrix ();

	if (r_shadows.value)
	{
		glPushMatrix ();
		R_RotateForEntity (e);
		glDisable (GL_TEXTURE_2D);
		glEnable (GL_BLEND);
		glColor4f (0,0,0,0.5);
		GL_DrawAliasShadow (paliashdr, lastposenum);
		glEnable (GL_TEXTURE_2D);
		glDisable (GL_BLEND);
		glColor4f (1,1,1,1);
		glPopMatrix ();
	}

}

//==================================================================================

/*
=============
R_DrawEntitiesOnList
=============
*/
void R_DrawEntitiesOnList (void)
{
	int		i;

	if (!r_drawentities.value)
		return;

	// draw sprites seperately, because of alpha blending
	for (i=0 ; i<cl_numvisedicts ; i++)
	{
		currententity = cl_visedicts[i];

		switch (currententity->model->type)
		{
		case mod_alias:
			R_DrawAliasModel (currententity);
			break;

		case mod_brush:
			R_DrawBrushModel (currententity);
			break;

		default:
			break;
		}
	}

	for (i=0 ; i<cl_numvisedicts ; i++)
	{
		currententity = cl_visedicts[i];

		switch (currententity->model->type)
		{
		case mod_sprite:
			R_DrawSpriteModel (currententity);
			break;

		default :
			break;
		}
	}
}

/*
=============
R_DrawViewModel
=============
*/
void R_DrawViewModel (void)
{
	float		ambient[4], diffuse[4];
	int			j;
	int			lnum;
	vec3_t		dist;
	float		add;
	dlight_t	*dl;
	int			ambientlight, shadelight;

	if (!r_drawviewmodel.value)
		return;

	if (chase_active.value)
		return;

	if (envmap)
		return;

	if (!r_drawentities.value)
		return;

	if (cl.items & IT_INVISIBILITY)
		return;

	if (cl.stats[STAT_HEALTH] <= 0)
		return;

	currententity = &cl.viewent;
	if (!currententity->model)
		return;

	j = R_LightPoint (currententity->origin);

	if (j < 24)
		j = 24;		// allways give some light on gun
	ambientlight = j;
	shadelight = j;

// add dynamic lights
	for (lnum=0 ; lnum<MAX_DLIGHTS ; lnum++)
	{
		dl = &cl_dlights[lnum];
		if (!dl->radius)
			continue;
		if (!dl->radius)
			continue;
		if (dl->die < cl.time)
			continue;

		VectorSubtract (currententity->origin, dl->origin, dist);
		add = dl->radius - Length(dist);
		if (add > 0)
			ambientlight += (int) add;
	}

	ambient[0] = ambient[1] = ambient[2] = ambient[3] = (float)ambientlight / 128;
	diffuse[0] = diffuse[1] = diffuse[2] = diffuse[3] = (float)shadelight / 128;

	// hack the depth range to prevent view model from poking into walls
#ifdef USE_OPENGLES
	glDepthRangef(gldepthmin, gldepthmin + 0.3f*(gldepthmax-gldepthmin));
	R_DrawAliasModel (currententity);
	glDepthRangef(gldepthmin, gldepthmax);
#else
	glDepthRange (gldepthmin, gldepthmin + 0.3*(gldepthmax-gldepthmin));
	R_DrawAliasModel (currententity);
	glDepthRange (gldepthmin, gldepthmax);
#endif
}


/*
============
R_PolyBlend
============
*/
void R_PolyBlend (void)
{
	if (!gl_polyblend.value)
		return;
	if (!v_blend[3])
		return;

	GL_DisableMultitexture();

	glDisable (GL_ALPHA_TEST);
	glEnable (GL_BLEND);
	glDisable (GL_DEPTH_TEST);
	glDisable (GL_TEXTURE_2D);

    glLoadIdentity ();

    glRotatef (-90,  1, 0, 0);	    // put Z going up
    glRotatef (90,  0, 0, 1);	    // put Z going up

	glColor4fv (v_blend);

#ifdef USE_OPENGLES
	float vertex[3*4] = {
		10, 100, 100,
		10, -100, 100,
		10, -100, -100,
		10, 100, -100
	};
	glDisableClientState(GL_TEXTURE_COORD_ARRAY);
	glVertexPointer( 3, GL_FLOAT, 0, vertex);
	glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
	glEnableClientState(GL_TEXTURE_COORD_ARRAY);
#else
	glBegin (GL_QUADS);

	glVertex3f (10, 100, 100);
	glVertex3f (10, -100, 100);
	glVertex3f (10, -100, -100);
	glVertex3f (10, 100, -100);
	glEnd ();
#endif

	glDisable (GL_BLEND);
	glEnable (GL_TEXTURE_2D);
	glEnable (GL_ALPHA_TEST);
}


int SignbitsForPlane (mplane_t *out)
{
	int	bits, j;

	// for fast box on planeside test

	bits = 0;
	for (j=0 ; j<3 ; j++)
	{
		if (out->normal[j] < 0)
			bits |= 1<<j;
	}
	return bits;
}


void R_SetFrustum (void)
{
	int		i;

	if (r_refdef.fov_x == 90)
	{
		// front side is visible

		VectorAdd (vpn, vright, frustum[0].normal);
		VectorSubtract (vpn, vright, frustum[1].normal);

		VectorAdd (vpn, vup, frustum[2].normal);
		VectorSubtract (vpn, vup, frustum[3].normal);
	}
	else
	{
		// rotate VPN right by FOV_X/2 degrees
		RotatePointAroundVector( frustum[0].normal, vup, vpn, -(90-r_refdef.fov_x / 2 ) );
		// rotate VPN left by FOV_X/2 degrees
		RotatePointAroundVector( frustum[1].normal, vup, vpn, 90-r_refdef.fov_x / 2 );
		// rotate VPN up by FOV_X/2 degrees
		RotatePointAroundVector( frustum[2].normal, vright, vpn, 90-r_refdef.fov_y / 2 );
		// rotate VPN down by FOV_X/2 degrees
		RotatePointAroundVector( frustum[3].normal, vright, vpn, -( 90 - r_refdef.fov_y / 2 ) );
	}

	for (i=0 ; i<4 ; i++)
	{
		frustum[i].type = PLANE_ANYZ;
		frustum[i].dist = DotProduct (r_origin, frustum[i].normal);
		frustum[i].signbits = SignbitsForPlane (&frustum[i]);
	}
}


/*
===============
R_SetupFrame
===============
*/
void R_SetupFrame (void)
{
	int				edgecount;
	vrect_t			vrect;
	float			w, h;

// don't allow cheats in multiplayer
	if (cl.maxclients > 1)
		Cvar_Set ("r_fullbright", "0");

	R_AnimateLight ();

	r_framecount++;

// build the transformation matrix for the given view angles
	VectorCopy (r_refdef.vieworg, r_origin);

	AngleVectors (r_refdef.viewangles, vpn, vright, vup);

// current viewleaf
	r_oldviewleaf = r_viewleaf;
	r_viewleaf = Mod_PointInLeaf (r_origin, cl.worldmodel);

	V_SetContentsColor (r_viewleaf->contents);
	V_CalcBlend ();

	r_cache_thrash = false;

	c_brush_polys = 0;
	c_alias_polys = 0;

}

#ifdef USE_OPENGLES

void MYgluPerspective( float fovy, float aspect,
		     float zNear, float zFar )
{
   float xmin, xmax, ymin, ymax;

   ymax = zNear * tan( fovy * M_PI / 360.0f );
   ymin = -ymax;

   xmin = ymin * aspect;
   xmax = ymax * aspect;

   glFrustumf( xmin, xmax, ymin, ymax, zNear, zFar );
}

#else

void MYgluPerspective( GLdouble fovy, GLdouble aspect,
		     GLdouble zNear, GLdouble zFar )
{
   GLdouble xmin, xmax, ymin, ymax;

   ymax = zNear * tan( fovy * M_PI / 360.0 );
   ymin = -ymax;

   xmin = ymin * aspect;
   xmax = ymax * aspect;

   glFrustum( xmin, xmax, ymin, ymax, zNear, zFar );
}
#endif

#define DO_OWN_MATRIX_MATH
#ifdef DO_OWN_MATRIX_MATH
// We can't count on being able to read back the model view matrix, so calculate it ourselves.

#define I(_i, _j) ((_j)+ 4*(_i))

void mulMM(float* r, const float* lhs, const float* rhs)
{
    float const* const m = lhs;
    for (int i=0 ; i<4 ; i++) {
        register const float rhs_i0 = rhs[ I(i,0) ];
        register float ri0 = m[ I(0,0) ] * rhs_i0;
        register float ri1 = m[ I(0,1) ] * rhs_i0;
        register float ri2 = m[ I(0,2) ] * rhs_i0;
        register float ri3 = m[ I(0,3) ] * rhs_i0;
        for (int j=1 ; j<4 ; j++) {
            register const float rhs_ij = rhs[ I(i,j) ];
            ri0 += m[ I(j,0) ] * rhs_ij;
            ri1 += m[ I(j,1) ] * rhs_ij;
            ri2 += m[ I(j,2) ] * rhs_ij;
            ri3 += m[ I(j,3) ] * rhs_ij;
        }
        r[ I(i,0) ] = ri0;
        r[ I(i,1) ] = ri1;
        r[ I(i,2) ] = ri2;
        r[ I(i,3) ] = ri3;
    }
}

static void setIdentityM(float* sm, int smOffset) {
    for (int i=0 ; i<16 ; i++) {
        sm[smOffset + i] = 0;
    }
    for(int i = 0; i < 16; i += 5) {
        sm[smOffset + i] = 1.0f;
    }
}

static void translateM(float* m, int mOffset,
        float x, float y, float z) {
    for (int i=0 ; i<4 ; i++) {
        int mi = mOffset + i;
        m[12 + mi] += m[mi] * x + m[4 + mi] * y + m[8 + mi] * z;
    }
}

static float length(float x, float y, float z) {
	return (float) sqrtf(x * x + y * y + z * z);
}

static void setRotateM(float* rm, int rmOffset,
            float a, float x, float y, float z)
{
    rm[rmOffset + 3] = 0;
    rm[rmOffset + 7] = 0;
    rm[rmOffset + 11]= 0;
    rm[rmOffset + 12]= 0;
    rm[rmOffset + 13]= 0;
    rm[rmOffset + 14]= 0;
    rm[rmOffset + 15]= 1;
    a *= (float) (M_PI / 180.0f);
    float s = (float) sinf(a);
    float c = (float) cosf(a);
    if (1.0f == x && 0.0f == y && 0.0f == z) {
        rm[rmOffset + 5] = c;   rm[rmOffset + 10]= c;
        rm[rmOffset + 6] = s;   rm[rmOffset + 9] = -s;
        rm[rmOffset + 1] = 0;   rm[rmOffset + 2] = 0;
        rm[rmOffset + 4] = 0;   rm[rmOffset + 8] = 0;
        rm[rmOffset + 0] = 1;
    } else if (0.0f == x && 1.0f == y && 0.0f == z) {
        rm[rmOffset + 0] = c;   rm[rmOffset + 10]= c;
        rm[rmOffset + 8] = s;   rm[rmOffset + 2] = -s;
        rm[rmOffset + 1] = 0;   rm[rmOffset + 4] = 0;
        rm[rmOffset + 6] = 0;   rm[rmOffset + 9] = 0;
        rm[rmOffset + 5] = 1;
    } else if (0.0f == x && 0.0f == y && 1.0f == z) {
        rm[rmOffset + 0] = c;   rm[rmOffset + 5] = c;
        rm[rmOffset + 1] = s;   rm[rmOffset + 4] = -s;
        rm[rmOffset + 2] = 0;   rm[rmOffset + 6] = 0;
        rm[rmOffset + 8] = 0;   rm[rmOffset + 9] = 0;
        rm[rmOffset + 10]= 1;
    } else {
        float len = length(x, y, z);
        if (1.0f != len) {
            float recipLen = 1.0f / len;
            x *= recipLen;
            y *= recipLen;
            z *= recipLen;
        }
        float nc = 1.0f - c;
        float xy = x * y;
        float yz = y * z;
        float zx = z * x;
        float xs = x * s;
        float ys = y * s;
        float zs = z * s;
        rm[rmOffset +  0] = x*x*nc +  c;
        rm[rmOffset +  4] =  xy*nc - zs;
        rm[rmOffset +  8] =  zx*nc + ys;
        rm[rmOffset +  1] =  xy*nc + zs;
        rm[rmOffset +  5] = y*y*nc +  c;
        rm[rmOffset +  9] =  yz*nc - xs;
        rm[rmOffset +  2] =  zx*nc - ys;
        rm[rmOffset +  6] =  yz*nc + xs;
        rm[rmOffset + 10] = z*z*nc +  c;
    }
}

static void rotateM(float* m,
            float a, float x, float y, float z) {
    float temp[16];
    float temp2[16];
    setRotateM(temp, 0, a, x, y, z);
    mulMM(temp2, m, temp);
    memcpy(m, temp2, 16 * sizeof(float));
}

#undef I

#endif // DO_OWN_MATRIX_MATH

/*
=============
R_SetupGL
=============
*/
void R_SetupGL (void)
{
	float	screenaspect;
	float	yfov;
	int		i;
	extern	int glwidth, glheight;
	int		x, x2, y2, y, w, h;

	//
	// set up viewpoint
	//
	glMatrixMode(GL_PROJECTION);
    glLoadIdentity ();
	x = r_refdef.vrect.x * glwidth/vid.width;
	x2 = (r_refdef.vrect.x + r_refdef.vrect.width) * glwidth/vid.width;
	y = (vid.height-r_refdef.vrect.y) * glheight/vid.height;
	y2 = (vid.height - (r_refdef.vrect.y + r_refdef.vrect.height)) * glheight/vid.height;

	// fudge around because of frac screen scale
	if (x > 0)
		x--;
	if (x2 < glwidth)
		x2++;
	if (y2 < 0)
		y2--;
	if (y < glheight)
		y++;

	w = x2 - x;
	h = y - y2;

	if (envmap)
	{
		x = y2 = 0;
		w = h = 256;
	}

	glViewport (glx + x, gly + y2, w, h);
    screenaspect = (float)r_refdef.vrect.width/r_refdef.vrect.height;
//	yfov = 2*atan((float)r_refdef.vrect.height/r_refdef.vrect.width)*180/M_PI;
    MYgluPerspective (r_refdef.fov_y,  screenaspect,  4,  4096);

	if (mirror)
	{
		if (mirror_plane->normal[2])
			glScalef (1, -1, 1);
		else
			glScalef (-1, 1, 1);
		glCullFace(GL_BACK);
	}
	else
		glCullFace(GL_FRONT);

	glMatrixMode(GL_MODELVIEW);

#ifdef DO_OWN_MATRIX_MATH

	float mv[16];
    setIdentityM(mv, 0);

    rotateM(mv, -90,  1, 0, 0);	    // put Z going up
    rotateM(mv, 90,  0, 0, 1);	    // put Z going up
    rotateM(mv, -r_refdef.viewangles[2],  1, 0, 0);
    rotateM(mv, -r_refdef.viewangles[0],  0, 1, 0);
    rotateM(mv, -r_refdef.viewangles[1],  0, 0, 1);
    translateM(mv, 0, -r_refdef.vieworg[0],  -r_refdef.vieworg[1],  -r_refdef.vieworg[2]);

    glLoadMatrixf(mv);

    memcpy(r_world_matrix, mv, sizeof(r_world_matrix));

#else
    glLoadIdentity ();

    glRotatef (-90,  1, 0, 0);	    // put Z going up
    glRotatef (90,  0, 0, 1);	    // put Z going up
    glRotatef (-r_refdef.viewangles[2],  1, 0, 0);
    glRotatef (-r_refdef.viewangles[0],  0, 1, 0);
    glRotatef (-r_refdef.viewangles[1],  0, 0, 1);
    glTranslatef (-r_refdef.vieworg[0],  -r_refdef.vieworg[1],  -r_refdef.vieworg[2]);

#ifdef USE_OPENGLES

    static qboolean initialized;
    static qboolean haveGL_OES_matrix_get;
    static qboolean haveGL_OES_query_matrix;

#if 0
    if (! initialized) {
        const char* extensions = (const char*) glGetString(GL_EXTENSIONS);
        haveGL_OES_matrix_get =
            strstr(extensions, "GL_OES_matrix_get") != NULL;
        haveGL_OES_query_matrix =
            strstr(extensions, "GL_OES_query_matrix") != NULL;
        initialized = true;
    }
    if (haveGL_OES_query_matrix) {
        GLfixed mantissa[16];
        GLint exponent[16];
        glQueryMatrixxOES( mantissa, exponent );
        for(int i = 0; i < 16; i++) {
            r_world_matrix[i] = scalbnf(mantissa[i], exponent[i]-16);
        }
    }
    else if (haveGL_OES_matrix_get) {
        glGetIntegerv (MODELVIEW_MATRIX_FLOAT_AS_INT_BITS_OES,
                (GLint*) r_world_matrix);
    }
    else
#endif
    	{
        // No way to get the world matix, set to identity
        memset(r_world_matrix, 0, sizeof(r_world_matrix));
        for(i = 0; i < 16; i += 5) {
            r_world_matrix[i] = 1.0f;
        }
    }
#else
	glGetFloatv (GL_MODELVIEW_MATRIX, r_world_matrix);
#endif
#endif // DO_OWN_MATRIX_MATH
	//
	// set drawing parms
	//
	if (gl_cull.value)
		glEnable(GL_CULL_FACE);
	else
		glDisable(GL_CULL_FACE);

	glDisable(GL_BLEND);
	glDisable(GL_ALPHA_TEST);
	glEnable(GL_DEPTH_TEST);
}

/*
================
R_RenderScene

r_refdef must be set before the first call
================
*/
void R_RenderScene (void)
{
	R_SetupFrame ();

	R_SetFrustum ();

	R_SetupGL ();

	R_MarkLeaves ();	// done here so we know if we're in water

	R_DrawWorld ();		// adds static entities to the list

	S_ExtraUpdate ();	// don't let sound get messed up if going slow

	R_DrawEntitiesOnList ();

	GL_DisableMultitexture();

	R_RenderDlights ();

	R_DrawParticles ();

#ifdef GLTEST
	Test_Draw ();
#endif

}


/*
=============
R_Clear
=============
*/
void R_Clear (void)
{
	if (r_mirroralpha.value != 1.0)
	{
		if (gl_clear.value)
			glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
		else
			glClear (GL_DEPTH_BUFFER_BIT);
		gldepthmin = 0;
		gldepthmax = 0.5;
		glDepthFunc (GL_LEQUAL);
	}
	else if (gl_ztrick.value)
	{
		static int trickframe;

		if (gl_clear.value)
			glClear (GL_COLOR_BUFFER_BIT);

		trickframe++;
		if (trickframe & 1)
		{
			gldepthmin = 0;
			gldepthmax = 0.49999;
			glDepthFunc (GL_LEQUAL);
		}
		else
		{
			gldepthmin = 1;
			gldepthmax = 0.5;
			glDepthFunc (GL_GEQUAL);
		}
	}
	else
	{
		if (gl_clear.value)
			glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
		else
			glClear (GL_DEPTH_BUFFER_BIT);
		gldepthmin = 0;
		gldepthmax = 1;
		glDepthFunc (GL_LEQUAL);
	}

#ifdef USE_OPENGLES
	glDepthRangef (gldepthmin, gldepthmax);
#else
	glDepthRange (gldepthmin, gldepthmax);
#endif
}

/*
=============
R_Mirror
=============
*/
void R_Mirror (void)
{
	float		d;
	msurface_t	*s;
	entity_t	*ent;

	if (!mirror)
		return;

	memcpy (r_base_world_matrix, r_world_matrix, sizeof(r_base_world_matrix));

	d = DotProduct (r_refdef.vieworg, mirror_plane->normal) - mirror_plane->dist;
	VectorMA (r_refdef.vieworg, -2*d, mirror_plane->normal, r_refdef.vieworg);

	d = DotProduct (vpn, mirror_plane->normal);
	VectorMA (vpn, -2*d, mirror_plane->normal, vpn);

	r_refdef.viewangles[0] = -asin (vpn[2])/M_PI*180;
	r_refdef.viewangles[1] = atan2 (vpn[1], vpn[0])/M_PI*180;
	r_refdef.viewangles[2] = -r_refdef.viewangles[2];

	ent = &cl_entities[cl.viewentity];
	if (cl_numvisedicts < MAX_VISEDICTS)
	{
		cl_visedicts[cl_numvisedicts] = ent;
		cl_numvisedicts++;
	}

	gldepthmin = 0.5;
	gldepthmax = 1;
#ifdef USE_OPENGLES
	glDepthRangef (gldepthmin, gldepthmax);
#else
	glDepthRange (gldepthmin, gldepthmax);
#endif
	glDepthFunc (GL_LEQUAL);

	R_RenderScene ();
	R_DrawWaterSurfaces ();

	gldepthmin = 0;
	gldepthmax = 0.5;
#ifdef USE_OPENGLES
	glDepthRangef (gldepthmin, gldepthmax);
#else
	glDepthRange (gldepthmin, gldepthmax);
#endif
	glDepthFunc (GL_LEQUAL);

	// blend on top
	glEnable (GL_BLEND);
	glMatrixMode(GL_PROJECTION);
	if (mirror_plane->normal[2])
		glScalef (1,-1,1);
	else
		glScalef (-1,1,1);
	glCullFace(GL_FRONT);
	glMatrixMode(GL_MODELVIEW);

	glLoadMatrixf (r_base_world_matrix);

	glColor4f (1,1,1,r_mirroralpha.value);
	s = cl.worldmodel->textures[mirrortexturenum]->texturechain;
	for ( ; s ; s=s->texturechain)
		R_RenderBrushPoly (s);
	cl.worldmodel->textures[mirrortexturenum]->texturechain = NULL;
	glDisable (GL_BLEND);
	glColor4f (1,1,1,1);
}

/*
================
R_RenderView

r_refdef must be set before the first call
================
*/
void R_RenderView (void)
{
	double time1 = 0.0;
	double time2;
	GLfloat colors[4] = {(GLfloat) 0.0, (GLfloat) 0.0, (GLfloat) 1, (GLfloat) 0.20};

	if (r_norefresh.value)
		return;

	if (!r_worldentity.model || !cl.worldmodel)
		Sys_Error ("R_RenderView: NULL worldmodel");

	if (r_speeds.value)
	{
		glFinish ();
		time1 = Sys_FloatTime ();
		c_brush_polys = 0;
		c_alias_polys = 0;
	}

	mirror = false;

	if (gl_finish.value)
		glFinish ();

	R_Clear ();

	// render normal view

/***** Experimental silly looking fog ******
****** Use r_fullbright if you enable ******
	glFogi(GL_FOG_MODE, GL_LINEAR);
	glFogfv(GL_FOG_COLOR, colors);
	glFogf(GL_FOG_END, 512.0);
	glEnable(GL_FOG);
********************************************/

	R_RenderScene ();
	R_DrawViewModel ();
	R_DrawWaterSurfaces ();

//  More fog right here :)
//	glDisable(GL_FOG);
//  End of all fog code...

	// render mirror view
	R_Mirror ();

	R_PolyBlend ();

	if (r_speeds.value)
	{
//		glFinish ();
		time2 = Sys_FloatTime ();
		Con_Printf ("%3i ms  %4i wpoly %4i epoly\n", (int)((time2-time1)*1000), c_brush_polys, c_alias_polys);
	}
}