fteqw/engine/gl/gl_rmain.c

/*
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"

#ifdef GLQUAKE
#include "glquake.h"
#include "renderque.h"
#include "shader.h"
#include "gl_draw.h"

void R_RenderBrushPoly (msurface_t *fa);

#define PROJECTION_DISTANCE			200
#define MAX_STENCIL_ENTS			128

extern int		gl_stencilbits;

FTEPFNGLCOMPRESSEDTEXIMAGE2DARBPROC qglCompressedTexImage2DARB;
FTEPFNGLGETCOMPRESSEDTEXIMAGEARBPROC qglGetCompressedTexImageARB;

vec3_t		modelorg, r_entorigin;

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

float		r_wateralphaval;	//allowed or not...

//mplane_t	frustum[4];

int			c_brush_polys, c_alias_polys;

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

cvar_t	r_norefresh = SCVAR("r_norefresh","0");

extern cvar_t	gl_part_flame;
extern cvar_t	r_bloom;

cvar_t	gl_affinemodels = SCVAR("gl_affinemodels","0");
cvar_t	gl_reporttjunctions = SCVAR("gl_reporttjunctions","0");
cvar_t	gl_finish = SCVAR("gl_finish","0");
cvar_t	gl_dither = SCVAR("gl_dither", "1");
extern cvar_t	r_stereo_separation;
extern cvar_t	r_stereo_method;
extern cvar_t	r_postprocshader;

extern cvar_t	gl_screenangle;

extern cvar_t	gl_mindist;

extern cvar_t	ffov;

extern cvar_t	gl_motionblur;
extern cvar_t	gl_motionblurscale;

extern cvar_t gl_ati_truform;
extern cvar_t gl_ati_truform_type;
extern cvar_t gl_ati_truform_tesselation;

extern cvar_t gl_blendsprites;

#ifdef R_XFLIP
cvar_t	r_xflip = SCVAR("leftisright", "0");
#endif

extern	cvar_t	scr_fov;

shader_t *scenepp_waterwarp;

// post processing stuff
texid_t sceneblur_texture;
texid_t scenepp_texture_warp;
texid_t scenepp_texture_edge;

texid_t scenepp_postproc_cube;
int scenepp_postproc_cube_size;

// KrimZon - init post processing - called in GL_CheckExtensions, when they're called
// I put it here so that only this file need be changed when messing with the post
// processing shaders
void GL_InitSceneProcessingShaders_WaterWarp (void)
{
	scenepp_waterwarp = NULL;
	if (gl_config.arb_shader_objects)
	{
		scenepp_waterwarp = R_RegisterShader("waterwarp",
			"{\n"
				"program underwaterwarp\n"
				"{\n"
					"map $currentrender\n"
				"}\n"
				"{\n"
					"map $upperoverlay\n"
				"}\n"
				"{\n"
					"map $loweroverlay\n"
				"}\n"
			"}\n"
			);
		scenepp_waterwarp->defaulttextures.upperoverlay = scenepp_texture_warp;
		scenepp_waterwarp->defaulttextures.loweroverlay = scenepp_texture_edge;
	}
}

void GL_InitSceneProcessingShaders (void)
{
	if (gl_config.arb_shader_objects)
	{
		GL_InitSceneProcessingShaders_WaterWarp();
	}

	gl_dither.modified = true;	//fixme: bad place for this, but hey
}

#define PP_WARP_TEX_SIZE 64
#define PP_AMP_TEX_SIZE 64
#define PP_AMP_TEX_BORDER 4
void GL_SetupSceneProcessingTextures (void)
{
	int i, x, y;
	unsigned char pp_warp_tex[PP_WARP_TEX_SIZE*PP_WARP_TEX_SIZE*3];
	unsigned char pp_edge_tex[PP_AMP_TEX_SIZE*PP_AMP_TEX_SIZE*3];

	scenepp_postproc_cube = r_nulltex;

	TEXASSIGN(sceneblur_texture, GL_AllocNewTexture("***postprocess_blur***", 0, 0, 0));

	if (!gl_config.arb_shader_objects)
		return;

	TEXASSIGN(scenepp_texture_warp, GL_AllocNewTexture("***postprocess_warp***", PP_WARP_TEX_SIZE, PP_WARP_TEX_SIZE, 0));
	TEXASSIGN(scenepp_texture_edge, GL_AllocNewTexture("***postprocess_edge***", PP_WARP_TEX_SIZE, PP_WARP_TEX_SIZE, 0));

	// init warp texture - this specifies offset in
	for (y=0; y<PP_WARP_TEX_SIZE; y++)
	{
		for (x=0; x<PP_WARP_TEX_SIZE; x++)
		{
			float fx, fy;

			i = (x + y*PP_WARP_TEX_SIZE) * 3;

			fx = sin(((double)y / PP_WARP_TEX_SIZE) * M_PI * 2);
			fy = cos(((double)x / PP_WARP_TEX_SIZE) * M_PI * 2);

			pp_warp_tex[i  ] = (fx+1.0f)*127.0f;
			pp_warp_tex[i+1] = (fy+1.0f)*127.0f;
			pp_warp_tex[i+2] = 0;
		}
	}

	GL_MTBind(0, GL_TEXTURE_2D, scenepp_texture_warp);
	qglTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	qglTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	qglTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, PP_WARP_TEX_SIZE, PP_WARP_TEX_SIZE, 0, GL_RGB, GL_UNSIGNED_BYTE, pp_warp_tex);

	// TODO: init edge texture - this is ampscale * 2, with ampscale calculated
	// init warp texture - this specifies offset in
	for (y=0; y<PP_AMP_TEX_SIZE; y++)
	{
		for (x=0; x<PP_AMP_TEX_SIZE; x++)
		{
			float fx = 1, fy = 1;

			i = (x + y*PP_AMP_TEX_SIZE) * 3;

			if (x < PP_AMP_TEX_BORDER)
			{
				fx = (float)x / PP_AMP_TEX_BORDER;
			}
			if (x > PP_AMP_TEX_SIZE - PP_AMP_TEX_BORDER)
			{
				fx = (PP_AMP_TEX_SIZE - (float)x) / PP_AMP_TEX_BORDER;
			}

			if (y < PP_AMP_TEX_BORDER)
			{
				fy = (float)y / PP_AMP_TEX_BORDER;
			}
			if (y > PP_AMP_TEX_SIZE - PP_AMP_TEX_BORDER)
			{
				fy = (PP_AMP_TEX_SIZE - (float)y) / PP_AMP_TEX_BORDER;
			}

			if (fx < fy)
			{
				fy = fx;
			}

			pp_edge_tex[i  ] = fy * 255;
			pp_edge_tex[i+1] = 0;
			pp_edge_tex[i+2] = 0;
		}
	}

	GL_MTBind(0, GL_TEXTURE_2D, scenepp_texture_edge);
	qglTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	qglTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	qglTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, PP_WARP_TEX_SIZE, PP_WARP_TEX_SIZE, 0, GL_RGB, GL_UNSIGNED_BYTE, pp_edge_tex);
}

void R_RotateForEntity (float *m, float *modelview, const entity_t *e, const model_t *mod)
{
	if (e->flags & Q2RF_WEAPONMODEL && r_refdef.currentplayernum>=0)
	{
		entity_t *view = &cl.viewent[r_refdef.currentplayernum];
		float em[16];
		float vm[16];

		vm[0] = view->axis[0][0];
		vm[1] = view->axis[0][1];
		vm[2] = view->axis[0][2];
		vm[3] = 0;

		vm[4] = view->axis[1][0];
		vm[5] = view->axis[1][1];
		vm[6] = view->axis[1][2];
		vm[7] = 0;

		vm[8] = view->axis[2][0];
		vm[9] = view->axis[2][1];
		vm[10] = view->axis[2][2];
		vm[11] = 0;

		vm[12] = view->origin[0];
		vm[13] = view->origin[1];
		vm[14] = view->origin[2];
		vm[15] = 1;

		em[0] = e->axis[0][0];
		em[1] = e->axis[0][1];
		em[2] = e->axis[0][2];
		em[3] = 0;

		em[4] = e->axis[1][0];
		em[5] = e->axis[1][1];
		em[6] = e->axis[1][2];
		em[7] = 0;

		em[8] = e->axis[2][0];
		em[9] = e->axis[2][1];
		em[10] = e->axis[2][2];
		em[11] = 0;

		em[12] = e->origin[0];
		em[13] = e->origin[1];
		em[14] = e->origin[2];
		em[15] = 1;

		Matrix4_Multiply(vm, em, m);
	}
	else
	{
		m[0] = e->axis[0][0];
		m[1] = e->axis[0][1];
		m[2] = e->axis[0][2];
		m[3] = 0;

		m[4] = e->axis[1][0];
		m[5] = e->axis[1][1];
		m[6] = e->axis[1][2];
		m[7] = 0;

		m[8] = e->axis[2][0];
		m[9] = e->axis[2][1];
		m[10] = e->axis[2][2];
		m[11] = 0;

		m[12] = e->origin[0];
		m[13] = e->origin[1];
		m[14] = e->origin[2];
		m[15] = 1;
	}

	if (e->scale != 1 && e->scale != 0)	//hexen 2 stuff
	{
		float z;
		float escale;
		escale = e->scale;
		switch(e->drawflags&SCALE_TYPE_MASKIN)
		{
		default:
		case SCALE_TYPE_UNIFORM:
			VectorScale((m+0), escale, (m+0));
			VectorScale((m+4), escale, (m+4));
			VectorScale((m+8), escale, (m+8));
			break;
		case SCALE_TYPE_XYONLY:
			VectorScale((m+0), escale, (m+0));
			VectorScale((m+4), escale, (m+4));
			break;
		case SCALE_TYPE_ZONLY:
			VectorScale((m+8), escale, (m+8));
			break;
		}
		if (mod && (e->drawflags&SCALE_TYPE_MASKIN) != SCALE_TYPE_XYONLY)
		{
			switch(e->drawflags&SCALE_ORIGIN_MASKIN)
			{
			case SCALE_ORIGIN_CENTER:
				z = ((mod->maxs[2] + mod->mins[2]) * (1-escale))/2;
				VectorMA((m+12), z, e->axis[2], (m+12));
				break;
			case SCALE_ORIGIN_BOTTOM:
				VectorMA((m+12), mod->mins[2]*(1-escale), e->axis[2], (m+12));
				break;
			case SCALE_ORIGIN_TOP:
				VectorMA((m+12), -mod->maxs[2], e->axis[2], (m+12));
				break;
			}
		}
	}
	else if (mod && !strcmp(mod->name, "progs/eyes.mdl"))
	{
		/*resize eyes, to make them easier to see*/
		m[14] -= (22 + 8);
		VectorScale((m+0), 2, (m+0));
		VectorScale((m+4), 2, (m+4));
		VectorScale((m+8), 2, (m+8));
	}
	if (mod && !ruleset_allow_larger_models.ival && mod->clampscale != 1 && mod->type == mod_alias)
	{	//possibly this should be on a per-frame basis, but that's a real pain to do
		Con_DPrintf("Rescaling %s by %f\n", mod->name, mod->clampscale);
		VectorScale((m+0), mod->clampscale, (m+0));
		VectorScale((m+4), mod->clampscale, (m+4));
		VectorScale((m+8), mod->clampscale, (m+8));
	}

	Matrix4_Multiply(r_refdef.m_view, m, modelview);
}

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

/*
=============
R_SetupGL
=============
*/
void R_SetupGL (float stereooffset)
{
	float	screenaspect;
	int		x, x2, y2, y, w, h;
	vec3_t newa;

	float fov_x, fov_y;

	if (!r_refdef.recurse)
	{
		AngleVectors (r_refdef.viewangles, vpn, vright, vup);
		VectorCopy (r_refdef.vieworg, r_origin);

		VectorMA(r_origin, stereooffset, vright, r_origin);

		//
		// set up viewpoint
		//
		x = r_refdef.vrect.x * vid.pixelwidth/(int)vid.width;
		x2 = (r_refdef.vrect.x + r_refdef.vrect.width) * vid.pixelwidth/(int)vid.width;
		y = (vid.height-r_refdef.vrect.y) * vid.pixelheight/(int)vid.height;
		y2 = ((int)vid.height - (r_refdef.vrect.y + r_refdef.vrect.height)) * (int)vid.pixelheight/(int)vid.height;

		// fudge around because of frac screen scale
		if (x > 0)
			x--;
		if (x2 < vid.pixelwidth)
			x2++;
		if (y2 < 0)
			y2--;
		if (y < vid.pixelheight)
			y++;

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

		r_refdef.pxrect.x = x;
		r_refdef.pxrect.y = y;
		r_refdef.pxrect.width = w;
		r_refdef.pxrect.height = h;

		qglViewport (x, y2, w, h);

		fov_x = r_refdef.fov_x;//+sin(cl.time)*5;
		fov_y = r_refdef.fov_y;//-sin(cl.time+1)*5;

		if (r_waterwarp.value<0 && (r_viewcontents & FTECONTENTS_FLUID))
		{
			fov_x *= 1 + (((sin(cl.time * 4.7) + 1) * 0.015) * r_waterwarp.value);
			fov_y *= 1 + (((sin(cl.time * 3.0) + 1) * 0.015) * r_waterwarp.value);
		}

		screenaspect = (float)r_refdef.vrect.width/r_refdef.vrect.height;
		if (r_refdef.useperspective)
		{
			int stencilshadows = 0;
	#ifdef RTLIGHTS
			stencilshadows |= r_shadow_realtime_dlight.ival && r_shadow_realtime_dlight_shadows.ival;
			stencilshadows |= r_shadow_realtime_world.ival && r_shadow_realtime_world_shadows.ival;
	#endif

			if ((!stencilshadows || !gl_stencilbits) && gl_maxdist.value>=100)//gl_nv_range_clamp)
			{
		//		yfov = 2*atan((float)r_refdef.vrect.height/r_refdef.vrect.width)*180/M_PI;
		//		yfov = (2.0 * tan (scr_fov.value/360*M_PI)) / screenaspect;
		//		yfov = 2*atan((float)r_refdef.vrect.height/r_refdef.vrect.width)*(scr_fov.value*2)/M_PI;
		//		MYgluPerspective (yfov,  screenaspect,  4,  4096);

				Matrix4x4_CM_Projection_Far(r_refdef.m_projection, fov_x, fov_y, gl_mindist.value, gl_maxdist.value);
			}
			else
			{
				Matrix4x4_CM_Projection_Inf(r_refdef.m_projection, fov_x, fov_y, gl_mindist.value);
			}
		}
		else
		{
			if (gl_maxdist.value>=1)
				Matrix4x4_CM_Orthographic(r_refdef.m_projection, -fov_x/2, fov_x/2, -fov_y/2, fov_y/2, -gl_maxdist.value, gl_maxdist.value);
			else
				Matrix4x4_CM_Orthographic(r_refdef.m_projection, 0, r_refdef.vrect.width, 0, r_refdef.vrect.height, -9999, 9999);
		}

		newa[0] = r_refdef.viewangles[0];
		newa[1] = r_refdef.viewangles[1];
		newa[2] = r_refdef.viewangles[2] + gl_screenangle.value;
		Matrix4x4_CM_ModelViewMatrix(r_refdef.m_view, newa, r_origin);
	}

	if (qglLoadMatrixf)
	{
		qglMatrixMode(GL_PROJECTION);
		qglLoadMatrixf(r_refdef.m_projection);

		qglMatrixMode(GL_MODELVIEW);
		qglLoadMatrixf(r_refdef.m_view);
	}

	if (!gl_config.gles && gl_dither.modified)
	{
		gl_dither.modified = false;
		if (gl_dither.ival)
		{
			qglEnable(GL_DITHER);
		}
		else
		{
			qglDisable(GL_DITHER);
		}
	}
}

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

r_refdef must be set before the first call
================
*/
void R_RenderScene (void)
{
	float stereooffset[2];
	int stereoframes = 1;
	int stereomode;
	int i;
	int tmpvisents = cl_numvisedicts;	/*world rendering is allowed to add additional ents, but we don't want to keep them for recursive views*/
	if (!cl.worldmodel || (!cl.worldmodel->nodes && cl.worldmodel->type != mod_heightmap))
		r_refdef.flags |= Q2RDF_NOWORLDMODEL;

	stereomode = r_stereo_method.ival;
	if (stereomode == 1)
	{
#ifdef GL_STEREO
		GLint glb;
		qglGetIntegerv(GL_STEREO, &glb);
		if (!glb)
#endif
			stereomode = 0;	//we are not a stereo context, so no stereoscopic rendering (this encourages it to otherwise be left enabled, which means the user is more likely to spot that they asked it to give a slower context.
	}


	if (r_refdef.recurse || !stereomode || !r_stereo_separation.value)
	{
		stereooffset[0] = 0;
		stereoframes = 1;
		stereomode = 0;
	}
	else	
	{
		stereooffset[0] = -r_stereo_separation.value;
		stereooffset[1] = r_stereo_separation.value;
		stereoframes = 2;
	}

	for (i = 0; i < stereoframes; i++)
	{
		switch (stereomode)
		{
		default:
		case 0:	//off
			if (i)
				return;
			break;
#ifdef GL_STEREO
		case 1:	//proper gl stereo rendering
			if (stereooffset[i] < 0)
				qglDrawBuffer(GL_BACK_LEFT);
			else
				qglDrawBuffer(GL_BACK_RIGHT);
			break;
#endif
		case 2:	//red/cyan
			if (stereooffset[i] < 0)
				qglColorMask(GL_TRUE, GL_FALSE, GL_FALSE, GL_TRUE);
			else
				qglColorMask(GL_FALSE, GL_TRUE, GL_TRUE, GL_TRUE);
			break;
		case 3: //red/blue
			if (stereooffset[i] < 0)
				qglColorMask(GL_TRUE, GL_FALSE, GL_FALSE, GL_TRUE);
			else
				qglColorMask(GL_FALSE, GL_FALSE, GL_TRUE, GL_TRUE);
			break;
		case 4:	//red/green
			if (stereooffset[i] < 0)
				qglColorMask(GL_TRUE, GL_FALSE, GL_FALSE, GL_TRUE);
			else
				qglColorMask(GL_FALSE, GL_TRUE, GL_FALSE, GL_TRUE);
			break;

		}
		if (i)
			qglClear (GL_DEPTH_BUFFER_BIT);

		TRACE(("dbg: calling R_SetupGL\n"));
		R_SetupGL (stereooffset[i]);

		TRACE(("dbg: calling R_SetFrustrum\n"));
		R_SetFrustum (r_refdef.m_projection, r_refdef.m_view);

		RQ_BeginFrame();

		TRACE(("dbg: calling Surf_DrawWorld\n"));
		Surf_DrawWorld ();		// adds static entities to the list

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

	//	R_DrawDecals();

		TRACE(("dbg: calling R_RenderDlights\n"));
		R_RenderDlights ();

		if (r_refdef.recurse)
			RQ_RenderBatch();
		else
			RQ_RenderBatchClear();

		cl_numvisedicts = tmpvisents;
	}

	switch (stereomode)
	{
	default:
	case 0:
		break;
	case 1:
		qglDrawBuffer(GL_BACK);
		break;
	case 2:
	case 3:
	case 4:
		qglColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
		break;

	}
}
/*generates a new modelview matrix, as well as vpn vectors*/
static void R_MirrorMatrix(plane_t *plane)
{
	float mirror[16];
	float view[16];
	float result[16];

	vec3_t pnorm;
	VectorNegate(plane->normal, pnorm);

	mirror[0] = 1-2*pnorm[0]*pnorm[0];
	mirror[1] = -2*pnorm[0]*pnorm[1];
	mirror[2] = -2*pnorm[0]*pnorm[2];
	mirror[3] = 0;

	mirror[4] = -2*pnorm[1]*pnorm[0];
	mirror[5] = 1-2*pnorm[1]*pnorm[1];
	mirror[6] = -2*pnorm[1]*pnorm[2] ;
	mirror[7] = 0;

	mirror[8]  = -2*pnorm[2]*pnorm[0];
	mirror[9]  = -2*pnorm[2]*pnorm[1];
	mirror[10] = 1-2*pnorm[2]*pnorm[2];
	mirror[11] = 0;

	mirror[12] = -2*pnorm[0]*plane->dist;
	mirror[13] = -2*pnorm[1]*plane->dist;
	mirror[14] = -2*pnorm[2]*plane->dist;
	mirror[15] = 1;

	view[0] = vpn[0];
	view[1] = vpn[1];
	view[2] = vpn[2];
	view[3] = 0;

	view[4] = -vright[0];
	view[5] = -vright[1];
	view[6] = -vright[2];
	view[7] = 0;

	view[8]  = vup[0];
	view[9]  = vup[1];
	view[10] = vup[2];
	view[11] = 0;

	view[12] = r_refdef.vieworg[0];
	view[13] = r_refdef.vieworg[1];
	view[14] = r_refdef.vieworg[2];
	view[15] = 1;

	VectorMA(r_refdef.vieworg, 0.25, plane->normal, r_refdef.pvsorigin);

	Matrix4_Multiply(mirror, view, result);

	vpn[0] = result[0];
	vpn[1] = result[1];
	vpn[2] = result[2];

	vright[0] = -result[4];
	vright[1] = -result[5];
	vright[2] = -result[6];

	vup[0] = result[8];
	vup[1] = result[9];
	vup[2] = result[10];

	r_refdef.vieworg[0] = result[12];
	r_refdef.vieworg[1] = result[13];
	r_refdef.vieworg[2] = result[14];
}
static entity_t *R_NearestPortal(plane_t *plane)
{
	int i;
	entity_t *best = NULL;
	float dist, bestd = 0;
	//for q3-compat, portals on world scan for a visedict to use for their view.
	for (i = 0; i < cl_numvisedicts; i++)
	{
		if (cl_visedicts[i].rtype == RT_PORTALSURFACE)
		{
			dist = DotProduct(cl_visedicts[i].origin, plane->normal)-plane->dist;
			dist = fabs(dist);
			if (dist < 64 && (!best || dist < bestd))
				best = &cl_visedicts[i];
		}
	}
	return best;
}

static void TransformCoord(vec3_t in, vec3_t planea[3], vec3_t planeo, vec3_t viewa[3], vec3_t viewo, vec3_t result)
{
	int		i;
	vec3_t	local;
	vec3_t	transformed;
	float	d;

	local[0] = in[0] - planeo[0];
	local[1] = in[1] - planeo[1];
	local[2] = in[2] - planeo[2];

	VectorClear(transformed);
	for ( i = 0 ; i < 3 ; i++ )
	{
		d = DotProduct(local, planea[i]);
		VectorMA(transformed, d, viewa[i], transformed);
	}

	result[0] = transformed[0] + viewo[0];
	result[1] = transformed[1] + viewo[1];
	result[2] = transformed[2] + viewo[2];
}
static void TransformDir(vec3_t in, vec3_t planea[3], vec3_t viewa[3], vec3_t result)
{
	int		i;
	float	d;
	vec3_t tmp;

	VectorCopy(in, tmp);

	VectorClear(result);
	for ( i = 0 ; i < 3 ; i++ )
	{
		d = DotProduct(tmp, planea[i]);
		VectorMA(result, d, viewa[i], result);
	}
}
static float sgn(float a)
{
    if (a > 0.0F) return (1.0F);
    if (a < 0.0F) return (-1.0F);
    return (0.0F);
}
void R_ObliqueNearClip(mplane_t *wplane)
{
	float f;
	vec4_t q, c;
	vec3_t ping, pong;
	vec4_t vplane;

	//convert world plane into view space
	Matrix4x4_CM_Transform3x3(r_refdef.m_view, wplane->normal, vplane);
	VectorScale(wplane->normal, wplane->dist, ping);
	Matrix4x4_CM_Transform3(r_refdef.m_view, ping, pong);
	vplane[3] = -DotProduct(pong, vplane);

	// Calculate the clip-space corner point opposite the clipping plane
	// as (sgn(clipPlane.x), sgn(clipPlane.y), 1, 1) and
	// transform it into camera space by multiplying it
	// by the inverse of the projection matrix

	q[0] = (sgn(vplane[0]) + r_refdef.m_projection[8]) / r_refdef.m_projection[0];
	q[1] = (sgn(vplane[1]) + r_refdef.m_projection[9]) / r_refdef.m_projection[5];
	q[2] = -1.0F;
	q[3] = (1.0F + r_refdef.m_projection[10]) / r_refdef.m_projection[14];

	// Calculate the scaled plane vector
	f = 2.0F / DotProduct4(vplane, q);
	Vector4Scale(vplane, f, c);

	// Replace the third row of the projection matrix
	r_refdef.m_projection[2] = c[0];
	r_refdef.m_projection[6] = c[1];
	r_refdef.m_projection[10] = c[2] + 1.0F;
	r_refdef.m_projection[14] = c[3];
}
void GLR_DrawPortal(batch_t *batch, batch_t **blist, int portaltype)
{
	entity_t *view;
//	GLdouble glplane[4];
	plane_t plane;
	refdef_t oldrefdef;
	mesh_t *mesh = batch->mesh[batch->firstmesh];
	int sort;
	qbyte newvis[(MAX_MAP_LEAFS+7)/8];

	if (r_refdef.recurse)
		return;

	if (!mesh->normals_array)
	{
		VectorSet(plane.normal, 0, 0, 1);
	}
	else
	{
		VectorCopy(mesh->normals_array[0], plane.normal);
	}
	plane.dist = DotProduct(mesh->xyz_array[0], plane.normal);

	//if we're too far away from the surface, don't draw anything
	if (batch->shader->flags & SHADER_AGEN_PORTAL)
	{
		/*there's a portal alpha blend on that surface, that fades out after this distance*/
		if (DotProduct(r_refdef.vieworg, plane.normal)-plane.dist > batch->shader->portaldist)
			return;
	}
	//if we're behind it, then also don't draw anything.
	if (DotProduct(r_refdef.vieworg, plane.normal)-plane.dist < 0)
		return;

	TRACE(("GLR_DrawPortal: portal type %i\n", portaltype));

	oldrefdef = r_refdef;
	r_refdef.recurse = true;

	r_refdef.externalview = true;

	switch(portaltype)
	{
	case 1: /*fbo explicit mirror (fucked depth, working clip plane)*/
		r_refdef.flipcull ^= true;
		R_MirrorMatrix(&plane);
		break;
	
	case 2:	/*fbo refraction (fucked depth, working clip plane)*/
	case 3:	/*screen copy refraction (screen depth, fucked clip planes)*/
		/*refraction image (same view, just with things culled*/
		r_refdef.externalview = oldrefdef.externalview;
		VectorNegate(plane.normal, plane.normal);
		plane.dist = -plane.dist;

		//use the player's origin for r_viewleaf, because there's not much we can do anyway*/
		VectorCopy(r_origin, r_refdef.pvsorigin);

		if (cl.worldmodel && cl.worldmodel->funcs.LeafPVS && !r_novis.ival)
		{
			int lnum, i, j;
			float d;
			vec3_t point;
			int pvsbytes = (cl.worldmodel->numleafs+7)>>3;
			if (pvsbytes > sizeof(newvis))
				pvsbytes = sizeof(newvis);
			r_refdef.forcevis = true;
			r_refdef.forcedvis = NULL;
			for (i = batch->firstmesh; i < batch->meshes; i++)
			{
				mesh = batch->mesh[i];
				VectorClear(point);
				for (j = 0; j < mesh->numvertexes; j++)
					VectorAdd(point, mesh->xyz_array[j], point);
				VectorScale(point, 1.0f/mesh->numvertexes, point);
				d = DotProduct(point, plane.normal) - plane.dist;
				d += 0.1;	//an epsilon on the far side
				VectorMA(point, d, plane.normal, point);

				lnum = cl.worldmodel->funcs.LeafnumForPoint(cl.worldmodel, point);
				if (i == batch->firstmesh)
					r_refdef.forcedvis = cl.worldmodel->funcs.LeafPVS(cl.worldmodel, lnum, newvis, sizeof(newvis));
				else
				{
					if (r_refdef.forcedvis != newvis)
					{
						memcpy(newvis, r_refdef.forcedvis, pvsbytes);
					}
					r_refdef.forcedvis = cl.worldmodel->funcs.LeafPVS(cl.worldmodel, lnum, NULL, sizeof(newvis));

					for (j = 0; j < pvsbytes; j+= 4)
					{
						*(int*)&newvis[j] |= *(int*)&r_refdef.forcedvis[j];
					}
					r_refdef.forcedvis = newvis;
				}
			}
//			memset(newvis, 0xff, pvsbytes);
		}
		break;

	default:	/*q3 portal*/
		if (batch->ent != &r_worldentity)
		{
			float d;
			view = batch->ent;
			d = DotProduct(r_refdef.vieworg, plane.normal) - plane.dist;
			d-= 0.1;	//nudge it past.
			VectorAdd(r_refdef.vieworg, view->oldorigin, r_refdef.vieworg);		//trivial offset for the warpzone.
			VectorMA(r_refdef.vieworg, -d, plane.normal, r_refdef.pvsorigin);	//clip the pvs origin to the plane.
		}
		else if (!(view = R_NearestPortal(&plane)) || VectorCompare(view->origin, view->oldorigin))
		{
			r_refdef.flipcull ^= true;
			R_MirrorMatrix(&plane);
		}
		else
		{
			float d;
			vec3_t paxis[3], porigin, vaxis[3], vorg;
			void PerpendicularVector( vec3_t dst, const vec3_t src );

			/*calculate where the surface is meant to be*/
			VectorCopy(mesh->normals_array[0], paxis[0]);
			PerpendicularVector(paxis[1], paxis[0]);
			CrossProduct(paxis[0], paxis[1], paxis[2]);
			d = DotProduct(view->origin, plane.normal) - plane.dist;
			VectorMA(view->origin, -d, paxis[0], porigin);

			/*grab the camera origin*/
			VectorNegate(view->axis[0], vaxis[0]);
			VectorNegate(view->axis[1], vaxis[1]);
			VectorCopy(view->axis[2], vaxis[2]);
			VectorCopy(view->oldorigin, vorg);

			VectorCopy(vorg, r_refdef.pvsorigin);

			/*rotate it a bit*/
			RotatePointAroundVector(vaxis[1], vaxis[0], view->axis[1], sin(realtime)*4);
			CrossProduct(vaxis[0], vaxis[1], vaxis[2]);

			TransformCoord(oldrefdef.vieworg, paxis, porigin, vaxis, vorg, r_refdef.vieworg);
			TransformDir(vpn, paxis, vaxis, vpn);
			TransformDir(vright, paxis, vaxis, vright);
			TransformDir(vup, paxis, vaxis, vup);
		}
		break;
	}
	Matrix4x4_CM_ModelViewMatrixFromAxis(r_refdef.m_view, vpn, vright, vup, r_refdef.vieworg);
	VectorAngles(vpn, vup, r_refdef.viewangles);
	VectorCopy(r_refdef.vieworg, r_origin);

/*FIXME: the batch stuff should be done in renderscene*/

	/*fixup the first mesh index*/
	for (sort = 0; sort < SHADER_SORT_COUNT; sort++)
	for (batch = blist[sort]; batch; batch = batch->next)
	{
		batch->firstmesh = batch->meshes;
	}

	GL_CullFace(0);

	/*FIXME: can we get away with stenciling the screen?*/
	/*Add to frustum culling instead of clip planes?*/
//	if (qglClipPlane)
//	{
//		glplane[0] = -plane.normal[0];
//		glplane[1] = -plane.normal[1];
//		glplane[2] = -plane.normal[2];
//		glplane[3] = plane.dist;
//		qglClipPlane(GL_CLIP_PLANE0, glplane);
//		qglEnable(GL_CLIP_PLANE0);
//	}
	frustum[4].normal[0] = plane.normal[0];
	frustum[4].normal[1] = plane.normal[1];
	frustum[4].normal[2] = plane.normal[2];
	frustum[4].dist	= plane.dist + 0.01;
	if (portaltype == 1 || portaltype == 2)
		R_ObliqueNearClip(&frustum[4]);
	R_RenderScene();
//	if (qglClipPlane)
//		qglDisable(GL_CLIP_PLANE0);

	for (sort = 0; sort < SHADER_SORT_COUNT; sort++)
	for (batch = blist[sort]; batch; batch = batch->next)
	{
		batch->firstmesh = 0;
	}
	r_refdef = oldrefdef;

	/*broken stuff*/
	AngleVectors (r_refdef.viewangles, vpn, vright, vup);
	VectorCopy (r_refdef.vieworg, r_origin);
	R_SetFrustum (r_refdef.m_projection, r_refdef.m_view);

	if (qglLoadMatrixf)
	{
		/*put GL back the way it was*/
		qglMatrixMode(GL_PROJECTION);
		qglLoadMatrixf(r_refdef.m_projection);

		qglMatrixMode(GL_MODELVIEW);
		qglLoadMatrixf(r_refdef.m_view);
	}

	GL_CullFace(0);

	TRACE(("GLR_DrawPortal: portal drawn\n"));

#ifdef warningmsg
#pragma warningmsg("warning: there's a bug with rtlights in portals, culling is broken or something. May also be loading the wrong matrix")
#endif
}


/*
=============
R_Clear
=============
*/
int gldepthfunc = GL_LEQUAL;
void R_Clear (void)
{
	/*tbh, this entire function should be in the backend*/
	GL_ForceDepthWritable();
	{
		if (r_clear.ival && !r_secondaryview && !r_refdef.currentplayernum && !(r_refdef.flags & Q2RDF_NOWORLDMODEL))
		{
			qglClearColor(1, 0, 0, 0);
			qglClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
		}
		else
			qglClear (GL_DEPTH_BUFFER_BIT);
		gldepthmin = 0;
		gldepthmax = 1;
		gldepthfunc=GL_LEQUAL;
	}
}

#if 0
void GLR_SetupFog (void)
{
	if (r_viewleaf)// && r_viewcontents != FTECONTENTS_EMPTY)
	{
		//	static fogcolour;
		float fogcol[4]={0};
		float fogperc;
		float fogdist;

		fogperc=0;
		fogdist=512;
		switch(r_viewcontents)
		{
		case FTECONTENTS_WATER:
			fogcol[0] = 64/255.0;
			fogcol[1] = 128/255.0;
			fogcol[2] = 192/255.0;
			fogperc=0.2;
			fogdist=512;
			break;
		case FTECONTENTS_SLIME:
			fogcol[0] = 32/255.0;
			fogcol[1] = 192/255.0;
			fogcol[2] = 92/255.0;
			fogperc=1;
			fogdist=256;
			break;
		case FTECONTENTS_LAVA:
			fogcol[0] = 192/255.0;
			fogcol[1] = 32/255.0;
			fogcol[2] = 64/255.0;
			fogperc=1;
			fogdist=128;
			break;
		default:
			fogcol[0] = 192/255.0;
			fogcol[1] = 192/255.0;
			fogcol[2] = 192/255.0;
			fogperc=1;
			fogdist=1024;
			break;
		}
		if (fogperc)
		{
			qglFogi(GL_FOG_MODE, GL_LINEAR);
			qglFogfv(GL_FOG_COLOR, fogcol);
			qglFogf(GL_FOG_DENSITY, fogperc);
			qglFogf(GL_FOG_START, 1);
			qglFogf(GL_FOG_END, fogdist);
			qglEnable(GL_FOG);
		}
	}
}
#endif

void GLBE_RenderToTexture(texid_t sourcecol, texid_t sourcedepth, texid_t destcol, qboolean usedepth);
static void R_RenderMotionBlur(void)
{
	int vwidth = 1, vheight = 1;
	float vs, vt, cs, ct;
	shader_t *shader;

#if !defined(ANDROID) && !defined(NACL)
	//figure out the size of our texture.
	if (r_config.texture_non_power_of_two)
	{	//we can use any size, supposedly
		vwidth = vid.pixelwidth;
		vheight = vid.pixelheight;
	}
	else
	{	//limit the texture size to square and use padding.
		while (vwidth < vid.pixelwidth)
			vwidth *= 2;
		while (vheight < vid.pixelheight)
			vheight *= 2;
	}

	//blend the last frame onto the scene
	//the maths is because our texture is over-sized (must be power of two)
	cs = vs = (float)vid.pixelwidth / vwidth * 0.5;
	ct = vt = (float)vid.pixelheight / vheight * 0.5;
	vs *= gl_motionblurscale.value;
	vt *= gl_motionblurscale.value;

	//render using our texture
	shader = R_RegisterShader("postproc_motionblur",
		"{\n"
			"program default2d\n"
			"{\n"
				"map $sourcecolour\n"
				"blendfunc blend\n"
			"}\n"
		"}\n"
		);
	GLBE_RenderToTexture(sceneblur_texture, r_nulltex, r_nulltex, false);
	R2D_ImageColours(1, 1, 1, gl_motionblur.value);
	R2D_Image(0, 0, vid.width, vid.height, cs-vs, ct+vt, cs+vs, ct-vt, shader);
	GLBE_RenderToTexture(r_nulltex, r_nulltex, r_nulltex, false);

	//grab the current image so we can feed that back into the next frame.
	GL_MTBind(0, GL_TEXTURE_2D, sceneblur_texture);
	//copy the image into the texture so that we can play with it next frame too!
	qglCopyTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 0, 0, vwidth, vheight, 0);
	qglTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	qglTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
#endif
}

/*FIXME: we could use geometry shaders to draw to all 6 faces at once*/
qboolean R_RenderScene_Cubemap(void)
{
	int cmapsize = 512;
	int i;
	static vec3_t ang[6] =
				{	{0, -90, 0}, {0, 90, 0},
					{90, 0, 0}, {-90, 0, 0},
					{0, 0, 0}, {0, -180, 0}	};
	vec3_t saveang;

	vrect_t vrect;
	vrect_t prect;

	shader_t *shader;
	int facemask;

	/*needs glsl*/
	if (!gl_config.arb_shader_objects)
		return false;
	if (!ffov.value)
		return false;
	if (!cls.allow_postproc)
		return false;

	facemask = 0;
	if (ffov.value < 0)
	{
		shader = R_RegisterShader("postproc_panorama",
				"{\n"
					"program postproc_panorama\n"
					"{\n"
						"map $sourcecube\n"
					"}\n"
				"}\n"
				);

		//panoramic view needs at most the four sides
		facemask |= 1<<4; /*front view*/
		if (ffov.value < -90)
		{
			facemask |= (1<<0) | (1<<1); /*side views*/
			if (ffov.value < -270)
				facemask |= 1<<5; /*back view*/
		}
	}
	else
	{
		shader = R_RegisterShader("postproc_fisheye",
				"{\n"
					"program postproc_fisheye\n"
					"{\n"
						"map $sourcecube\n"
					"}\n"
				"}\n"
				);

		//fisheye view sees up to a full sphere
		facemask |= 1<<4; /*front view*/
		if (ffov.value > 77)
			facemask |= (1<<0) | (1<<1) | (1<<2) | (1<<3); /*side/top/bottom views*/
		if (ffov.value > 270)
			facemask |= 1<<5; /*back view*/
	}

//fixme: should already have the vrect somewhere.
	SCR_VRectForPlayer(&vrect, r_refdef.currentplayernum);
	prect.x = (vrect.x * vid.pixelwidth)/vid.width;
	prect.width = (vrect.width * vid.pixelwidth)/vid.width;
	prect.y = (vrect.y * vid.pixelheight)/vid.height;
	prect.height = (vrect.height * vid.pixelheight)/vid.height;

	if (r_config.texture_non_power_of_two)
	{
		if (prect.width < prect.height)
			cmapsize = prect.width;
		else
			cmapsize = prect.height;
	}
	else
	{
		while (cmapsize > prect.width || cmapsize > prect.height)
		{
			cmapsize /= 2;
		}
	}

	VectorCopy(r_refdef.viewangles, saveang);
	saveang[2] = 0;

	if (!TEXVALID(scenepp_postproc_cube) || cmapsize != scenepp_postproc_cube_size)
	{
		if (TEXVALID(scenepp_postproc_cube))
			GL_DestroyTexture(scenepp_postproc_cube);
		scenepp_postproc_cube = GL_AllocNewTexture("***fish***", cmapsize, cmapsize, 0);

		GL_MTBind(0, GL_TEXTURE_CUBE_MAP_ARB, scenepp_postproc_cube);
		for (i = 0; i < 6; i++)
			qglCopyTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB + i, 0, GL_RGB, 0, 0, cmapsize, cmapsize, 0);
		qglTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
		qglTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
		qglTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
		qglTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

		scenepp_postproc_cube_size = cmapsize;
	}

	vrect = r_refdef.vrect;	//save off the old vrect

	r_refdef.vrect.width = (cmapsize * vid.width) / vid.pixelwidth;
	r_refdef.vrect.height = (cmapsize * vid.height) / vid.pixelheight;
	r_refdef.vrect.x = 0;
	r_refdef.vrect.y = prect.y;

	ang[0][0] = -saveang[0];
	ang[0][1] = -90;
	ang[0][2] = -saveang[0];

	ang[1][0] = -saveang[0];
	ang[1][1] = 90;
	ang[1][2] = saveang[0];
	ang[5][0] = -saveang[0]*2;
	for (i = 0; i < 6; i++)
	{
		if (!(facemask & (1<<i)))
			continue;

		r_refdef.fov_x = 90;
		r_refdef.fov_y = 90;
		r_refdef.viewangles[0] = saveang[0]+ang[i][0];
		r_refdef.viewangles[1] = saveang[1]+ang[i][1];
		r_refdef.viewangles[2] = saveang[2]+ang[i][2];

		R_Clear ();

		GL_SetShaderState2D(false);

		// render normal view
		R_RenderScene ();

		GL_MTBind(0, GL_TEXTURE_CUBE_MAP_ARB, scenepp_postproc_cube);
//FIXME: use a render target instead.
		qglCopyTexSubImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB + i, 0, 0, 0, 0, vid.pixelheight - (prect.y + cmapsize), cmapsize, cmapsize);
	}

	r_refdef.vrect = vrect;

	qglViewport (prect.x, vid.pixelheight - (prect.y+prect.height), prect.width, prect.height);

	// go 2d
	qglMatrixMode(GL_PROJECTION);
	qglPushMatrix();
	qglLoadIdentity ();
	qglOrtho  (0, vid.width, vid.height, 0, -99999, 99999);
	qglMatrixMode(GL_MODELVIEW);
	qglPushMatrix();
	qglLoadIdentity ();

	// draw it through the shader
	R2D_Image(0, 0, vid.width, vid.height, -0.5, 0.5, 0.5, -0.5, shader);

	//revert the matricies
	qglMatrixMode(GL_PROJECTION);
	qglPopMatrix();
	qglMatrixMode(GL_MODELVIEW);
	qglPopMatrix();

	return true;
}

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

r_refdef must be set before the first call
================
*/
void GLR_RenderView (void)
{
	double	time1 = 0, time2;

	checkglerror();

	if (r_norefresh.value || !vid.pixelwidth || !vid.pixelheight)
	{
		GL_DoSwap();
		return;
	}

	if (!(r_refdef.flags & Q2RDF_NOWORLDMODEL))
		if (!r_worldentity.model || !cl.worldmodel)
		{
			GL_DoSwap();
			return;
		}
//		Sys_Error ("R_RenderView: NULL worldmodel");



	if (qglPNTrianglesiATI)
	{
		if (gl_ati_truform_type.ival)
		{	//linear
			qglPNTrianglesiATI(GL_PN_TRIANGLES_NORMAL_MODE_ATI, GL_PN_TRIANGLES_NORMAL_MODE_LINEAR_ATI);
			qglPNTrianglesiATI(GL_PN_TRIANGLES_POINT_MODE_ATI, GL_PN_TRIANGLES_POINT_MODE_CUBIC_ATI);
		}
		else
		{	//quadric
			qglPNTrianglesiATI(GL_PN_TRIANGLES_NORMAL_MODE_ATI, GL_PN_TRIANGLES_NORMAL_MODE_QUADRATIC_ATI);
			qglPNTrianglesiATI(GL_PN_TRIANGLES_POINT_MODE_ATI, GL_PN_TRIANGLES_POINT_MODE_CUBIC_ATI);
		}
	    qglPNTrianglesfATI(GL_PN_TRIANGLES_TESSELATION_LEVEL_ATI, gl_ati_truform_tesselation.value);
	}

	if (gl_finish.ival)
	{
		RSpeedMark();
		qglFinish ();
		RSpeedEnd(RSPEED_FINISH);
	}

	if (r_speeds.ival)
	{
		time1 = Sys_DoubleTime ();
		c_brush_polys = 0;
		c_alias_polys = 0;
	}

	if (!(r_refdef.flags & Q2RDF_NOWORLDMODEL) && R_RenderScene_Cubemap())
	{

	}
	else
	{
		GL_SetShaderState2D(false);

		R_Clear ();

	//	GLR_SetupFog ();

		// render normal view
		R_RenderScene ();
	}

//	qglDisable(GL_FOG);

	if (r_speeds.ival)
	{
//		glFinish ();
		time2 = Sys_DoubleTime ();

		RQuantAdd(RQUANT_MSECS, (int)((time2-time1)*1000000));

		RQuantAdd(RQUANT_WPOLYS, c_brush_polys);
		RQuantAdd(RQUANT_EPOLYS, c_alias_polys);
	//	Con_Printf ("%3i ms  %4i wpoly %4i epoly\n", (int)((time2-time1)*1000), c_brush_polys, c_alias_polys);
	}

	checkglerror();

	GL_Set2D (false);

	if (r_refdef.flags & Q2RDF_NOWORLDMODEL)
		return;

	if (r_bloom.value)
		R_BloomBlend();

	// SCENE POST PROCESSING
	// we check if we need to use any shaders - currently it's just waterwarp
	if ((r_waterwarp.value>0 && (r_viewcontents & FTECONTENTS_WATER)))
	{
		if (scenepp_waterwarp)
		{
			R2D_ScalePic(0, 0, vid.width, vid.height, scenepp_waterwarp);
		}
	}



	if (gl_motionblur.value>0 && gl_motionblur.value < 1 && qglCopyTexImage2D)
		R_RenderMotionBlur();

	if (*r_postprocshader.string)
	{
		shader_t *postproc = R_RegisterCustom(r_postprocshader.string, NULL, NULL);
		if (postproc)
		{
			R2D_ScalePic(0, 0, vid.width, vid.height, postproc);
		}
	}

	checkglerror();
}

#endif