/*
Copyright (C) 1997-2001 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_warp.c -- sky and water polygons

#include "r_local.h"

extern	model_t	*loadmodel;
msurface_t	*warpface;

#define	SUBDIVIDE_SIZE	64
//#define	SUBDIVIDE_SIZE	1024

void BoundPoly (int numverts, float *verts, vec3_t mins, vec3_t maxs)
{
	int		i, j;
	float	*v;

	mins[0] = mins[1] = mins[2] = 9999;
	maxs[0] = maxs[1] = maxs[2] = -9999;
	v = verts;
	for (i=0 ; i<numverts ; i++)
		for (j=0 ; j<3 ; j++, v++)
		{
			if (*v < mins[j])
				mins[j] = *v;
			if (*v > maxs[j])
				maxs[j] = *v;
		}
}

void SubdividePolygon (int numverts, float *verts)
{
	int		i, j, k;
	vec3_t	mins, maxs;
	float	m;
	float	*v;
	vec3_t	front[64], back[64];
	int		f, b;
	float	dist[64];
	float	frac;
	glpoly_t	*poly;
	float	s, t;
	vec3_t	total;
	float	total_s, total_t;

	if (numverts > 60)
		VID_Error (ERR_DROP, "numverts = %i", numverts);

	BoundPoly (numverts, verts, mins, maxs);

	for (i=0 ; i<3 ; i++)
	{
		m = (mins[i] + maxs[i]) * 0.5;
		m = SUBDIVIDE_SIZE * floor (m/SUBDIVIDE_SIZE + 0.5);
		if (maxs[i] - m < 8)
			continue;
		if (m - mins[i] < 8)
			continue;

		// cut it
		v = verts + i;
		for (j=0 ; j<numverts ; j++, v+= 3)
			dist[j] = *v - m;

		// wrap cases
		dist[j] = dist[0];
		v-=i;
		VectorCopy (verts, v);

		f = b = 0;
		v = verts;
		for (j=0 ; j<numverts ; j++, v+= 3)
		{
			if (dist[j] >= 0)
			{
				VectorCopy (v, front[f]);
				f++;
			}
			if (dist[j] <= 0)
			{
				VectorCopy (v, back[b]);
				b++;
			}
			if (dist[j] == 0 || dist[j+1] == 0)
				continue;
			if ( (dist[j] > 0) != (dist[j+1] > 0) )
			{
				// clip point
				frac = dist[j] / (dist[j] - dist[j+1]);
				for (k=0 ; k<3 ; k++)
					front[f][k] = back[b][k] = v[k] + frac*(v[3+k] - v[k]);
				f++;
				b++;
			}
		}

		SubdividePolygon (f, front[0]);
		SubdividePolygon (b, back[0]);
		return;
	}

	// add a point in the center to help keep warp valid
	poly = Hunk_Alloc (sizeof(glpoly_t) + ((numverts-4)+2) * VERTEXSIZE*sizeof(float));
	poly->next = warpface->polys;
	warpface->polys = poly;
	poly->numverts = numverts+2;
	VectorClear (total);
	total_s = 0;
	total_t = 0;
	for (i=0 ; i<numverts ; i++, verts+= 3)
	{
		VectorCopy (verts, poly->verts[i+1]);
		s = DotProduct (verts, warpface->texinfo->vecs[0]);
		t = DotProduct (verts, warpface->texinfo->vecs[1]);

		total_s += s;
		total_t += t;
		VectorAdd (total, verts, total);

		poly->verts[i+1][3] = s;
		poly->verts[i+1][4] = t;
	}

	VectorScale (total, (1.0/numverts), poly->verts[0]);
	poly->verts[0][3] = total_s/numverts;
	poly->verts[0][4] = total_t/numverts;

	// copy first vertex to last
	memcpy (poly->verts[i+1], poly->verts[1], sizeof(poly->verts[0]));
}

/*
================
GL_SubdivideSurface

Breaks a polygon up along axial 64 unit
boundaries so that turbulent and sky warps
can be done reasonably.
================
*/
void GL_SubdivideSurface (msurface_t *fa)
{
	vec3_t		verts[64];
	int			numverts;
	int			i;
	int			lindex;
	float		*vec;

	warpface = fa;

	//
	// convert edges back to a normal polygon
	//
	numverts = 0;
	for (i=0 ; i<fa->numedges ; i++)
	{
		lindex = loadmodel->surfedges[fa->firstedge + i];

		if (lindex > 0)
			vec = loadmodel->vertexes[loadmodel->edges[lindex].v[0]].position;
		else
			vec = loadmodel->vertexes[loadmodel->edges[-lindex].v[1]].position;
		VectorCopy (vec, verts[numverts]);
		numverts++;
	}

	SubdividePolygon (numverts, verts[0]);
}

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



// speed up sin calculations - Ed
float	r_turbsin[] =
{
	#include "warpsin.h"
};
#define TURBSCALE (256.0 / (2 * M_PI))

// MrG - texture shader stuffs
#define DST_SIZE 16
unsigned int dst_texture = 0;



/*
===============
CreateDSTTex

Create the texture which warps texture shaders
===============
*/
void CreateDSTTex()
{
	char data[DST_SIZE][DST_SIZE][2];
	int x,y;

	for (x=0;x<DST_SIZE;x++)
		for (y=0;y<DST_SIZE;y++)
		{
			data[x][y][0]=rand()%255-128;
			data[x][y][1]=rand()%255-128;
		}

	qglGenTextures(1,&dst_texture);
	qglBindTexture(GL_TEXTURE_2D, dst_texture);
	qglTexImage2D(GL_TEXTURE_2D, 0, GL_DSDT8_NV, DST_SIZE, DST_SIZE, 0, GL_DSDT_NV,
				GL_BYTE, data);
	qglTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	qglTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	qglTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
	qglTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
	qglTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
}
//end MrG


/*
===============
ResetDSTTex

Resets the texture which warps texture shaders
Needed after a vid_restart
===============
*/
void ResetDSTTex ()
{
	dst_texture = 0;
}


/*
=============
EmitWaterPolys

Does a water warp on the pre-fragmented glpoly_t chain
=============
*/

// Knightmare added- Psychospaz's lightmaps on alpha surfaces
void EmitWaterPolys (msurface_t *fa, qboolean light, float alpha)
{
	glpoly_t	*p, *bp;
	float		*v;
	int			i;
	float		s, t, os, ot;
	float		scroll;
	float		rdt = r_newrefdef.time;
	vec3_t		point;
	//MrG
	float		dstscroll;
	float		args[7] = {0,0.05,0,0,0.04,0,0};

	//if (light) //Quake2Max add
	//	SetVertexOverbrights(true);
	/*
	Texture Shader waterwarp
	Damn this looks fantastic

	WHY texture shaders? because I can!
	- MrG
	*/
	// Knightmare- allow disabling of this
	// some maps may have too many warp surfaces, giving the vid card a fit
	if (gl_config.NV_texshaders && gl_pixel_shader_warp->value)
	{
		qglActiveTextureARB(GL_TEXTURE0_ARB);
		if (!dst_texture)
			CreateDSTTex();
		qglBindTexture(GL_TEXTURE_2D,dst_texture);
		qglTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_TEXTURE_2D);

	    qglActiveTextureARB(GL_TEXTURE1_ARB);
		qglBindTexture(GL_TEXTURE_2D,fa->texinfo->image->texnum);
		qglEnable(GL_TEXTURE_2D);

		qglTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_TEXTURE_2D);
		qglTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_OFFSET_TEXTURE_2D_NV);
		qglTexEnvi(GL_TEXTURE_SHADER_NV, GL_PREVIOUS_TEXTURE_INPUT_NV, GL_TEXTURE0_ARB);
		qglTexEnvfv(GL_TEXTURE_SHADER_NV, GL_OFFSET_TEXTURE_MATRIX_NV, &args[1]);

		// Psychospaz's lighting
		// use this so that the new water isnt so bright anymore
		// We wont bother check for the extensions availabiliy, as the hardware required
		// to make it this far definately supports this as well
		qglTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_EXT);

		qglEnable(GL_TEXTURE_SHADER_NV);
		dstscroll = -64 * ( (r_newrefdef.time*0.15) - (int)(r_newrefdef.time*0.15) );
	}
	//end MrG's changes

	if (fa->texinfo->flags & SURF_FLOWING)
		scroll = -64 * ( (r_newrefdef.time*0.5) - (int)(r_newrefdef.time*0.5) );
	else
		scroll = 0;

	for (bp=fa->polys; bp; bp=bp->next)
	{
		p = bp;

		// Knightmare added- Psychospaz's lightmaps on alpha surfaces
		if (light)
			GL_ShadeModel (GL_SMOOTH);
		else
			qglColor4f( gl_state.inverse_intensity, gl_state.inverse_intensity, gl_state.inverse_intensity, alpha);

		qglBegin (GL_TRIANGLE_FAN);
		for (i=0, v=p->verts[0]; i<p->numverts; i++, v+=VERTEXSIZE)
		{
			os = v[3];
			ot = v[4];

			VectorCopy(v, point);

		#if !id386
			s = os + r_turbsin[(int)((ot*0.125+r_newrefdef.time) * TURBSCALE) & 255];
		#else
			s = os + r_turbsin[Q_ftol( ((ot*0.125+rdt) * TURBSCALE) ) & 255];
		#endif
			s += scroll;
			s *= (1.0/64);

		#if !id386
			t = ot + r_turbsin[(int)((os*0.125+rdt) * TURBSCALE) & 255];
		#else
			t = ot + r_turbsin[Q_ftol( ((os*0.125+rdt) * TURBSCALE) ) & 255];
		#endif
			t *= (1.0/64);

//=============== Water waves ========================
			if (!(fa->texinfo->flags & SURF_FLOWING) && fa->plane->normal[2] > 0
				&& fa->plane->normal[2] > fa->plane->normal[0]
				&& fa->plane->normal[2] > fa->plane->normal[1])
			{
			#if !id386
				point[2] = v[2] + r_waterwave->value * sin(v[0]*0.025+r_newrefdef.time) * sin(v[2]*0.05+r_newrefdef.time)
							 + r_waterwave->value * sin(v[1]*0.025+r_newrefdef.time) * sin(v[2]*0.05+r_newrefdef.time);
			#else
				point[2] = v[2] + r_waterwave->value * sin(v[0]*0.025+rdt) * sin(v[2]*0.05+r_newrefdef.time)
							 + r_waterwave->value * sin(v[1]*0.025+rdt) * sin(v[2]*0.05+rdt);
			#endif
			}
//=============== End water waves ====================

			// Knightmare added- Psychospaz's lightmaps on alpha surfaces
			if (light)// && p->vertexlight)
			{	//Quake2Max change
				/*qglColor4ub( 
					p->vertexlight[i*3+0], 
					p->vertexlight[i*3+1], 
					p->vertexlight[i*3+2], 
					alpha*255);*/
				vec3_t color;
				R_LightPoint (point, color, false);
				R_MaxColorVec (color);
				qglColor4f( color[0], color[1], color[2], alpha);
			}

			// MrG - texture shader waterwarp
			// Knightmare- allow disabling of this
			// some maps may have too many warp surfaces, giving the vid card a fit
			if (gl_config.NV_texshaders && gl_pixel_shader_warp->value)
			{ 
				qglMTexCoord2fSGIS(GL_TEXTURE0_ARB,(v[3]+dstscroll)*0.015625,v[4]*0.015625);
				qglMTexCoord2fSGIS(GL_TEXTURE1_ARB,s,t);
			}
			else
				qglTexCoord2f(s,t);
			//end MrG

			qglVertex3fv (point);
		}
		qglEnd ();

		// Knightmare added- Psychospaz's lightmaps on alpha surfaces
		if (light)
			GL_ShadeModel (GL_FLAT);
	}
	// MrG - texture shader waterwarp
	// Knightmare- allow disabling of this
	// some maps may have too many warp surfaces, giving the vid card a fit
	if (gl_config.NV_texshaders && gl_pixel_shader_warp->value)
	{ 
		qglDisable(GL_TEXTURE_2D);
		qglTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE); // Psychospaz's lighting
		qglActiveTextureARB(GL_TEXTURE0_ARB);
		qglDisable(GL_TEXTURE_SHADER_NV);
	}
	//end MrG

	//if (light) //Quake2Max add
	//	SetVertexOverbrights(false); 
}

/*
void EmitWaterPolys (msurface_t *fa)
{
	glpoly_t	*p, *bp;
	float		*v;
	int			i;
	float		s, t, os, ot;
	float		scroll;
	float		rdt = r_newrefdef.time;
	//MrG
	float		dstscroll;
	float		args[7] = {0,0.05,0,0,0.04,0,0};

	vec3_t		nv;		// Knightmare- water waves

	
	//	Texture Shader waterwarp
	//	Damn this looks fantastic
	//	WHY texture shaders? because I can!
	//	- MrG
	
	// Knightmare- allow disabling of this
	// some maps may have too many warp surfaces, giving the vid card a fit
	if (gl_config.NV_texshaders && gl_pixel_shader_warp->value)
	{
		qglActiveTextureARB(GL_TEXTURE0_ARB);
		if (!dst_texture)
			CreateDSTTex();
		qglBindTexture(GL_TEXTURE_2D,dst_texture);
		qglTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_TEXTURE_2D);

	    qglActiveTextureARB(GL_TEXTURE1_ARB);
		qglBindTexture(GL_TEXTURE_2D,fa->texinfo->image->texnum);
		qglEnable(GL_TEXTURE_2D);
		qglEnable(GL_TEXTURE_SHADER_NV);

		qglTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_TEXTURE_2D);
		qglTexEnvi(GL_TEXTURE_SHADER_NV, GL_SHADER_OPERATION_NV, GL_OFFSET_TEXTURE_2D_NV);
		qglTexEnvi(GL_TEXTURE_SHADER_NV, GL_PREVIOUS_TEXTURE_INPUT_NV, GL_TEXTURE0_ARB);
		qglTexEnvfv(GL_TEXTURE_SHADER_NV, GL_OFFSET_TEXTURE_MATRIX_NV, &args[1]);

		dstscroll = -64 * ( (r_newrefdef.time*0.15) - (int)(r_newrefdef.time*0.15) );
	}
	//end MrG's changes

	if (fa->texinfo->flags & SURF_FLOWING)
		scroll = -64 * ( (r_newrefdef.time*0.5) - (int)(r_newrefdef.time*0.5) );
	else
		scroll = 0;

	for (bp=fa->polys ; bp ; bp=bp->next)
	{
		p = bp;

		qglBegin (GL_TRIANGLE_FAN);
		for (i=0,v=p->verts[0] ; i<p->numverts ; i++, v+=VERTEXSIZE)
		{
			os = v[3];
			ot = v[4];

#if !id386
			s = os + r_turbsin[(int)((ot*0.125+r_newrefdef.time) * TURBSCALE) & 255];
#else
			s = os + r_turbsin[Q_ftol( ((ot*0.125+rdt) * TURBSCALE) ) & 255];
#endif
			s += scroll;
			s *= (1.0/64);

#if !id386
			t = ot + r_turbsin[(int)((os*0.125+rdt) * TURBSCALE) & 255];
#else
			t = ot + r_turbsin[Q_ftol( ((os*0.125+rdt) * TURBSCALE) ) & 255];
#endif
			t *= (1.0/64);

			// MrG - texture shader waterwarp
			// Knightmare- allow disabling of this
			// some maps may have too many warp surfaces, giving the vid card a fit
			if (gl_config.NV_texshaders && gl_pixel_shader_warp->value)
			{ 
				qglMTexCoord2fSGIS(GL_TEXTURE0_ARB,(v[3]+dstscroll)*0.015625,v[4]*0.015625);
				qglMTexCoord2fSGIS(GL_TEXTURE1_ARB,s,t);
			}
			else
				qglTexCoord2f(s,t);
			//end MrG

//=============== Water waves ========================
			if (!(fa->texinfo->flags & SURF_FLOWING))
			{
				nv[0] = v[0];
				nv[1] = v[1];
			#if !id386
				nv[2] = v[2] + r_waterwave->value * sin(v[0]*0.025+r_newrefdef.time) * sin(v[2]*0.05+r_newrefdef.time)
							 + r_waterwave->value * sin(v[1]*0.025+r_newrefdef.time) * sin(v[2]*0.05+r_newrefdef.time);
			#else
				nv[2] = v[2] + r_waterwave->value * sin(v[0]*0.025+rdt) * sin(v[2]*0.05+r_newrefdef.time)
							 + r_waterwave->value * sin(v[1]*0.025+rdt) * sin(v[2]*0.05+rdt);
			#endif
				qglVertex3fv (nv);
			}
			else
//=============== End water waves ====================

				qglVertex3fv (v);
		}
		qglEnd ();
	}
	// MrG - texture shader waterwarp
	// Knightmare- allow disabling of this
	// some maps may have too many warp surfaces, giving the vid card a fit
	if (gl_config.NV_texshaders && gl_pixel_shader_warp->value)
	{ 
		qglDisable(GL_TEXTURE_2D);
		qglActiveTextureARB(GL_TEXTURE0_ARB);
		qglDisable(GL_TEXTURE_SHADER_NV);
	}
	//end MrG
}
*/