/*
 * Light.java
 * Copyright (C) 2003
 *
 * $Id: Light.java,v 1.3 2004-07-08 20:56:55 hzi Exp $
 */
/*
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.

*/
package jake2.render.jogl;

import java.nio.ByteBuffer;
import java.nio.FloatBuffer;
import java.util.Arrays;

import net.java.games.jogl.GL;

import jake2.Defines;
import jake2.Globals;
import jake2.client.dlight_t;
import jake2.client.lightstyle_t;
import jake2.game.GameBase;
import jake2.game.cplane_t;
import jake2.qcommon.longjmpException;
import jake2.render.mnode_t;
import jake2.render.msurface_t;
import jake2.render.mtexinfo_t;
import jake2.util.Lib;
import jake2.util.Math3D;

/**
 * Light
 *  
 * @author cwei
 */
public abstract class Light extends Warp {
	// r_light.c

	int r_dlightframecount;

	static final int DLIGHT_CUTOFF = 64;

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

	DYNAMIC LIGHTS BLEND RENDERING

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

	void R_RenderDlight (dlight_t light)
	{
		int i, j;
		float	a;
		float[] v = {0, 0, 0};
		float	rad;

		rad = light.intensity * 0.35f;

		Math3D.VectorSubtract (light.origin, r_origin, v);

		gl.glBegin (GL.GL_TRIANGLE_FAN);
		gl.glColor3f (light.color[0]*0.2f, light.color[1]*0.2f, light.color[2]*0.2f);
		for (i=0 ; i<3 ; i++)
			v[i] = light.origin[i] - vpn[i]*rad;
		gl.glVertex3fv (v);
		gl.glColor3f (0,0,0);
		for (i=16 ; i>=0 ; i--)
		{
			a = (float)(i/16.0f * Math.PI*2);
			for (j=0 ; j<3 ; j++)
				v[j] = (float)(light.origin[j] + vright[j]*Math.cos(a)*rad
					+ vup[j]*Math.sin(a)*rad);
			gl.glVertex3fv (v);
		}
		gl.glEnd ();
	}

	/*
	=============
	R_RenderDlights
	=============
	*/
	void R_RenderDlights()
	{
		int i;
		dlight_t l;

		if (gl_flashblend.value == 0)
			return;

		r_dlightframecount = r_framecount + 1;	// because the count hasn't
												//  advanced yet for this frame
		gl.glDepthMask(false);
		gl.glDisable(GL.GL_TEXTURE_2D);
		gl.glShadeModel (GL.GL_SMOOTH);
		gl.glEnable (GL.GL_BLEND);
		gl.glBlendFunc (GL.GL_ONE, GL.GL_ONE);

		for (i=0 ; i<r_newrefdef.num_dlights ; i++)
		{
			l = r_newrefdef.dlights[i];
			R_RenderDlight (l);
		}

		gl.glColor3f (1,1,1);
		gl.glDisable(GL.GL_BLEND);
		gl.glEnable(GL.GL_TEXTURE_2D);
		gl.glBlendFunc(GL.GL_SRC_ALPHA, GL.GL_ONE_MINUS_SRC_ALPHA);
		gl.glDepthMask(true);
	}


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

	DYNAMIC LIGHTS

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

	/*
	=============
	R_MarkLights
	=============
	*/
	void R_MarkLights (dlight_t light, int bit, mnode_t node)
	{
		cplane_t splitplane;
		float dist;
		msurface_t	surf;
		int i;
		int sidebit;
	
		if (node.contents != -1)
			return;

		splitplane = node.plane;
		dist = Math3D.DotProduct (light.origin, splitplane.normal) - splitplane.dist;
	
		if (dist > light.intensity - DLIGHT_CUTOFF)
		{
			R_MarkLights (light, bit, node.children[0]);
			return;
		}
		if (dist < -light.intensity + DLIGHT_CUTOFF)
		{
			R_MarkLights (light, bit, node.children[1]);
			return;
		}
		
		// mark the polygons
		for (i=0 ; i<node.numsurfaces ; i++)
		{

			surf = r_worldmodel.surfaces[node.firstsurface + i];

			/*
			 * cwei
			 * bugfix for dlight behind the walls
			 */			
			dist = Math3D.DotProduct (light.origin, surf.plane.normal) - surf.plane.dist;
			sidebit = (dist >= 0) ? 0 : Defines.SURF_PLANEBACK;
			if ( (surf.flags & Defines.SURF_PLANEBACK) != sidebit )
				continue;
			/*
			 * cwei
			 * bugfix end
			 */			

			if (surf.dlightframe != r_dlightframecount)
			{
				surf.dlightbits = 0;
				surf.dlightframe = r_dlightframecount;
			}
			surf.dlightbits |= bit;
		}

		R_MarkLights (light, bit, node.children[0]);
		R_MarkLights (light, bit, node.children[1]);
	}


	/*
	=============
	R_PushDlights
	=============
	*/
	void R_PushDlights()
	{
		int i;
		dlight_t l;

		if (gl_flashblend.value != 0)
			return;

		r_dlightframecount = r_framecount + 1;	// because the count hasn't
												//  advanced yet for this frame
		for (i=0 ; i<r_newrefdef.num_dlights ; i++) {
			l = r_newrefdef.dlights[i];
			R_MarkLights( l, 1<<i, r_worldmodel.nodes[0] );
		}
	}


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

	LIGHT SAMPLING

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

	float[] pointcolor = {0, 0, 0}; // vec3_t
	cplane_t lightplane; // used as shadow plane
	float[] lightspot = {0, 0, 0}; // vec3_t

	int RecursiveLightPoint (mnode_t node, float[] start, float[] end)
	{
		float front, back, frac;
		boolean side;
		int sideIndex;
		cplane_t plane;
		float[] mid = {0, 0, 0};
		msurface_t surf;
		int s, t, ds, dt;
		int i;
		mtexinfo_t tex;
		ByteBuffer lightmap;
		int maps;
		int r;

		if (node.contents != -1)
			return -1;		// didn't hit anything
	
		// calculate mid point

		// FIXME: optimize for axial
		plane = node.plane;
		front = Math3D.DotProduct (start, plane.normal) - plane.dist;
		back = Math3D.DotProduct (end, plane.normal) - plane.dist;
		side = (front < 0);
		sideIndex = (side) ? 1 : 0;
	
		if ( (back < 0) == side)
			return RecursiveLightPoint (node.children[sideIndex], start, end);
	
		frac = front / (front-back);
		mid[0] = start[0] + (end[0] - start[0])*frac;
		mid[1] = start[1] + (end[1] - start[1])*frac;
		mid[2] = start[2] + (end[2] - start[2])*frac;
	
		// go down front side	
		r = RecursiveLightPoint (node.children[sideIndex], start, mid);
		if (r >= 0)
			return r;		// hit something
		
		if ( (back < 0) == side )
			return -1; // didn't hit anuthing
		
		// check for impact on this node
		Math3D.VectorCopy (mid, lightspot);
		lightplane = plane;

		int surfIndex = node.firstsurface;
		for (i=0 ; i<node.numsurfaces ; i++, surfIndex++)
		{
			surf = r_worldmodel.surfaces[surfIndex];
			
			if ((surf.flags & (Defines.SURF_DRAWTURB | Defines.SURF_DRAWSKY)) != 0) 
				continue;	// no lightmaps

			tex = surf.texinfo;
		
			s = (int)(Math3D.DotProduct (mid, tex.vecs[0]) + tex.vecs[0][3]);
			t = (int)(Math3D.DotProduct (mid, tex.vecs[1]) + tex.vecs[1][3]);

			if (s < surf.texturemins[0] || t < surf.texturemins[1])
				continue;
		
			ds = s - surf.texturemins[0];
			dt = t - surf.texturemins[1];
		
			if ( ds > surf.extents[0] || dt > surf.extents[1] )
				continue;

			if (surf.samples == null)
				return 0;

			ds >>= 4;
			dt >>= 4;

			//surf.samples.reset();
			lightmap = surf.samples.slice();

			int lightmapIndex = 0;
			Math3D.VectorCopy (Globals.vec3_origin, pointcolor);
			if (lightmap != null)
			{
				float[] scale = {0, 0, 0};

//				lightmap += 3*(dt * ((surf.extents[0]>>4)+1) + ds);
				lightmapIndex += 3 * (dt * ((surf.extents[0] >> 4) + 1) + ds);

				for (maps = 0 ; maps < Defines.MAXLIGHTMAPS && surf.styles[maps] != (byte)255; maps++)
				{
					for (i=0 ; i<3 ; i++)
						scale[i] = gl_modulate.value * r_newrefdef.lightstyles[surf.styles[maps] & 0xFF].rgb[i];

					pointcolor[0] += (lightmap.get(lightmapIndex + 0) & 0xFF) * scale[0] * (1.0f/255);
					pointcolor[1] += (lightmap.get(lightmapIndex + 1) & 0xFF) * scale[1] * (1.0f/255);
					pointcolor[2] += (lightmap.get(lightmapIndex + 2) & 0xFF) * scale[2] * (1.0f/255);
//					lightmap += 3*((surf.extents[0]>>4)+1) *
//							((surf.extents[1]>>4)+1);
					lightmapIndex += 3 * ((surf.extents[0] >> 4) + 1) * ((surf.extents[1] >> 4) + 1);
				}
			}
		
			return 1;
		}

		// go down back side
		return RecursiveLightPoint (node.children[1 - sideIndex], mid, end);
	}

	/*
	===============
	R_LightPoint
	===============
	*/
	void R_LightPoint (float[] p, float[] color)
	{
		assert (p.length == 3) : "vec3_t bug";
		assert (color.length == 3) : "rgb bug";

		float[] end = {0, 0, 0};
		float r;
		int lnum;
		dlight_t dl;
		float light;
		float[] dist = {0, 0, 0};
		float add;
	
		if (r_worldmodel.lightdata == null)
		{
			color[0] = color[1] = color[2] = 1.0f;
			return;
		}
	
		end[0] = p[0];
		end[1] = p[1];
		end[2] = p[2] - 2048;
	
		r = RecursiveLightPoint(r_worldmodel.nodes[0], p, end);
	
		if (r == -1)
		{
			Math3D.VectorCopy (GameBase.vec3_origin, color);
		}
		else
		{
			Math3D.VectorCopy (pointcolor, color);
		}

		//
		// add dynamic lights
		//
		light = 0;
		for (lnum=0 ; lnum<r_newrefdef.num_dlights ; lnum++)
		{
			dl = r_newrefdef.dlights[lnum];
			
			Math3D.VectorSubtract (currententity.origin, dl.origin, dist);
			add = dl.intensity - Math3D.VectorLength(dist);
			add *= (1.0f/256);
			if (add > 0)
			{
				Math3D.VectorMA (color, add, dl.color, color);
			}
		}

		Math3D.VectorScale (color, gl_modulate.value, color);
	}


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

	float[] s_blocklights = new float[34 * 34 * 3];
	
	/*
	===============
	R_AddDynamicLights
	===============
	*/
	void R_AddDynamicLights(msurface_t surf)
	{
		int lnum;
		int sd, td;
		float fdist, frad, fminlight;
		float[] impact = {0, 0, 0};
		float[] local = {0, 0, 0};
		int s, t;
		int i;
		int smax, tmax;
		mtexinfo_t tex;
		dlight_t dl;
		float[] pfBL;
		float fsacc, ftacc;

		smax = (surf.extents[0]>>4)+1;
		tmax = (surf.extents[1]>>4)+1;
		tex = surf.texinfo;

		for (lnum=0 ; lnum<r_newrefdef.num_dlights ; lnum++)
		{
			if ( (surf.dlightbits & (1<<lnum)) == 0 )
				continue;		// not lit by this light

			dl = r_newrefdef.dlights[lnum];
			frad = dl.intensity;
			fdist = Math3D.DotProduct (dl.origin, surf.plane.normal) -
					surf.plane.dist;
			frad -= Math.abs(fdist);
			// rad is now the highest intensity on the plane

			fminlight = DLIGHT_CUTOFF;	// FIXME: make configurable?
			if (frad < fminlight)
				continue;
			fminlight = frad - fminlight;

			for (i=0 ; i<3 ; i++)
			{
				impact[i] = dl.origin[i] -
						surf.plane.normal[i]*fdist;
			}

			local[0] = Math3D.DotProduct (impact, tex.vecs[0]) + tex.vecs[0][3] - surf.texturemins[0];
			local[1] = Math3D.DotProduct (impact, tex.vecs[1]) + tex.vecs[1][3] - surf.texturemins[1];

			pfBL = s_blocklights;
			int pfBLindex = 0;
			for (t = 0, ftacc = 0 ; t<tmax ; t++, ftacc += 16)
			{
				td = (int)(local[1] - ftacc);
				if ( td < 0 )
					td = -td;

				for ( s=0, fsacc = 0 ; s<smax ; s++, fsacc += 16, pfBLindex += 3)
				{
					sd = (int)( local[0] - fsacc );

					if ( sd < 0 )
						sd = -sd;

					if (sd > td)
						fdist = sd + (td>>1);
					else
						fdist = td + (sd>>1);

					if ( fdist < fminlight )
					{
						pfBL[pfBLindex + 0] += ( frad - fdist ) * dl.color[0];
						pfBL[pfBLindex + 1] += ( frad - fdist ) * dl.color[1];
						pfBL[pfBLindex + 2] += ( frad - fdist ) * dl.color[2];
					}
				}
			}
		}
	}


	/*
	** R_SetCacheState
	*/
	void R_SetCacheState( msurface_t surf )
	{
		int maps;

		for (maps = 0 ; maps < Defines.MAXLIGHTMAPS && surf.styles[maps] != (byte)255 ;
			 maps++)
		{
			surf.cached_light[maps] = r_newrefdef.lightstyles[surf.styles[maps] & 0xFF].white;
		}
	}

	/*
	===============
	R_BuildLightMap

	Combine and scale multiple lightmaps into the floating format in blocklights
	===============
	*/
	void R_BuildLightMap(msurface_t surf, ByteBuffer dest, int stride)
	{
		int smax, tmax;
		int r, g, b, a, max;
		int i, j, size;
		ByteBuffer lightmap;
		float[] scale = {0, 0, 0, 0};
		int nummaps;
		float[] bl;
		lightstyle_t	style;
		int monolightmap;

		if ( (surf.texinfo.flags & (Defines.SURF_SKY | Defines.SURF_TRANS33 | Defines.SURF_TRANS66 | Defines.SURF_WARP)) != 0 )
			ri.Sys_Error(Defines.ERR_DROP, "R_BuildLightMap called for non-lit surface");

		smax = (surf.extents[0] >> 4) + 1;
		tmax = (surf.extents[1] >> 4) + 1;
		size = smax * tmax;
		if (size > ((s_blocklights.length * Defines.SIZE_OF_FLOAT) >> 4) )
			ri.Sys_Error(Defines.ERR_DROP, "Bad s_blocklights size");

		try {
			// set to full bright if no light data
			if (surf.samples == null)
			{
				int maps;
	
				for (i=0 ; i<size*3 ; i++)
					s_blocklights[i] = 255;
	
				for (maps = 0 ; maps < Defines.MAXLIGHTMAPS && surf.styles[maps] != (byte)255; maps++)
				{
					style = r_newrefdef.lightstyles[surf.styles[maps] & 0xFF];
				}
				// goto store;
				throw new longjmpException();
			}
	
			// count the # of maps
			for ( nummaps = 0 ; nummaps < Defines.MAXLIGHTMAPS && surf.styles[nummaps] != (byte)255 ;
				 nummaps++)
				;
	
			//surf.samples.reset();	
			lightmap = surf.samples.slice();
	
			// add all the lightmaps
			if ( nummaps == 1 )
			{
				int maps;
	
				for (maps = 0 ; maps < Defines.MAXLIGHTMAPS && surf.styles[maps] != (byte)255 ;
					 maps++)
				{
					bl = s_blocklights;
					int blp = 0;
	
					for (i=0 ; i<3 ; i++)
						scale[i] = gl_modulate.value * r_newrefdef.lightstyles[surf.styles[maps] & 0xFF].rgb[i];
	
					if ( scale[0] == 1.0F &&
						 scale[1] == 1.0F &&
						 scale[2] == 1.0F )
					{
						for (i=0 ; i<size ; i++)
						{
							bl[blp++] = lightmap.get() & 0xFF;
							bl[blp++] = lightmap.get() & 0xFF;
							bl[blp++] = lightmap.get() & 0xFF;
						}
					}
					else
					{
						for (i=0 ; i<size ; i++)
						{
							bl[blp++] = (lightmap.get() & 0xFF) * scale[0];
							bl[blp++] = (lightmap.get()  & 0xFF) * scale[1];
							bl[blp++] = (lightmap.get() & 0xFF) * scale[2];
						}
					}
					//lightmap += size*3;		// skip to next lightmap
				}
			}
			else
			{
				int maps;
	
	//			memset( s_blocklights, 0, sizeof( s_blocklights[0] ) * size * 3 );
	
				Arrays.fill(s_blocklights, 0, size * 3, 0.0f);
	
				for (maps = 0 ; maps < Defines.MAXLIGHTMAPS && surf.styles[maps] != (byte)255 ;
					 maps++)
				{
					bl = s_blocklights;
					int blp = 0;
	
					for (i=0 ; i<3 ; i++)
						scale[i] = gl_modulate.value*r_newrefdef.lightstyles[surf.styles[maps] & 0xFF].rgb[i];
	
					if ( scale[0] == 1.0F &&
						 scale[1] == 1.0F &&
						 scale[2] == 1.0F )
					{
						for (i=0 ; i<size ; i++)
						{
							bl[blp++] += lightmap.get() & 0xFF;
							bl[blp++] += lightmap.get() & 0xFF;
							bl[blp++] += lightmap.get() & 0xFF;
						}
					}
					else
					{
						for (i=0 ; i<size ; i++)
						{
							bl[blp++] += (lightmap.get() & 0xFF) * scale[0];
							bl[blp++] += (lightmap.get() & 0xFF) * scale[1];
							bl[blp++] += (lightmap.get() & 0xFF) * scale[2];
						}
					}
					//lightmap += size*3;		// skip to next lightmap
				}
			}
	
			// add all the dynamic lights
			if (surf.dlightframe == r_framecount)
				R_AddDynamicLights(surf);
	
		// label store:
		} catch (longjmpException store) {}
	
		// put into texture format
		stride -= (smax<<2);
		bl = s_blocklights;
		int blp = 0;

		monolightmap = gl_monolightmap.string.charAt(0);

		int destp = 0;

		if ( monolightmap == '0' )
		{
			for (i=0 ; i<tmax ; i++, destp += stride)
			{
				dest.position(destp);
				
				for (j=0 ; j<smax ; j++)
				{
				
					r = (int)bl[blp++];
					g = (int)bl[blp++];
					b = (int)bl[blp++];

					// catch negative lights
					if (r < 0)
						r = 0;
					if (g < 0)
						g = 0;
					if (b < 0)
						b = 0;

					/*
					** determine the brightest of the three color components
					*/
					if (r > g)
						max = r;
					else
						max = g;
					if (b > max)
						max = b;

					/*
					** alpha is ONLY used for the mono lightmap case.  For this reason
					** we set it to the brightest of the color components so that 
					** things don't get too dim.
					*/
					a = max;

					/*
					** rescale all the color components if the intensity of the greatest
					** channel exceeds 1.0
					*/
					if (max > 255)
					{
						float t = 255.0F / max;

						r = (int)(r*t);
						g = (int)(g*t);
						b = (int)(b*t);
						a = (int)(a*t);
					}
					dest.put((byte)r).put((byte)g).put((byte)b).put((byte)a);
					destp += 4;
				}
			}
		}
		else
		{
			for (i=0 ; i<tmax ; i++, destp += stride)
			{
				dest.position(destp);

				for (j=0 ; j<smax ; j++)
				{
				
					r = (int) bl[blp++];
					g = (int) bl[blp++];
					b = (int) bl[blp++];

					// catch negative lights
					if (r < 0)
						r = 0;
					if (g < 0)
						g = 0;
					if (b < 0)
						b = 0;

					/*
					** determine the brightest of the three color components
					*/
					if (r > g)
						max = r;
					else
						max = g;
					if (b > max)
						max = b;

					/*
					** alpha is ONLY used for the mono lightmap case.  For this reason
					** we set it to the brightest of the color components so that 
					** things don't get too dim.
					*/
					a = max;

					/*
					** rescale all the color components if the intensity of the greatest
					** channel exceeds 1.0
					*/
					if (max > 255)
					{
						float t = 255.0F / max;

						r = (int)(r*t);
						g = (int)(g*t);
						b = (int)(b*t);
						a = (int)(a*t);
					}

					/*
					** So if we are doing alpha lightmaps we need to set the R, G, and B
					** components to 0 and we need to set alpha to 1-alpha.
					*/
					switch ( monolightmap )
					{
					case 'L':
					case 'I':
						r = a;
						g = b = 0;
						break;
					case 'C':
						// try faking colored lighting
						a = 255 - ((r+g+b)/3);
						r *= a/255.0f;
						g *= a/255.0f;
						b *= a/255.0f;
						break;
					case 'A':
					default:
						r = g = b = 0;
						a = 255 - a;
						break;
					}

					dest.put((byte)r).put((byte)g).put((byte)b).put((byte)a);
					destp += 4;
				}
			}
		}
	}

}