light.java

Jake2是一个Java 3D游戏引擎.

/*
 * Light.java
 * Copyright (C) 2003
 *
 * $Id: Light.java,v 1.4 2005/05/07 17:21:42 cawe 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.lwjgl;

import jake2.Defines;
import jake2.Globals;
import jake2.client.dlight_t;
import jake2.game.cplane_t;
import jake2.qcommon.Com;
import jake2.render.*;
import jake2.util.Math3D;
import jake2.util.Vec3Cache;

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

import org.lwjgl.opengl.GL11;

/**
 * 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

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

	// stack variable
	private final float[] v = {0, 0, 0};
	/**
	 * R_RenderDlight
	 */
	void R_RenderDlight(dlight_t light)
	{
		float rad = light.intensity * 0.35f;

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

		gl.glBegin (GL11.GL_TRIANGLE_FAN);
		gl.glColor3f (light.color[0]*0.2f, light.color[1]*0.2f, light.color[2]*0.2f);
		int i;
		for (i=0 ; i<3 ; i++)
			v[i] = light.origin[i] - vpn[i]*rad;
		
		gl.glVertex3f(v[0], v[1], v[2]);
		gl.glColor3f (0,0,0);

		int j;
		float a;
		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.glVertex3f(v[0], v[1], v[2]);
		}
		gl.glEnd ();
	}

	/**
	 * R_RenderDlights
	 */
	void R_RenderDlights()
	{
		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(GL11.GL_TEXTURE_2D);
		gl.glShadeModel (GL11.GL_SMOOTH);
		gl.glEnable (GL11.GL_BLEND);
		gl.glBlendFunc (GL11.GL_ONE, GL11.GL_ONE);

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

		gl.glColor3f (1,1,1);
		gl.glDisable(GL11.GL_BLEND);
		gl.glEnable(GL11.GL_TEXTURE_2D);
		gl.glBlendFunc(GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA);
		gl.glDepthMask(true);
	}


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

	DYNAMIC LIGHTS

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

	/**
	 * R_MarkLights
	 */
	void R_MarkLights (dlight_t light, int bit, mnode_t node)
	{
		if (node.contents != -1)
			return;

		cplane_t 	splitplane = node.plane;
		float 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
		msurface_t	surf;
		int sidebit;
		for (int 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()
	{
		if (gl_flashblend.value != 0)
			return;

		r_dlightframecount = r_framecount + 1;	// because the count hasn't
												//  advanced yet for this frame
		dlight_t l;
		for (int 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

	/**
	 * RecursiveLightPoint
	 * @param node
	 * @param start
	 * @param end
	 * @return
	 */
	int RecursiveLightPoint (mnode_t node, float[] start, float[] end)
	{
		if (node.contents != -1)
			return -1;		// didn't hit anything

		// calculate mid point

		// FIXME: optimize for axial
		cplane_t plane = node.plane;
		float front = Math3D.DotProduct (start, plane.normal) - plane.dist;
		float back = Math3D.DotProduct (end, plane.normal) - plane.dist;
		boolean side = (front < 0);
		int sideIndex = (side) ? 1 : 0;
	
		if ( (back < 0) == side)
			return RecursiveLightPoint (node.children[sideIndex], start, end);
	
		float frac = front / (front-back);
		float[] mid = Vec3Cache.get();
		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	
		int r = RecursiveLightPoint (node.children[sideIndex], start, mid);
		if (r >= 0) {
			Vec3Cache.release(); // mid
			return r;		// hit something
		}
		
		if ( (back < 0) == side ) {
			Vec3Cache.release(); // mid
			return -1; // didn't hit anuthing
		}
		
		// check for impact on this node
		Math3D.VectorCopy (mid, lightspot);
		lightplane = plane;
		int surfIndex = node.firstsurface;

		msurface_t surf;
		int s, t, ds, dt;
		mtexinfo_t tex;
		ByteBuffer lightmap;
		int maps;
		for (int 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;

			lightmap = surf.samples;
			int lightmapIndex = 0;

			Math3D.VectorCopy (Globals.vec3_origin, pointcolor);
			if (lightmap != null)
			{
				float[] rgb;
				lightmapIndex += 3 * (dt * ((surf.extents[0] >> 4) + 1) + ds);

				float scale0, scale1, scale2;
				for (maps = 0 ; maps < Defines.MAXLIGHTMAPS && surf.styles[maps] != (byte)255; maps++)
				{
					rgb = r_newrefdef.lightstyles[surf.styles[maps] & 0xFF].rgb;
					scale0 = gl_modulate.value * rgb[0];
					scale1 = gl_modulate.value * rgb[1];
					scale2 = gl_modulate.value * rgb[2];

					pointcolor[0] += (lightmap.get(lightmapIndex + 0) & 0xFF) * scale0 * (1.0f/255);
					pointcolor[1] += (lightmap.get(lightmapIndex + 1) & 0xFF) * scale1 * (1.0f/255);
					pointcolor[2] += (lightmap.get(lightmapIndex + 2) & 0xFF) * scale2 * (1.0f/255);
					lightmapIndex += 3 * ((surf.extents[0] >> 4) + 1) * ((surf.extents[1] >> 4) + 1);
				}
			}
			Vec3Cache.release(); // mid
			return 1;
		}

		// go down back side
		r = RecursiveLightPoint (node.children[1 - sideIndex], mid, end);
		Vec3Cache.release(); // mid
		return r;
	}

	// stack variable
	private final float[] end = {0, 0, 0};
	/**
	 * R_LightPoint
	 */
	void R_LightPoint (float[] p, float[] color)
	{
		assert (p.length == 3) : "vec3_t bug";
		assert (color.length == 3) : "rgb bug";

		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;
	
		float r = RecursiveLightPoint(r_worldmodel.nodes[0], p, end);
	
		if (r == -1)
		{
			Math3D.VectorCopy (Globals.vec3_origin, color);
		}
		else
		{
			Math3D.VectorCopy (pointcolor, color);
		}

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