shithub: qk1

ref: 57bae65b26afd0c01b4c65b3d7538cc96ef80ae8
dir: /r_light.c/

#include "quakedef.h"

int	r_dlightframecount;


/*
==================
R_AnimateLight
==================
*/
void R_AnimateLight (void)
{
	int			i,j,k;

	// light animations
	// 'm' is normal light, 'a' is no light, 'z' is double bright
	i = (int)(cl.time*10);
	for (j=0 ; j<Nlights ; j++)
	{
		if (!cl_lightstyle[j].length)
		{
			d_lightstylevalue[j] = 256;
			continue;
		}
		k = i % cl_lightstyle[j].length;
		k = cl_lightstyle[j].map[k] - 'a';
		k = k*22;
		d_lightstylevalue[j] = k;
	}
}


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

DYNAMIC LIGHTS

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

/*
=============
R_MarkLights
=============
*/
void R_MarkLights (dlight_t *light, int bit, mnode_t *node)
{
	mplane_t	*splitplane;
	float		dist;
	msurface_t	*surf;
	unsigned	i;

	if (node->contents < 0)
		return;

	splitplane = node->plane;
	dist = DotProduct (light->origin, splitplane->normal) - splitplane->dist;

	if (dist > light->radius)
	{
		R_MarkLights (light, bit, node->children[0]);
		return;
	}
	if (dist < -light->radius)
	{
		R_MarkLights (light, bit, node->children[1]);
		return;
	}

	// mark the polygons
	surf = cl.worldmodel->surfaces + node->firstsurface;
	for (i=0 ; i<node->numsurfaces ; i++, surf++)
	{
		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 (void)
{
	int		i;
	dlight_t	*l;

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

	for (i=0 ; i<MAX_DLIGHTS ; i++, l++)
	{
		if (l->die < cl.time || !l->radius)
			continue;
		R_MarkLights ( l, 1<<i, cl.worldmodel->nodes );
	}
}


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

LIGHT SAMPLING

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

static int
RecursiveLightPoint(mnode_t *node, vec3_t start, vec3_t end, int *r)
{
	float		front, back, frac;
	int			side;
	mplane_t	*plane;
	vec3_t		mid;
	msurface_t	*surf;
	int			s, t, ds, dt;
	unsigned	i;
	mtexinfo_t	*tex;
	byte		*lightmap;
	unsigned	scale;
	int			maps;

	if(node->contents < 0)
		return -1;		// didn't hit anything

	// calculate mid point

	// FIXME: optimize for axial
	plane = node->plane;
	front = DotProduct(start, plane->normal) - plane->dist;
	back = DotProduct(end, plane->normal) - plane->dist;
	side = front < 0;

	if((back < 0) == side)
		return RecursiveLightPoint(node->children[side], start, end, r);

	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
	if(RecursiveLightPoint(node->children[side], start, mid, r) >= 0)
		return 0;		// hit something

	if((back < 0) == side)
		return -1;		// didn't hit anything

	// check for impact on this node

	surf = cl.worldmodel->surfaces + node->firstsurface;
	for(i = 0; i < node->numsurfaces; i++, surf++){
		if(surf->flags & SURF_DRAWTILED)
			continue;	// no lightmaps

		tex = surf->texinfo;

		s = DotProductDouble(mid, tex->vecs[0]) + tex->vecs[0][3];
		t = DotProductDouble(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)
			return 0;

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

		lightmap = surf->samples;
		r[0] = r[1] = r[2] = 0;
		if(lightmap != nil){
			lightmap += (dt * ((surf->extents[0]>>4)+1) + ds) * 3;

			for(maps = 0; maps < MAXLIGHTMAPS && surf->styles[maps] != 255; maps++){
				scale = d_lightstylevalue[surf->styles[maps]];
				r[0] += lightmap[0] * scale;
				r[1] += lightmap[1] * scale;
				r[2] += lightmap[2] * scale;
				lightmap += ((surf->extents[0]>>4)+1) * ((surf->extents[1]>>4)+1) * 3;
			}

			r[0] >>= 8;
			r[1] >>= 8;
			r[2] >>= 8;
		}

		return 0;
	}

	// go down back side
	return RecursiveLightPoint(node->children[!side], mid, end, r);
}

void
R_LightPoint(vec3_t p, int *r)
{
	vec3_t		end;

	if (!cl.worldmodel->lightdata){
		r[0] = 255;
		r[1] = 255;
		r[2] = 255;
		return;
	}

	end[0] = p[0];
	end[1] = p[1];
	end[2] = p[2] - 2048;

	r[0] = r[1] = r[2] = -1024;
	RecursiveLightPoint (cl.worldmodel->nodes, p, end, r);
	r[0] = max(r[0], r_refdef.ambientlight[0]);
	r[1] = max(r[1], r_refdef.ambientlight[1]);
	r[2] = max(r[2], r_refdef.ambientlight[2]);
}