r_bsp.c

quake1 dos源代码最新版本

/*
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_bsp.c

#include "quakedef.h"
#include "r_local.h"

//
// current entity info
//
qboolean		insubmodel;
entity_t		*currententity;
vec3_t			modelorg, base_modelorg;
								// modelorg is the viewpoint reletive to
								// the currently rendering entity
vec3_t			r_entorigin;	// the currently rendering entity in world
								// coordinates

float			entity_rotation[3][3];

vec3_t			r_worldmodelorg;

int				r_currentbkey;

typedef enum {touchessolid, drawnode, nodrawnode} solidstate_t;

#define MAX_BMODEL_VERTS	500			// 6K
#define MAX_BMODEL_EDGES	1000		// 12K

static mvertex_t	*pbverts;
static bedge_t		*pbedges;
static int			numbverts, numbedges;

static mvertex_t	*pfrontenter, *pfrontexit;

static qboolean		makeclippededge;


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

/*
================
R_EntityRotate
================
*/
void R_EntityRotate (vec3_t vec)
{
	vec3_t	tvec;

	VectorCopy (vec, tvec);
	vec[0] = DotProduct (entity_rotation[0], tvec);
	vec[1] = DotProduct (entity_rotation[1], tvec);
	vec[2] = DotProduct (entity_rotation[2], tvec);
}


/*
================
R_RotateBmodel
================
*/
void R_RotateBmodel (void)
{
	float	angle, s, c, temp1[3][3], temp2[3][3], temp3[3][3];

// TODO: should use a look-up table
// TODO: should really be stored with the entity instead of being reconstructed
// TODO: could cache lazily, stored in the entity
// TODO: share work with R_SetUpAliasTransform

// yaw
	angle = currententity->angles[YAW];
	angle = angle * M_PI*2 / 360;
	s = sin(angle);
	c = cos(angle);

	temp1[0][0] = c;
	temp1[0][1] = s;
	temp1[0][2] = 0;
	temp1[1][0] = -s;
	temp1[1][1] = c;
	temp1[1][2] = 0;
	temp1[2][0] = 0;
	temp1[2][1] = 0;
	temp1[2][2] = 1;


// pitch
	angle = currententity->angles[PITCH];
	angle = angle * M_PI*2 / 360;
	s = sin(angle);
	c = cos(angle);

	temp2[0][0] = c;
	temp2[0][1] = 0;
	temp2[0][2] = -s;
	temp2[1][0] = 0;
	temp2[1][1] = 1;
	temp2[1][2] = 0;
	temp2[2][0] = s;
	temp2[2][1] = 0;
	temp2[2][2] = c;

	R_ConcatRotations (temp2, temp1, temp3);

// roll
	angle = currententity->angles[ROLL];
	angle = angle * M_PI*2 / 360;
	s = sin(angle);
	c = cos(angle);

	temp1[0][0] = 1;
	temp1[0][1] = 0;
	temp1[0][2] = 0;
	temp1[1][0] = 0;
	temp1[1][1] = c;
	temp1[1][2] = s;
	temp1[2][0] = 0;
	temp1[2][1] = -s;
	temp1[2][2] = c;

	R_ConcatRotations (temp1, temp3, entity_rotation);

//
// rotate modelorg and the transformation matrix
//
	R_EntityRotate (modelorg);
	R_EntityRotate (vpn);
	R_EntityRotate (vright);
	R_EntityRotate (vup);

	R_TransformFrustum ();
}


/*
================
R_RecursiveClipBPoly
================
*/
void R_RecursiveClipBPoly (bedge_t *pedges, mnode_t *pnode, msurface_t *psurf)
{
	bedge_t		*psideedges[2], *pnextedge, *ptedge;
	int			i, side, lastside;
	float		dist, frac, lastdist;
	mplane_t	*splitplane, tplane;
	mvertex_t	*pvert, *plastvert, *ptvert;
	mnode_t		*pn;

	psideedges[0] = psideedges[1] = NULL;

	makeclippededge = false;

// transform the BSP plane into model space
// FIXME: cache these?
	splitplane = pnode->plane;
	tplane.dist = splitplane->dist -
			DotProduct(r_entorigin, splitplane->normal);
	tplane.normal[0] = DotProduct (entity_rotation[0], splitplane->normal);
	tplane.normal[1] = DotProduct (entity_rotation[1], splitplane->normal);
	tplane.normal[2] = DotProduct (entity_rotation[2], splitplane->normal);

// clip edges to BSP plane
	for ( ; pedges ; pedges = pnextedge)
	{
		pnextedge = pedges->pnext;

	// set the status for the last point as the previous point
	// FIXME: cache this stuff somehow?
		plastvert = pedges->v[0];
		lastdist = DotProduct (plastvert->position, tplane.normal) -
				   tplane.dist;

		if (lastdist > 0)
			lastside = 0;
		else
			lastside = 1;

		pvert = pedges->v[1];

		dist = DotProduct (pvert->position, tplane.normal) - tplane.dist;

		if (dist > 0)
			side = 0;
		else
			side = 1;

		if (side != lastside)
		{
		// clipped
			if (numbverts >= MAX_BMODEL_VERTS)
				return;

		// generate the clipped vertex
			frac = lastdist / (lastdist - dist);
			ptvert = &pbverts[numbverts++];
			ptvert->position[0] = plastvert->position[0] +
					frac * (pvert->position[0] -
					plastvert->position[0]);
			ptvert->position[1] = plastvert->position[1] +
					frac * (pvert->position[1] -
					plastvert->position[1]);
			ptvert->position[2] = plastvert->position[2] +
					frac * (pvert->position[2] -
					plastvert->position[2]);

		// split into two edges, one on each side, and remember entering
		// and exiting points
		// FIXME: share the clip edge by having a winding direction flag?
			if (numbedges >= (MAX_BMODEL_EDGES - 1))
			{
				Con_Printf ("Out of edges for bmodel\n");
				return;
			}

			ptedge = &pbedges[numbedges];
			ptedge->pnext = psideedges[lastside];
			psideedges[lastside] = ptedge;
			ptedge->v[0] = plastvert;
			ptedge->v[1] = ptvert;

			ptedge = &pbedges[numbedges + 1];
			ptedge->pnext = psideedges[side];
			psideedges[side] = ptedge;
			ptedge->v[0] = ptvert;
			ptedge->v[1] = pvert;

			numbedges += 2;

			if (side == 0)
			{
			// entering for front, exiting for back
				pfrontenter = ptvert;
				makeclippededge = true;
			}
			else
			{
				pfrontexit = ptvert;
				makeclippededge = true;
			}
		}
		else
		{
		// add the edge to the appropriate side
			pedges->pnext = psideedges[side];
			psideedges[side] = pedges;
		}
	}

// if anything was clipped, reconstitute and add the edges along the clip
// plane to both sides (but in opposite directions)
	if (makeclippededge)
	{
		if (numbedges >= (MAX_BMODEL_EDGES - 2))
		{
			Con_Printf ("Out of edges for bmodel\n");
			return;
		}

		ptedge = &pbedges[numbedges];
		ptedge->pnext = psideedges[0];
		psideedges[0] = ptedge;
		ptedge->v[0] = pfrontexit;
		ptedge->v[1] = pfrontenter;

		ptedge = &pbedges[numbedges + 1];
		ptedge->pnext = psideedges[1];
		psideedges[1] = ptedge;
		ptedge->v[0] = pfrontenter;
		ptedge->v[1] = pfrontexit;

		numbedges += 2;
	}

// draw or recurse further
	for (i=0 ; i<2 ; i++)
	{
		if (psideedges[i])
		{
		// draw if we've reached a non-solid leaf, done if all that's left is a
		// solid leaf, and continue down the tree if it's not a leaf
			pn = pnode->children[i];

		// we're done with this branch if the node or leaf isn't in the PVS
			if (pn->visframe == r_visframecount)
			{
				if (pn->contents < 0)
				{
					if (pn->contents != CONTENTS_SOLID)
					{
						r_currentbkey = ((mleaf_t *)pn)->key;
						R_RenderBmodelFace (psideedges[i], psurf);
					}
				}
				else
				{
					R_RecursiveClipBPoly (psideedges[i], pnode->children[i],
									  psurf);
				}
			}
		}
	}
}


/*
================
R_DrawSolidClippedSubmodelPolygons
================
*/
void R_DrawSolidClippedSubmodelPolygons (model_t *pmodel)
{
	int			i, j, lindex;
	vec_t		dot;
	msurface_t	*psurf;
	int			numsurfaces;
	mplane_t	*pplane;
	mvertex_t	bverts[MAX_BMODEL_VERTS];
	bedge_t		bedges[MAX_BMODEL_EDGES], *pbedge;
	medge_t		*pedge, *pedges;