cm_load.c

quakeIII源码这个不用我多说吧

	cm.brushsides = Hunk_Alloc( ( BOX_SIDES + count ) * sizeof( *cm.brushsides ), h_high );
	cm.numBrushSides = count;

	out = cm.brushsides;	

	for ( i=0 ; i<count ; i++, in++, out++) {
		num = LittleLong( in->planeNum );
		out->plane = &cm.planes[num];
		out->shaderNum = LittleLong( in->shaderNum );
		if ( out->shaderNum < 0 || out->shaderNum >= cm.numShaders ) {
			Com_Error( ERR_DROP, "CMod_LoadBrushSides: bad shaderNum: %i", out->shaderNum );
		}
		out->surfaceFlags = cm.shaders[out->shaderNum].surfaceFlags;
	}
}


/*
=================
CMod_LoadEntityString
=================
*/
void CMod_LoadEntityString( lump_t *l ) {
	cm.entityString = Hunk_Alloc( l->filelen, h_high );
	cm.numEntityChars = l->filelen;
	Com_Memcpy (cm.entityString, cmod_base + l->fileofs, l->filelen);
}

/*
=================
CMod_LoadVisibility
=================
*/
#define	VIS_HEADER	8
void CMod_LoadVisibility( lump_t *l ) {
	int		len;
	byte	*buf;

    len = l->filelen;
	if ( !len ) {
		cm.clusterBytes = ( cm.numClusters + 31 ) & ~31;
		cm.visibility = Hunk_Alloc( cm.clusterBytes, h_high );
		Com_Memset( cm.visibility, 255, cm.clusterBytes );
		return;
	}
	buf = cmod_base + l->fileofs;

	cm.vised = qtrue;
	cm.visibility = Hunk_Alloc( len, h_high );
	cm.numClusters = LittleLong( ((int *)buf)[0] );
	cm.clusterBytes = LittleLong( ((int *)buf)[1] );
	Com_Memcpy (cm.visibility, buf + VIS_HEADER, len - VIS_HEADER );
}

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


/*
=================
CMod_LoadPatches
=================
*/
#define	MAX_PATCH_VERTS		1024
void CMod_LoadPatches( lump_t *surfs, lump_t *verts ) {
	drawVert_t	*dv, *dv_p;
	dsurface_t	*in;
	int			count;
	int			i, j;
	int			c;
	cPatch_t	*patch;
	vec3_t		points[MAX_PATCH_VERTS];
	int			width, height;
	int			shaderNum;

	in = (void *)(cmod_base + surfs->fileofs);
	if (surfs->filelen % sizeof(*in))
		Com_Error (ERR_DROP, "MOD_LoadBmodel: funny lump size");
	cm.numSurfaces = count = surfs->filelen / sizeof(*in);
	cm.surfaces = Hunk_Alloc( cm.numSurfaces * sizeof( cm.surfaces[0] ), h_high );

	dv = (void *)(cmod_base + verts->fileofs);
	if (verts->filelen % sizeof(*dv))
		Com_Error (ERR_DROP, "MOD_LoadBmodel: funny lump size");

	// scan through all the surfaces, but only load patches,
	// not planar faces
	for ( i = 0 ; i < count ; i++, in++ ) {
		if ( LittleLong( in->surfaceType ) != MST_PATCH ) {
			continue;		// ignore other surfaces
		}
		// FIXME: check for non-colliding patches

		cm.surfaces[ i ] = patch = Hunk_Alloc( sizeof( *patch ), h_high );

		// load the full drawverts onto the stack
		width = LittleLong( in->patchWidth );
		height = LittleLong( in->patchHeight );
		c = width * height;
		if ( c > MAX_PATCH_VERTS ) {
			Com_Error( ERR_DROP, "ParseMesh: MAX_PATCH_VERTS" );
		}

		dv_p = dv + LittleLong( in->firstVert );
		for ( j = 0 ; j < c ; j++, dv_p++ ) {
			points[j][0] = LittleFloat( dv_p->xyz[0] );
			points[j][1] = LittleFloat( dv_p->xyz[1] );
			points[j][2] = LittleFloat( dv_p->xyz[2] );
		}

		shaderNum = LittleLong( in->shaderNum );
		patch->contents = cm.shaders[shaderNum].contentFlags;
		patch->surfaceFlags = cm.shaders[shaderNum].surfaceFlags;

		// create the internal facet structure
		patch->pc = CM_GeneratePatchCollide( width, height, points );
	}
}

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

unsigned CM_LumpChecksum(lump_t *lump) {
	return LittleLong (Com_BlockChecksum (cmod_base + lump->fileofs, lump->filelen));
}

unsigned CM_Checksum(dheader_t *header) {
	unsigned checksums[16];
	checksums[0] = CM_LumpChecksum(&header->lumps[LUMP_SHADERS]);
	checksums[1] = CM_LumpChecksum(&header->lumps[LUMP_LEAFS]);
	checksums[2] = CM_LumpChecksum(&header->lumps[LUMP_LEAFBRUSHES]);
	checksums[3] = CM_LumpChecksum(&header->lumps[LUMP_LEAFSURFACES]);
	checksums[4] = CM_LumpChecksum(&header->lumps[LUMP_PLANES]);
	checksums[5] = CM_LumpChecksum(&header->lumps[LUMP_BRUSHSIDES]);
	checksums[6] = CM_LumpChecksum(&header->lumps[LUMP_BRUSHES]);
	checksums[7] = CM_LumpChecksum(&header->lumps[LUMP_MODELS]);
	checksums[8] = CM_LumpChecksum(&header->lumps[LUMP_NODES]);
	checksums[9] = CM_LumpChecksum(&header->lumps[LUMP_SURFACES]);
	checksums[10] = CM_LumpChecksum(&header->lumps[LUMP_DRAWVERTS]);

	return LittleLong(Com_BlockChecksum(checksums, 11 * 4));
}

/*
==================
CM_LoadMap

Loads in the map and all submodels
==================
*/
void CM_LoadMap( const char *name, qboolean clientload, int *checksum ) {
	int				*buf;
	int				i;
	dheader_t		header;
	int				length;
	static unsigned	last_checksum;

	if ( !name || !name[0] ) {
		Com_Error( ERR_DROP, "CM_LoadMap: NULL name" );
	}

#ifndef BSPC
	cm_noAreas = Cvar_Get ("cm_noAreas", "0", CVAR_CHEAT);
	cm_noCurves = Cvar_Get ("cm_noCurves", "0", CVAR_CHEAT);
	cm_playerCurveClip = Cvar_Get ("cm_playerCurveClip", "1", CVAR_ARCHIVE|CVAR_CHEAT );
#endif
	Com_DPrintf( "CM_LoadMap( %s, %i )\n", name, clientload );

	if ( !strcmp( cm.name, name ) && clientload ) {
		*checksum = last_checksum;
		return;
	}

	// free old stuff
	Com_Memset( &cm, 0, sizeof( cm ) );
	CM_ClearLevelPatches();

	if ( !name[0] ) {
		cm.numLeafs = 1;
		cm.numClusters = 1;
		cm.numAreas = 1;
		cm.cmodels = Hunk_Alloc( sizeof( *cm.cmodels ), h_high );
		*checksum = 0;
		return;
	}

	//
	// load the file
	//
#ifndef BSPC
	length = FS_ReadFile( name, (void **)&buf );
#else
	length = LoadQuakeFile((quakefile_t *) name, (void **)&buf);
#endif

	if ( !buf ) {
		Com_Error (ERR_DROP, "Couldn't load %s", name);
	}

	last_checksum = LittleLong (Com_BlockChecksum (buf, length));
	*checksum = last_checksum;

	header = *(dheader_t *)buf;
	for (i=0 ; i<sizeof(dheader_t)/4 ; i++) {
		((int *)&header)[i] = LittleLong ( ((int *)&header)[i]);
	}

	if ( header.version != BSP_VERSION ) {
		Com_Error (ERR_DROP, "CM_LoadMap: %s has wrong version number (%i should be %i)"
		, name, header.version, BSP_VERSION );
	}

	cmod_base = (byte *)buf;

	// load into heap
	CMod_LoadShaders( &header.lumps[LUMP_SHADERS] );
	CMod_LoadLeafs (&header.lumps[LUMP_LEAFS]);
	CMod_LoadLeafBrushes (&header.lumps[LUMP_LEAFBRUSHES]);
	CMod_LoadLeafSurfaces (&header.lumps[LUMP_LEAFSURFACES]);
	CMod_LoadPlanes (&header.lumps[LUMP_PLANES]);
	CMod_LoadBrushSides (&header.lumps[LUMP_BRUSHSIDES]);
	CMod_LoadBrushes (&header.lumps[LUMP_BRUSHES]);
	CMod_LoadSubmodels (&header.lumps[LUMP_MODELS]);
	CMod_LoadNodes (&header.lumps[LUMP_NODES]);
	CMod_LoadEntityString (&header.lumps[LUMP_ENTITIES]);
	CMod_LoadVisibility( &header.lumps[LUMP_VISIBILITY] );
	CMod_LoadPatches( &header.lumps[LUMP_SURFACES], &header.lumps[LUMP_DRAWVERTS] );

	// we are NOT freeing the file, because it is cached for the ref
	FS_FreeFile (buf);

	CM_InitBoxHull ();

	CM_FloodAreaConnections ();

	// allow this to be cached if it is loaded by the server
	if ( !clientload ) {
		Q_strncpyz( cm.name, name, sizeof( cm.name ) );
	}
}

/*
==================
CM_ClearMap
==================
*/
void CM_ClearMap( void ) {
	Com_Memset( &cm, 0, sizeof( cm ) );
	CM_ClearLevelPatches();
}

/*
==================
CM_ClipHandleToModel
==================
*/
cmodel_t	*CM_ClipHandleToModel( clipHandle_t handle ) {
	if ( handle < 0 ) {
		Com_Error( ERR_DROP, "CM_ClipHandleToModel: bad handle %i", handle );
	}
	if ( handle < cm.numSubModels ) {
		return &cm.cmodels[handle];
	}
	if ( handle == BOX_MODEL_HANDLE ) {
		return &box_model;
	}
	if ( handle < MAX_SUBMODELS ) {
		Com_Error( ERR_DROP, "CM_ClipHandleToModel: bad handle %i < %i < %i", 
			cm.numSubModels, handle, MAX_SUBMODELS );
	}
	Com_Error( ERR_DROP, "CM_ClipHandleToModel: bad handle %i", handle + MAX_SUBMODELS );

	return NULL;

}

/*
==================
CM_InlineModel
==================
*/
clipHandle_t	CM_InlineModel( int index ) {
	if ( index < 0 || index >= cm.numSubModels ) {
		Com_Error (ERR_DROP, "CM_InlineModel: bad number");
	}
	return index;
}

int		CM_NumClusters( void ) {
	return cm.numClusters;
}

int		CM_NumInlineModels( void ) {
	return cm.numSubModels;
}

char	*CM_EntityString( void ) {
	return cm.entityString;
}

int		CM_LeafCluster( int leafnum ) {
	if (leafnum < 0 || leafnum >= cm.numLeafs) {
		Com_Error (ERR_DROP, "CM_LeafCluster: bad number");
	}
	return cm.leafs[leafnum].cluster;
}

int		CM_LeafArea( int leafnum ) {
	if ( leafnum < 0 || leafnum >= cm.numLeafs ) {
		Com_Error (ERR_DROP, "CM_LeafArea: bad number");
	}
	return cm.leafs[leafnum].area;
}

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


/*
===================
CM_InitBoxHull

Set up the planes and nodes so that the six floats of a bounding box
can just be stored out and get a proper clipping hull structure.
===================
*/
void CM_InitBoxHull (void)
{
	int			i;
	int			side;
	cplane_t	*p;
	cbrushside_t	*s;

	box_planes = &cm.planes[cm.numPlanes];

	box_brush = &cm.brushes[cm.numBrushes];
	box_brush->numsides = 6;
	box_brush->sides = cm.brushsides + cm.numBrushSides;
	box_brush->contents = CONTENTS_BODY;

	box_model.leaf.numLeafBrushes = 1;
//	box_model.leaf.firstLeafBrush = cm.numBrushes;
	box_model.leaf.firstLeafBrush = cm.numLeafBrushes;
	cm.leafbrushes[cm.numLeafBrushes] = cm.numBrushes;

	for (i=0 ; i<6 ; i++)
	{
		side = i&1;

		// brush sides
		s = &cm.brushsides[cm.numBrushSides+i];
		s->plane = 	cm.planes + (cm.numPlanes+i*2+side);
		s->surfaceFlags = 0;

		// planes
		p = &box_planes[i*2];
		p->type = i>>1;
		p->signbits = 0;
		VectorClear (p->normal);
		p->normal[i>>1] = 1;

		p = &box_planes[i*2+1];
		p->type = 3 + (i>>1);
		p->signbits = 0;
		VectorClear (p->normal);
		p->normal[i>>1] = -1;

		SetPlaneSignbits( p );
	}	
}

/*
===================
CM_TempBoxModel

To keep everything totally uniform, bounding boxes are turned into small
BSP trees instead of being compared directly.
Capsules are handled differently though.
===================
*/
clipHandle_t CM_TempBoxModel( const vec3_t mins, const vec3_t maxs, int capsule ) {

	VectorCopy( mins, box_model.mins );
	VectorCopy( maxs, box_model.maxs );

	if ( capsule ) {
		return CAPSULE_MODEL_HANDLE;
	}

	box_planes[0].dist = maxs[0];
	box_planes[1].dist = -maxs[0];
	box_planes[2].dist = mins[0];
	box_planes[3].dist = -mins[0];
	box_planes[4].dist = maxs[1];
	box_planes[5].dist = -maxs[1];
	box_planes[6].dist = mins[1];
	box_planes[7].dist = -mins[1];
	box_planes[8].dist = maxs[2];
	box_planes[9].dist = -maxs[2];
	box_planes[10].dist = mins[2];
	box_planes[11].dist = -mins[2];

	VectorCopy( mins, box_brush->bounds[0] );
	VectorCopy( maxs, box_brush->bounds[1] );

	return BOX_MODEL_HANDLE;
}

/*
===================
CM_ModelBounds
===================
*/
void CM_ModelBounds( clipHandle_t model, vec3_t mins, vec3_t maxs ) {
	cmodel_t	*cmod;

	cmod = CM_ClipHandleToModel( model );
	VectorCopy( cmod->mins, mins );
	VectorCopy( cmod->maxs, maxs );
}