tr_bsp.c

3D 游戏界的大牛人 John Carmack 终于放出了 Q3 的源代码

	surf->data = (surfaceType_t *)tri;

	// copy vertexes
	ClearBounds( tri->bounds[0], tri->bounds[1] );
	verts += LittleLong( ds->firstVert );
	for ( i = 0 ; i < numVerts ; i++ ) {
		for ( j = 0 ; j < 3 ; j++ ) {
			tri->verts[i].xyz[j] = LittleFloat( verts[i].xyz[j] );
			tri->verts[i].normal[j] = LittleFloat( verts[i].normal[j] );
		}
		AddPointToBounds( tri->verts[i].xyz, tri->bounds[0], tri->bounds[1] );
		for ( j = 0 ; j < 2 ; j++ ) {
			tri->verts[i].st[j] = LittleFloat( verts[i].st[j] );
			tri->verts[i].lightmap[j] = LittleFloat( verts[i].lightmap[j] );
		}

		R_ColorShiftLightingBytes( verts[i].color, tri->verts[i].color );
	}

	// copy indexes
	indexes += LittleLong( ds->firstIndex );
	for ( i = 0 ; i < numIndexes ; i++ ) {
		tri->indexes[i] = LittleLong( indexes[i] );
		if ( tri->indexes[i] < 0 || tri->indexes[i] >= numVerts ) {
			ri.Error( ERR_DROP, "Bad index in triangle surface" );
		}
	}
}

/*
===============
ParseFlare
===============
*/
static void ParseFlare( dsurface_t *ds, drawVert_t *verts, msurface_t *surf, int *indexes ) {
	srfFlare_t		*flare;
	int				i;

	// get fog volume
	surf->fogIndex = LittleLong( ds->fogNum ) + 1;

	// get shader
	surf->shader = ShaderForShaderNum( ds->shaderNum, LIGHTMAP_BY_VERTEX );
	if ( r_singleShader->integer && !surf->shader->isSky ) {
		surf->shader = tr.defaultShader;
	}

	flare = ri.Hunk_Alloc( sizeof( *flare ), h_low );
	flare->surfaceType = SF_FLARE;

	surf->data = (surfaceType_t *)flare;

	for ( i = 0 ; i < 3 ; i++ ) {
		flare->origin[i] = LittleFloat( ds->lightmapOrigin[i] );
		flare->color[i] = LittleFloat( ds->lightmapVecs[0][i] );
		flare->normal[i] = LittleFloat( ds->lightmapVecs[2][i] );
	}
}


/*
=================
R_MergedWidthPoints

returns true if there are grid points merged on a width edge
=================
*/
int R_MergedWidthPoints(srfGridMesh_t *grid, int offset) {
	int i, j;

	for (i = 1; i < grid->width-1; i++) {
		for (j = i + 1; j < grid->width-1; j++) {
			if ( fabs(grid->verts[i + offset].xyz[0] - grid->verts[j + offset].xyz[0]) > .1) continue;
			if ( fabs(grid->verts[i + offset].xyz[1] - grid->verts[j + offset].xyz[1]) > .1) continue;
			if ( fabs(grid->verts[i + offset].xyz[2] - grid->verts[j + offset].xyz[2]) > .1) continue;
			return qtrue;
		}
	}
	return qfalse;
}

/*
=================
R_MergedHeightPoints

returns true if there are grid points merged on a height edge
=================
*/
int R_MergedHeightPoints(srfGridMesh_t *grid, int offset) {
	int i, j;

	for (i = 1; i < grid->height-1; i++) {
		for (j = i + 1; j < grid->height-1; j++) {
			if ( fabs(grid->verts[grid->width * i + offset].xyz[0] - grid->verts[grid->width * j + offset].xyz[0]) > .1) continue;
			if ( fabs(grid->verts[grid->width * i + offset].xyz[1] - grid->verts[grid->width * j + offset].xyz[1]) > .1) continue;
			if ( fabs(grid->verts[grid->width * i + offset].xyz[2] - grid->verts[grid->width * j + offset].xyz[2]) > .1) continue;
			return qtrue;
		}
	}
	return qfalse;
}

/*
=================
R_FixSharedVertexLodError_r

NOTE: never sync LoD through grid edges with merged points!

FIXME: write generalized version that also avoids cracks between a patch and one that meets half way?
=================
*/
void R_FixSharedVertexLodError_r( int start, srfGridMesh_t *grid1 ) {
	int j, k, l, m, n, offset1, offset2, touch;
	srfGridMesh_t *grid2;

	for ( j = start; j < s_worldData.numsurfaces; j++ ) {
		//
		grid2 = (srfGridMesh_t *) s_worldData.surfaces[j].data;
		// if this surface is not a grid
		if ( grid2->surfaceType != SF_GRID ) continue;
		// if the LOD errors are already fixed for this patch
		if ( grid2->lodFixed == 2 ) continue;
		// grids in the same LOD group should have the exact same lod radius
		if ( grid1->lodRadius != grid2->lodRadius ) continue;
		// grids in the same LOD group should have the exact same lod origin
		if ( grid1->lodOrigin[0] != grid2->lodOrigin[0] ) continue;
		if ( grid1->lodOrigin[1] != grid2->lodOrigin[1] ) continue;
		if ( grid1->lodOrigin[2] != grid2->lodOrigin[2] ) continue;
		//
		touch = qfalse;
		for (n = 0; n < 2; n++) {
			//
			if (n) offset1 = (grid1->height-1) * grid1->width;
			else offset1 = 0;
			if (R_MergedWidthPoints(grid1, offset1)) continue;
			for (k = 1; k < grid1->width-1; k++) {
				for (m = 0; m < 2; m++) {

					if (m) offset2 = (grid2->height-1) * grid2->width;
					else offset2 = 0;
					if (R_MergedWidthPoints(grid2, offset2)) continue;
					for ( l = 1; l < grid2->width-1; l++) {
					//
						if ( fabs(grid1->verts[k + offset1].xyz[0] - grid2->verts[l + offset2].xyz[0]) > .1) continue;
						if ( fabs(grid1->verts[k + offset1].xyz[1] - grid2->verts[l + offset2].xyz[1]) > .1) continue;
						if ( fabs(grid1->verts[k + offset1].xyz[2] - grid2->verts[l + offset2].xyz[2]) > .1) continue;
						// ok the points are equal and should have the same lod error
						grid2->widthLodError[l] = grid1->widthLodError[k];
						touch = qtrue;
					}
				}
				for (m = 0; m < 2; m++) {

					if (m) offset2 = grid2->width-1;
					else offset2 = 0;
					if (R_MergedHeightPoints(grid2, offset2)) continue;
					for ( l = 1; l < grid2->height-1; l++) {
					//
						if ( fabs(grid1->verts[k + offset1].xyz[0] - grid2->verts[grid2->width * l + offset2].xyz[0]) > .1) continue;
						if ( fabs(grid1->verts[k + offset1].xyz[1] - grid2->verts[grid2->width * l + offset2].xyz[1]) > .1) continue;
						if ( fabs(grid1->verts[k + offset1].xyz[2] - grid2->verts[grid2->width * l + offset2].xyz[2]) > .1) continue;
						// ok the points are equal and should have the same lod error
						grid2->heightLodError[l] = grid1->widthLodError[k];
						touch = qtrue;
					}
				}
			}
		}
		for (n = 0; n < 2; n++) {
			//
			if (n) offset1 = grid1->width-1;
			else offset1 = 0;
			if (R_MergedHeightPoints(grid1, offset1)) continue;
			for (k = 1; k < grid1->height-1; k++) {
				for (m = 0; m < 2; m++) {

					if (m) offset2 = (grid2->height-1) * grid2->width;
					else offset2 = 0;
					if (R_MergedWidthPoints(grid2, offset2)) continue;
					for ( l = 1; l < grid2->width-1; l++) {
					//
						if ( fabs(grid1->verts[grid1->width * k + offset1].xyz[0] - grid2->verts[l + offset2].xyz[0]) > .1) continue;
						if ( fabs(grid1->verts[grid1->width * k + offset1].xyz[1] - grid2->verts[l + offset2].xyz[1]) > .1) continue;
						if ( fabs(grid1->verts[grid1->width * k + offset1].xyz[2] - grid2->verts[l + offset2].xyz[2]) > .1) continue;
						// ok the points are equal and should have the same lod error
						grid2->widthLodError[l] = grid1->heightLodError[k];
						touch = qtrue;
					}
				}
				for (m = 0; m < 2; m++) {

					if (m) offset2 = grid2->width-1;
					else offset2 = 0;
					if (R_MergedHeightPoints(grid2, offset2)) continue;
					for ( l = 1; l < grid2->height-1; l++) {
					//
						if ( fabs(grid1->verts[grid1->width * k + offset1].xyz[0] - grid2->verts[grid2->width * l + offset2].xyz[0]) > .1) continue;
						if ( fabs(grid1->verts[grid1->width * k + offset1].xyz[1] - grid2->verts[grid2->width * l + offset2].xyz[1]) > .1) continue;
						if ( fabs(grid1->verts[grid1->width * k + offset1].xyz[2] - grid2->verts[grid2->width * l + offset2].xyz[2]) > .1) continue;
						// ok the points are equal and should have the same lod error
						grid2->heightLodError[l] = grid1->heightLodError[k];
						touch = qtrue;
					}
				}
			}
		}
		if (touch) {
			grid2->lodFixed = 2;
			R_FixSharedVertexLodError_r ( start, grid2 );
			//NOTE: this would be correct but makes things really slow
			//grid2->lodFixed = 1;
		}
	}
}

/*
=================
R_FixSharedVertexLodError

This function assumes that all patches in one group are nicely stitched together for the highest LoD.
If this is not the case this function will still do its job but won't fix the highest LoD cracks.
=================
*/
void R_FixSharedVertexLodError( void ) {
	int i;
	srfGridMesh_t *grid1;

	for ( i = 0; i < s_worldData.numsurfaces; i++ ) {
		//
		grid1 = (srfGridMesh_t *) s_worldData.surfaces[i].data;
		// if this surface is not a grid
		if ( grid1->surfaceType != SF_GRID )
			continue;
		//
		if ( grid1->lodFixed )
			continue;
		//
		grid1->lodFixed = 2;
		// recursively fix other patches in the same LOD group
		R_FixSharedVertexLodError_r( i + 1, grid1);
	}
}


/*
===============
R_StitchPatches
===============
*/
int R_StitchPatches( int grid1num, int grid2num ) {
	float *v1, *v2;
	srfGridMesh_t *grid1, *grid2;
	int k, l, m, n, offset1, offset2, row, column;

	grid1 = (srfGridMesh_t *) s_worldData.surfaces[grid1num].data;
	grid2 = (srfGridMesh_t *) s_worldData.surfaces[grid2num].data;
	for (n = 0; n < 2; n++) {
		//
		if (n) offset1 = (grid1->height-1) * grid1->width;
		else offset1 = 0;
		if (R_MergedWidthPoints(grid1, offset1))
			continue;
		for (k = 0; k < grid1->width-2; k += 2) {

			for (m = 0; m < 2; m++) {

				if ( grid2->width >= MAX_GRID_SIZE )
					break;
				if (m) offset2 = (grid2->height-1) * grid2->width;
				else offset2 = 0;
				for ( l = 0; l < grid2->width-1; l++) {
				//
					v1 = grid1->verts[k + offset1].xyz;
					v2 = grid2->verts[l + offset2].xyz;
					if ( fabs(v1[0] - v2[0]) > .1)
						continue;
					if ( fabs(v1[1] - v2[1]) > .1)
						continue;
					if ( fabs(v1[2] - v2[2]) > .1)
						continue;

					v1 = grid1->verts[k + 2 + offset1].xyz;
					v2 = grid2->verts[l + 1 + offset2].xyz;
					if ( fabs(v1[0] - v2[0]) > .1)
						continue;
					if ( fabs(v1[1] - v2[1]) > .1)
						continue;
					if ( fabs(v1[2] - v2[2]) > .1)
						continue;
					//
					v1 = grid2->verts[l + offset2].xyz;
					v2 = grid2->verts[l + 1 + offset2].xyz;
					if ( fabs(v1[0] - v2[0]) < .01 &&
							fabs(v1[1] - v2[1]) < .01 &&
							fabs(v1[2] - v2[2]) < .01)
						continue;
					//
					//ri.Printf( PRINT_ALL, "found highest LoD crack between two patches\n" );
					// insert column into grid2 right after after column l
					if (m) row = grid2->height-1;
					else row = 0;
					grid2 = R_GridInsertColumn( grid2, l+1, row,
									grid1->verts[k + 1 + offset1].xyz, grid1->widthLodError[k+1]);
					grid2->lodStitched = qfalse;
					s_worldData.surfaces[grid2num].data = (void *) grid2;
					return qtrue;
				}
			}
			for (m = 0; m < 2; m++) {

				if (grid2->height >= MAX_GRID_SIZE)
					break;
				if (m) offset2 = grid2->width-1;
				else offset2 = 0;
				for ( l = 0; l < grid2->height-1; l++) {
					//
					v1 = grid1->verts[k + offset1].xyz;
					v2 = grid2->verts[grid2->width * l + offset2].xyz;
					if ( fabs(v1[0] - v2[0]) > .1)
						continue;
					if ( fabs(v1[1] - v2[1]) > .1)
						continue;
					if ( fabs(v1[2] - v2[2]) > .1)
						continue;

					v1 = grid1->verts[k + 2 + offset1].xyz;
					v2 = grid2->verts[grid2->width * (l + 1) + offset2].xyz;
					if ( fabs(v1[0] - v2[0]) > .1)
						continue;
					if ( fabs(v1[1] - v2[1]) > .1)
						continue;
					if ( fabs(v1[2] - v2[2]) > .1)
						continue;
					//
					v1 = grid2->verts[grid2->width * l + offset2].xyz;
					v2 = grid2->verts[grid2->width * (l + 1) + offset2].xyz;
					if ( fabs(v1[0] - v2[0]) < .01 &&
							fabs(v1[1] - v2[1]) < .01 &&
							fabs(v1[2] - v2[2]) < .01)
						continue;
					//
					//ri.Printf( PRINT_ALL, "found highest LoD crack between two patches\n" );
					// insert row into grid2 right after after row l
					if (m) column = grid2->width-1;
					else column = 0;
					grid2 = R_GridInsertRow( grid2, l+1, column,
										grid1->verts[k + 1 + offset1].xyz, grid1->widthLodError[k+1]);
					grid2->lodStitched = qfalse;
					s_worldData.surfaces[grid2num].data = (void *) grid2;
					return qtrue;
				}
			}
		}
	}
	for (n = 0; n < 2; n++) {
		//
		if (n) offset1 = grid1->width-1;
		else offset1 = 0;
		if (R_MergedHeightPoints(grid1, offset1))
			continue;
		for (k = 0; k < grid1->height-2; k += 2) {
			for (m = 0; m < 2; m++) {

				if ( grid2->width >= MAX_GRID_SIZE )
					break;
				if (m) offset2 = (grid2->height-1) * grid2->width;
				else offset2 = 0;
				for ( l = 0; l < grid2->width-1; l++) {
				//
					v1 = grid1->verts[grid1->width * k + offset1].xyz;
					v2 = grid2->verts[l + offset2].xyz;
					if ( fabs(v1[0] - v2[0]) > .1)
						continue;
					if ( fabs(v1[1] - v2[1]) > .1)
						continue;
					if ( fabs(v1[2] - v2[2]) > .1)
						continue;

					v1 = grid1->verts[grid1->width * (k + 2) + offset1].xyz;
					v2 = grid2->verts[l + 1 + offset2].xyz;
					if ( fabs(v1[0] - v2[0]) > .1)
						continue;
					if ( fabs(v1[1] - v2[1]) > .1)
						continue;
					if ( fabs(v1[2] - v2[2]) > .1)
						continue;
					//
					v1 = grid2->verts[l + offset2].xyz;
					v2 = grid2->verts[(l + 1) + offset2].xyz;
					if ( fabs(v1[0] - v2[0]) < .01 &&
							fabs(v1[1] - v2[1]) < .01 &&
							fabs(v1[2] - v2[2]) < .01)
						continue;
					//
					//ri.Printf( PRINT_ALL, "found highest LoD crack between two patches\n" );
					// insert column into grid2 right after after column l
					if (m) row = grid2->height-1;
					else row = 0;
					grid2 = R_GridInsertColumn( grid2, l+1, row,
									grid1->verts[grid1->width * (k + 1) + offset1].xyz, grid1->heightLodError[k+1]);
					grid2->lodStitched = qfalse;
					s_worldData.surfaces[grid2num].data = (void *) grid2;
					return qtrue;
				}
			}
			for (m = 0; m < 2; m++) {

				if (grid2->height >= MAX_GRID_SIZE)
					break;
				if (m) offset2 = grid2->width-1;
				else offset2 = 0;
				for ( l = 0; l < grid2->height-1; l++) {
				//
					v1 = grid1->verts[grid1->width * k + offset1].xyz;
					v2 = grid2->verts[grid2->width * l + offset2].xyz;
					if ( fabs(v1[0] - v2[0]) > .1)
						continue;
					if ( fabs(v1[1] - v2[1]) > .1)
						continue;
					if ( fabs(v1[2] - v2[2]) > .1)
						continue;

					v1 = grid1->verts[grid1->width * (k + 2) + offset1].xyz;
					v2 = grid2->verts[grid2->width * (l + 1) + offset2].xyz;
					if ( fabs(v1[0] - v2[0]) > .1)
						continue;
					if ( fabs(v1[1] - v2[1]) > .1)
						continue;
					if ( fabs(v1[2] - v2[2]) > .1)
						continue;
					//
					v1 = grid2->verts[grid2->width * l + offset2].xyz;
					v2 = grid2->verts[grid2->width * (l + 1) + offset2].xyz;
					if ( fabs(v1[0] - v2[0]) < .01 &&
							fabs(v1[1] - v2[1]) < .01 &&
							fabs(v1[2] - v2[2]) < .01)
						continue;
					//
					//ri.Printf( PRINT_ALL, "found highest LoD crack between two patches\n" );
					// insert row into grid2 right after after row l
					if (m) column = grid2->width-1;
					else column = 0;
					grid2 = R_GridInsertRow( grid2, l+1, column,
									grid1->verts[grid1->width * (k + 1) + offset1].xyz, grid1->heightLodError[k+1]);
					grid2->lodStitched = qfalse;
					s_worldData.surfaces[grid2num].data = (void *) grid2;
					return qtrue;
				}
			}
		}
	}
	for (n = 0; n < 2; n++) {
		//
		if (n) offset1 = (grid1->height-1) * grid1->width;
		else offset1 = 0;
		if (R_MergedWidthPoints(grid1, offset1))
			continue;
		for (k = grid1->width-1; k > 1; k -= 2) {

			for (m = 0; m < 2; m++) {

				if ( grid2->width >= MAX_GRID_SIZE )
					break;
				if (m) offset2 = (grid2->height-1) * grid2->width;
				else offset2 = 0;
				for ( l = 0; l < grid2->width-1; l++) {