Function CM_PatchCollideFromGrid

code/qcommon/cm_patch.cpp:1017–1184

================== CM_PatchCollideFromGrid ================== */

==================
*/
static void CM_PatchCollideFromGrid( cGrid_t *grid, patchCollide_t *pf ) {
	int				i, j;
	float			*p1, *p2, *p3;
	int				gridPlanes[CM_MAX_GRID_SIZE][CM_MAX_GRID_SIZE][2];
	facet_t			*facet;
	int				borders[4];
	qboolean		noAdjust[4];

	int numFacets;
	facets = (facet_t*) Z_Malloc(MAX_FACETS*sizeof(facet_t), TAG_TEMP_WORKSPACE, qfalse);

	numPlanes = 0;
	numFacets = 0;

	// find the planes for each triangle of the grid
	for ( i = 0 ; i < grid->width - 1 ; i++ ) {
		for ( j = 0 ; j < grid->height - 1 ; j++ ) {
			p1 = grid->points[i][j];
			p2 = grid->points[i+1][j];
			p3 = grid->points[i+1][j+1];
			gridPlanes[i][j][0] = CM_FindPlane( p1, p2, p3 );

			p1 = grid->points[i+1][j+1];
			p2 = grid->points[i][j+1];
			p3 = grid->points[i][j];
			gridPlanes[i][j][1] = CM_FindPlane( p1, p2, p3 );
		}
	}

	// create the borders for each facet
	for ( i = 0 ; i < grid->width - 1 ; i++ ) {
		for ( j = 0 ; j < grid->height - 1 ; j++ ) {

			borders[EN_TOP] = -1;
			if ( j > 0 ) {
				borders[EN_TOP] = gridPlanes[i][j-1][1];
			} else if ( grid->wrapHeight ) {
				borders[EN_TOP] = gridPlanes[i][grid->height-2][1];
			}
			noAdjust[EN_TOP] = (qboolean)( borders[EN_TOP] == gridPlanes[i][j][0] );
			if ( borders[EN_TOP] == -1 || noAdjust[EN_TOP] ) {
				borders[EN_TOP] = CM_EdgePlaneNum( grid, gridPlanes, i, j, 0 );
			}

			borders[EN_BOTTOM] = -1;
			if ( j < grid->height - 2 ) {
				borders[EN_BOTTOM] = gridPlanes[i][j+1][0];
			} else if ( grid->wrapHeight ) {
				borders[EN_BOTTOM] = gridPlanes[i][0][0];
			}
			noAdjust[EN_BOTTOM] = (qboolean)( borders[EN_BOTTOM] == gridPlanes[i][j][1] );
			if ( borders[EN_BOTTOM] == -1 || noAdjust[EN_BOTTOM] ) {
				borders[EN_BOTTOM] = CM_EdgePlaneNum( grid, gridPlanes, i, j, 2 );
			}

			borders[EN_LEFT] = -1;
			if ( i > 0 ) {
				borders[EN_LEFT] = gridPlanes[i-1][j][0];