Public API Reference

csPolygonMeshTools Class Reference
[Geometry utilities]

A set of tools to work with iPolygonMesh instances. More...

#include <csgeom/pmtools.h>

List of all members.

Static Public Member Functions
static bool	BoxInClosedMesh (const csBox3 &box, csVector3 *vertices, csTriangleMinMax *tris, int tri_count, csPlane3 *planes)
	Test if a box is in a closed mesh.
static csPolygonMeshEdge *	CalculateEdges (iPolygonMesh *, int &num_edges)
	Create a table of edges for this mesh.
static void	CalculateNormals (iPolygonMesh *mesh, csVector3 *normals)
	This function will calculate normals for all polygons in the mesh.
static void	CalculateOutline (csPolygonMeshEdge *edges, int num_edges, csPlane3 *planes, int num_vertices, const csVector3 &pos, int *outline_edges, int &num_outline_edges, bool *outline_verts, float &valid_radius)
	Given a table of edges (as calculated with CalculateEdges()), a table of planes (as calculated with CalculatePlanes()), and a position in space.
static void	CalculatePlanes (iPolygonMesh *mesh, csPlane3 *planes)
	This function will calculate planes for all polygons in the mesh.
static int	CheckActiveEdges (csPolygonMeshEdge *edges, int num_edges, csPlane3 *planes)
	This function will check all edges and mark them as active if the two polygons are not co-planar.
static void	CloseMesh (iPolygonMesh *polyMesh, csArray< csMeshedPolygon > &newPolys, int *&vertidx, int &vertidx_len)
	Close a polygon mesh.
static bool	IsMeshClosed (iPolygonMesh *polyMesh)
	Test whether a polygon mesh is closed.
static bool	IsMeshConvex (iPolygonMesh *polyMesh)
	Test whether a polygon mesh is convex.
static bool	LineInClosedMesh (const csVector3 &p1, const csVector3 &p2, csVector3 *vertices, csTriangleMinMax *tris, int tri_count, csPlane3 *planes)
	Test if a line is in a closed mesh.
static bool	PointInClosedMesh (const csVector3 &point, csVector3 *vertices, csTriangleMinMax *tris, int tri_count, csPlane3 *planes)
	Test if a point is in a closed mesh.
static void	Polygonize (iPolygonMesh *polymesh, csMeshedPolygon *&polygons, int &poly_count)
	Take a polygon mesh that has a valid set of triangles and generate a polygon table for that (delete with delete[]).
static void	SortTrianglesX (iPolygonMesh *polymesh, csTriangleMinMax *&tris, int &tri_count, csPlane3 *&planes)
	Take a polygon mesh and sort triangles on maximum x coordinate.
static void	Triangulate (iPolygonMesh *polymesh, csTriangle *&tris, int &tri_count)
	Triangulate a mesh from the polygon mesh data in the iPolygonMesh.

---

Detailed Description

A set of tools to work with iPolygonMesh instances.

Definition at line 78 of file pmtools.h.

---

Member Function Documentation

static bool csPolygonMeshTools::BoxInClosedMesh	(	const csBox3 &	box,
		csVector3 *	vertices,
		csTriangleMinMax *	tris,
		int	tri_count,
		csPlane3 *	planes
	)			[static]

Test if a box is in a closed mesh.

The mesh is defined by an array of triangles which should be sorted on x using the SortTrianglesX() function. This function does not check if the mesh is really closed. This function also needs an array of planes. You can calculate that with CalculatePlanes(). This function does not check if the eight corner points are actually in the object. If they are not then you will actually reverse the check and this function will return true if the box is completely outside the object. Basically this function tests if the box intersects some polygon in the object and it will return false if it does.

static csPolygonMeshEdge* csPolygonMeshTools::CalculateEdges	(	iPolygonMesh *	,
		int &	num_edges
	)			[static]

Create a table of edges for this mesh.

The resulting table may later be deleted with 'delete[]'. Note that every edge will only connect two polygons. If more polygons connect to an edge then the edge will be duplicated. The 'active' flag of the returned edges is not calculated by this routine. Use 'CheckActiveEdges()' for that.

static void csPolygonMeshTools::CalculateNormals	(	iPolygonMesh *	mesh,
		csVector3 *	normals
	)			[static]

This function will calculate normals for all polygons in the mesh.

The given array of 'normals' should be big enough to have normals for the number of polygons as defined in the mesh itself.

static void csPolygonMeshTools::CalculateOutline	(	csPolygonMeshEdge *	edges,
		int	num_edges,
		csPlane3 *	planes,
		int	num_vertices,
		const csVector3 &	pos,
		int *	outline_edges,
		int &	num_outline_edges,
		bool *	outline_verts,
		float &	valid_radius
	)			[static]

Given a table of edges (as calculated with CalculateEdges()), a table of planes (as calculated with CalculatePlanes()), and a position in space.

This function will calculate an outline that is valid from that position. This outline will be given as an array of bool indicating which vertex indices that are used (so these have to be transformed from 3D to 2D) and also an array of double vertex indices (every set of two vertex indices forms one edge) that form the outline. This function will also return a radius. As long as the position doesn't move outside this radius the outline will be valid. The two input tables should have enough space for the returned number of edges and vertex indices. The safest way is to allocate double the amount of vertices as there are active edges in the input edge table and enough vertices as the polygon mesh supports.
Note: this function requires that the given edges are marked as active or not (use CheckActiveEdges()).
Note: num_outline_edges will be the amount of edges (which means that there will be twice as much vertices in the 'outline_edges' table.

static void csPolygonMeshTools::CalculatePlanes	(	iPolygonMesh *	mesh,
		csPlane3 *	planes
	)			[static]

This function will calculate planes for all polygons in the mesh.

The given array of 'planes' should be big enough to have planes for the number of polygons as defined in the mesh itself.

static int csPolygonMeshTools::CheckActiveEdges	(	csPolygonMeshEdge *	edges,
		int	num_edges,
		csPlane3 *	planes
	)			[static]

This function will check all edges and mark them as active if the two polygons are not co-planar.

This function will return the number of active edges.

static void csPolygonMeshTools::CloseMesh	(	iPolygonMesh *	polyMesh,
		csArray< csMeshedPolygon > &	newPolys,
		int *&	vertidx,
		int &	vertidx_len
	)			[static]

Close a polygon mesh.

The current implementation is rather naive; it just returns all faces, but flipped. The returned table is a table of indices that are used in the returned polygons. Don't forget to delete[] that table!

static bool csPolygonMeshTools::IsMeshClosed

(

iPolygonMesh *

polyMesh

)

[static]

Test whether a polygon mesh is closed.

Remarks:

This function works best if vertices are shared.

static bool csPolygonMeshTools::IsMeshConvex

(

iPolygonMesh *

polyMesh

)

[static]

Test whether a polygon mesh is convex.

Note! This is NOT a fast function. Use with care.

Remarks:

This function works best if vertices are shared.

static bool csPolygonMeshTools::LineInClosedMesh	(	const csVector3 &	p1,
		const csVector3 &	p2,
		csVector3 *	vertices,
		csTriangleMinMax *	tris,
		int	tri_count,
		csPlane3 *	planes
	)			[static]

Test if a line is in a closed mesh.

The mesh is defined by an array of triangles which should be sorted on x using the SortTrianglesX() function. This function does not check if the mesh is really closed. This function also needs an array of planes. You can calculate that with CalculatePlanes(). This function does not check if the two points are actually in the object. If they are not then you will actually reverse the check and this function will return true if the line is completely outside the object. Basically this function tests if the line intersects some polygon in the object and it will return false if it does.

static bool csPolygonMeshTools::PointInClosedMesh	(	const csVector3 &	point,
		csVector3 *	vertices,
		csTriangleMinMax *	tris,
		int	tri_count,
		csPlane3 *	planes
	)			[static]

Test if a point is in a closed mesh.

The mesh is defined by an array of triangles which should be sorted on x using the SortTrianglesX() function. This function does not check if the mesh is really closed. This function also needs an array of planes. You can calculate that with CalculatePlanes().

static void csPolygonMeshTools::Polygonize	(	iPolygonMesh *	polymesh,
		csMeshedPolygon *&	polygons,
		int &	poly_count
	)			[static]

Take a polygon mesh that has a valid set of triangles and generate a polygon table for that (delete with delete[]).

Note that the polygons will point inside the triangle table!

static void csPolygonMeshTools::SortTrianglesX	(	iPolygonMesh *	polymesh,
		csTriangleMinMax *&	tris,
		int &	tri_count,
		csPlane3 *&	planes
	)			[static]

Take a polygon mesh and sort triangles on maximum x coordinate.

That means that the first triangle in the returned array will have a minimum x coordinates that is lower then further triangles. This is useful for the SortedIn() routine below. This routine will also calculate planes. When done delete the returned arrays.

static void csPolygonMeshTools::Triangulate	(	iPolygonMesh *	polymesh,
		csTriangle *&	tris,
		int &	tri_count
	)			[static]

Triangulate a mesh from the polygon mesh data in the iPolygonMesh.

Returns a table of triangles (delete with delete[]). Note that this function will always triangulate the polygons even if there is a perfectly usable array of triangles in the mesh. You should test for this outside of this function.

---

The documentation for this class was generated from the following file:

• csgeom/pmtools.h

---