/*!********************************************************************************************
@Function TriangulatePolygon
@Input coordinates Coordinate array for the polygon.
@Input polygons The polygon definitions.
@Output triangle_coords The resulting coordinates of the triangulation.
@Output triangle_indices The resulting triangle indices of the polygon.
@Return True if the polygon could be triangulated, false otherwise.
@Description Triangulates the exterior polygon of a set of non-self-intersecting polygons.
Note that this will not be able to deal with holes etc.
***********************************************************************************************/
bool TriangulatePolygon(const PVRTCoordinateVector &coordinates, const PVRTMultiPolygon &polygons, PVRTCoordinateVector &triangle_coords, PVRTTriangleVector &triangle_indices)
{
// There must be at least one
if (polygons.polygons.empty())
return false;
// Only triangulate the exterior polygon.
// For information on how to handle it properly, please have a look at the polygon triangulation section in the whitepaper.
return TriangulatePolygon(coordinates, polygons.polygons.front(), triangle_coords, triangle_indices);
}
GLTriangleMesh SweepPolygon2DToGLMesh(const Polygon2D &polygon, GLfloat depth) {
std::vector<GLTriangleMesh> gl_meshes;
gl_meshes.emplace_back(SweeptPath2DToGLMesh(polygon.path, depth));
for (const auto &hole : polygon.holes) {
gl_meshes.emplace_back(SweeptPath2DToGLMesh(hole, depth, true, false));
}
auto diag_mesh = TriangulatePolygon(polygon);
gl_meshes.emplace_back(
ConvertDiagMesh2DToGLMesh(diag_mesh, -0.5 * depth, false));
gl_meshes.emplace_back(
ConvertDiagMesh2DToGLMesh(diag_mesh, depth * 0.5, true));
return CombineGLMesh(gl_meshes);
}
GLTriangleMesh GLTriangulate2DShape2D(const CollisionShape2D *shape_ptr) {
switch (shape_ptr->shape_type) {
case Shape2DType::kDisk: {
auto disk_ptr = dynamic_cast<const Disk2D *>(shape_ptr);
const size_t num_vertices = 30;
Polygon2D polygon(SketchDiskEdge(*disk_ptr, num_vertices));
auto diag_mesh = TriangulatePolygon(polygon);
return ConvertDiagMesh2DToGLMesh(diag_mesh, 0.0);
} break;
case Shape2DType::kPolygon: {
auto poly_ptr = dynamic_cast<const Polygon2D *>(shape_ptr);
auto diag_mesh = TriangulatePolygon(*poly_ptr);
return ConvertDiagMesh2DToGLMesh(diag_mesh, 0.0);
} break;
case Shape2DType::kPolyLine: {
auto line_ptr = dynamic_cast<const Line2D *>(shape_ptr);
auto diag_mesh = TriangulatePolyline(line_ptr->path, 1.5);
return ConvertDiagMesh2DToGLMesh(diag_mesh, 0.0);
} break;
default:
break;
}
return GLTriangleMesh();
}
