extract_contour_regions Function

public function extract_contour_regions(x_grid, y_grid, z_grid, levels) result(regions)

Extract polygonal regions between contour levels using marching squares

Given: 2D grid data and contour levels When: Processing grid to find regions between levels Then: Returns array of regions with boundary polygons

This is the main function for contour polygon decomposition that enables filled contour rendering across all backends.

Arguments

Type	Intent	Optional	Attributes		Name
real(kind=wp),	intent(in)			::	x_grid(:)
real(kind=wp),	intent(in)			::	y_grid(:)
real(kind=wp),	intent(in)			::	z_grid(:,:)
real(kind=wp),	intent(in)			::	levels(:)

Return Value type(contour_region_t), allocatable, (:)