fortplot_streamline_placement Module

Streamline placement algorithms for matplotlib compatibility

Implements matplotlib's approach: - StreamMask for collision detection (30x30 base grid scaled by density) - Spiral seed point generation starting from boundaries - Coordinate system mapping between data, grid, and mask coordinates

Following SOLID principles with single responsibility for placement logic StreamMask for collision detection - equivalent to matplotlib's StreamMask Coordinate mapper for data ↔ grid ↔ mask transformations

Derived Types

type, public ::  stream_mask_t

Components

Type	Visibility	Attributes		Name		Initial
integer,	public		::	nx			Mask dimensions
integer,	public		::	ny			Mask dimensions
integer,	public,	allocatable	::	mask(:,:)			Collision mask (0=free, 1=occupied)
integer,	public,	allocatable	::	trajectory(:,:)			Current trajectory points for undo
integer,	public		::	traj_length	=	0	Length of current trajectory
integer,	public		::	current_x	=	-1	Current position
integer,	public		::	current_y	=	-1	Current position

Type-Bound Procedures

procedure, public :: initialize => mask_initialize
procedure, public :: is_free => mask_is_free
procedure, public :: start_trajectory => mask_start_trajectory
procedure, public :: update_trajectory => mask_update_trajectory
procedure, public :: try_update_trajectory => mask_try_update_trajectory
procedure, public :: undo_trajectory => mask_undo_trajectory

type, public ::  coordinate_mapper_t

Components

Type	Visibility	Attributes		Name		Initial
real(kind=wp),	public		::	x_min			Data bounds
real(kind=wp),	public		::	x_max			Data bounds
real(kind=wp),	public		::	y_min			Data bounds
real(kind=wp),	public		::	y_max			Data bounds
integer,	public		::	grid_nx			Grid dimensions
integer,	public		::	grid_ny			Grid dimensions
integer,	public		::	mask_nx			Mask dimensions
integer,	public		::	mask_ny			Mask dimensions
real(kind=wp),	public		::	x_grid2mask			Grid to mask scaling
real(kind=wp),	public		::	y_grid2mask			Grid to mask scaling
real(kind=wp),	public		::	x_mask2grid			Mask to grid scaling
real(kind=wp),	public		::	y_mask2grid			Mask to grid scaling
real(kind=wp),	public		::	x_data2grid			Data to grid scaling
real(kind=wp),	public		::	y_data2grid			Data to grid scaling

Type-Bound Procedures

procedure, public :: initialize => mapper_initialize
procedure, public :: data2grid => mapper_data2grid
procedure, public :: grid2data => mapper_grid2data
procedure, public :: mask2grid => mapper_mask2grid
procedure, public :: grid2mask => mapper_grid2mask

Subroutines

public subroutine generate_spiral_seeds(mask_shape, seed_points, n_seeds)

Generate seed points in spiral pattern starting from boundary Implements matplotlib's _gen_starting_points algorithm

Arguments

Type	Intent	Optional	Attributes		Name
integer,	intent(in)			::	mask_shape(2)
integer,	intent(out),		allocatable	::	seed_points(:,:)
integer,	intent(out)			::	n_seeds