Module LineFuncs 

Line functions

Functions for working directly with the tg_line type.

There are no direct spatial predicates for tg_line. If you want to perform operations like “intersects” or “covers” then you must upcast the line to a tg_geom, like such:

tg_geom_intersects((struct tg_geom*)line, geom);

Functions

tg_line_clockwise^⚠

Returns true if winding order is clockwise. @param line Input line @return True if clockwise @return False if counter-clockwise

tg_line_clone^⚠

Clones a line @param line Input line, caller retains ownership. @return A duplicate of the provided line. @note The caller is responsible for freeing with tg_line_free(). @note This method of cloning uses implicit sharing through an atomic reference counter.

tg_line_copy^⚠

Copies a line @param line Input line, caller retains ownership. @return A duplicate of the provided line. @return NULL if out of memory @note The caller is responsible for freeing with tg_line_free(). @note This method performs a deep copy of the entire geometry to new memory.

tg_line_free^⚠

Releases the memory associated with a line. @param line Input line

tg_line_index_level_num_rects^⚠

Returns the number of rectangles at level. @param line Input line @param levelidx The index of level @return The number of index levels @return Zero if line has no indexing or levelidx is out of bounds. @see tg_line_index_spread() @see tg_line_index_num_levels() @see tg_line_index_level_rect()

tg_line_index_level_rect^⚠

Returns a specific level rectangle. @param line Input line @param levelidx The index of level @param rectidx The index of rectangle @return The rectangle @return Empty rectangle if line has no indexing, or levelidx or rectidx is out of bounds. @see tg_line_index_spread() @see tg_line_index_num_levels() @see tg_line_index_level_num_rects()

tg_line_index_num_levels^⚠

Returns the number of levels. @param line Input line @return The number of levels @return Zero if line has no indexing @see tg_line_index_spread() @see tg_line_index_level_num_rects() @see tg_line_index_level_rect()

tg_line_index_spread^⚠

Returns the indexing spread for a line.

tg_line_length^⚠

Calculate the length of a line.

tg_line_line_search^⚠

Iterates over all segments in line A that intersect with segments in line B. @note This efficently uses the indexes of each geometry, if available.

tg_line_memsize^⚠

Returns the allocation size of the line. @param line Input line @return Size of line in bytes

tg_line_nearest_segment^⚠

Iterates over segments from nearest to farthest. @see tg_ring_nearest_segment()`, which shares the same interface, for a detailed description.

tg_line_new^⚠

Creates a line from a series of points. @param points Array of points @param npoints Number of points in array @return A newly allocated line @return NULL if out of memory @note A tg_line can be safely upcasted to a tg_geom. (struct tg_geom*)line @note All lines with 32 or more points are automatically indexed.

tg_line_new_ix^⚠

Creates a line from a series of points using provided index option. @param points Array of points @param npoints Number of points in array @param ix Indexing option, e.g. TG_NONE, TG_NATURAL, TG_YSTRIPES @return A newly allocated line @return NULL if out of memory @note A tg_line can be safely upcasted to a tg_geom. (struct tg_geom*)poly @see tg_index

tg_line_num_points^⚠

Returns the number of points. @param line Input line @return Number of points @see tg_line_point_at()

tg_line_num_segments^⚠

Returns the number of segments. @param line Input line @return Number of segments @see tg_line_segment_at() @see LineFuncs

tg_line_point_at^⚠

Returns the point at index. @param line Input line @param index Index of point @return The point at index @note This function performs bounds checking. Use tg_line_points() for direct access to the points. @see tg_line_num_points()

tg_line_points^⚠

Returns the underlying point array of a line. @param line Input line @return Array or points @see tg_line_num_points() @see LineFuncs

tg_line_rect^⚠

Returns the minimum bounding rectangle of a line.

tg_line_segment_at^⚠

Returns the segment at index. @param line Input line @param index Index of segment @return The segment at index @see tg_line_num_segments()