al_triangulate_polygon - Allegro 5 API
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#include <allegro5/allegro_primitives.h>
bool al_triangulate_polygon(
const float* vertices, size_t vertex_stride, const int* vertex_counts,
void (*emit_triangle)(int, int, int, void*), void* userdata)
Divides a simple polygon into triangles, with zero or more other
simple polygons subtracted from it - the holes. The holes cannot touch or
intersect with the outline of the main polygon. Simple means the polygon
does not have to be convex but must not be self-overlapping.
Parameters:
- vertices - Interleaved array of (x, y) vertex coordinates for each of the
polygons, including holes.
- vertex_stride - distance (in bytes) between successive pairs of vertices
in the array.
- vertex_counts - Number of vertices for each polygon. The number of
vertices in the main polygon is given by vertex_counts[0] and must be at
least three. Subsequent elements indicate the number of vertices in each
hole. The array must be terminated with an element with value zero.
- emit_triangle - a function to be called for every set of three points that
form a triangle. The function is passed the indices of the points in
vertices and
userdata.
- userdata - arbitrary data to be passed to emit_triangle.
al_draw_filled_polygon_with_holes(3)