Math 2D Functions

Math Class

Members

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void findIntersection ( const vec2 & p1, const vec2 & p2, const vec2 & p3, const vec2 & p4, int & lines_intersect, int & segments_intersect, vec2 & intersection, vec2 & close_p1, vec2 & close_p2 ) #

Finds the point of intersection between the two lines specified by the pairs of points p1 - p2 and p3 - p4 and fills in the values of the last 5 arguments.

Arguments

• const vec2 & p1 - Start point coordinates of the first line segment.
• const vec2 & p2 - End point coordinates of the first line segment.
• const vec2 & p3 - Start point coordinates of the second line segment.
• const vec2 & p4 - End point coordinates of the second line segment.
• int & lines_intersect - 1 if the lines to which the segments belong intersect; otherwise, 0.
• int & segments_intersect - 1 if the segments intersect; otherwise, 0.
• vec2 & intersection - Coordinates of the point of intersection between the two line segments.
• vec2 & close_p1 - Coordinates of the first of the two closest points belonging to the first segment.
• vec2 & close_p2 - Coordinates of the second of the two closest points belonging to the second segment.

int findIntersection ( const vec2 & p1, const vec2 & p2, const vec2 & p3, const vec2 & p4, vec2 & intersection ) #

Finds the point of intersection between the two lines specified by the pairs of points p1 - p2 and p3 - p4.

Arguments

• const vec2 & p1 - Start point coordinates of the first line segment.
• const vec2 & p2 - End point coordinates of the first line segment.
• const vec2 & p3 - Start point coordinates of the second line segment.
• const vec2 & p4 - End point coordinates of the second line segment.
• vec2 & intersection - Coordinates of the point of intersection between the two line segments.

Return value

1 if the segments intersect; otherwise, 0.

void findIntersection ( const dvec2 & p1, const dvec2 & p2, const dvec2 & p3, const dvec2 & p4, int & lines_intersect, int & segments_intersect, vec2 & intersection, vec2 & close_p1, vec2 & close_p2 ) #

Finds the point of intersection between the two lines specified by the pairs of points p1 - p2 and p3 - p4 and fills in the values of the last 5 arguments.

Arguments

• const dvec2 & p1 - Start point coordinates of the first line segment.
• const dvec2 & p2 - End point coordinates of the first line segment.
• const dvec2 & p3 - Start point coordinates of the second line segment.
• const dvec2 & p4 - End point coordinates of the second line segment.
• int & lines_intersect - 1 if the lines to which the segments belong intersect; otherwise, 0.
• int & segments_intersect - 1 if the segments intersect; otherwise, 0.
• vec2 & intersection - Coordinates of the point of intersection between the two line segments.
• vec2 & close_p1 - Coordinates of the first of the two closest points belonging to the first segment.
• vec2 & close_p2 - Coordinates of the second of the two closest points belonging to the second segment.

int findIntersection ( const dvec2 & p1, const dvec2 & p2, const dvec2 & p3, const dvec2 & p4, dvec2 & intersection ) #

Finds the point of intersection between the two lines specified by the pairs of points p1 - p2 and p3 - p4.

Arguments

• const dvec2 & p1 - Start point coordinates of the first line segment.
• const dvec2 & p2 - End point coordinates of the first line segment.
• const dvec2 & p3 - Start point coordinates of the second line segment.
• const dvec2 & p4 - End point coordinates of the second line segment.
• dvec2 & intersection - Coordinates of the point of intersection between the two line segments.

Return value

1 if the segments intersect; otherwise, 0.

float getPolygonArea ( const Vector<vec2> & points ) #

Returns the area of the given polygon in square units.

Arguments

• const Vector<vec2> & points - Vector containing all points of the polygon.

Return value

Polygon's area, in square units.

float getPolygonAreaSigned ( const Vector<vec2> & points ) #

Returns the area of the given polygon in square units.

Arguments

• const Vector<vec2> & points - Vector containing all points of the polygon.

Return value

Polygon's area, in square units.

float getTriangleArea ( const vec2 & p1, const vec2 & p2, const vec2 & p3 ) #

Returns the area of the given triangle in square units.

Arguments

• const vec2 & p1 - Coordinates of the first triangle vertex.
• const vec2 & p2 - Coordinates of the second triangle vertex.
• const vec2 & p3 - Coordinates of the third triangle vertex.

Return value

Triangle area, in square units.

int pointTriangleInside ( const vec2 & point, const vec2 & v0, const vec2 & v1, const vec2 & v2 ) #

Returns a value indicating if a given point is inside the specified triangle.

Arguments

• const vec2 & point - Coordinates of the point to be checked.
• const vec2 & v0 - Coordinates of the first triangle vertex.
• const vec2 & v1 - Coordinates of the second triangle vertex.
• const vec2 & v2 - Coordinates of the third triangle vertex.

Return value

1 if a given point is inside the specified triangle; otherwise, 0.

int polygonIsOrientedClockwise ( const Vector<vec2> & points ) #

Returns a value indicating if a given polygon is oriented clockwise.

Arguments

• const Vector<vec2> & points - Vector containing all points of the polygon.

Return value

1 if a given polygon is oriented clockwise; otherwise, 0.

void resizePolygon ( const Vector<vec2> & points, float offset, Vector<vec2> & result_points, int append_to_result ) #

Returns a set of points representing a resized polygon. The polygon is modified by moving its edges inward or outward by a specified offset. This is commonly referred to as "inflating" or "deflating" a polygon, depending on whether the offset is positive (expansion) or negative (contraction). Supports concave polygons, CCW and CW orientations.

Arguments

• const Vector<vec2> & points - Vector containing all points of the polygon.
• float offset - The value to which each polygon point is moved outward (positive value) or inward (negative value).
• Vector<vec2> & result_points - Vector containing all points of the deflated/inflated polygon.
• int append_to_result - Flag indicating if resulting points should be appended to the points of initial polygon - 0 (the default value), or replace them - 1.

int setPolygonToCCW ( Vector<vec2> & points ) #

Sets the counter-clockwise orientation for the polygon.

Arguments

• Vector<vec2> & points - Vector containing all points of the polygon.

Return value

1 if the counter-clockwise orientation for the polygon is set successfully; otherwise, 0.

float sign ( const vec2 & point, const vec2 & segment_p1, const vec2 & segment_p2 ) #

Returns a value indicating to which part of the segment the point belongs.

Arguments

• const vec2 & point - Coordinates of the point to be checked.
• const vec2 & segment_p1 - Segment start point coordinates.
• const vec2 & segment_p2 - Segment end point coordinates.

void triangulatePolygon ( const Vector<vec2> & points, Vector<unsigned short> & indices, int append_to_result ) #

Performs triangulation by ear clipping algorithm (complexity: O(n^2)/O(n)).

Arguments

• const Vector<vec2> & points - Vector containing all points of the polygon.
• Vector<unsigned short> & indices - Vector containing all points indices.
• int append_to_result - Flag indicating if resulting points should be appended to the points of initial polygon - 0 (the default value), or replace them - 1.