Rectangle intersection with a Line Segment
Algorithm
For each line segment that your rectangle could be intersecting with, do the following:
- For each corner of your rectangle, check if the distance from that point to the line is less than some epsilon, where epsilon is a reasonable small number (usually a 1 or 2 units, depending on the size of your lines).
- To check each point, use the "distance from point to line segment" formula, which can be found here (I will not derive it just yet)
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If a collision is found, we have all of the information required to solve the collision:
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Collision Normal: This is the perpendicular to the line segment, which can be found by:
Vector2 getNormalToLineSegment(LineSegment* segment) { Vector2 direction = segment->end - segment->start; return *Vector2 { -direction.y, direction.x }).normalize(); }
- First Point of Application: Get the vector from the center of the rectangle (most like your position) to the corner which intersected.
- Second Point of Application: Get vector from center of line to the corner which intersected.
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Collision Normal: This is the perpendicular to the line segment, which can be found by: