Click to place points A, B, C. Drag to move them. Watch the triangle color change based on C's position relative to line AB.
Controls
Legend
Point A
Point B
Point C
Triangle Color
Left / CCW
Right / CW
Collinear
Click to create two segments
Result
Draw two segments
How to Use
Click 4 points to create two segments. Drag points to move them. The test checks if the segments intersect.
Controls
Click to draw polygon · Click to place test point · Drag to move
Result
Draw a polygon and move your mouse
How to Use
Click to draw a polygon. Close it by double-clicking or snapping to first point. Then click anywhere to place a test point. Drag the point to move it. Green = inside, Red = outside.
Controls
Click to draw polygon · Double-click or snap to first point to close
Result
Draw a polygon to test
How to Use
Click to add vertices. Double-click or snap to first point to close. Drag vertices to test different shapes. Green = simple, Red = self-intersecting.
Controls
Info
A simple polygon has no self-intersections. Draw carefully!
Click to add points
Stats
Points: 0
Hull vertices: 0
How to Use
Click to add points or use +10 random. The purple polygon shows the convex hull (smallest convex shape containing all points).
Controls
Click to draw polygon vertices
Stats
Vertices: 0
Edges: 0
How to Use
Draw a polygon. Dotted green lines show internal visibility. Hover over vertices to see which other vertices are visible from it.
Controls
Info
Shows which vertices can "see" each other inside the polygon
💡 Hover over a vertex to highlight its visibility
Vertex Colors
Active (hover)
Visible
Not visible
Click to draw polygon · Double-click or snap to first point to close
Stats
Triangles: 0
Area: —
How to Use
Click to draw a polygon. Close it by double-clicking or snapping to the first point. The polygon will be decomposed into triangles.
Controls
Click to add points · Drag to move
Stats
Points: 0
Triangles: —
How to Use
Click to add points. Drag to move them. The triangulation maximizes minimum angles, avoiding thin triangles.
Controls
Click to add sites · Drag to move
Stats
Sites: 0
Cells: —
How to Use
Click to add sites. Each colored cell contains all points closest to that site. Drag sites to see cells update dynamically.