Denote the point (x,y)(x,y)(x,y) by RRR. This LPQ(x,y)L_{PQ}(x,y)LPQ(x,y) value is equal to the dot product of PR⃗\vec{PR}PR⃗ and the vector PQ⃗\vec{PQ}PQ⃗ rotated 90 degrees counterclockwise. \Reference slide: https://cs184.eecs.berkeley.edu/sp24/lecture/2-43/drawing-triangles
Denote the point (x,y) by R. This LPQ(x,y) value is equal to the dot product of PR⃗ and the vector PQ⃗ rotated 90 degrees counterclockwise. \Reference slide: https://cs184.eecs.berkeley.edu/sp24/lecture/2-43/drawing-triangles