Angle measurement actually starts from a vertical 270deg?

Question

I think the angle measurement described here (as well as w3schools) is confusing/wrong. To determine the angle parameter you should measure starting from a vertical vector pointing down at 270deg counter-clockwise to the gradient angle you want. See https://www.w3.org/TR/SVG/pservers.html#LinearGradients. for a good diagram.

Answer 1

The general explanation is a little bit confusing but the examples are correct - see my code example https://code.sololearn.com/Wt3RL9A6r5v2