path - Delphi fillpath

Question

So first some background. Im developing a really simple 2D game, in Delphi 10.3, FMX, which at the bottom of the screen draws a random terrain for each level of the game. Anyway, the terrain is just some random numbers which are used in Tpathdata and then i use fillpath to draw this 2d "terrain". I want to check when a "falling" object, a trect for example, intersects with this terrain. My idea was to get all the points of the tpathdata, every Y position of every X position of the screen width. This way i could easily check when an object intersects with the terrain. I just cannout figure the way how to do it, or if anyone has any other solution. Id really appreciate any help. Thanks

Answer 1

This is not really a Delphi problem but a math problem.

You should have a math representation of your terrain. The polygon representing the boundary of the terrain. Then you need to use the math to know if a point is inside the polygon. See Wikipedia.

You may also implement it purely graphically using a B/W bitmap of the same resolution of the screen. You set the entire bitmap as white and draw the terrain on the bottom in white. Then checking the color of a pixel in that bitmap you'll know if it is outside of the terrain (black) or inside the terrain (white).