module Dodge.Base.Coordinate (
    worldPosToScreen,
    screenToWorldPos,
    mouseWorldPos,
) where

import Control.Lens
import Dodge.Data.Camera
import Dodge.Data.Input
import Geometry

{- | Transform world coordinates to scaled screen coordinates.
 - These have to be scaled according to the size of the window to get actual screen positions.
 - This allows for line thicknesses etc to correspond to pixel sizes.
 - I believe the resulting point is the number of pixels from the center of
 - the screen, I am not sure how rounding affects this though.
-}
worldPosToScreen :: Camera -> Point2 -> Point2
worldPosToScreen cam =
    rotateV (negate $ cam ^. camRot)
        . ((cam ^. camZoom) *.*)
        . (-.- (cam ^. camCenter))

-- | The mouse position in world coordinates.
mouseWorldPos :: Input -> Camera -> Point2
mouseWorldPos inp cam = screenToWorldPos cam (inp ^. mousePos)

screenToWorldPos :: Camera -> Point2 -> Point2
screenToWorldPos cam p =
    (cam ^. camCenter) + (1 / (cam ^. camZoom)) *.* rotateV (cam ^. camRot) p