terrain-height-at ( segment point -- height )

Vocabulary

terrain

Inputs

segment	an object
point	an object

Outputs

height

an object

Definition

USING: accessors grouping kernel math math.vectors sequences ;

IN: terrain

:: terrain-height-at ( segment point -- height )
    segment dim>> :> dim dim point v*
    :> pixel pixel dup vfloor v-
    :> pixel-mantissa segment bitmap>> 4 <groups>
    :> pixels pixel dim pixel-indices :> indices indices
    [ pixels nth COMPONENT-SCALE vdot 255.0 / ] map
    first4 pixel-mantissa bilerp ;