image-placement>texcoords ( image-placement atlas-image -- image texcoords )

Vocabulary

images.atlas

Inputs

image-placement	an object
atlas-image	an object

Outputs

image	an object
texcoords	an object

Definition

USING: accessors arrays kernel math sequences ;

IN: images.atlas

:: image-placement>texcoords
    ( image-placement atlas-image -- image texcoords )
    atlas-image dim>> first2 :> ( aw ah ) image-placement
    image>> :> image image-placement loc>> first2 :> ( x y )
    image dim>> first2 :> ( w h ) x aw /f :> left-u y ah /f
    :> top-v x w + aw /f :> right-u y h + ah /f
    :> bottom-v image dup upside-down?>>
    [ left-u top-v right-u bottom-v ]
    [ left-u bottom-v right-u top-v ] if 4array ; inline