# $real_*   = echte Koordinaten
# $scaled_* = skalierte Koordinaten

my $obj_x = ($c->canvasx($x) - $scaled_left) * ($real_right - $real_left) / ($scaled_right - $scaled_left);
my $obj_y = ($c->canvasy($y) - $scaled_top ) * ($real_down  - $real_top ) / ($scaled_down  - $scaled_top );