Callbacks

A list of all callbacks that can be passed to penumbra.app/start:

:update [[delta time] state]

Called every time a frame is rendered. delta is the elapsed time, in seconds, since :update was last called. time is the elapsed time, in seconds, since the application started running.

:display [[delta time] state]

Called every time a frame is rendered. Return values from :display are ignored.

:init [state]

Called once, when application begins.

:close [state]

Called once, when application ends.

:reshape [[x y width height] state]

Called when application begins, and every subsequent time the window is resized.

:mouse-drag [[dx dy] [x y] button state]

Called when mouse moves with a button pressed. [dx dy] contains relative motion since last time :mouse-drag was called, and [x y] contains absolute position of the mouse. button will be equal to one of :left, :right, :center, :mouse-4, or :mouse-5. If the mouse is moving when two or more buttons are pressed, :mouse-drag will be called once for each button.

:mouse-move [[dx dy] [x y] state]

Same as :mouse-drag, but when no button is pressed.

:mouse-down [[x y] button state]

Called whenever a button is pressed.

:mouse-up [[x y] button state]

Called whenever a button is released.

:mouse-click [[x y] button state]

Called whenever a mouse is clicked (pressed and released). Gives [x y] of where mouse was originally pressed.

:key-press [key state]

Called whenever a key is pressed. If the key is something that would normally show up in a text entry field, key is a case-sensitive string. Examples include “a”, “&”, and " ". If it is not, key is a keyword. Examples include :left, :control, and :escape

:key-release [key state]

Called whenever a key is released.

:key-type [key state]

Called whenever a key is pressed and released. This is the only key event which will expose auto-repeated keys.