pmouse_x

The system variable pmouse_x always contains the horizontal position of the mouse in the frame previous to the current frame.

Examples

# move the mouse quickly to see the difference
# between the current and previous position
def draw():
    py5.background(204)
    py5.line(py5.mouse_x, 20, py5.pmouse_x, 80)
    py5.println(py5.mouse_x, ":", py5.pmouse_x)

Description

The system variable pmouse_x always contains the horizontal position of the mouse in the frame previous to the current frame.

You may find that pmouse_x and pmouse_y have different values when referenced inside of draw() and inside of mouse events like mouse_pressed() and mouse_moved(). Inside draw(), pmouse_x and pmouse_y update only once per frame (once per trip through the draw() loop). But inside mouse events, they update each time the event is called. If these values weren’t updated immediately during mouse events, then the mouse position would be read only once per frame, resulting in slight delays and choppy interaction. If the mouse variables were always updated multiple times per frame, then something like line(pmouse_x, pmouse_y, mouse_x, mouse_y) inside draw() would have lots of gaps, because pmouse_x may have changed several times in between the calls to line().

If you want values relative to the previous frame, use pmouse_x and pmouse_y inside draw(). If you want continuous response, use pmouse_x and pmouse_y inside the mouse event functions.

Underlying Processing field: pmouseX

Updated on March 06, 2023 02:49:26am UTC