Clip device-space line segments to a rectangle before they are drawn. Backends call this so that data far outside the visible area (e.g. y ~ 1e21 under a small ylim) cost work proportional to what is seen.
Liang-Barsky clip of (px1,py1)-(px2,py2) to [lo(1),hi(1)] x [lo(2),hi(2)]. A clipped end is placed exactly on the edge it crosses; t_start is the segment parameter of (x0, y0).
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| real(kind=wp), | intent(in) | :: | px1 | |||
| real(kind=wp), | intent(in) | :: | py1 | |||
| real(kind=wp), | intent(in) | :: | px2 | |||
| real(kind=wp), | intent(in) | :: | py2 | |||
| real(kind=wp), | intent(in) | :: | lo(2) | |||
| real(kind=wp), | intent(in) | :: | hi(2) | |||
| real(kind=wp), | intent(out) | :: | x0 | |||
| real(kind=wp), | intent(out) | :: | y0 | |||
| real(kind=wp), | intent(out) | :: | x1 | |||
| real(kind=wp), | intent(out) | :: | y1 | |||
| real(kind=wp), | intent(out) | :: | t_start | |||
| logical, | intent(out) | :: | visible |