plcalc_world - Calculate world coordinates and
corresponding window index from relative device coordinates
plcalc_world(rx, ry, wx, wy,
window)
Calculate world coordinates, wx and wy, and
corresponding window index from relative device coordinates,
rx and ry.
Redacted form: General: plcalc_world(rx, ry, wx, wy,
window)
This function is used in example 31.
- rx (PLFLT(3plplot),
input)
- Input relative device coordinate (0.0-1.0) for the x coordinate.
- ry (PLFLT(3plplot),
input)
- Input relative device coordinate (0.0-1.0) for the y coordinate.
- wx
(PLFLT_NC_SCALAR(3plplot), output)
- Returned value of the x world coordinate corresponding to the relative
device coordinates rx and ry.
- wy
(PLFLT_NC_SCALAR(3plplot), output)
- Returned value of the y world coordinate corresponding to the relative
device coordinates rx and ry.
- window
(PLINT_NC_SCALAR(3plplot), output)
- Returned value of the last defined window index that corresponds to the
input relative device coordinates (and the returned world coordinates). To
give some background on the window index, for each page the initial window
index is set to zero, and each time plwind(3plplot) is called
within the page, world and device coordinates are stored for the window
and the window index is incremented. Thus, for a simple page layout with
non-overlapping viewports and one window per viewport, window
corresponds to the viewport index (in the order which the viewport/windows
were created) of the only viewport/window corresponding to rx and
ry. However, for more complicated layouts with potentially
overlapping viewports and possibly more than one window (set of world
coordinates) per viewport, window and the corresponding output
world coordinates corresponds to the last window created that fulfills the
criterion that the relative device coordinates are inside it. Finally, in
all cases where the input relative device coordinates are not inside any
viewport/window, then the returned value of the last defined window index
is set to -1.
Many developers (who are credited at
http://plplot.org/credits.php) have contributed to PLplot over its long
history.
PLplot documentation at http://plplot.org/documentation.php.