nancie@hal.CSS.GOV (Nancie Matson) (12/30/89)
I would like to find out if there is an Xlib command similar to the GKS command gpolymarker. I have tried using the XDrawPoints command, but the points that are plotted to the screen are barely visible. I was wondering if there is a way to resize the plotted point, or even change it's representation to a X, * or even a hollow circle. I haven't been able to locate anything in the documentation that would suggest that these capabilities exist, so I would appreciate it if anyone has tried to do something of a similar nature. I have thought of just placing the text symbol for the 'o' to the screen, but text characters are not centered about an x,y location, they are merely placed to the right of the specified starting location. (At least this was the case in GKS...) Thanx in advance! nancie INTERNET: nancie@hal.CSS.GOV
klee@chico.pa.dec.com (Ken Lee) (12/30/89)
In article <210@hal.CSS.GOV>, nancie@hal.CSS.GOV (Nancie Matson) writes: > I would like to find out if there is an Xlib command > similar to the GKS command gpolymarker. I have tried > using the XDrawPoints command, but the points that are > plotted to the screen are barely visible. I was wondering > if there is a way to resize the plotted point, or even > change it's representation to a X, * or even a hollow circle. The graphics facilities in X are somewhat primitive, as X is intended to be a layer below graphics systems like PHIGS, GKS, or Display PostScript. If you're planning to do sophisticated graphics, you're probably best off getting one of these higher level graphics systems, built on top of X. Many vendors sell them (I can recommend one :-)). If all you need is markers, you can build a marker facility based on X line segments, circles, pixmaps, images, and/or characters. Use the geometry/extents attributes to center/size the markers. None of these objects support resizing, moving, or repainting. You'll have to do that yourself. Ken Lee DEC Western Software Laboratory, Palo Alto, Calif. Internet: klee@decwrl.dec.com uucp: uunet!decwrl!klee
rws@EXPO.LCS.MIT.EDU (Bob Scheifler) (12/30/89)
I would like to find out if there is an Xlib command
similar to the GKS command gpolymarker.
No, there isn't. You can either use multiple points per marker, or
explicitly draw an X or a hollow circle, or you a text symbol.
I have thought of just placing the text symbol for the 'o' to the
screen, but text characters are not centered about an x,y location,
they are merely placed to the right of the specified starting
location.
Glyphs aren't centered on the x,y position you specify, but you can
certainly find out the ink width and height of the glyph, and the
baseline, and compute a relative x,y position to achieve centering.