Function:ns2vpa
From S2PLOT
ns2vpa
Draw a thick, transparent point.
Prototype
void ns2vpa(XYZ P, COLOUR icol, float isize, char itrans, float ialpha);
Description
Draw a thick, transparent point with specified size (isize), transparency is one of 's' (standard blend), 't' (transparent) or 'o' (opaque), and alpha channel (ialpha). Takes vector inputs for position P and colour icol.
See Also
| ns2vpoint | Draw a point at the given position and colour - vector input. |
| ns2thpoint | Draw a thick point at given position, in colour and thickness in pixels (not world coords). |
| ns2vthpoint | Draw a thick point at given position, in colour and thickness in pixels (not world coords) - vector input. |
| struct_COLOUR | Data structure for (r,g,b) colour indices. |
| struct_XYZ | Data structure for (x,y,z) coordinates. |
Code Example
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include "s2plot.h"
int main(int argc, char *argv[])
{
XYZ xyz; /* Position */
COLOUR col; /* Colour */
float isize; /* Dot size */
char itrans; /* Transparency type */
float ialpha; /* Alpha channel */
int i;
srand48((long)time(NULL)); /* Seed random numbers */
s2opend("/?",argc, argv); /* Open the display */
s2swin(-1.,1., -1.,1., -1.,1.); /* Set the window coordinates */
s2box("BCDET",0,0,"BCDET",0,0,"BCDET",0,0); /* Draw coordinate box */
for (i=0;i<50;i++) {
xyz.x = drand48()*2.0 - 1.0; /* Random position */
xyz.y = drand48()*2.0 - 1.0;
xyz.z = drand48()*2.0 - 1.0;
col.r = drand48(); /* Random colour */
col.g = drand48();
col.b = drand48();
itrans = 't'; /* Transparency */
ialpha = 0.5; /* Alpha channel */
isize = 8.0; /* Point size */
ns2vpa(xyz, col, isize, itrans, ialpha); /* Draw transparent point */
}
s2show(1); /* Open the s2plot window */
return 1;
}
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