Function:ns2vf3na
From S2PLOT
(Difference between revisions)
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| - | ==ns2vf3nc== | + | ==ns2vf3na== |
| - | 3-vertex facet with coloured vertices and normals given. | + | 3-vertex facet with coloured vertices, normals and alpha given. |
| ==Prototype== | ==Prototype== | ||
| <code><pre> | <code><pre> | ||
| - | void ns2vf3nc(XYZ *P, XYZ *N, COLOUR *col); | + | void ns2vf3na(XYZ *P, XYZ *N, COLOUR col, char trans, float alpha); |
| </pre></code> | </pre></code> | ||
| ==Description== | ==Description== | ||
| - | The most general function for drawing a 3-vertex facet with coloured vertices. The vertices are given by the array P, normals are in the array N, and the RGB colours for vertices are in col. The other 3-vertex functions call this function. | + | Function for drawing a 3-vertex facet with coloured vertices, with normals, and a single alpha transparency value for the facet. The vertices are given by the array P, normals are in the array N, and the RGB colours for vertices are in col. |
| + | Transparency parameter trans is one of 'o' (opaque), 't' (addition blend - never gets dimmer) or 's' (standard blend, can get dimmer), and the alpha value is in the range [0,1]. | ||
| == See Also == | == See Also == | ||
| Line 35: | Line 36: | ||
| XYZ vertex[3]; /* 3 vertices */ | XYZ vertex[3]; /* 3 vertices */ | ||
| XYZ normal[3]; /* 3 vertices */ | XYZ normal[3]; /* 3 vertices */ | ||
| - | COLOUR col[3]; /* 3 vertices */ | + | COLOUR col; /* Polygon colour */ |
| + | char trans = 't'; /* Transparency type */ | ||
| + | float alpha = 0.7; /* Alpha channel value */ | ||
| int i; | int i; | ||
| Line 50: | Line 53: | ||
| normal[i].y = drand48()*2.0 - 1.0; | normal[i].y = drand48()*2.0 - 1.0; | ||
| normal[i].z = drand48()*2.0 - 1.0; | normal[i].z = drand48()*2.0 - 1.0; | ||
| - | col[i].r = drand48(); /* Random colour for vertex */ | ||
| - | col[i].g = drand48(); | ||
| - | col[i].b = drand48(); | ||
| } | } | ||
| - | ns2vf3nc(vertex, normal, col); | + | col.r = drand48(); /* Random colour for polygon*/ |
| + | col.g = drand48(); | ||
| + | col.b = drand48(); | ||
| + | ns2vf3na(vertex, normal, col, trans, alpha); | ||
| + | /* Draw polygon with specified vertices, normals, */ | ||
| + | /* colour and single alpha channel */ | ||
| s2show(1); /* Open the s2plot window */ | s2show(1); /* Open the s2plot window */ | ||
Revision as of 03:40, 29 August 2011
ns2vf3na
3-vertex facet with coloured vertices, normals and alpha given.
Prototype
void ns2vf3na(XYZ *P, XYZ *N, COLOUR col, char trans, float alpha);
Description
Function for drawing a 3-vertex facet with coloured vertices, with normals, and a single alpha transparency value for the facet. The vertices are given by the array P, normals are in the array N, and the RGB colours for vertices are in col. Transparency parameter trans is one of 'o' (opaque), 't' (addition blend - never gets dimmer) or 's' (standard blend, can get dimmer), and the alpha value is in the range [0,1].
See Also
| ns2vf3 | 3-vertex facet with single colour and automatic normals. |
| ns2vf3n | 3-vertex facet with single colour and normals given. |
| ns2vf3c | 3-vertex facet with coloured vertices and autmoatic normals. |
| ns2vf3a | 3-vertex facet with transparency |
| 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 vertex[3]; /* 3 vertices */
XYZ normal[3]; /* 3 vertices */
COLOUR col; /* Polygon colour */
char trans = 't'; /* Transparency type */
float alpha = 0.7; /* Alpha channel value */
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<3;i++) {
vertex[i].x = drand48()*2.0 - 1.0; /* Random corners to facet */
vertex[i].y = drand48()*2.0 - 1.0;
vertex[i].z = drand48()*2.0 - 1.0;
normal[i].x = drand48()*2.0 - 1.0; /* Random normal for facet */
normal[i].y = drand48()*2.0 - 1.0;
normal[i].z = drand48()*2.0 - 1.0;
}
col.r = drand48(); /* Random colour for polygon*/
col.g = drand48();
col.b = drand48();
ns2vf3na(vertex, normal, col, trans, alpha);
/* Draw polygon with specified vertices, normals, */
/* colour and single alpha channel */
s2show(1); /* Open the s2plot window */
return 1;
}
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