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/* xscreensaver, Copyright (c) 1998-2014 Jamie Zawinski <jwz@jwz.org>
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation. No representations are made about the suitability of this
* software for any purpose. It is provided "as is" without express or
* implied warranty.
*/
#include "gllist.h"
void
renderList (const struct gllist *list, int wire_p)
{
while (list)
{
if (!wire_p || list->primitive == GL_LINES ||
list->primitive == GL_POINTS)
{
glInterleavedArrays (list->format, 0, list->data);
glDrawArrays (list->primitive, 0, list->points);
}
else
{
/* For wireframe, do it the hard way: treat every tuple of
points as its own line loop.
*/
const GLfloat *p = (GLfloat *) list->data;
int i, j, tick, skip, stride;
switch (list->primitive) {
case GL_QUADS: tick = 4; break;
case GL_TRIANGLES: tick = 3; break;
default: abort(); break; /* write me */
}
switch (list->format) {
case GL_C3F_V3F: case GL_N3F_V3F: skip = 3; stride = 6; break;
default: abort(); break; /* write me */
}
glBegin (GL_LINE_LOOP);
for (i = 0, j = skip;
i < list->points;
i++, j += stride)
{
if (i && !(i % tick))
{
glEnd();
glBegin (GL_LINE_LOOP);
}
glVertex3f (p[j], p[j+1], p[j+2]);
}
glEnd();
}
list = list->next;
}
}
void
renderListNormals (const struct gllist *list, GLfloat length, int faces_p)
{
while (list)
{
const GLfloat *p = (GLfloat *) list->data;
int i, j, tick, skip, stride;
GLfloat v[3], n[3];
if (list->primitive == GL_LINES) continue;
if (! faces_p)
tick = 1;
else
switch (list->primitive) {
case GL_QUADS: tick = 4; break;
case GL_TRIANGLES: tick = 3; break;
default: abort(); break; /* write me */
}
switch (list->format) {
case GL_N3F_V3F: skip = 0; stride = 6; break;
case GL_C3F_V3F: continue; break;
default: abort(); break; /* write me */
}
v[0] = v[1] = v[2] = 0;
n[0] = n[1] = n[2] = 0;
for (i = 0, j = skip;
i <= list->points;
i++, j += stride)
{
if (i && !(i % tick))
{
n[0] /= tick;
n[1] /= tick;
n[2] /= tick;
v[0] /= tick;
v[1] /= tick;
v[2] /= tick;
glPushMatrix();
glTranslatef (v[0], v[1], v[2]);
glScalef (length, length, length);
glBegin (GL_LINES);
glVertex3f (0, 0, 0);
glVertex3f (n[0], n[1], n[2]);
glEnd();
glPopMatrix();
v[0] = v[1] = v[2] = 0;
n[0] = n[1] = n[2] = 0;
}
if (i == list->points) break;
n[0] += p[j];
n[1] += p[j+1];
n[2] += p[j+2];
v[0] += p[j+3];
v[1] += p[j+4];
v[2] += p[j+5];
}
list = list->next;
}
}
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