/*
* Render the volume described by the given volume struct.
* Return: 1 = ok
* 0 = bad volume struct.
*/
static int render_volume( Context ctx,
struct volume *v, unsigned int ctable[] )
{
register int rows, cols, slices, i, j, s;
register int rows1, cols1;
register uint_1 *cp0, *cp1;
register float *vp0, *vp1;
int fastdraw;
int stride = 1;
if (!v || !v->slices)
return 0;
#if defined (HAVE_SGI_GL) || defined (DENALI)
lmcolor( LMC_COLOR ); /* no shading */
blendfunction( BF_SA, BF_MSA ); /* enable alpha blending */
#endif
#ifdef HAVE_OPENGL
glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
glEnable( GL_BLEND );
check_gl_error( "render_volume (glBlendFunc)" );
#endif
/* put rows, cols, slices values into registers */
rows = v->rows-1; /* number of quad strips = number of data rows - 1 */
cols = v->cols;
slices = v->slices;
/* setup color and vertex pointers */
cp0 = v->index;
cp1 = cp0 + cols;
vp0 = v->vertex;
vp1 = vp0 + cols * 3; /* 3 floats per vertex */
/* MJK 12.15.98 */
#ifdef HAVE_PEX
rows++;
j = rows * cols;
for (s = 0; s < slices; s++)
{
draw_volume_quadmesh (rows, cols, vp0, cp0, ctable);
vp0 += j * 3;
cp0 += j;
}
return 1;
#endif
vis5d_check_fastdraw(ctx->dpy_ctx->dpy_context_index, &fastdraw);
if (fastdraw) {
stride = ctx->dpy_ctx->VStride;
}
/* sanity check */
if(stride<=0)
stride = 1;
/*
** adjust rows and cols based on stride. N.B. appears to be one more
** row than we actually use
*/
rows1 = (rows + 1 - 1) / stride;
cols1 = ((cols - 1) / stride) + 1;
/* loop over slices */
for (s=0;s<slices;s+=stride) {
cp0 = v->index + (s * rows * cols) +
(s * cols); /* skip a row after each slice */
vp0 = v->vertex + (s * rows * cols * 3) +
(s * cols * 3); /* skip a row after each slice */
cp1 = cp0 + (cols * stride);
vp1 = vp0 + (cols * stride * 3); /* 3 floats per vertex */
/* draw 'rows' quadrilateral strips */
for (i=0;i<rows1;i++) {
#if defined(SGI_GL) || defined(DENALI)
bgnqstrip();
for (j=0;j<cols1;j++) {
cpack( ctable[cp0[i*stride*cols+j*stride]] );
v3f( &vp0[i*stride*cols+j*stride] );
cpack( ctable[cp1[i*stride*cols+j*stride]] );
v3f( &vp1[i*stride*cols+j*stride] );
}
endqstrip();
#endif
#ifdef HAVE_OPENGL
glBegin( GL_QUAD_STRIP );
for (j=0;j<cols1;j++) {
glColor4ubv( (GLubyte *) &ctable[cp0[i*stride*cols+j*stride]] );
glVertex3fv( &vp0[(i*stride*cols+j*stride)*3] );
glColor4ubv( (GLubyte *) &ctable[cp1[i*stride*cols+j*stride]] );
glVertex3fv( &vp1[(i*stride*cols+j*stride)*3] );
}
glEnd();
#endif
}
}
#if defined(HAVE_SGI_GL) || defined(DENALI)
blendfunction( BF_ONE, BF_ZERO ); /* disable alpha blending */
#endif
#ifdef HAVE_OPENGL
glDisable( GL_BLEND );
check_gl_error( "render_volume (glDisable)" );
#endif
return 1;
}
/*-------------------------------------------------------------------------
* makeMesh - make the mesh of points on lattice
*-------------------------------------------------------------------------
*/
void
_SoNurbsSurfaceEvaluator::makeMesh( long umin, long umax, long vmin, long vmax )
{
assert( umax - umin >= 0 );
assert( vmax - vmin >= 0 );
REAL domain[2];
REAL v0;
int vstart;
REAL v1 = vs + dvs * vmin;
int lastv = (int) (vmax + 1);
for( int gridv1 = (int) (vmin)+1; gridv1 != lastv; gridv1++ ) {
v0 = v1;
/* strength reduction == roundoff error */
v1 = vs + dvs * gridv1;
if( equal(v0, vvals[1]) ) {
if( ! equal( v1, vvals[0]) ) {
setv( v1, 0 );
}
vstart = 1;
} else if( equal(v0, vvals[0]) ) {
if( ! equal(v1, vvals[1]) ) {
setv( v1, 1 );
}
vstart = 0;
} else if( equal(v1, vvals[1]) ) {
setv( v0, 0 );
vstart = 0;
} else {
setv( v0, 1 );
setv( v1, 0 );
vstart = 1;
}
assert( equal(vvals[vstart],v0) );
assert( equal(vvals[1-vstart],v1) );
bgnqstrip();
if( vstart == 1 ) {
int lastu = (int) (umax + 1);
int gridi = (int) umin;
for( int gridu = gridi++; gridu != lastu; gridu = gridi++ ) {
/* strength reduction == roundoff error */
domain[0] = us + dus * gridu;
domain[1] = vvals[1];
compute( domain, 1, gridi );
domain[1] = vvals[0];
compute( domain, 0, gridi );
}
} else {
int lastu = (int) (umax + 1);
int gridi = (int) umin;
for( int gridu = gridi++; gridu != lastu; gridu = gridi++ ) {
/* strength reduction == roundoff error */
domain[0] = us + dus * gridu;
domain[1] = vvals[0];
compute( domain, 0, gridi );
domain[1] = vvals[1];
compute( domain, 1, gridi );
}
}
endqstrip();
}
}
