SGI SI GLU library

1 files changed, 105 insertions, 0 deletions

diff --git a/src/glu/sgi/libnurbs/internals/curvesub.cc b/src/glu/sgi/libnurbs/internals/curvesub.cc
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+++ b/src/glu/sgi/libnurbs/internals/curvesub.cc
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+/*
+** License Applicability. Except to the extent portions of this file are
+** made subject to an alternative license as permitted in the SGI Free
+** Software License B, Version 1.1 (the "License"), the contents of this
+** file are subject only to the provisions of the License. You may not use
+** this file except in compliance with the License. You may obtain a copy
+** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
+** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
+**
+** http://oss.sgi.com/projects/FreeB
+**
+** Note that, as provided in the License, the Software is distributed on an
+** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
+** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
+** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
+** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
+**
+** Original Code. The Original Code is: OpenGL Sample Implementation,
+** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
+** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
+** Copyright in any portions created by third parties is as indicated
+** elsewhere herein. All Rights Reserved.
+**
+** Additional Notice Provisions: The application programming interfaces
+** established by SGI in conjunction with the Original Code are The
+** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
+** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
+** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
+** Window System(R) (Version 1.3), released October 19, 1998. This software
+** was created using the OpenGL(R) version 1.2.1 Sample Implementation
+** published by SGI, but has not been independently verified as being
+** compliant with the OpenGL(R) version 1.2.1 Specification.
+*/
+
+/*
+ * curvesub.c++
+ *
+ * $Date: 2001/03/17 00:25:40 $ $Revision: 1.1 $
+ * $Header: /home/krh/git/sync/mesa-cvs-repo/Mesa/src/glu/sgi/libnurbs/internals/curvesub.cc,v 1.1 2001/03/17 00:25:40 brianp Exp $
+ */
+
+#include "glimports.h"
+#include "myassert.h"
+#include "mystdio.h"
+#include "subdivider.h"
+#include "renderhints.h"
+#include "backend.h"
+#include "quilt.h"
+#include "curvelist.h"
+#include "curve.h"
+#include "nurbsconsts.h"
+
+/*--------------------------------------------------------------------------
+ * drawCurves - main curve rendering entry point
+ *--------------------------------------------------------------------------
+ */
+
+void
+Subdivider::drawCurves( void )
+{
+    REAL 	from[1], to[1];
+    Flist	bpts;
+    qlist->getRange( from, to, bpts );
+
+    renderhints.init( );
+
+    backend.bgncurv();
+    for( int i=bpts.start; i<bpts.end-1; i++ ) {
+        REAL pta, ptb;
+	pta = bpts.pts[i];
+	ptb = bpts.pts[i+1];
+
+	qlist->downloadAll( &pta, &ptb, backend );
+
+	Curvelist curvelist( qlist, pta, ptb );
+	samplingSplit( curvelist, renderhints.maxsubdivisions );
+    }
+    backend.endcurv();
+}
+
+
+/*--------------------------------------------------------------------------
+ * samplingSplit - recursively subdivide patch, cull check each subpatch  
+ *--------------------------------------------------------------------------
+ */
+
+void
+Subdivider::samplingSplit( Curvelist& curvelist, int subdivisions )
+{
+    if( curvelist.cullCheck() == CULL_TRIVIAL_REJECT )  return;
+
+    curvelist.getstepsize();
+
+    if( curvelist.needsSamplingSubdivision() && (subdivisions > 0) ) {
+	REAL mid = ( curvelist.range[0] + curvelist.range[1] ) * 0.5;
+	Curvelist lowerlist( curvelist, mid );
+	samplingSplit( lowerlist, subdivisions-1 ); // lower
+	samplingSplit( curvelist, subdivisions-1 ); // upper
+    } else {
+	long nu = 1 + ((long) (curvelist.range[2] / curvelist.stepsize));
+	backend.curvgrid( curvelist.range[0], curvelist.range[1], nu );
+	backend.curvmesh( 0, nu );
+    }
+}
+