SGI SI GLU library

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diff --git a/src/glu/sgi/libnurbs/internals/mesher.cc b/src/glu/sgi/libnurbs/internals/mesher.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.
+*/
+
+/*
+ * mesher.c++
+ *
+ * $Date: 2001/03/17 00:25:41 $ $Revision: 1.1 $
+ * $Header: /home/krh/git/sync/mesa-cvs-repo/Mesa/src/glu/sgi/libnurbs/internals/mesher.cc,v 1.1 2001/03/17 00:25:41 brianp Exp $
+ */
+
+#include "glimports.h"
+#include "myassert.h"
+#include "mystdio.h"
+#include "mesher.h"
+#include "gridvertex.h"
+#include "gridtrimvertex.h"
+#include "jarcloc.h"
+#include "gridline.h"
+#include "trimline.h"
+#include "uarray.h"
+#include "backend.h"
+
+
+const float Mesher::ZERO = 0.0;
+
+Mesher::Mesher( Backend& b ) 
+	: backend( b ), 
+	p( sizeof( GridTrimVertex ), 100, "GridTrimVertexPool" )
+{
+    stacksize = 0;
+    vdata = 0;
+    lastedge = 0; //needed to prevent purify UMR 
+}
+
+Mesher::~Mesher( void )
+{
+    if( vdata ) delete[] vdata;
+}
+
+void 
+Mesher::init( unsigned int npts )
+{
+    p.clear();
+    if( stacksize < npts ) {
+	stacksize = 2 * npts;
+	if( vdata ) delete[] vdata;		
+	vdata = new GridTrimVertex_p[stacksize];
+    } 
+}
+
+inline void
+Mesher::push( GridTrimVertex *gt )
+{
+    assert( itop+1 != stacksize );
+    vdata[++itop] = gt;
+}
+
+inline void
+Mesher::pop( long )
+{
+}
+
+inline void
+Mesher::openMesh()
+{
+    backend.bgntmesh( "addedge" );
+}
+
+inline void
+Mesher::closeMesh()
+{
+    backend.endtmesh();
+}
+
+inline void
+Mesher::swapMesh()
+{
+    backend.swaptmesh();
+}
+
+inline void
+Mesher::clearStack()
+{
+    itop = -1;
+    last[0] = 0;
+}
+
+void
+Mesher::finishLower( GridTrimVertex *gtlower )
+{
+    for( push(gtlower); 
+	 nextlower( gtlower=new(p) GridTrimVertex ); 
+	 push(gtlower) ) 
+	    addLower();
+    addLast();
+}
+
+void
+Mesher::finishUpper( GridTrimVertex *gtupper )
+{
+    for( push(gtupper); 
+	 nextupper( gtupper=new(p) GridTrimVertex ); 
+	 push(gtupper) ) 
+	    addUpper();
+    addLast();
+}
+
+void
+Mesher::mesh( void )
+{
+    GridTrimVertex *gtlower, *gtupper;
+
+    Hull::init( );
+    nextupper( gtupper = new(p) GridTrimVertex );
+    nextlower( gtlower = new(p) GridTrimVertex );
+
+    clearStack();
+    openMesh();
+    push(gtupper);
+
+    nextupper( gtupper = new(p) GridTrimVertex );
+    nextlower( gtlower );
+
+    assert( gtupper->t && gtlower->t );
+    
+    if( gtupper->t->param[0] < gtlower->t->param[0] ) {
+	push(gtupper);
+	lastedge = 1;
+	if( nextupper( gtupper=new(p) GridTrimVertex ) == 0 ) {
+	    finishLower(gtlower);
+	    return;
+	}
+    } else if( gtupper->t->param[0] > gtlower->t->param[0] ) {
+	push(gtlower);
+	lastedge = 0;
+	if( nextlower( gtlower=new(p) GridTrimVertex ) == 0 ) {
+	    finishUpper(gtupper);
+	    return;
+	}
+    } else {
+	if( lastedge == 0 ) {
+	    push(gtupper);
+	    lastedge = 1;
+	    if( nextupper(gtupper=new(p) GridTrimVertex) == 0 ) {
+		finishLower(gtlower);
+		return;
+	    }
+	} else {
+	    push(gtlower);
+	    lastedge = 0;
+	    if( nextlower( gtlower=new(p) GridTrimVertex ) == 0 ) {
+		finishUpper(gtupper);
+		return;
+	    }
+	}
+    }
+
+    while ( 1 ) {
+	if( gtupper->t->param[0] < gtlower->t->param[0] ) {
+            push(gtupper);
+	    addUpper();
+	    if( nextupper( gtupper=new(p) GridTrimVertex ) == 0 ) {
+		finishLower(gtlower);
+		return;
+	    }
+	} else if( gtupper->t->param[0] > gtlower->t->param[0] ) {
+    	    push(gtlower);
+	    addLower();
+	    if( nextlower( gtlower=new(p) GridTrimVertex ) == 0 ) {
+		finishUpper(gtupper);
+		return;
+	    }
+	} else {
+	    if( lastedge == 0 ) {
+		push(gtupper);
+		addUpper();
+		if( nextupper( gtupper=new(p) GridTrimVertex ) == 0 ) {
+		    finishLower(gtlower);
+		    return;
+		}
+	    } else {
+		push(gtlower);
+		addLower();
+		if( nextlower( gtlower=new(p) GridTrimVertex ) == 0 ) {
+		    finishUpper(gtupper);
+		    return;
+		}
+	    }
+	}
+    }
+}
+
+inline int
+Mesher::isCcw( int ilast )
+{
+    REAL area = det3( vdata[ilast]->t, vdata[itop-1]->t, vdata[itop-2]->t );
+    return (area < ZERO) ? 0 : 1;
+}
+
+inline int
+Mesher::isCw( int ilast  )
+{
+    REAL area = det3( vdata[ilast]->t, vdata[itop-1]->t, vdata[itop-2]->t );
+    return (area > -ZERO) ? 0 : 1;
+}
+
+inline int
+Mesher::equal( int x, int y )
+{
+    return( last[0] == vdata[x] && last[1] == vdata[y] );
+}
+
+inline void
+Mesher::copy( int x, int y )
+{
+    last[0] = vdata[x]; last[1] = vdata[y];
+}
+ 
+inline void
+Mesher::move( int x, int y ) 
+{
+    vdata[x] = vdata[y];
+}
+
+inline void
+Mesher::output( int x )
+{
+    backend.tmeshvert( vdata[x] );
+}
+
+/*---------------------------------------------------------------------------
+ * addedge - addedge an edge to the triangulation
+ *
+ *	This code has been re-written to generate large triangle meshes
+ *	from a monotone polygon.  Although smaller triangle meshes
+ *	could be generated faster and with less code, larger meshes
+ *	actually give better SYSTEM performance.  This is because
+ *	vertices are processed in the backend slower than they are
+ *	generated by this code and any decrease in the number of vertices
+ *	results in a decrease in the time spent in the backend.
+ *---------------------------------------------------------------------------
+ */
+
+void
+Mesher::addLast( )
+{
+    register int ilast = itop;
+
+    if( lastedge == 0 ) {
+	if( equal( 0, 1 ) ) {
+	    output( ilast );
+	    swapMesh();
+	    for( register int i = 2; i < ilast; i++ ) {
+		swapMesh();
+		output( i );
+	    }
+	    copy( ilast, ilast-1 );
+	} else if( equal( ilast-2, ilast-1) ) {
+	    swapMesh();
+	    output( ilast );
+	    for( register int i = ilast-3; i >= 0; i-- ) {
+		output( i );
+		swapMesh();
+	    }
+	    copy( 0, ilast );
+	} else {
+	    closeMesh();	openMesh();
+	    output( ilast );
+	    output( 0 );
+	    for( register int i = 1; i < ilast; i++ ) {
+		swapMesh();
+		output( i );
+	    }
+	    copy( ilast, ilast-1 );
+	}
+    } else {
+	if( equal( 1, 0) ) {
+	    swapMesh();
+	    output( ilast );
+	    for( register int i = 2; i < ilast; i++ ) {
+		output( i );
+		swapMesh();
+	    }
+	    copy( ilast-1, ilast );
+	} else if( equal( ilast-1, ilast-2) ) {
+	    output( ilast );
+	    swapMesh();
+	    for( register int i = ilast-3; i >= 0; i-- ) {
+		swapMesh();
+		output( i );
+	    }
+	    copy( ilast, 0 );
+	} else {
+	    closeMesh();	openMesh();
+	    output( 0 );
+	    output( ilast );
+	    for( register int i = 1; i < ilast; i++ ) {
+		output( i );
+		swapMesh();
+	    }
+	    copy( ilast-1, ilast );
+	}
+    }
+    closeMesh();
+    //for( register long k=0; k<=ilast; k++ ) pop( k );
+}
+
+void
+Mesher::addUpper( )
+{
+    register int ilast = itop;
+
+    if( lastedge == 0 ) {
+	if( equal( 0, 1 ) ) {
+	    output( ilast );
+	    swapMesh();
+	    for( register int i = 2; i < ilast; i++ ) {
+		swapMesh();
+		output( i );
+	    }
+	    copy( ilast, ilast-1 );
+	} else if( equal( ilast-2, ilast-1) ) {
+	    swapMesh();
+	    output( ilast );
+	    for( register int i = ilast-3; i >= 0; i-- ) {
+		output( i );
+		swapMesh();
+	    }
+	    copy( 0, ilast );
+	} else {
+	    closeMesh();	openMesh();
+	    output( ilast );
+	    output( 0 );
+	    for( register int i = 1; i < ilast; i++ ) {
+		swapMesh();
+		output( i );
+	    }
+	    copy( ilast, ilast-1 );
+	}
+	lastedge = 1;
+        //for( register long k=0; k<ilast-1; k++ ) pop( k );
+	move( 0, ilast-1 );
+	move( 1, ilast );
+	itop = 1;
+    } else {
+	if( ! isCcw( ilast ) ) return;
+	do {
+	    itop--;
+	} while( (itop > 1) && isCcw( ilast ) );
+
+	if( equal( ilast-1, ilast-2 ) ) {
+	    output( ilast );
+	    swapMesh();
+	    for( register int i=ilast-3; i>=itop-1; i-- ) {
+		swapMesh();
+		output( i );
+	    }
+	    copy( ilast, itop-1 );
+	} else if( equal( itop, itop-1 ) ) {
+	    swapMesh();
+	    output( ilast );
+	    for( register int i = itop+1; i < ilast; i++ ) {
+		output( i );
+		swapMesh();
+	    }
+	    copy( ilast-1, ilast );
+	} else {
+	    closeMesh();	openMesh();
+	    output( ilast );
+	    output( ilast-1 );
+	    for( register int i=ilast-2; i>=itop-1; i-- ) {
+		swapMesh();
+		output( i );
+	    } 
+	    copy( ilast, itop-1 );
+	}
+        //for( register int k=itop; k<ilast; k++ ) pop( k );
+	move( itop, ilast );
+    }
+}
+
+void
+Mesher::addLower()
+{
+    register int ilast = itop;
+
+    if( lastedge == 1 ) {
+	if( equal( 1, 0) ) {
+	    swapMesh();
+	    output( ilast );
+	    for( register int i = 2; i < ilast; i++ ) {
+		output( i );
+		swapMesh();
+	    }
+	    copy( ilast-1, ilast );
+	} else if( equal( ilast-1, ilast-2) ) {
+	    output( ilast );
+	    swapMesh();
+	    for( register int i = ilast-3; i >= 0; i-- ) {
+		swapMesh();
+		output( i );
+	    }
+	    copy( ilast, 0 );
+	} else {
+	    closeMesh();	openMesh();
+	    output( 0 );
+	    output( ilast );
+	    for( register int i = 1; i < ilast; i++ ) {
+		output( i );
+		swapMesh();
+	    }
+	    copy( ilast-1, ilast );
+	}
+
+	lastedge = 0;
+        //for( register long k=0; k<ilast-1; k++ ) pop( k );
+	move( 0, ilast-1 );
+	move( 1, ilast );
+	itop = 1;
+    } else {
+	if( ! isCw( ilast ) ) return;
+	do {
+	    itop--;
+	} while( (itop > 1) && isCw( ilast ) );
+
+	if( equal( ilast-2, ilast-1) ) {
+	    swapMesh();
+	    output( ilast );
+	    for( register int i=ilast-3; i>=itop-1; i--) {
+		output( i );
+		swapMesh( );
+	    }
+	    copy( itop-1, ilast );
+	} else if( equal( itop-1, itop) ) {
+	    output( ilast );
+	    swapMesh();
+	    for( register int i=itop+1; i<ilast; i++ ) {
+		swapMesh( );
+		output( i );
+	    }
+	    copy( ilast, ilast-1 );
+	} else {
+	    closeMesh();	openMesh();
+	    output( ilast-1 );
+	    output( ilast );
+	    for( register int i=ilast-2; i>=itop-1; i-- ) {
+		output( i );
+		swapMesh( );
+	    }
+	    copy( itop-1, ilast );
+	}
+        //for( register int k=itop; k<ilast; k++ ) pop( k );
+	move( itop, ilast );
+    }
+}
+
+