Added Ruben Lopez's Inventor/VRML 1.0 loader.

src/osgPlugins/iv/normals.cpp

@@ -0,0 +1,107 @@
+/*
+ * osgDB::wrl - a VRML 1.0 loader for OpenSceneGraph
+ * Copyright (C) 2002 Ruben Lopez <ryu@gpul.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+
+#include "normals.h"
+#include <osg/Matrix>
+
+#define CREASE_ANGLE 3.14159265356 * 45 / 180
+
+float difAng(osg::Vec3 a, osg::Vec3 b) {
+    float div = a.length() * b.length();
+    return (div != 0.0f ? acosf( (a*b) / div) : 0.0f );
+}
+
+osg::Vec3 calcNormal(osg::Vec3 &a, osg::Vec3 &b, osg::Vec3 &c) {
+    osg::Vec3 norm;
+    osg::Vec3 v1;
+    osg::Vec3 v2;
+    v1=b-c;
+    v2=a-b;
+    norm=v1 ^ v2; // cross product
+    norm.normalize();
+    return norm;
+}
+
+void get3v(VertexList &vertices, VertexIndexList &vindex, int &a, int &b, int &c) {
+    unsigned tam=vindex.size();
+    unsigned i;
+    b=0;c=0;
+    a=vindex[0];
+    for (i=1;i<tam;i++) {
+	if (vertices[vindex[i]] != vertices[a]) { b=vindex[i];break; }
+    }
+    for (i=1;i<tam;i++) {
+	if (vertices[vindex[i]] != vertices[a] && vertices[vindex[i]] != vertices[b]) { c=vindex[i];break; }
+    }
+}
+
+osg::Vec3 *calcNormals(VertexList &vertices, PolygonList &polygons, unsigned nvert_total) {
+    unsigned nPoly=polygons.size();
+    osg::Vec3 *normales_polys = new osg::Vec3[nPoly];
+    osg::Vec3 *normales = new osg::Vec3[nvert_total];
+    unsigned pos=0;
+    unsigned poly;
+    /* Phase 1: Get flat normals */
+    for (poly=0;poly<nPoly;poly++) {
+	VertexIndexList vindex=*polygons[poly];
+	if (vindex.size() > 2) {
+            int v0,v1,v2;
+            get3v(vertices,vindex,v0,v1,v2);
+	    if (v0 == v1 || v0 == v2) {
+		std::cerr << "ERROR: Vertices alineados: nv=" << vindex.size() <<  std::endl;
+	    }
+	    normales_polys[poly] = calcNormal(vertices[v0],
+					      vertices[v1],
+					      vertices[v2]);
+	    if (normales_polys[poly] == osg::Vec3(0,0,0) && vindex.size() > 2) {
+		std::cerr << "##***" << "Normal nula VERTICES=" << vindex.size() << " " << vertices[v0] << " " << vertices[v1] << " " << vertices[v2] << std::endl;
+	    }
+	}
+    }
+    /* Phase 2: Selective smooth depending on crease angle */
+    for (poly=0;poly<nPoly;poly++) {
+	VertexIndexList vindex=*polygons[poly];
+        unsigned j;
+	osg::Vec3 pnormal=normales_polys[poly];
+	for (j=0;j<vindex.size();j++) {
+	    int vertice=vindex[j];
+	    normales[pos]=osg::Vec3(pnormal[0],pnormal[1],pnormal[2]);
+	    unsigned poly2;
+	    for (poly2=0;poly2<nPoly;poly2++) {
+                if (poly2 == poly) continue;
+		VertexIndexList vindex2=*polygons[poly2];
+		unsigned k;
+		osg::Vec3 pnormal2=normales_polys[poly2];
+		for (k=0;k<vindex2.size();k++) {
+		    if (vindex2[k] == vertice) {
+			float ang=difAng(pnormal,pnormal2);
+			if (ang < CREASE_ANGLE) {
+			    normales[pos]+=osg::Vec3(pnormal2[0],pnormal2[1],pnormal2[2]);
+			}
+		    }
+		}
+	    }
+	    normales[pos].normalize();
+	    pos++;
+	}
+    }
+    /* Phase 3: All done ;) */
+    return normales;
+}