Initial revision

source/gameengine/Rasterizer/RAS_texmatrix.cpp

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+/**
+ * $Id$
+ * ***** BEGIN GPL/BL DUAL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version. The Blender
+ * Foundation also sells licenses for use in proprietary software under
+ * the Blender License.  See http://www.blender.org/BL/ for information
+ * about this.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
+ * All rights reserved.
+ *
+ * The Original Code is: all of this file.
+ *
+ * Contributor(s): none yet.
+ *
+ * ***** END GPL/BL DUAL LICENSE BLOCK *****
+ */
+
+
+
+#include "RAS_TexMatrix.h"
+
+
+void RAS_CalcTexMatrix(RAS_TexVert p[3],MT_Point3& origin,MT_Vector3& udir,MT_Vector3& vdir)
+{
+// precondition: 3 vertices are non-colinear
+
+	MT_Vector3 vec1 = p[1].xyz()-p[0].xyz();
+	MT_Vector3 vec2 = p[2].xyz()-p[0].xyz();
+	MT_Vector3 normal = vec1.cross(vec2);
+	normal.normalize();
+
+	// determine which coordinate we drop, ie. max coordinate in the normal
+	
+
+	int ZCOORD = normal.closestAxis();
+	int XCOORD = (ZCOORD+1)%3;
+	int YCOORD = (ZCOORD+2)%3;
+		
+	// ax+by+cz+d=0
+	MT_Scalar d = -p[0].xyz().dot(normal);
+	
+
+	MT_Matrix3x3 mat3(	p[0].getUV1()[0],p[0].getUV1()[1],	1,
+						p[1].getUV1()[0],p[1].getUV1()[1],	1,
+						p[2].getUV1()[0],p[2].getUV1()[1],	1);
+
+
+	MT_Matrix3x3 mat3inv = mat3.inverse();
+
+	MT_Vector3 p123x(p[0].xyz()[XCOORD],p[1].xyz()[XCOORD],p[2].xyz()[XCOORD]);
+	MT_Vector3 resultx = mat3inv*p123x;
+	MT_Vector3 p123y(p[0].xyz()[YCOORD],p[1].xyz()[YCOORD],p[2].xyz()[YCOORD]);
+	MT_Vector3 resulty = mat3inv*p123y;
+
+	// normal[ZCOORD] is not zero, because it's chosen to be maximal (absolute), and normal has length 1, 
+	// so at least on of the coords is <> 0
+
+	//droppedvalue udir.dot(normal) =0
+	MT_Scalar droppedu = -(resultx.x()*normal[XCOORD]+resulty.x()*normal[YCOORD])/normal[ZCOORD];
+	udir[XCOORD] = resultx.x();
+	udir[YCOORD] = resulty.x();
+	udir[ZCOORD] = droppedu;
+	MT_Scalar droppedv = -(resultx.y()*normal[XCOORD]+resulty.y()*normal[YCOORD])/normal[ZCOORD];
+	vdir[XCOORD] = resultx.y();
+	vdir[YCOORD] = resulty.y();
+	vdir[ZCOORD] = droppedv;
+	// droppedvalue b = -(ax+cz+d)/y;
+	MT_Scalar droppedvalue = -((resultx.z()*normal[XCOORD] + resulty.z()*normal[YCOORD]+d))/normal[ZCOORD];
+	origin[XCOORD] = resultx.z();
+	origin[YCOORD] = resulty.z();
+	origin[ZCOORD] = droppedvalue;
+	
+
+}
+
+#ifdef _TEXOWNMAIN
+
+int main()
+{
+
+	MT_Point2 puv0={0,0};
+	MT_Point3 pxyz0 (0,0,128);
+
+	MT_Scalar puv1[2]={1,0};
+	MT_Point3 pxyz1(128,0,128);
+
+	MT_Scalar puv2[2]={1,1};
+	MT_Point3 pxyz2(128,0,0);
+
+	RAS_TexVert p0(pxyz0,puv0);
+	RAS_TexVert p1(pxyz1,puv1);
+	RAS_TexVert p2(pxyz2,puv2);
+
+	RAS_TexVert vertices[3] = 
+	{
+		p0,
+		p1,
+		p2
+	};
+
+	MT_Vector3 udir,vdir;
+	MT_Point3 origin;
+	CalcTexMatrix(vertices,origin,udir,vdir);
+
+	MT_Point3 testpoint(128,32,64);
+
+	MT_Scalar lenu = udir.length2();
+	MT_Scalar lenv = vdir.length2();
+
+	MT_Scalar testu=((pxyz2-origin).dot(udir))/lenu;
+	MT_Scalar testv=((pxyz2-origin).dot(vdir))/lenv;
+
+
+
+
+	return 0;
+}
+
+#endif // _TEXOWNMAIN