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Diffstat (limited to 'nx-X11/extras/ogl-sample/main/gfx/lib/glu/libnurbs/nurbtess/partitionY.h')
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diff --git a/nx-X11/extras/ogl-sample/main/gfx/lib/glu/libnurbs/nurbtess/partitionY.h b/nx-X11/extras/ogl-sample/main/gfx/lib/glu/libnurbs/nurbtess/partitionY.h new file mode 100644 index 000000000..96d6a4c96 --- /dev/null +++ b/nx-X11/extras/ogl-sample/main/gfx/lib/glu/libnurbs/nurbtess/partitionY.h @@ -0,0 +1,104 @@ +/* +** 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. +** +** $Date: 2004/03/14 08:29:11 $ $Revision: 1.1.1.4 $ +*/ +/* + *partitionY.h: + *partition a polygon into a Y-monotone polygon: + * A polygon is Y-monotone if the boundary can be split into two polygon chains + *A and B such that each chain is Y-monotonic that is the intersection of any + *horizontal line intersects each chain has at most one connected componenets + * (empty, single point or a single line). + * + * A vertex is a cusp if both its ajacent vertices are either at or above v, + *or both at or below v. In addition, at least one of the ajacent verteces is + *strictly below or above v. + * A vertex is a relex vertex if the internals angle is strictly greater than + *180. In other words, if the the signed area is negative: + *(x1, y1), (x2, y2), (x3, y3) are the three vertices along a polygon, the + *order is such that left hand side is inside the polygon. Then (x2,y2) is + *reflex if: + * (x2-x1, y2-y1) cross (x3-x1, y3-y1) <0. + *A vertex is an interior cusp if it is a cusp and a reflex. + *A vertex is an exterior cusp if it is a cusp but not a reflex. + * + * $Header: /cvs/xorg/xc/extras/ogl-sample/main/gfx/lib/glu/libnurbs/nurbtess/partitionY.h,v 1.1.1.4 2004/03/14 08:29:11 eich Exp $ + */ + +#ifndef _PARTITIONY_H +#define _PARTITIONY_H + +#include "directedLine.h" + +/*whether an edge is below a vertex*/ +Int isBelow(directedLine *v, directedLine *e); + +/*whether an edge is above a vertex*/ +Int isAbove(directedLine *v, directedLine *e); + +/*not-cusp, + *inerior cusp + *exterior cusp + */ +Int cuspType(directedLine *v); + +/*used in trapezoidalization*/ +typedef struct sweepRange{ + directedLine *left; + Int leftType; /*either a vertex (leftType=0) or an edge (leftType =1) */ + directedLine *right; + Int rightType; /*either a vertex (rightType=0) or an edge (rightType =1) */ +} sweepRange; + +sweepRange* sweepRangeMake(directedLine* left, Int leftType, + directedLine* right, Int rightType); + +void sweepRangeDelete(sweepRange* range); +Int sweepRangeEqual(sweepRange* sr1, sweepRange* sr2); + +/*given a set of simple polygons where the interior + *is decided by left-hand principle, + *return a range (sight) for each vertex. This is called + *Trapezoidalization. + */ +void sweepY(Int nVertices, directedLine **sortedVerteces, sweepRange** ret_ranges); + + +directedLine* partitionY(directedLine *polygons, sampledLine **retSampledLines); + +void findDiagonals(Int total_num_edges, directedLine** sortedVertices, sweepRange** ranges, Int& num_diagonals, directedLine** diagonal_vertices); + +directedLine** DBGfindDiagonals(directedLine *polygons, Int& num_diagonals); + +#endif |