diff options
Diffstat (limited to 'basegfx/source/polygon/b2dpolygonclipper.cxx')
| -rw-r--r-- | basegfx/source/polygon/b2dpolygonclipper.cxx | 88 |
1 files changed, 44 insertions, 44 deletions
diff --git a/basegfx/source/polygon/b2dpolygonclipper.cxx b/basegfx/source/polygon/b2dpolygonclipper.cxx index e368f7dbb3bd..6f38b54dd992 100644 --- a/basegfx/source/polygon/b2dpolygonclipper.cxx +++ b/basegfx/source/polygon/b2dpolygonclipper.cxx @@ -2,7 +2,7 @@ /************************************************************************* * * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. - * + * * Copyright 2000, 2010 Oracle and/or its affiliates. * * OpenOffice.org - a multi-platform office productivity suite @@ -94,15 +94,15 @@ namespace basegfx { // add cuts with axis to polygon, including bezier segments // Build edge to cut with. Make it a little big longer than needed for - // numerical stability. We want to cut against the edge seen as endless + // numerical stability. We want to cut against the edge seen as endless // ray here, but addPointsAtCuts() will limit itself to the // edge's range ]0.0 .. 1.0[. const double fSmallExtension((aCandidateRange.getWidth() + aCandidateRange.getHeight()) * (0.5 * 0.1)); const B2DPoint aStart( - bParallelToXAxis ? aCandidateRange.getMinX() - fSmallExtension : fValueOnOtherAxis, + bParallelToXAxis ? aCandidateRange.getMinX() - fSmallExtension : fValueOnOtherAxis, bParallelToXAxis ? fValueOnOtherAxis : aCandidateRange.getMinY() - fSmallExtension); const B2DPoint aEnd( - bParallelToXAxis ? aCandidateRange.getMaxX() + fSmallExtension : fValueOnOtherAxis, + bParallelToXAxis ? aCandidateRange.getMaxX() + fSmallExtension : fValueOnOtherAxis, bParallelToXAxis ? fValueOnOtherAxis : aCandidateRange.getMaxY() + fSmallExtension); const B2DPolygon aCandidate(addPointsAtCuts(rCandidate, aStart, aEnd)); const sal_uInt32 nPointCount(aCandidate.count()); @@ -249,7 +249,7 @@ namespace basegfx // This needs to be done with the topology knowlegde and is unfurtunately // more expensive, too. const B2DPolygon aClip(createPolygonFromRect(rRange)); - + return clipPolygonOnPolyPolygon(rCandidate, B2DPolyPolygon(aClip), bInside, bStroke); } @@ -338,10 +338,10 @@ namespace basegfx } else { - // for details, see comment in clipPolygonOnRange for the "cutting off + // for details, see comment in clipPolygonOnRange for the "cutting off // the outer parts of filled polygons at parallell lines" explanations const B2DPolygon aClip(createPolygonFromRect(rRange)); - + return clipPolyPolygonOnPolyPolygon(rCandidate, B2DPolyPolygon(aClip), bInside, bStroke); } @@ -419,7 +419,7 @@ namespace basegfx B2DPolyPolygon clipPolyPolygonOnPolyPolygon(const B2DPolyPolygon& rCandidate, const B2DPolyPolygon& rClip, bool bInside, bool bStroke) { B2DPolyPolygon aRetval; - + if(rCandidate.count() && rClip.count()) { if(bStroke) @@ -493,10 +493,10 @@ namespace basegfx // area clipping B2DPolyPolygon aMergePolyPolygonA(rClip); - // First solve all polygon-self and polygon-polygon intersections. - // Also get rid of some not-needed polygons (neutral, no area -> when + // First solve all polygon-self and polygon-polygon intersections. + // Also get rid of some not-needed polygons (neutral, no area -> when // no intersections, these are tubes). - // Now it is possible to correct the orientations in the cut-free + // Now it is possible to correct the orientations in the cut-free // polygons to values corresponding to painting the PolyPolygon with // a XOR-WindingRule. aMergePolyPolygonA = solveCrossovers(aMergePolyPolygonA); @@ -575,28 +575,28 @@ namespace basegfx * */ struct scissor_plane { - double nx,ny; // plane normal - double d; // [-] minimum distance from origin - sal_uInt32 clipmask; // clipping mask, e.g. 1000 1000 + double nx,ny; // plane normal + double d; // [-] minimum distance from origin + sal_uInt32 clipmask; // clipping mask, e.g. 1000 1000 }; /* * * polygon clipping rules (straight out of Foley and Van Dam) * =========================================================== - * current |next |emit + * current |next |emit * ____________________________________ - * inside |inside |next - * inside |outside |intersect with clip plane - * outside |outside |nothing - * outside |inside |intersect with clip plane follwed by next + * inside |inside |next + * inside |outside |intersect with clip plane + * outside |outside |nothing + * outside |inside |intersect with clip plane follwed by next * */ - sal_uInt32 scissorLineSegment( ::basegfx::B2DPoint *in_vertex, // input buffer - sal_uInt32 in_count, // number of verts in input buffer - ::basegfx::B2DPoint *out_vertex, // output buffer - scissor_plane *pPlane, // scissoring plane - const ::basegfx::B2DRectangle &rR ) // clipping rectangle + sal_uInt32 scissorLineSegment( ::basegfx::B2DPoint *in_vertex, // input buffer + sal_uInt32 in_count, // number of verts in input buffer + ::basegfx::B2DPoint *out_vertex, // output buffer + scissor_plane *pPlane, // scissoring plane + const ::basegfx::B2DRectangle &rR ) // clipping rectangle { ::basegfx::B2DPoint *curr; ::basegfx::B2DPoint *next; @@ -605,7 +605,7 @@ namespace basegfx // process all the verts for(sal_uInt32 i=0; i<in_count; i++) { - + // vertices are relative to the coordinate // system defined by the rectangle. curr = &in_vertex[i]; @@ -663,7 +663,7 @@ namespace basegfx return out_count; } - B2DPolygon clipTriangleListOnRange( const B2DPolygon& rCandidate, + B2DPolygon clipTriangleListOnRange( const B2DPolygon& rCandidate, const B2DRange& rRange ) { B2DPolygon aResult; @@ -699,13 +699,13 @@ namespace basegfx //////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////// - // + // // Upper bound for the maximal number of vertices when intersecting an // axis-aligned rectangle with a triangle in E2 - // + // // The rectangle and the triangle are in general position, and have 4 and 3 // vertices, respectively. - // + // // Lemma: Since the rectangle is a convex polygon ( see // http://mathworld.wolfram.com/ConvexPolygon.html for a definition), and // has no holes, it follows that any straight line will intersect the @@ -717,7 +717,7 @@ namespace basegfx // other 'outside') will at utmost add _one_ vertex to the resulting // intersection polygon (adding two intersection vertices, and removing at // least one rectangle vertex): - // + // // * // +--+-----------------+ // | * | @@ -726,7 +726,7 @@ namespace basegfx // *| | // * | | // +--------------------+ - // + // // Proof: If the straight line intersects the rectangle two // times, it does so for distinct edges, i.e. the intersection has // minimally one of the rectangle's vertices on either side of the straight @@ -734,17 +734,17 @@ namespace basegfx // minimally _one_ rectangle vertex removed from the resulting clip // polygon, and therefore, a clip against a half-plane has the net effect // of adding at utmost _one_ vertex to the resulting clip polygon. - // + // // Theorem: The intersection of a rectangle and a triangle results in a // polygon with at utmost 7 vertices. - // + // // Proof: The inside of the triangle can be described as the consecutive // intersection with three half-planes. Together with the lemma above, this // results in at utmost 3 additional vertices added to the already existing 4 // rectangle vertices. - // + // // This upper bound is attained with the following example configuration: - // + // // * // *** // ** * @@ -766,7 +766,7 @@ namespace basegfx // --*6-----5----- // ** * // ** - // + // // As we need to scissor all triangles against the // output rectangle we employ an output buffer for the // resulting vertices. the question is how large this @@ -801,7 +801,7 @@ namespace basegfx ::basegfx::B2DPoint stack[3]; unsigned int clipflag = 0; - for(sal_uInt32 nIndex=0; nIndex<nVertexCount; ++nIndex) + for(sal_uInt32 nIndex=0; nIndex<nVertexCount; ++nIndex) { // rotate stack stack[0] = stack[1]; @@ -811,14 +811,14 @@ namespace basegfx // clipping judgement clipflag |= !(rRange.isInside(stack[2])); - if(nIndex > 1) + if(nIndex > 1) { // consume vertices until a single seperate triangle has been visited. - if(!((nIndex+1)%3)) + if(!((nIndex+1)%3)) { // if any of the last three vertices was outside // we need to scissor against the destination rectangle - if(clipflag & 7) + if(clipflag & 7) { ::basegfx::B2DPoint buf0[16]; ::basegfx::B2DPoint buf1[16]; @@ -832,12 +832,12 @@ namespace basegfx vertex_count = scissorLineSegment(buf0,vertex_count,buf1,&sp[2],rRange); vertex_count = scissorLineSegment(buf1,vertex_count,buf0,&sp[3],rRange); - if(vertex_count >= 3) + if(vertex_count >= 3) { // convert triangle fan back to triangle list. ::basegfx::B2DPoint v0(buf0[0]); ::basegfx::B2DPoint v1(buf0[1]); - for(sal_uInt32 i=2; i<vertex_count; ++i) + for(sal_uInt32 i=2; i<vertex_count; ++i) { ::basegfx::B2DPoint v2(buf0[i]); aResult.append(v0); @@ -847,10 +847,10 @@ namespace basegfx } } } - else + else { // the last triangle has not been altered, simply copy to result - for(sal_uInt32 i=0; i<3; ++i) + for(sal_uInt32 i=0; i<3; ++i) aResult.append(stack[i]); } } |