[Libreoffice-commits] .: basegfx/inc
Libreoffice Gerrit user
logerrit at kemper.freedesktop.org
Thu Jan 10 08:51:03 PST 2013
basegfx/inc/basegfx/polygon/b2dpolypolygoncutter.hxx | 104 ++++++++++++-------
1 file changed, 68 insertions(+), 36 deletions(-)
New commits:
commit 9a11737360528249437bccbb374201453f5cddfe
Author: Thorsten Behrens <tbehrens at suse.com>
Date: Thu Jan 10 17:50:02 2013 +0100
Doxygenify helpful basegfx comments.
Change-Id: I60a49e643c336c8834862735f93f1b41d6dad348
diff --git a/basegfx/inc/basegfx/polygon/b2dpolypolygoncutter.hxx b/basegfx/inc/basegfx/polygon/b2dpolypolygoncutter.hxx
index dcd4841..31bd8b6 100644
--- a/basegfx/inc/basegfx/polygon/b2dpolypolygoncutter.hxx
+++ b/basegfx/inc/basegfx/polygon/b2dpolypolygoncutter.hxx
@@ -29,44 +29,76 @@ namespace basegfx
{
namespace tools
{
- // Solve all crossovers in a polyPolygon. This re-layouts all contained polygons so that the
- // result will contain only non-cutting polygons. For that reason, points will be added at
- // crossover and touch points and the single Polygons may be re-combined. The orientations
- // of the contained polygons in not changed but used as topological information.
- // Self crossovers of the contained sub-polygons are implicitely handled, but to not lose
- // the topological information, it may be necessary to remove self-intersections of the
- // contained sub-polygons in a preparing step and to explicitly correct their orientations.
+ /** Solve all crossovers (aka self-intersections) in a polyPolygon.
+
+ This re-layouts all contained polygons so that the result
+ will contain only non-cutting polygons. For that reason,
+ points will be added at crossover and touch points and the
+ single Polygons may be re-combined. The orientations of
+ the contained polygons in not changed but used as
+ topological information. Self crossovers of the contained
+ sub-polygons are implicitely handled, but to not lose the
+ topological information, it may be necessary to remove
+ self-intersections of the contained sub-polygons in a
+ preparing step and to explicitly correct their
+ orientations.
+ */
BASEGFX_DLLPUBLIC B2DPolyPolygon solveCrossovers(const B2DPolyPolygon& rCandidate);
- // Version for single polygons. This is for solving self-intersections. Result will be free of
- // crossovers. When result contains multiple polygons, it may be necessary to rearrange their
- // orientations since holes may have been created (use correctOrientations eventually).
+ /** Solve all crossovers (aka self-intersections) in a Polygon
+
+ Same as above, but for single polygons. Result will be
+ free of self-intersections. When result contains multiple
+ polygons, it may be necessary to rearrange their
+ orientations since holes may have been created (use
+ correctOrientations eventually).
+ */
BASEGFX_DLLPUBLIC B2DPolyPolygon solveCrossovers(const B2DPolygon& rCandidate);
- // Neutral polygons will be stripped. Neutral polygons are ones who's orientation is
- // neutral, so normally they have no volume -> just closed paths. A polygon with the same
- // positive and negative oriented volume is also neutral, so this may not be wanted. It is
- // safe to call with crossover-free polygons, though (that's where it's mostly used).
+ /** Strip neutral polygons from PolyPolygon.
+
+ Neutral polygons are ones who's orientation is neutral, so
+ normally they have no volume -> just closed paths. A
+ polygon with the same positive and negative oriented
+ volume is also neutral, so this may not be wanted. It is
+ safe to call with self-intersection-free polygons, though
+ (that's where it's mostly used).
+ */
BASEGFX_DLLPUBLIC B2DPolyPolygon stripNeutralPolygons(const B2DPolyPolygon& rCandidate);
- // Remove not necessary polygons. Works only correct with crossover-free polygons. For each
- // polygon, the depth for the PolyPolygon is calculated. The orientation is used to identify holes.
- // Start value for holes is -1, for polygons it's zero. Ech time a polygon is contained in another one,
- // it's depth is increased when inside a polygon, decreased when inside a hole. The result is a depth
- // which e.g. is -1 for holes outside everything, 1 for a polygon covered by another polygon and zero
- // for e.g. holes in a polygon or polygons outside everythig else.
- // In the 2nd step, all polygons with depth other than zero are removed. If bKeepAboveZero is used,
- // all polygons < 1 are removed. The bKeepAboveZero mode is useful for clipping, e.g. just append
- // one polygon to another and use this mode -> only parts where two polygons overlapped will be kept.
- // In combination with correct orientation of the input orientations and the SolveCrossover calls this
- // can be combined for logical polygon operations or polygon clipping.
+ /** Remove unnecessary/non-displayed polygons.
+
+ Works only correct with self-intersection-free
+ polygons. For each polygon, the depth for the PolyPolygon
+ is calculated. The orientation is used to identify holes.
+ Start value for holes is -1, for polygons it's zero. Ech
+ time a polygon is contained in another one, it's depth is
+ increased when inside a polygon, decreased when inside a
+ hole. The result is a depth which e.g. is -1 for holes
+ outside everything, 1 for a polygon covered by another
+ polygon and zero for e.g. holes in a polygon or polygons
+ outside everythig else. In the 2nd step, all polygons
+ with depth other than zero are removed. If bKeepAboveZero
+ is used, all polygons < 1 are removed. The bKeepAboveZero
+ mode is useful for clipping, e.g. just append one polygon
+ to another and use this mode -> only parts where two
+ polygons overlapped will be kept. In combination with
+ correct orientation of the input orientations and the
+ SolveCrossover calls this can be combined for logical
+ polygon operations or polygon clipping.
+ */
BASEGFX_DLLPUBLIC B2DPolyPolygon stripDispensablePolygons(const B2DPolyPolygon& rCandidate, bool bKeepAboveZero = false);
- // geometrically convert PolyPolygons which are proposed to use nonzero fill rule
- // to a representation where evenodd paint will give the same result. To do this
- // all intersections and self-intersections get solved (the polygons will be rearranged
- // if needed). Then all polygons which are inside another one with the same orientation
- // get deleted
+ /** Emulate nonzero winding rule filling.
+
+ Geometrically convert PolyPolygons which are proposed to
+ use nonzero fill rule to a representation where evenodd
+ paint will give the same result. To do this all
+ intersections and self-intersections get solved (the
+ polygons will be rearranged if needed). Then all polygons
+ which are inside another one with the same orientation get
+ deleted
+ */
BASEGFX_DLLPUBLIC B2DPolyPolygon createNonzeroConform(const B2DPolyPolygon& rCandidate);
// For convenience: The four basic operations OR, XOR, AND and DIFF for
@@ -84,21 +116,21 @@ namespace basegfx
// different since the simple concatenation will be seen as XOR. To work correctly, You
// may need to OR those polygons.
- // Preparations: solve self-intersections and intersections, remove neutral
- // parts and correct orientations.
+ /// prep for ops - solve self-intersections and intersections, remove neutral parts and check orientations.
BASEGFX_DLLPUBLIC B2DPolyPolygon prepareForPolygonOperation(const B2DPolygon& rCandidate);
+ /// prep for ops - solve self-intersections and intersections, remove neutral parts and check orientations.
BASEGFX_DLLPUBLIC B2DPolyPolygon prepareForPolygonOperation(const B2DPolyPolygon& rCandidate);
- // OR: Return all areas where CandidateA or CandidateB exist
+ /// OR: Return all areas where CandidateA or CandidateB exist
BASEGFX_DLLPUBLIC B2DPolyPolygon solvePolygonOperationOr(const B2DPolyPolygon& rCandidateA, const B2DPolyPolygon& rCandidateB);
- // XOR: Return all areas where CandidateA or CandidateB exist, but not both
+ /// XOR: Return all areas where CandidateA or CandidateB exist, but not both
BASEGFX_DLLPUBLIC B2DPolyPolygon solvePolygonOperationXor(const B2DPolyPolygon& rCandidateA, const B2DPolyPolygon& rCandidateB);
- // AND: Return all areas where CandidateA and CandidateB exist
+ /// AND: Return all areas where CandidateA and CandidateB exist
BASEGFX_DLLPUBLIC B2DPolyPolygon solvePolygonOperationAnd(const B2DPolyPolygon& rCandidateA, const B2DPolyPolygon& rCandidateB);
- // DIFF: Return all areas where CandidateA is not covered by CandidateB (cut B out of A)
+ /// DIFF: Return all areas where CandidateA is not covered by CandidateB (cut B out of A)
BASEGFX_DLLPUBLIC B2DPolyPolygon solvePolygonOperationDiff(const B2DPolyPolygon& rCandidateA, const B2DPolyPolygon& rCandidateB);
/** merge all single PolyPolygons to a single, OR-ed PolyPolygon
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