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21
22
23
24
25 // MARKER(update_precomp.py): autogen include statement, do not remove
26 #include "precompiled_chart2.hxx"
27
28 #include "Clipping.hxx"
29 #include "CommonConverters.hxx"
30 #include "BaseGFXHelper.hxx"
31
32 #include <com/sun/star/drawing/Position3D.hpp>
33 #include <com/sun/star/drawing/DoubleSequence.hpp>
34
35 //.............................................................................
36 namespace chart
37 {
38 //.............................................................................
39 using namespace ::com::sun::star;
40 using ::basegfx::B2DRectangle;
41 using ::basegfx::B2DTuple;
42
43 //-----------------------------------------------------------------------------
44 //-----------------------------------------------------------------------------
45 //-----------------------------------------------------------------------------
46
47 namespace{
48 /** @descr This is a supporting function for lcl_clip2d. It computes a new parametric
49 value for an entering (dTE) or leaving (dTL) intersection point with one
50 of the edges bounding the clipping area.
51 For explanation of the parameters please refer to :
52
53 Liang-Biarsky parametric line-clipping algorithm as described in:
54 Computer Graphics: principles and practice, 2nd ed.,
55 James D. Foley et al.,
56 Section 3.12.4 on page 117.
57 */
lcl_CLIPt(double fDenom,double fNum,double & fTE,double & fTL)58 bool lcl_CLIPt(double fDenom,double fNum, double & fTE, double & fTL)
59 {
60 double fT;
61
62 if (fDenom > 0) // Intersection enters: PE
63 {
64 fT = fNum / fDenom; // Parametric value at the intersection.
65 if (fT > fTL) // fTE and fTL crossover
66 return false; // therefore reject the line.
67 else if (fT > fTE) // A new fTE has been found.
68 fTE = fT;
69 }
70 else if (fDenom < 0) // Intersection leaves: PL
71 {
72 fT = fNum / fDenom; // Parametric Value at the intersection.
73 if (fT < fTE) // fTE and fTL crossover
74 return false; // therefore reject the line.
75 else if (fT < fTL) // A new fTL has been found.
76 fTL = fT;
77 }
78 else if (fNum > 0)
79 return false; // Line lies on the outside of the edge.
80
81 return true;
82 }
83
84 /** @descr The line given by it's two endpoints rP0 and rP1 is clipped at the rectangle
85 rRectangle. If there is at least a part of it visible then sal_True is returned and
86 the endpoints of that part are stored in rP0 and rP1. The points rP0 and rP1
87 may have the same coordinates.
88 @param rP0 Start point of the line to clip. Modified to contain a start point inside
89 the clipping area if possible.
90 @param rP1 End point of the line to clip. Modified to contain an end point inside
91 the clipping area if possible.
92 @param rRectangle Clipping area.
93 @return If the line lies completely or partly inside the clipping area then TRUE
94 is returned. If the line lies completely outside then sal_False is returned and rP0 and
95 rP1 are left unmodified.
96 */
lcl_clip2d(B2DTuple & rPoint0,B2DTuple & rPoint1,const B2DRectangle & rRectangle)97 bool lcl_clip2d(B2DTuple& rPoint0, B2DTuple& rPoint1, const B2DRectangle& rRectangle)
98 {
99 //Direction vector of the line.
100 B2DTuple aDirection = rPoint1 - rPoint0;
101
102 if( aDirection.getX()==0 && aDirection.getY()==0 && rRectangle.isInside(rPoint0) )
103 {
104 // Degenerate case of a zero length line.
105 return true;
106 }
107 else
108 {
109 // Values of the line parameter where the line enters resp. leaves the rectangle.
110 double fTE = 0,
111 fTL = 1;
112
113 // Test whether at least a part lies in the four half-planes with respect to
114 // the rectangles four edges.
115 if( lcl_CLIPt(aDirection.getX(), rRectangle.getMinX() - rPoint0.getX(), fTE, fTL) )
116 if( lcl_CLIPt(-aDirection.getX(), rPoint0.getX() - rRectangle.getMaxX(), fTE, fTL) )
117 if( lcl_CLIPt(aDirection.getY(), rRectangle.getMinY() - rPoint0.getY(), fTE, fTL) )
118 if( lcl_CLIPt(-aDirection.getY(), rPoint0.getY() - rRectangle.getMaxY(), fTE, fTL) )
119 {
120 // At least a part is visible.
121 if (fTL < 1)
122 {
123 // Compute the new end point.
124 rPoint1.setX( rPoint0.getX() + fTL * aDirection.getX() );
125 rPoint1.setY( rPoint0.getY() + fTL * aDirection.getY() );
126 }
127 if (fTE > 0)
128 {
129 // Compute the new starting point.
130 rPoint0.setX( rPoint0.getX() + fTE * aDirection.getX() );
131 rPoint0.setY( rPoint0.getY() + fTE * aDirection.getY() );
132 }
133 return true;
134 }
135
136 // Line is not visible.
137 return false;
138 }
139 }
140
lcl_clip2d_(drawing::Position3D & rPoint0,drawing::Position3D & rPoint1,const B2DRectangle & rRectangle)141 bool lcl_clip2d_(drawing::Position3D& rPoint0, drawing::Position3D& rPoint1, const B2DRectangle& rRectangle)
142 {
143 B2DTuple aP0(rPoint0.PositionX,rPoint0.PositionY);
144 B2DTuple aP1(rPoint1.PositionX,rPoint1.PositionY);
145 bool bRet = lcl_clip2d( aP0, aP1, rRectangle );
146
147 rPoint0.PositionX = aP0.getX();
148 rPoint0.PositionY = aP0.getY();
149 rPoint1.PositionX = aP1.getX();
150 rPoint1.PositionY = aP1.getY();
151
152 return bRet;
153 }
154
lcl_addPointToPoly(drawing::PolyPolygonShape3D & rPoly,const drawing::Position3D & rPos,sal_Int32 nPolygonIndex,std::vector<sal_Int32> & rResultPointCount,sal_Int32 nReservePointCount)155 void lcl_addPointToPoly( drawing::PolyPolygonShape3D& rPoly
156 , const drawing::Position3D& rPos
157 , sal_Int32 nPolygonIndex
158 , std::vector< sal_Int32 >& rResultPointCount
159 , sal_Int32 nReservePointCount )
160 {
161 if(nPolygonIndex<0)
162 {
163 OSL_ENSURE( false, "The polygon index needs to be > 0");
164 nPolygonIndex=0;
165 }
166
167 //make sure that we have enough polygons
168 if(nPolygonIndex >= rPoly.SequenceX.getLength() )
169 {
170 rPoly.SequenceX.realloc(nPolygonIndex+1);
171 rPoly.SequenceY.realloc(nPolygonIndex+1);
172 rPoly.SequenceZ.realloc(nPolygonIndex+1);
173 rResultPointCount.resize(nPolygonIndex+1,0);
174 }
175
176 drawing::DoubleSequence* pOuterSequenceX = &rPoly.SequenceX.getArray()[nPolygonIndex];
177 drawing::DoubleSequence* pOuterSequenceY = &rPoly.SequenceY.getArray()[nPolygonIndex];
178 drawing::DoubleSequence* pOuterSequenceZ = &rPoly.SequenceZ.getArray()[nPolygonIndex];
179
180 sal_Int32 nNewResultPointCount = rResultPointCount[nPolygonIndex]+1;
181 sal_Int32 nSeqLength = pOuterSequenceX->getLength();
182
183 if( nSeqLength <= nNewResultPointCount )
184 {
185 sal_Int32 nReallocLength = nReservePointCount;
186 if( nNewResultPointCount > nReallocLength )
187 {
188 nReallocLength = nNewResultPointCount;
189 DBG_ERROR("this should not be the case to avoid performance problems");
190 }
191 pOuterSequenceX->realloc(nReallocLength);
192 pOuterSequenceY->realloc(nReallocLength);
193 pOuterSequenceZ->realloc(nReallocLength);
194 }
195
196 double* pInnerSequenceX = pOuterSequenceX->getArray();
197 double* pInnerSequenceY = pOuterSequenceY->getArray();
198 double* pInnerSequenceZ = pOuterSequenceZ->getArray();
199
200 pInnerSequenceX[nNewResultPointCount-1] = rPos.PositionX;
201 pInnerSequenceY[nNewResultPointCount-1] = rPos.PositionY;
202 pInnerSequenceZ[nNewResultPointCount-1] = rPos.PositionZ;
203 rResultPointCount[nPolygonIndex]=nNewResultPointCount;
204 }
205
206 }//end anonymous namespace
207
clipPolygonAtRectangle(const drawing::PolyPolygonShape3D & rPolygon,const B2DRectangle & rRectangle,drawing::PolyPolygonShape3D & aResult,bool bSplitPiecesToDifferentPolygons)208 void Clipping::clipPolygonAtRectangle( const drawing::PolyPolygonShape3D& rPolygon
209 , const B2DRectangle& rRectangle
210 , drawing::PolyPolygonShape3D& aResult
211 , bool bSplitPiecesToDifferentPolygons )
212 {
213 aResult.SequenceX.realloc(0);
214 aResult.SequenceY.realloc(0);
215 aResult.SequenceZ.realloc(0);
216
217 if(!rPolygon.SequenceX.getLength())
218 return;
219
220 //need clipping?:
221 {
222 ::basegfx::B3DRange a3DRange( BaseGFXHelper::getBoundVolume( rPolygon ) );
223 ::basegfx::B2DRange a2DRange( a3DRange.getMinX(), a3DRange.getMinY(), a3DRange.getMaxX(), a3DRange.getMaxY() );
224 if( rRectangle.isInside( a2DRange ) )
225 {
226 aResult = rPolygon;
227 return;
228 }
229 else
230 {
231 a2DRange.intersect( rRectangle );
232 if( a2DRange.isEmpty() )
233 return;
234 }
235 }
236
237 //
238 std::vector< sal_Int32 > aResultPointCount;//per polygon index
239
240 //apply clipping:
241 drawing::Position3D aFrom;
242 drawing::Position3D aTo;
243
244 sal_Int32 nNewPolyIndex = 0;
245 sal_Int32 nOldPolyCount = rPolygon.SequenceX.getLength();
246 for(sal_Int32 nOldPolyIndex=0; nOldPolyIndex<nOldPolyCount; nOldPolyIndex++, nNewPolyIndex++ )
247 {
248 sal_Int32 nOldPointCount = rPolygon.SequenceX[nOldPolyIndex].getLength();
249
250 // set last point to a position outside the rectangle, such that the first
251 // time lcl_clip2d returns true, the comparison to last will always yield false
252 drawing::Position3D aLast(rRectangle.getMinX()-1.0,rRectangle.getMinY()-1.0, 0.0 );
253
254 for(sal_Int32 nOldPoint=1; nOldPoint<nOldPointCount; nOldPoint++)
255 {
256 aFrom = getPointFromPoly(rPolygon,nOldPoint-1,nOldPolyIndex);
257 aTo = getPointFromPoly(rPolygon,nOldPoint,nOldPolyIndex);
258 if( lcl_clip2d_(aFrom, aTo, rRectangle) )
259 {
260 // compose an Polygon of as many consecutive points as possible
261 if(aFrom == aLast)
262 {
263 if( !(aTo==aFrom) )
264 {
265 lcl_addPointToPoly( aResult, aTo, nNewPolyIndex, aResultPointCount, nOldPointCount );
266 }
267 }
268 else
269 {
270 if( bSplitPiecesToDifferentPolygons && nOldPoint!=1 )
271 {
272 if( nNewPolyIndex < aResult.SequenceX.getLength()
273 && aResultPointCount[nNewPolyIndex]>0 )
274 nNewPolyIndex++;
275 }
276 lcl_addPointToPoly( aResult, aFrom, nNewPolyIndex, aResultPointCount, nOldPointCount );
277 if( !(aTo==aFrom) )
278 lcl_addPointToPoly( aResult, aTo, nNewPolyIndex, aResultPointCount, nOldPointCount );
279 }
280 aLast = aTo;
281 }
282 }
283 }
284 //free unused space
285 for( sal_Int32 nPolygonIndex = aResultPointCount.size(); nPolygonIndex--; )
286 {
287 drawing::DoubleSequence* pOuterSequenceX = &aResult.SequenceX.getArray()[nPolygonIndex];
288 drawing::DoubleSequence* pOuterSequenceY = &aResult.SequenceY.getArray()[nPolygonIndex];
289 drawing::DoubleSequence* pOuterSequenceZ = &aResult.SequenceZ.getArray()[nPolygonIndex];
290
291 sal_Int32 nUsedPointCount = aResultPointCount[nPolygonIndex];
292 pOuterSequenceX->realloc(nUsedPointCount);
293 pOuterSequenceY->realloc(nUsedPointCount);
294 pOuterSequenceZ->realloc(nUsedPointCount);
295 }
296 }
297
298 //.............................................................................
299 } //namespace chart
300 //.............................................................................
301