summaryrefslogtreecommitdiffstats
path: root/chart2/source/view/main/Clipping.cxx
blob: 713e88c26bd0f784bc15c5ccefe5d9187b07e1c7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
 */

#include <Clipping.hxx>
#include <CommonConverters.hxx>
#include <BaseGFXHelper.hxx>

#include <o3tl/safeint.hxx>
#include <osl/diagnose.h>

#include <com/sun/star/drawing/Position3D.hpp>
#include <com/sun/star/drawing/DoubleSequence.hpp>

namespace chart
{
using namespace ::com::sun::star;
using ::basegfx::B2DRectangle;
using ::basegfx::B2DTuple;

namespace{
/** @descr  This is a supporting function for lcl_clip2d.  It computes a new parametric
            value for an entering (dTE) or leaving (dTL) intersection point with one
            of the edges bounding the clipping area.
            For explanation of the parameters please refer to :

            Liang-Biarsky parametric line-clipping algorithm as described in:
            Computer Graphics: principles and practice, 2nd ed.,
            James D. Foley et al.,
            Section 3.12.4 on page 117.
*/
bool lcl_CLIPt(double fDenom,double fNum, double & fTE, double & fTL)
{
    double  fT;

    if (fDenom > 0)             //  Intersection enters: PE
    {
        fT = fNum / fDenom;     //  Parametric value at the intersection.
        if (fT > fTL)           //  fTE and fTL crossover
            return false;       //    therefore reject the line.
        else if (fT > fTE)      //  A new fTE has been found.
            fTE = fT;
    }
    else if (fDenom < 0)        //  Intersection leaves: PL
    {
        fT = fNum / fDenom;     //  Parametric Value at the intersection.
        if (fT < fTE)           //  fTE and fTL crossover
            return false;       //    therefore reject the line.
        else if (fT < fTL)      //  A new fTL has been found.
            fTL = fT;
    }
    else if (fNum > 0)
        return false;           //  Line lies on the outside of the edge.

    return true;
}

/** @descr  The line given by its two endpoints rP0 and rP1 is clipped at the rectangle
            rRectangle.  If there is at least a part of it visible then sal_True is returned and
            the endpoints of that part are stored in rP0 and rP1.  The points rP0 and rP1
            may have the same coordinates.
        @param  rP0 Start point of the line to clip.  Modified to contain a start point inside
            the clipping area if possible.
        @param  rP1 End point of the line to clip.  Modified to contain an end point inside
            the clipping area if possible.
        @param  rRectangle Clipping area.
        @return If the line lies completely or partly inside the clipping area then TRUE
            is returned.  If the line lies completely outside then sal_False is returned and rP0 and
            rP1 are left unmodified.
*/
bool lcl_clip2d(B2DTuple& rPoint0, B2DTuple& rPoint1, const B2DRectangle& rRectangle)
{
    //Direction vector of the line.
    B2DTuple aDirection = rPoint1 - rPoint0;

    if( aDirection.getX()==0 && aDirection.getY()==0 && rRectangle.isInside(rPoint0) )
    {
        //  Degenerate case of a zero length line.
        return true;
    }
    else
    {
        //  Values of the line parameter where the line enters resp. leaves the rectangle.
        double fTE = 0,
               fTL = 1;

        //  Test whether at least a part lies in the four half-planes with respect to
        //  the rectangles four edges.
        if( lcl_CLIPt(aDirection.getX(), rRectangle.getMinX() - rPoint0.getX(), fTE, fTL) )
            if( lcl_CLIPt(-aDirection.getX(), rPoint0.getX() - rRectangle.getMaxX(), fTE, fTL) )
                if( lcl_CLIPt(aDirection.getY(), rRectangle.getMinY() - rPoint0.getY(), fTE, fTL) )
                    if( lcl_CLIPt(-aDirection.getY(), rPoint0.getY() - rRectangle.getMaxY(), fTE, fTL) )
                    {
                        //  At least a part is visible.
                        if (fTL < 1)
                        {
                            //  Compute the new end point.
                            rPoint1.setX( rPoint0.getX() + fTL * aDirection.getX() );
                            rPoint1.setY( rPoint0.getY() + fTL * aDirection.getY() );
                        }
                        if (fTE > 0)
                        {
                            //  Compute the new starting point.
                            rPoint0.setX( rPoint0.getX() + fTE * aDirection.getX() );
                            rPoint0.setY( rPoint0.getY() + fTE * aDirection.getY() );
                        }
                        return true;
                    }

        //  Line is not visible.
        return false;
    }
}

bool lcl_clip2d_(drawing::Position3D& rPoint0, drawing::Position3D& rPoint1, const B2DRectangle& rRectangle)
{
    B2DTuple aP0(rPoint0.PositionX,rPoint0.PositionY);
    B2DTuple aP1(rPoint1.PositionX,rPoint1.PositionY);
    bool bRet = lcl_clip2d( aP0, aP1, rRectangle );

    rPoint0.PositionX = aP0.getX();
    rPoint0.PositionY = aP0.getY();
    rPoint1.PositionX = aP1.getX();
    rPoint1.PositionY = aP1.getY();

    return bRet;
}

unsigned int round_up_nearest_pow2(unsigned int v)
{
    // compute the next highest power of 2 of 32-bit v
    --v;
    v |= v >> 1;
    v |= v >> 2;
    v |= v >> 4;
    v |= v >> 8;
    v |= v >> 16;
    ++v;
    return v;
}

void lcl_addPointToPoly( drawing::PolyPolygonShape3D& rPoly
        , const drawing::Position3D& rPos
        , sal_Int32 nPolygonIndex
        , std::vector< sal_Int32 >& rResultPointCount
        , sal_Int32 nReservePointCount )
{
    if(nPolygonIndex<0)
    {
        OSL_FAIL( "The polygon index needs to be > 0");
        nPolygonIndex=0;
    }

    //make sure that we have enough polygons
    if(nPolygonIndex >= rPoly.SequenceX.getLength() )
    {
        rPoly.SequenceX.realloc(nPolygonIndex+1);
        rPoly.SequenceY.realloc(nPolygonIndex+1);
        rPoly.SequenceZ.realloc(nPolygonIndex+1);
        rResultPointCount.resize(nPolygonIndex+1,0);
    }

    drawing::DoubleSequence* pOuterSequenceX = &rPoly.SequenceX.getArray()[nPolygonIndex];
    drawing::DoubleSequence* pOuterSequenceY = &rPoly.SequenceY.getArray()[nPolygonIndex];
    drawing::DoubleSequence* pOuterSequenceZ = &rPoly.SequenceZ.getArray()[nPolygonIndex];

    sal_Int32 nNewResultPointCount = rResultPointCount[nPolygonIndex]+1;
    sal_Int32 nSeqLength = pOuterSequenceX->getLength();

    if( nSeqLength <= nNewResultPointCount )
    {
        sal_Int32 nReallocLength = nReservePointCount > SAL_MAX_INT16 ? round_up_nearest_pow2(nNewResultPointCount) * 2 : nReservePointCount;
        if( nNewResultPointCount > nReallocLength )
        {
            nReallocLength = nNewResultPointCount;
            OSL_FAIL("this should not be the case to avoid performance problems");
        }
        pOuterSequenceX->realloc(nReallocLength);
        pOuterSequenceY->realloc(nReallocLength);
        pOuterSequenceZ->realloc(nReallocLength);
    }

    double* pInnerSequenceX = pOuterSequenceX->getArray();
    double* pInnerSequenceY = pOuterSequenceY->getArray();
    double* pInnerSequenceZ = pOuterSequenceZ->getArray();

    pInnerSequenceX[nNewResultPointCount-1] = rPos.PositionX;
    pInnerSequenceY[nNewResultPointCount-1] = rPos.PositionY;
    pInnerSequenceZ[nNewResultPointCount-1] = rPos.PositionZ;
    rResultPointCount[nPolygonIndex]=nNewResultPointCount;
}

void lcl_addPointToPoly( std::vector<std::vector<css::drawing::Position3D>>& rPoly
        , const drawing::Position3D& rPos
        , sal_Int32 nPolygonIndex
        , std::vector< sal_Int32 >& rResultPointCount
        , sal_Int32 nReservePointCount )
{
    if(nPolygonIndex<0)
    {
        OSL_FAIL( "The polygon index needs to be > 0");
        nPolygonIndex=0;
    }

    //make sure that we have enough polygons
    if(o3tl::make_unsigned(nPolygonIndex) >= rPoly.size() )
    {
        rPoly.resize(nPolygonIndex+1);
        rResultPointCount.resize(nPolygonIndex+1,0);
    }

    std::vector<css::drawing::Position3D>* pOuterSequence = &rPoly[nPolygonIndex];

    sal_Int32 nNewResultPointCount = rResultPointCount[nPolygonIndex]+1;
    sal_Int32 nSeqLength = pOuterSequence->size();

    if( nSeqLength <= nNewResultPointCount )
    {
        sal_Int32 nReallocLength = nReservePointCount > SAL_MAX_INT16 ? round_up_nearest_pow2(nNewResultPointCount) * 2 : nReservePointCount;
        if( nNewResultPointCount > nReallocLength )
        {
            nReallocLength = nNewResultPointCount;
            OSL_FAIL("this should not be the case to avoid performance problems");
        }
        pOuterSequence->resize(nReallocLength);
    }

    css::drawing::Position3D* pInnerSequence = pOuterSequence->data();

    pInnerSequence[nNewResultPointCount-1] = rPos;
    rResultPointCount[nPolygonIndex]=nNewResultPointCount;
}

}//end anonymous namespace

void Clipping::clipPolygonAtRectangle( const drawing::PolyPolygonShape3D& rPolygon
                                      , const B2DRectangle& rRectangle
                                      , drawing::PolyPolygonShape3D& aResult
                                      , bool bSplitPiecesToDifferentPolygons )
{
    aResult.SequenceX.realloc(0);
    aResult.SequenceY.realloc(0);
    aResult.SequenceZ.realloc(0);

    if(!rPolygon.SequenceX.hasElements())
        return;

    //need clipping?:
    {
        ::basegfx::B3DRange a3DRange( BaseGFXHelper::getBoundVolume( rPolygon ) );
        ::basegfx::B2DRange a2DRange( a3DRange.getMinX(), a3DRange.getMinY(), a3DRange.getMaxX(), a3DRange.getMaxY() );
        if( rRectangle.isInside( a2DRange ) )
        {
            aResult = rPolygon;
            return;
        }
        else
        {
            a2DRange.intersect( rRectangle );
            if( a2DRange.isEmpty() )
                return;
        }
    }

    std::vector< sal_Int32 > aResultPointCount;//per polygon index

    //apply clipping:
    drawing::Position3D aFrom;
    drawing::Position3D aTo;

    sal_Int32 nNewPolyIndex = 0;
    sal_Int32 nOldPolyCount = rPolygon.SequenceX.getLength();
    for(sal_Int32 nOldPolyIndex=0; nOldPolyIndex<nOldPolyCount; nOldPolyIndex++, nNewPolyIndex++ )
    {
        sal_Int32 nOldPointCount = rPolygon.SequenceX[nOldPolyIndex].getLength();

        // set last point to a position outside the rectangle, such that the first
        // time lcl_clip2d returns true, the comparison to last will always yield false
        drawing::Position3D aLast(rRectangle.getMinX()-1.0,rRectangle.getMinY()-1.0, 0.0 );

        for(sal_Int32 nOldPoint=1; nOldPoint<nOldPointCount; nOldPoint++)
        {
            aFrom = getPointFromPoly(rPolygon,nOldPoint-1,nOldPolyIndex);
            aTo = getPointFromPoly(rPolygon,nOldPoint,nOldPolyIndex);
            if( lcl_clip2d_(aFrom, aTo, rRectangle) )
            {
                // compose a Polygon of as many consecutive points as possible
                if(aFrom == aLast)
                {
                    if( aTo != aFrom )
                    {
                        lcl_addPointToPoly( aResult, aTo, nNewPolyIndex, aResultPointCount, nOldPointCount );
                    }
                }
                else
                {
                    if( bSplitPiecesToDifferentPolygons && nOldPoint!=1 )
                    {
                        if( nNewPolyIndex < aResult.SequenceX.getLength()
                                && aResultPointCount[nNewPolyIndex]>0 )
                            nNewPolyIndex++;
                    }
                    lcl_addPointToPoly( aResult, aFrom, nNewPolyIndex, aResultPointCount, nOldPointCount );
                    if( aTo != aFrom )
                        lcl_addPointToPoly( aResult, aTo, nNewPolyIndex, aResultPointCount, nOldPointCount );
                }
                aLast = aTo;
            }
        }
    }
    //free unused space
    for( sal_Int32 nPolygonIndex = aResultPointCount.size(); nPolygonIndex--; )
    {
        drawing::DoubleSequence* pOuterSequenceX = &aResult.SequenceX.getArray()[nPolygonIndex];
        drawing::DoubleSequence* pOuterSequenceY = &aResult.SequenceY.getArray()[nPolygonIndex];
        drawing::DoubleSequence* pOuterSequenceZ = &aResult.SequenceZ.getArray()[nPolygonIndex];

        sal_Int32 nUsedPointCount = aResultPointCount[nPolygonIndex];
        pOuterSequenceX->realloc(nUsedPointCount);
        pOuterSequenceY->realloc(nUsedPointCount);
        pOuterSequenceZ->realloc(nUsedPointCount);
    }
}

void Clipping::clipPolygonAtRectangle( const std::vector<std::vector<css::drawing::Position3D>>& rPolygon
                                      , const B2DRectangle& rRectangle
                                      , std::vector<std::vector<css::drawing::Position3D>>& aResult
                                      , bool bSplitPiecesToDifferentPolygons )
{
    aResult.clear();

    if(rPolygon.empty())
        return;

    //need clipping?:
    {
        ::basegfx::B3DRange a3DRange( BaseGFXHelper::getBoundVolume( rPolygon ) );
        ::basegfx::B2DRange a2DRange( a3DRange.getMinX(), a3DRange.getMinY(), a3DRange.getMaxX(), a3DRange.getMaxY() );
        if( rRectangle.isInside( a2DRange ) )
        {
            aResult = rPolygon;
            return;
        }
        else
        {
            a2DRange.intersect( rRectangle );
            if( a2DRange.isEmpty() )
                return;
        }
    }

    std::vector< sal_Int32 > aResultPointCount;//per polygon index

    //apply clipping:
    drawing::Position3D aFrom;
    drawing::Position3D aTo;

    sal_Int32 nNewPolyIndex = 0;
    sal_Int32 nOldPolyCount = rPolygon.size();
    for(sal_Int32 nOldPolyIndex=0; nOldPolyIndex<nOldPolyCount; nOldPolyIndex++, nNewPolyIndex++ )
    {
        sal_Int32 nOldPointCount = rPolygon[nOldPolyIndex].size();

        // set last point to a position outside the rectangle, such that the first
        // time lcl_clip2d returns true, the comparison to last will always yield false
        drawing::Position3D aLast(rRectangle.getMinX()-1.0,rRectangle.getMinY()-1.0, 0.0 );

        for(sal_Int32 nOldPoint=1; nOldPoint<nOldPointCount; nOldPoint++)
        {
            aFrom = getPointFromPoly(rPolygon,nOldPoint-1,nOldPolyIndex);
            aTo = getPointFromPoly(rPolygon,nOldPoint,nOldPolyIndex);
            if( lcl_clip2d_(aFrom, aTo, rRectangle) )
            {
                // compose a Polygon of as many consecutive points as possible
                if(aFrom == aLast)
                {
                    if( aTo != aFrom )
                    {
                        lcl_addPointToPoly( aResult, aTo, nNewPolyIndex, aResultPointCount, nOldPointCount );
                    }
                }
                else
                {
                    if( bSplitPiecesToDifferentPolygons && nOldPoint!=1 )
                    {
                        if( nNewPolyIndex < static_cast<sal_Int32>(aResult.size())
                                && aResultPointCount[nNewPolyIndex]>0 )
                            nNewPolyIndex++;
                    }
                    lcl_addPointToPoly( aResult, aFrom, nNewPolyIndex, aResultPointCount, nOldPointCount );
                    if( aTo != aFrom )
                        lcl_addPointToPoly( aResult, aTo, nNewPolyIndex, aResultPointCount, nOldPointCount );
                }
                aLast = aTo;
            }
        }
    }
    //free unused space
    for( sal_Int32 nPolygonIndex = aResultPointCount.size(); nPolygonIndex--; )
    {
        std::vector<css::drawing::Position3D>* pOuterSequence = &aResult[nPolygonIndex];

        sal_Int32 nUsedPointCount = aResultPointCount[nPolygonIndex];
        pOuterSequence->resize(nUsedPointCount);
    }
}

} //namespace chart

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */