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liberosteliosliberostelios
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Refactoring on tesselator and other remarks applied
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‎src/3d/qgstessellator.cpp

Lines changed: 128 additions & 116 deletions
Original file line numberDiff line numberDiff line change
@@ -19,6 +19,7 @@
1919
#include "qgsgeometry.h"
2020
#include "qgspoint.h"
2121
#include "qgspolygon.h"
22+
#include "qgis_sip.h"
2223

2324
#include "poly2tri/poly2tri.h"
2425

@@ -110,6 +111,28 @@ static void _makeWalls( const QgsCurve &ring, bool ccw, float extrusionHeight, Q
110111
}
111112
}
112113

114+
static QVector3D _calculateNormal( const QgsCurve *curve )
115+
{
116+
QgsVertexId::VertexType vt;
117+
QgsPoint pt1, pt2;
118+
QVector3D normal( 0, 0, 0 );
119+
120+
for ( int i = 0; i < curve->numPoints() - 1; i++ )
121+
{
122+
QgsPoint pt1, pt2;
123+
curve->pointAt( i, pt1, vt );
124+
curve->pointAt( i + 1, pt2, vt );
125+
126+
normal.setX( normal.x() + ( pt1.y() - pt2.y() ) * ( pt1.z() + pt2.z() ) );
127+
normal.setY( normal.y() + ( pt1.z() - pt2.z() ) * ( pt1.x() + pt2.x() ) );
128+
normal.setZ( normal.z() + ( pt1.x() - pt2.x() ) * ( pt1.y() + pt2.y() ) );
129+
}
130+
131+
normal.normalize();
132+
133+
return normal;
134+
}
135+
113136
void QgsTessellator::addPolygon( const QgsPolygonV2 &polygon, float extrusionHeight )
114137
{
115138
// At this point we assume that input polygons are valid according to the OGC definition.
@@ -159,20 +182,8 @@ void QgsTessellator::addPolygon( const QgsPolygonV2 &polygon, float extrusionHei
159182
QgsVertexId::VertexType vt;
160183
QgsPoint pt;
161184

162-
QVector3D pNormal( 0, 0, 0 );
185+
QVector3D pNormal = _calculateNormal( exterior );
163186
const int pCount = exterior->numPoints();
164-
for ( int i = 0; i < pCount - 1; i++ )
165-
{
166-
QgsPoint pt1, pt2;
167-
exterior->pointAt( i, pt1, vt );
168-
exterior->pointAt( i + 1, pt2, vt );
169-
170-
pNormal.setX( pNormal.x() + ( pt1.y() - pt2.y() ) * ( pt1.z() + pt2.z() ) );
171-
pNormal.setY( pNormal.y() + ( pt1.z() - pt2.z() ) * ( pt1.x() + pt2.x() ) );
172-
pNormal.setZ( pNormal.z() + ( pt1.x() - pt2.x() ) * ( pt1.y() + pt2.y() ) );
173-
}
174-
175-
pNormal.normalize();
176187

177188
// Polygon is a triangle
178189
if ( pCount == 4 )
@@ -185,76 +196,43 @@ void QgsTessellator::addPolygon( const QgsPolygonV2 &polygon, float extrusionHei
185196
if ( mAddNormals )
186197
mData << pNormal.x() << pNormal.z() << - pNormal.y();
187198
}
188-
189-
return;
190-
}
191-
192-
if ( pNormal.length() < 0.999 || pNormal.length() > 1.001 )
193-
{
194-
return;
195-
}
196-
197-
const QgsPoint ptFirst( exterior->startPoint() );
198-
QVector3D pOrigin( ptFirst.x(), ptFirst.y(), ptFirst.z() ), pXVector;
199-
// Here we define the two perpendicular vectors that define the local
200-
// 2D space on the plane. They will act as axis for which we will
201-
// calculate the projection coordinates of a 3D point to the plane.
202-
if ( pNormal.z() > 0.001 || pNormal.z() < -0.001 )
203-
{
204-
pXVector = QVector3D( 1, 0, -pNormal.x() / pNormal.z() );
205-
}
206-
else if ( pNormal.y() > 0.001 || pNormal.y() < -0.001 )
207-
{
208-
pXVector = QVector3D( 1, -pNormal.x() / pNormal.y(), 0 );
209199
}
210200
else
211201
{
212-
pXVector = QVector3D( -pNormal.y() / pNormal.x(), 1, 0 );
213-
}
214-
pXVector.normalize();
215-
QVector3D pYVector = QVector3D::normal( pNormal, pXVector );
216-
217-
for ( int i = 0; i < pCount - 1; ++i )
218-
{
219-
exterior->pointAt( i, pt, vt );
220-
QVector3D tempPt( pt.x(), pt.y(), ( qIsNaN( pt.z() ) ? 0 : pt.z() ) );
221-
const float x = QVector3D::dotProduct( tempPt - pOrigin, pXVector );
222-
const float y = QVector3D::dotProduct( tempPt - pOrigin, pYVector );
223-
224-
const bool found = std::find_if( polyline.begin(), polyline.end(), [x, y]( p2t::Point *&p ) { return *p == *new p2t::Point( x, y ); } ) != polyline.end();
225202

226-
if ( found )
203+
if ( !qgsDoubleNear( pNormal.length(), 1, 0.001 ) )
227204
{
228-
continue;
205+
return;
229206
}
230207

231-
p2t::Point *pt2 = new p2t::Point( x, y );
232-
polyline.push_back( pt2 );
233-
234-
z[pt2] = qIsNaN( pt.z() ) ? 0 : pt.z();
235-
}
236-
polylinesToDelete << polyline;
237-
238-
if ( polyline.size() < 3 )
239-
return;
240-
241-
p2t::CDT *cdt = new p2t::CDT( polyline );
208+
const QgsPoint ptFirst( exterior->startPoint() );
209+
QVector3D pOrigin( ptFirst.x(), ptFirst.y(), ptFirst.z() ), pXVector;
210+
// Here we define the two perpendicular vectors that define the local
211+
// 2D space on the plane. They will act as axis for which we will
212+
// calculate the projection coordinates of a 3D point to the plane.
213+
if ( pNormal.z() > 0.001 || pNormal.z() < -0.001 )
214+
{
215+
pXVector = QVector3D( 1, 0, -pNormal.x() / pNormal.z() );
216+
}
217+
else if ( pNormal.y() > 0.001 || pNormal.y() < -0.001 )
218+
{
219+
pXVector = QVector3D( 1, -pNormal.x() / pNormal.y(), 0 );
220+
}
221+
else
222+
{
223+
pXVector = QVector3D( -pNormal.y() / pNormal.x(), 1, 0 );
224+
}
225+
pXVector.normalize();
226+
QVector3D pYVector = QVector3D::normal( pNormal, pXVector );
242227

243-
// polygon holes
244-
for ( int i = 0; i < polygon.numInteriorRings(); ++i )
245-
{
246-
std::vector<p2t::Point *> holePolyline;
247-
holePolyline.reserve( exterior->numPoints() );
248-
const QgsCurve *hole = polygon.interiorRing( i );
249-
for ( int j = 0; j < hole->numPoints() - 1; ++j )
228+
for ( int i = 0; i < pCount - 1; ++i )
250229
{
251-
hole->pointAt( j, pt, vt );
230+
exterior->pointAt( i, pt, vt );
252231
QVector3D tempPt( pt.x(), pt.y(), ( qIsNaN( pt.z() ) ? 0 : pt.z() ) );
253-
254232
const float x = QVector3D::dotProduct( tempPt - pOrigin, pXVector );
255233
const float y = QVector3D::dotProduct( tempPt - pOrigin, pYVector );
256234

257-
const bool found = std::find_if( polyline.begin(), polyline.end(), [x, y]( p2t::Point *&p ) { return *p == *new p2t::Point( x, y ); } ) != polyline.end();
235+
const bool found = std::find_if( polyline.begin(), polyline.end(), [x, y]( p2t::Point *&p ) { return *p == p2t::Point( x, y ); } ) != polyline.end();
258236

259237
if ( found )
260238
{
@@ -266,62 +244,96 @@ void QgsTessellator::addPolygon( const QgsPolygonV2 &polygon, float extrusionHei
266244

267245
z[pt2] = qIsNaN( pt.z() ) ? 0 : pt.z();
268246
}
269-
cdt->AddHole( holePolyline );
270-
polylinesToDelete << holePolyline;
271-
}
247+
polylinesToDelete << polyline;
272248

273-
// TODO: robustness (no nearly duplicate points, invalid geometries ...)
249+
if ( polyline.size() < 3 )
250+
return;
274251

275-
if ( polyline.size() == 3 )
276-
{
277-
for ( std::vector<p2t::Point *>::iterator it = polyline.begin(); it != polyline.end(); it++ )
252+
p2t::CDT *cdt = new p2t::CDT( polyline );
253+
254+
// polygon holes
255+
for ( int i = 0; i < polygon.numInteriorRings(); ++i )
278256
{
279-
p2t::Point *p = *it;
280-
const double zPt = z[p];
281-
QVector3D nPoint = pOrigin + pXVector * p->x + pYVector * p->y;
282-
const double fx = nPoint.x() - mOriginX;
283-
const double fy = nPoint.y() - mOriginY;
284-
const double fz = extrusionHeight + ( qIsNaN( zPt ) ? 0 : zPt );
285-
mData << fx << fz << -fy;
286-
if ( mAddNormals )
287-
mData << pNormal.x() << pNormal.z() << - pNormal.y();
288-
}
257+
std::vector<p2t::Point *> holePolyline;
258+
holePolyline.reserve( exterior->numPoints() );
259+
const QgsCurve *hole = polygon.interiorRing( i );
260+
for ( int j = 0; j < hole->numPoints() - 1; ++j )
261+
{
262+
hole->pointAt( j, pt, vt );
263+
QVector3D tempPt( pt.x(), pt.y(), ( qIsNaN( pt.z() ) ? 0 : pt.z() ) );
289264

290-
return;
291-
}
265+
const float x = QVector3D::dotProduct( tempPt - pOrigin, pXVector );
266+
const float y = QVector3D::dotProduct( tempPt - pOrigin, pYVector );
292267

293-
try
294-
{
295-
cdt->Triangulate();
296-
}
297-
catch ( ... )
298-
{
299-
qDebug() << "Triangulation failed. Skipping polygon...";
300-
return;
301-
}
268+
const bool found = std::find_if( polyline.begin(), polyline.end(), [x, y]( p2t::Point *&p ) { return *p == p2t::Point( x, y ); } ) != polyline.end();
269+
270+
if ( found )
271+
{
272+
continue;
273+
}
302274

303-
std::vector<p2t::Triangle *> triangles = cdt->GetTriangles();
275+
p2t::Point *pt2 = new p2t::Point( x, y );
276+
polyline.push_back( pt2 );
304277

305-
for ( size_t i = 0; i < triangles.size(); ++i )
306-
{
307-
p2t::Triangle *t = triangles[i];
308-
for ( int j = 0; j < 3; ++j )
278+
z[pt2] = qIsNaN( pt.z() ) ? 0 : pt.z();
279+
}
280+
cdt->AddHole( holePolyline );
281+
polylinesToDelete << holePolyline;
282+
}
283+
284+
// TODO: robustness (no nearly duplicate points, invalid geometries ...)
285+
286+
if ( polyline.size() == 3 && polygon.numInteriorRings() == 0 )
309287
{
310-
p2t::Point *p = t->GetPoint( j );
311-
float zPt = z[p];
312-
QVector3D nPoint = pOrigin + pXVector * p->x + pYVector * p->y;
313-
float fx = nPoint.x() - mOriginX;
314-
float fy = nPoint.y() - mOriginY;
315-
float fz = extrusionHeight + ( qIsNaN( zPt ) ? 0 : zPt );
316-
mData << fx << fz << -fy;
317-
if ( mAddNormals )
318-
mData << pNormal.x() << pNormal.z() << - pNormal.y();
288+
for ( std::vector<p2t::Point *>::iterator it = polyline.begin(); it != polyline.end(); it++ )
289+
{
290+
p2t::Point *p = *it;
291+
const double zPt = z[p];
292+
QVector3D nPoint = pOrigin + pXVector * p->x + pYVector * p->y;
293+
const double fx = nPoint.x() - mOriginX;
294+
const double fy = nPoint.y() - mOriginY;
295+
const double fz = extrusionHeight + ( qIsNaN( zPt ) ? 0 : zPt );
296+
mData << fx << fz << -fy;
297+
if ( mAddNormals )
298+
mData << pNormal.x() << pNormal.z() << - pNormal.y();
299+
}
300+
}
301+
else
302+
{
303+
try
304+
{
305+
cdt->Triangulate();
306+
}
307+
catch ( ... )
308+
{
309+
qDebug() << "Triangulation failed. Skipping polygon...";
310+
return;
311+
}
312+
313+
std::vector<p2t::Triangle *> triangles = cdt->GetTriangles();
314+
315+
for ( size_t i = 0; i < triangles.size(); ++i )
316+
{
317+
p2t::Triangle *t = triangles[i];
318+
for ( int j = 0; j < 3; ++j )
319+
{
320+
p2t::Point *p = t->GetPoint( j );
321+
float zPt = z[p];
322+
QVector3D nPoint = pOrigin + pXVector * p->x + pYVector * p->y;
323+
float fx = nPoint.x() - mOriginX;
324+
float fy = nPoint.y() - mOriginY;
325+
float fz = extrusionHeight + ( qIsNaN( zPt ) ? 0 : zPt );
326+
mData << fx << fz << -fy;
327+
if ( mAddNormals )
328+
mData << pNormal.x() << pNormal.z() << - pNormal.y();
329+
}
330+
}
319331
}
320-
}
321332

322-
delete cdt;
323-
for ( int i = 0; i < polylinesToDelete.count(); ++i )
324-
qDeleteAll( polylinesToDelete[i] );
333+
delete cdt;
334+
for ( int i = 0; i < polylinesToDelete.count(); ++i )
335+
qDeleteAll( polylinesToDelete[i] );
336+
}
325337

326338
// add walls if extrusion is enabled
327339
if ( extrusionHeight != 0 )

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