Reverted commit 5064, as QgsClipper _is_ still required (if one

zooms in enough, qgis will crash while drawing with r5064, but won't
crash under r5063).


git-svn-id: http://svn.osgeo.org/qgis/trunk@5065 c8812cc2-4d05-0410-92ff-de0c093fc19c

src/gui/qgsvectorlayer.cpp

@@ -78,6 +78,9 @@
 #include "qgsattributetabledisplay.h"
 #include "qgsdistancearea.h"
 #include "qgsvectordataprovider.h"
+#ifdef Q_WS_X11
+#include "qgsclipper.h"
+#endif
 #include "qgssvgcache.h"
 #include "qgsspatialrefsys.h"
 #include "qgis.h" //for globals
@@ -460,6 +463,22 @@ unsigned char* QgsVectorLayer::drawLineString(unsigned char* feature,
 
   transformPoints(x, y, z, mtp, projectionsEnabledFlag);
 
+#if defined(Q_WS_X11)
+  // Work around a +/- 32768 limitation on coordinates in X11
+
+  // Look through the x and y coordinates and see if there are any
+  // that need trimming. If one is found, there's no need to look at
+  // the rest of them so end the loop at that point. 
+  for (register unsigned int i = 0; i < nPoints; ++i)
+    if (std::abs(x[i]) > QgsClipper::maxX ||
+        std::abs(y[i]) > QgsClipper::maxY)
+    {
+      QgsClipper::trimFeature(x, y, true); // true = polyline
+      nPoints = x.size(); // trimming may change nPoints.
+      break;
+    }
+#endif
+
   // set up QPolygonF class with transformed points
   QPolygonF pa(nPoints);
   for (register unsigned int i = 0; i < nPoints; ++i)
@@ -564,6 +583,33 @@ std::cerr << jdx << ": "
 
     transformPoints(ring->first, ring->second, zVector, mtp, projectionsEnabledFlag);
 
+#if defined(Q_WS_X11)
+    // Work around a +/- 32768 limitation on coordinates in X11
+
+    // Look through the x and y coordinates and see if there are any
+    // that need trimming. If one is found, there's no need to look at
+    // the rest of them so end the loop at that point. 
+    for (register unsigned int i = 0; i < nPoints; ++i)
+    {
+      if (std::abs(ring->first[i]) > QgsClipper::maxX ||
+          std::abs(ring->second[i]) > QgsClipper::maxY)
+      {
+        QgsClipper::trimFeature(ring->first, ring->second, false);
+        /*
+#ifdef QGISDEBUG
+std::cerr << "Trimmed points (" << ring->first.size() << ")\n";
+for (int i = 0; i < ring->first.size(); ++i)
+std::cerr << i << ": " << ring->first[i] 
+<< ", " << ring->second[i] << '\n';
+#endif
+*/
+        break;
+      }
+      //std::cout << "POLYGONTRANSFORM: " << ring->first[i] << ", " << ring->second[i] << std::endl; 
+    }
+
+#endif
+
     // Don't bother keeping the ring if it has been trimmed out of
     // existence.
     if (ring->first.size() == 0)
@@ -650,6 +696,27 @@ std::cerr << jdx << ": "
       << ", " << outerRingPt.y() << '\n';
 #endif
 
+    /*
+    // A bit of code to aid in working out what values of
+    // QgsClipper::minX, etc cause the X11 zoom bug.
+    int largestX  = -std::numeric_limits<int>::max();
+    int smallestX = std::numeric_limits<int>::max();
+    int largestY  = -std::numeric_limits<int>::max();
+    int smallestY = std::numeric_limits<int>::max();
+
+    for (int i = 0; i < pa.size(); ++i)
+    {
+    largestX  = std::max(largestX,  pa.point(i).x());
+    smallestX = std::min(smallestX, pa.point(i).x());
+    largestY  = std::max(largestY,  pa.point(i).y());
+    smallestY = std::min(smallestY, pa.point(i).y());
+    }
+    std::cerr << "Largest  X coordinate was " << largestX  << '\n';
+    std::cerr << "Smallest X coordinate was " << smallestX << '\n';
+    std::cerr << "Largest  Y coordinate was " << largestY  << '\n';
+    std::cerr << "Smallest Y coordinate was " << smallestY << '\n';
+    */
+
     //preserve a copy of the brush and pen before we start fiddling with it
     QBrush brush = p->brush(); //to be kept as original
     QPen pen = p->pen(); // to be kept original
@@ -3127,6 +3194,13 @@ void QgsVectorLayer::drawFeature(QPainter* p, QgsFeature* fet, QgsMapToPixel * t
           transformPoint(x, y, theMapToPixelTransform, projectionsEnabledFlag);
           QPointF pt(x - (marker->width()/2),  y - (marker->height()/2));
 
+#if defined(Q_WS_X11)
+          // Work around a +/- 32768 limitation on coordinates in X11
+          if (std::abs(x) > QgsClipper::maxX ||
+              std::abs(y) > QgsClipper::maxY)
+            needToTrim = true;
+          else
+#endif
           p->drawPixmap(pt, *marker);
         }
         p->restore();