QgsRasterLayer::getPaletteAsPixmap crash fix

git-svn-id: http://svn.osgeo.org/qgis/trunk@2068 c8812cc2-4d05-0410-92ff-de0c093fc19c

src/qgscolortable.cpp

@@ -53,6 +53,14 @@ void QgsColorTable::add ( int index, unsigned char c1, unsigned char c2, unsigne
     std::cerr << "QgsColorTable::add() index = " << index << std::endl;
     #endif
 
+    if ( mDiscrete.size() == 0 ) {
+	mMin = index;
+	mMax = index;
+    } else { 
+	if ( index < mMin ) mMin = index;
+	if ( index > mMax ) mMax = index;
+    }
+
     if ( mDiscrete.size() <= index ) {
        mDiscrete.resize ( index + 1 ); 
     }
@@ -73,6 +81,14 @@ void QgsColorTable::add ( double min,  double max,
     std::cerr << "QgsColorTable::add() min = " << min << " max = " << max << std::endl;
     #endif
 
+    if ( mRamp.size() == 0 ) {
+	mMin = min;
+	mMax = max;
+    } else { 
+	if ( min < mMin ) mMin = min;
+	if ( max > mMax ) mMax = max;
+    }
+
     ramp.min = min;
     ramp.max = max;
     ramp.min_c1 = min_c1;
@@ -145,6 +161,16 @@ int QgsColorTable::interpretation ( void )
     return mInterp;
 }
 
+double QgsColorTable::min ( void )
+{
+    return mMin;
+}
+
+double QgsColorTable::max ( void )
+{
+    return mMax;
+}
+
 void QgsColorTable::print ( void )
 {
     std::cerr << "******** Color table ********" << std::endl;

src/qgscolortable.h

@@ -91,6 +91,12 @@ public:
     /** \brief Print to stderr - for debuging */
     void print ( void );
 
+    /** \brief Minimum value */
+    double min ( void );
+
+    /** \brief Maximum value */
+    double max ( void );
+
 private:
     /** \brief vector of discrete values */
     std::vector<DISCRETE> mDiscrete;
@@ -100,6 +106,12 @@ private:
 
     /** \brief color table interpretation */
     int  mInterp;
+
+    /** \brief min value */
+    double mMin;
+
+    /** \brief max value */
+    double mMax;
 };
 
 #endif

src/qgsrasterlayer.cpp

@@ -679,53 +679,50 @@ QPixmap QgsRasterLayer::getPaletteAsPixmap()
 #ifdef QGISDEBUG
   std::cout << "QgsRasterLayer::getPaletteAsPixmap" << std::endl;
 #endif
-  if (hasBand("Palette")) //dont tr() this its a gdal word!
+  if (hasBand("Palette") ) //dont tr() this its a gdal word!
   {
 #ifdef QGISDEBUG
     std::cout << "....found paletted image" << std::endl;
 #endif
+    QgsColorTable *myColorTable = colorTable ( 1 );
     GDALRasterBandH myGdalBand = gdalDataset->GetRasterBand(1);
-    if( GDALGetRasterColorInterpretation(myGdalBand) == GCI_PaletteIndex )
+    if( GDALGetRasterColorInterpretation(myGdalBand) == GCI_PaletteIndex && myColorTable->defined() )
     {
 #ifdef QGISDEBUG
       std::cout << "....found GCI_PaletteIndex" << std::endl;
 #endif
-      GDALColorTableH myTable;
-      myTable = GDALGetRasterColorTable( myGdalBand );
-      int myColourCountInt = GDALGetColorEntryCount( myTable ) ;
+      double myMinDouble = myColorTable->min();
+      double myMaxDouble = myColorTable->max();
 
-      //we would like to have the palette drawn onto a more or less
-      //square pixmap. So we need to determine the square root of the 
-      //total palette entry count and handle any non int remainders
-      //by adding an extra row if neccessary
-      //
-      int myWidth=(int) sqrt(myColourCountInt);
-      int myHeight;
-      if ((myWidth*myWidth) < myColourCountInt)
-      {
-        //add an extra row for the remainder
-        myHeight=myWidth+1;
-      }
-      else
-      {
-        //pixmap is exactly proporational
-        myHeight=myWidth;
-      }
-      QPixmap myPalettePixmap(myWidth,myHeight);
+#ifdef QGISDEBUG
+      std::cout << "myMinDouble = " << myMinDouble << " myMaxDouble = " << myMaxDouble << std::endl;
+#endif
+
+      // Draw image
+      int mySizeInt = 100;
+      QPixmap myPalettePixmap( mySizeInt, mySizeInt);
       QPainter myQPainter(&myPalettePixmap);
 
-      QImage myQImage = QImage(myWidth,myHeight, 32);
+      QImage myQImage = QImage( mySizeInt, mySizeInt, 32);
       myQImage.fill(0);
-      myQImage.setAlphaBuffer(true);
+      myQImage.setAlphaBuffer(false);
       myPalettePixmap.fill();
 
-      for( int myIteratorInt = 0; myIteratorInt < myColourCountInt; myIteratorInt++ )
-      {
-        GDALColorEntry myEntry;
-        GDALGetColorEntryAsRGB( myTable, myIteratorInt, &myEntry );
-        myQImage.setPixel(myIteratorInt % myWidth,(int)(myIteratorInt/myWidth)
-                ,qRgba(myEntry.c1, myEntry.c2, myEntry.c3, myEntry.c4));
+      double myStepDouble = ( myMaxDouble - myMinDouble ) / ( mySizeInt * mySizeInt);
+      
+      for( int myRowInt = 0; myRowInt < mySizeInt; myRowInt++ ) {
+          for( int myColInt = 0; myColInt < mySizeInt; myColInt++ ) {
+	      
+	      double myValueDouble = myMinDouble + myStepDouble * (myColInt + myRowInt * mySizeInt);
+	      
+	      int c1, c2, c3;
+	      bool found = myColorTable->color ( myValueDouble, &c1, &c2, &c3 );
+              
+	      if ( found )
+                  myQImage.setPixel( myColInt, myRowInt, qRgb(c1, c2, c3));
+	  }
       }
+
       myQPainter.drawImage(0,0,myQImage);
       return myPalettePixmap; 
     }