=== modified file 'VisualizationModule/src/org/gephi/visualization/swing/StandardGraphIO.java'
--- VisualizationModule/src/org/gephi/visualization/swing/StandardGraphIO.java	2010-04-29 20:47:13 +0000
+++ VisualizationModule/src/org/gephi/visualization/swing/StandardGraphIO.java	2010-07-13 11:10:27 +0000
@@ -20,11 +20,14 @@
  */
 package org.gephi.visualization.swing;
 
+import com.sun.opengl.util.BufferUtil;
 import java.awt.Cursor;
 import java.awt.event.InputEvent;
 import java.awt.event.KeyEvent;
 import java.awt.event.MouseEvent;
 import java.awt.event.MouseWheelEvent;
+import java.nio.DoubleBuffer;
+import javax.media.opengl.GLDrawable;
 import javax.swing.SwingUtilities;
 import org.gephi.visualization.GraphLimits;
 import org.gephi.visualization.VizArchitecture;
@@ -57,6 +60,10 @@
     protected float[] mouseDrag3d = new float[2];
     protected float[] mouseDrag = new float[2];
     protected float[] startDrag2d = new float[2];
+    // Camera location, camera target, and model view matrix at start of drag
+    protected float[] cameraLocationAtDragStart = new float[3];
+    protected float[] cameraTargetAtDragStart = new float[3];
+    protected DoubleBuffer modelMatrixAtDragStart;
     //Flags
     protected boolean draggingEnable = true;
     protected boolean dragging = false;
@@ -103,6 +110,18 @@
             //Save the coordinate of the start
             rightButtonMoving[0] = x;
             rightButtonMoving[1] = y;
+
+            // Store camera location, camera target, and model view matrix at beginning of drag
+            cameraLocationAtDragStart[0] = graphDrawable.cameraLocation[0];
+            cameraLocationAtDragStart[1] = graphDrawable.cameraLocation[1];
+            cameraLocationAtDragStart[2] = graphDrawable.cameraLocation[2];
+
+            cameraTargetAtDragStart[0] = graphDrawable.cameraTarget[0];
+            cameraTargetAtDragStart[1] = graphDrawable.cameraTarget[1];
+            cameraTargetAtDragStart[2] = graphDrawable.cameraTarget[2];
+
+            modelMatrixAtDragStart = graphDrawable.modelMatrix.duplicate();
+
             graphDrawable.graphComponent.setCursor(Cursor.getPredefinedCursor(Cursor.MOVE_CURSOR));
             vizEventManager.mouseRightPress();
         } else if (vizController.getVizModel().isRotatingEnable() && SwingUtilities.isMiddleMouseButton(e)) {
@@ -209,16 +228,81 @@
 
         if (rightButtonMoving[0] != -1) {
             //The right button is pressed
-            float proche = graphDrawable.cameraTarget[2] - graphDrawable.cameraLocation[2];
-            proche = proche / 300;
-
-            graphDrawable.cameraTarget[0] += (x - rightButtonMoving[0]) * proche;
-            graphDrawable.cameraTarget[1] += (rightButtonMoving[1] - y) * proche;
-            graphDrawable.cameraLocation[0] += (x - rightButtonMoving[0]) * proche;
-            graphDrawable.cameraLocation[1] += (rightButtonMoving[1] - y) * proche;
-
-            rightButtonMoving[0] = x;
-            rightButtonMoving[1] = y;
+
+            // The following is the original code for draging the canvas
+
+            // float proche = graphDrawable.cameraTarget[2] - graphDrawable.cameraLocation[2];
+            // proche = proche / 300;
+            // proche = -1;
+
+            // graphDrawable.cameraTarget[0] += (x - rightButtonMoving[0]) * proche;
+            // graphDrawable.cameraTarget[1] += (rightButtonMoving[1] - y) * proche;
+            // graphDrawable.cameraLocation[0] += (x - rightButtonMoving[0]) * proche;
+            // graphDrawable.cameraLocation[1] += (rightButtonMoving[1] - y) * proche;
+
+            // rightButtonMoving[0] = x;
+            // rightButtonMoving[1] = y;
+
+            DoubleBuffer buffer = BufferUtil.newDoubleBuffer(3);
+            double[] p = new double[3];
+            double[] q = new double[3];
+            double[] ray = new double[3];
+            double t;
+
+            // Construct ray (p --> q) into scene using mouse position at start of drag
+            // Note: flip y axis
+            GraphDrawableImpl.glu.gluUnProject(rightButtonMoving[0], graphDrawable.getViewportHeight() - rightButtonMoving[1], 0, modelMatrixAtDragStart, graphDrawable.projMatrix, graphDrawable.viewport, buffer);
+            buffer.get(p);
+            buffer.rewind();
+            GraphDrawableImpl.glu.gluUnProject(rightButtonMoving[0], graphDrawable.getViewportHeight() - rightButtonMoving[1], 1, modelMatrixAtDragStart, graphDrawable.projMatrix, graphDrawable.viewport, buffer);
+            buffer.get(q);
+            buffer.rewind();
+
+            // Project ray to x-y plane (z = 0)
+            ray[0] = q[0] - p[0];
+            ray[1] = q[1] - p[1];
+            ray[2] = q[2] - p[2];
+
+            t = -p[2] / ray[2];
+            ray[0] *= t;
+            ray[1] *= t;
+            ray[2] *= t;
+
+            // Mouse position projected to plane in world coordinates (at start of drag)
+            double[] origin = new double[]{ray[0] + p[0], ray[1] + p[1], 0};
+
+            // Construct ray (p --> q) into scene using current mouse position
+            // Note: flip y axis
+            GraphDrawableImpl.glu.gluUnProject(x, graphDrawable.getViewportHeight() - y, 0, modelMatrixAtDragStart, graphDrawable.projMatrix, graphDrawable.viewport, buffer);
+            buffer.get(p);
+            buffer.rewind();
+            GraphDrawableImpl.glu.gluUnProject(x, graphDrawable.getViewportHeight() - y, 1, modelMatrixAtDragStart, graphDrawable.projMatrix, graphDrawable.viewport, buffer);
+            buffer.get(q);
+            buffer.rewind();
+
+            // Project ray to x-y plane (z = 0)
+            ray[0] = q[0] - p[0];
+            ray[1] = q[1] - p[1];
+            ray[2] = q[2] - p[2];
+
+            t = -p[2] / ray[2];
+            ray[0] *= t;
+            ray[1] *= t;
+            ray[2] *= t;
+
+            // Mouse position projected to plane in world coordinates (current mouse position)
+            double[] destination = new double[]{ray[0] + p[0], ray[1] + p[1], 0};
+
+            // Determine translation in world coordinates
+            double dx = origin[0] - destination[0];
+            double dy = origin[1] - destination[1];
+
+            // Translate camera location and camera target accordingly
+            graphDrawable.cameraLocation[0] = (float) (cameraLocationAtDragStart[0] + dx);
+            graphDrawable.cameraLocation[1] = (float) (cameraLocationAtDragStart[1] + dy);
+            graphDrawable.cameraTarget[0] = (float) (cameraTargetAtDragStart[0] + dx);
+            graphDrawable.cameraTarget[1] = (float) (cameraTargetAtDragStart[1] + dy);
+
             engine.getScheduler().requireUpdateVisible();
         }