X-Git-Url: https://gerrit.simantics.org/r/gitweb?a=blobdiff_plain;f=bundles%2Forg.simantics.debug.graphical%2Fsrc%2Forg%2Fsimantics%2Fdebug%2Fgraphical%2Flayout%2FLayoutAlgorithm.java;fp=bundles%2Forg.simantics.debug.graphical%2Fsrc%2Forg%2Fsimantics%2Fdebug%2Fgraphical%2Flayout%2FLayoutAlgorithm.java;h=1fe13a433b667cbb4c06a39af69abb7a8036ced8;hb=969bd23cab98a79ca9101af33334000879fb60c5;hp=0000000000000000000000000000000000000000;hpb=866dba5cd5a3929bbeae85991796acb212338a08;p=simantics%2Fplatform.git

diff --git a/bundles/org.simantics.debug.graphical/src/org/simantics/debug/graphical/layout/LayoutAlgorithm.java b/bundles/org.simantics.debug.graphical/src/org/simantics/debug/graphical/layout/LayoutAlgorithm.java
new file mode 100644
index 000000000..1fe13a433
--- /dev/null
+++ b/bundles/org.simantics.debug.graphical/src/org/simantics/debug/graphical/layout/LayoutAlgorithm.java
@@ -0,0 +1,107 @@
+package org.simantics.debug.graphical.layout;
+
+public class LayoutAlgorithm {
+
+    final double OPTIMAL_DISTANCE = 150.0;   
+    final double C = 0.1;
+    final double K = C / OPTIMAL_DISTANCE;
+    final double G = K;
+    final double Q = C * OPTIMAL_DISTANCE * OPTIMAL_DISTANCE;
+    final double TOLERANCE = 1e-3;
+    final int MAX_ITERATIONS = 10000;
+    final double MAX_MOVE2 = 40000.0;
+    
+    int size;
+    double[] posX;
+    double[] posY;
+    double[] forceX;
+    double[] forceY;
+    
+    int[][] neighbors;
+    
+    public LayoutAlgorithm(int[][] neighbors) {
+        this.size = neighbors.length;
+        this.neighbors = neighbors;
+        this.posX = new double[size];
+        this.posY = new double[size];
+        this.forceX = new double[size];
+        this.forceY = new double[size];
+    }
+    
+    public double[] getPosX() {
+        return posX;
+    }
+    
+    public double[] getPosY() {
+        return posY;
+    }
+    
+    private void computeForces() {
+        for(int i=0;i<size;++i) {
+            double x = posX[i];
+            double y = posY[i];
+            double fx = -G * x;
+            double fy = -G * y;
+            
+            for(int j=0;j<size;++j)
+                if(j != i) {
+                    double dx = posX[j] - x;
+                    double dy = posY[j] - y;
+                    double l2 = dx*dx + dy*dy;
+                    /*double l = Math.sqrt(l2);
+                    double l3 = l*l2;*/
+                    fx -= Q * dx / l2;
+                    fy -= Q * dy / l2;
+                }
+            
+            for(int j : neighbors[i]) {
+                double dx = posX[j] - x;
+                double dy = posY[j] - y;       
+                double l2 = dx*dx + dy*dy;
+                double l = Math.sqrt(l2);
+                fx += K * l * dx;
+                fy += K * l * dy;
+            }
+            
+            forceX[i] = fx;
+            forceY[i] = fy;
+        }
+    }
+    
+    private boolean converged() {
+        for(int i=0;i<size;++i) {
+            double fx = forceX[i];
+            double fy = forceY[i];
+            double f2 = fx*fx + fy*fy;
+            if(f2 > TOLERANCE)
+                return false;
+        }
+        return true;
+    }
+    
+    private void moveAll() {
+        for(int i=0;i<size;++i) {
+            double fx = forceX[i];
+            double fy = forceY[i];
+            double f2 = fx*fx + fy*fy;
+            if(f2 > MAX_MOVE2) {
+                double s = Math.sqrt(MAX_MOVE2 / f2);
+                fx *= s;
+                fy *= s;
+            }
+            posX[i] += fx;
+            posY[i] += fy;
+        }
+        computeForces();
+    }
+    
+    public void optimize() {
+        computeForces();
+        
+        for(int iter=0;iter<MAX_ITERATIONS;++iter) {
+            if(converged())
+                break;
+            moveAll();
+        }
+    }
+}