Changeset 7968 for OpenSceneGraph/trunk/src/osg/AutoTransform.cpp

Timestamp:

03/18/08 16:37:38 (5 years ago)

Author:

robert

Message:

To osg::AutoTransform? added support for MinimumScale?, MaximumScale? and AutoScaleTransitionWidth? parameters
and a new scheme for computing the scaling when using autoscale that introduces smooth
transitions to the scaling of the subgraph so that it looks more natural.

Files:

• OpenSceneGraph/trunk/src/osg/AutoTransform.cpp (modified) (3 diffs)

OpenSceneGraph/trunk/src/osg/AutoTransform.cpp

@@ -26 +26 @@
     _minimumScale(0.0f),
     _maximumScale(FLT_MAX),
+    _autoScaleTransitionWidthRatio(0.25f),
     _matrixDirty(true)
 {
@@ -43 +44 @@
     _minimumScale(pat._minimumScale),
     _maximumScale(pat._maximumScale),
+    _autoScaleTransitionWidthRatio(pat._autoScaleTransitionWidthRatio),
     _matrixDirty(true)
 {
@@ -179 +181 @@
                     {
                         float size = 1.0f/cs->pixelSize(getPosition(),0.48f);
-                        
-                        if (size<_minimumScale) size = _minimumScale;
-                        if (size>_maximumScale) size = _maximumScale;
+
+                        if (_autoScaleTransitionWidthRatio>0.0f)
+                        { 
+                            if (_minimumScale>0.0f)
+                            {
+                                float j = _minimumScale;
+                                float i = (_maximumScale<FLT_MAX) ? 
+                                            _minimumScale+(_maximumScale-_minimumScale)*_autoScaleTransitionWidthRatio :
+                                            _minimumScale*(1.0f+_autoScaleTransitionWidthRatio);
+                                float c = 1.0f/(4.0f*(i-j));
+                                float b = 1.0f - 2.0f*c*i;
+                                float a = j + b*b / (4.0f*c);
+                                float k = -b / (2.0f*c);
+
+                                if (size<k) size = _minimumScale;
+                                else if (size<i) size = a + b*size + c*(size*size);
+                            }
+
+                            if (_maximumScale<FLT_MAX)
+                            {
+                                float n = _maximumScale;
+                                float m = (_minimumScale>0.0) ?
+                                            _maximumScale+(_minimumScale-_maximumScale)*_autoScaleTransitionWidthRatio :
+                                            _maximumScale*(1.0f-_autoScaleTransitionWidthRatio);
+                                float c = 1.0f / (4.0f*(m-n));
+                                float b = 1.0f - 2.0f*c*m;
+                                float a = n + b*b/(4.0f*c);
+                                float p = -b / (2.0f*c);
+
+                                if (size>p) size = _maximumScale;
+                                else if (size>m) size = a + b*size + c*(size*size);
+                            }        
+                        }
                         
                         setScale(size);