Changeset 61

Timestamp:

Dec 14, 2004, 10:26:37 PM (20 years ago)

Author:

darran

Message:

• Added AlphaFunc? for threshold (-alphamin <float>) culling of pixels
• Prettified Ole's source code modifications to swwreader ;-)

Location:

Swollen

Files:

• include/swwreader.h (modified) (1 diff)
• swollen/watersurface.cpp (modified) (1 diff)
• swwreader/swwreader.cpp (modified) (1 diff)

Swollen/include/swwreader.h

@@ -149 +149 @@
     std::vector<triangle_list> _connectivity;
 
-    // alpha based culling
+    // define alpha (transparency) function
     float _alphamax, _alphamin, _heightmax, _heightmin;
 

Swollen/swollen/watersurface.cpp

@@ -56 +56 @@
     _stateset->setAttribute(osgBlendFunc);
     _stateset->setMode(GL_BLEND, osg::StateAttribute::ON);
+    _stateset->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);
 
+    // discard pixels with an alpha value below threshold
     osg::AlphaFunc* alphaFunc = new osg::AlphaFunc;
-    
-    //Commented out by OMN
-    //alphaFunc->setFunction( osg::AlphaFunc::GEQUAL, _sww->getAlphaThreshold() );
-    //_stateset->setAttributeAndModes( alphaFunc, osg::StateAttribute::ON );
-    
-    _stateset->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);
+    alphaFunc->setFunction( osg::AlphaFunc::GREATER, _sww->getAlphaMin() );
+    _stateset->setAttributeAndModes( alphaFunc, osg::StateAttribute::ON );
 
     // automatically generate texture coords

Swollen/swwreader/swwreader.cpp

@@ -292 +292 @@
     for (iv=0; iv < _npoints; iv++)
     {
-        height = _stagevertices->at(iv).z() - _bedslopevertices->at(iv).z();
+        height = _stagevertices->at(iv).z() - _bedslopevertices->at(iv).z();
         
-        if (height < _heightmin) {
-          alpha = 0.0;
-        } else {
-          alpha = alphascale*(height - _heightmin) + _alphamin;
-          if( alpha > _alphamax ) alpha = _alphamax;      
+        if (height < _heightmin)
+        {
+            alpha = 0.0;
+        } 
+        else 
+        {
+            alpha = alphascale * (height - _heightmin) + _alphamin;
+            if( alpha > _alphamax ) 
+                alpha = _alphamax;        
         }
-        _stagecolors->push_back( osg::Vec4( 1.0, 1.0, 1.0, alpha ) );
+        _stagecolors->push_back( osg::Vec4( 1.0, 1.0, 1.0, alpha ) );
     }