Changeset 3211

Timestamp:

08/02/04 09:25:28 (9 years ago)

Author:

robert

Message:

From Tom Jolly. a couple of small changes to osgParticle.

"The first is with
Particle.cpp. I made a change so that when the lifetime is 0 (lasts
forever) the sizeRange, colorRange, and alphaRange are used to create
a random size, color, and alpha."

"The second change is with range and SectorPlacer?. The distribution of
particles across the sector was not uniform. I added get_random_sqrtf()
function where it is used in SectorPlacer::Place(). This seems to make
the distribution uniform (at least when minimum radius is 0)."

Location:

OpenSceneGraph/trunk

Files:

• include/osgParticle/SectorPlacer (modified) (1 diff)
• include/osgParticle/range (modified) (1 diff)
• src/osgParticle/Particle.cpp (modified) (1 diff)

OpenSceneGraph/trunk/include/osgParticle/SectorPlacer

@@ -117 +117 @@
     inline void SectorPlacer::place(Particle *P) const
     {
-        float rad = rad_range_.get_random();
+        float rad = rad_range_.get_random_sqrtf();
         float phi = phi_range_.get_random();
         

OpenSceneGraph/trunk/include/osgParticle/range

@@ -65 +65 @@
         }
 
+        /// Get a random square root value between min and max.
+        T_ get_random_sqrtf() const
+        {
+            return minimum + (maximum - minimum) * sqrtf( static_cast<float>(rand()) / static_cast<float>(RAND_MAX) );
+        }
+
     };
 

OpenSceneGraph/trunk/src/osgParticle/Particle.cpp

@@ -87 +87 @@
         
     // compute the current values for size, alpha and color.
-    current_size_ = si_.get()->interpolate(x, sr_);
-    current_alpha_ = ai_.get()->interpolate(x, ar_);
-    current_color_ = ci_.get()->interpolate(x, cr_);
+    if (lifetime_ <= 0) {
+       if (dt == t0_) {
+          current_size_ = sr_.get_random();
+          current_alpha_ = ar_.get_random();
+          current_color_ = cr_.get_random();
+       }
+    } else {
+       current_size_ = si_.get()->interpolate(x, sr_);
+       current_alpha_ = ai_.get()->interpolate(x, ar_);
+       current_color_ = ci_.get()->interpolate(x, cr_);
+    }
 
     // update position