From cdab058b32319645630f18151126bdb69c5e3e11 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Fri, 6 May 2005 10:32:31 +0000
Subject: [PATCH] Added osg_DeltaFrameTime uniform to default set.

---
 include/osgUtil/SceneView |  9 ++++++---
 src/osgUtil/SceneView.cpp | 13 ++++++++++++-
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/include/osgUtil/SceneView b/include/osgUtil/SceneView
index f08dee03c..dd1f5d617 100644
--- a/include/osgUtil/SceneView
+++ b/include/osgUtil/SceneView
@@ -135,10 +135,12 @@ class OSGUTIL_EXPORT SceneView : public osg::Referenced, public osg::CullSetting
         {
             FRAME_NUMBER_UNIFORM            = 0x1,
             FRAME_TIME_UNIFORM              = 0x2,
-            VIEW_MATRIX_UNIFORM             = 0x4,
-            INVERSE_VIEW_MATRIX_UNIFORM     = 0x8,
+            DELTA_FRAME_TIME_UNIFORM        = 0x4,
+            VIEW_MATRIX_UNIFORM             = 0x8,
+            INVERSE_VIEW_MATRIX_UNIFORM     = 0x16,
             DEFAULT_UNIFORMS                = FRAME_NUMBER_UNIFORM |
                                               FRAME_TIME_UNIFORM |
+                                              DELTA_FRAME_TIME_UNIFORM |
                                               VIEW_MATRIX_UNIFORM |
                                               INVERSE_VIEW_MATRIX_UNIFORM,
             ALL_UNIFORMS                    = 0xFFFFFFFF
@@ -507,7 +509,8 @@ class OSGUTIL_EXPORT SceneView : public osg::Referenced, public osg::CullSetting
         
         bool                                        _requiresFlush;
         
-        int                                         _activeUniforms;
+        int                                         _activeUniforms;        
+        double                                      _previousFrameTime;
         
 };
 
diff --git a/src/osgUtil/SceneView.cpp b/src/osgUtil/SceneView.cpp
index b1cc34f51..339a60923 100644
--- a/src/osgUtil/SceneView.cpp
+++ b/src/osgUtil/SceneView.cpp
@@ -54,6 +54,8 @@ SceneView::SceneView(DisplaySettings* ds)
     _requiresFlush = true;
     
     _activeUniforms = DEFAULT_UNIFORMS;
+    
+    _previousFrameTime = 0;
 }
 
 
@@ -207,7 +209,16 @@ void SceneView::updateUniforms()
         osg::Uniform* uniform = _localStateSet->getOrCreateUniform("osg_FrameTime",osg::Uniform::FLOAT);
         uniform->set(static_cast<float>(_frameStamp->getReferenceTime()));
     }
-
+    
+    if ((_activeUniforms & DELTA_FRAME_TIME_UNIFORM) && _frameStamp.valid())
+    {
+        float delta_frame_time = (_previousFrameTime != 0.0) ? static_cast<float>(_frameStamp->getReferenceTime()-_previousFrameTime) : 0.0f;
+        _previousFrameTime = _frameStamp->getReferenceTime();
+        
+        osg::Uniform* uniform = _localStateSet->getOrCreateUniform("osg_DeltaFrameTime",osg::Uniform::FLOAT);
+        uniform->set(delta_frame_time);
+    }
+    
     if (_activeUniforms & VIEW_MATRIX_UNIFORM)
     {
         osg::Uniform* uniform = _localStateSet->getOrCreateUniform("osg_ViewMatrix",osg::Uniform::FLOAT_MAT4);