Harald JOHNSEN:

[simgear.git] / simgear / scene / sky / cloud.hxx

diff --git a/simgear/scene/sky/cloud.hxx b/simgear/scene/sky/cloud.hxx
index 369dbfa784f9da747e38c11785e203d5a3d7f17d..6a179d9f768719ef2d8d7ac67564d419ad089e3d 100644 (file)
--- a/simgear/scene/sky/cloud.hxx
+++ b/simgear/scene/sky/cloud.hxx
@@ -5,7 +5,7 @@
 
 // Written by Curtis Olson, started June 2000.
 //
-// Copyright (C) 2000  Curtis L. Olson  - curt@flightgear.org
+// Copyright (C) 2000  Curtis L. Olson  - http://www.flightgear.org/~curt
 //
 // This library is free software; you can redistribute it and/or
 // modify it under the terms of the GNU Library General Public
@@ -39,6 +39,7 @@ SG_USING_STD(string);
 // SG_USING_STD(cout);
 // SG_USING_STD(endl);
 
+class SGCloudField;
 
 /**
  * A class layer to model a single cloud layer
@@ -143,6 +144,18 @@ public:
     /** get the cloud movement speed */
     inline float getSpeed() { return speed; }
 
+    /**
+     * set the alpha component of the cloud base color.  Normally this
+     * should be 1.0, but you can set it anywhere in the range of 0.0
+     * to 1.0 to fade a cloud layer in or out.
+     * @param alpha cloud alpha value (0.0 to 1.0)
+     */
+    inline void setAlpha( float alpha ) {
+        if ( alpha < 0.0 ) { alpha = 0.0; }
+        if ( alpha > 1.0 ) { alpha = 1.0; }
+        cloud_alpha = alpha;
+    }
+
     /** build the cloud object */
     void rebuild();
 
@@ -171,6 +184,9 @@ public:
 
     static bool enable_bump_mapping;
 
+       /** return the 3D layer cloud associated with this 2D layer */
+       SGCloudField *get_layer3D(void) { return layer3D; }
+
 private:
 
     struct CloudVertex {
@@ -191,6 +207,8 @@ private:
     ssgLeaf *layer[4];
     ssgStateSelector *state_sel;
 
+    float cloud_alpha;          // 1.0 = drawn fully, 0.0 faded out completely
+
     ssgColourArray *cl[4]; 
     ssgVertexArray *vl[4];
     ssgTexCoordArray *tl[4];
@@ -211,6 +229,8 @@ private:
     // position, not view position
     // double xoff, yoff;
     double last_lon, last_lat, last_course;
+
+       SGCloudField *layer3D;
 };