Merge branch 'timoore/mat-effect'

[simgear.git] / simgear / scene / sky / newcloud.cxx

diff --git a/simgear/scene/sky/newcloud.cxx b/simgear/scene/sky/newcloud.cxx
index d4219210e1619965fe753a5db7ada51b79208ff3..162f137a0c58c38941c449d99cbdd2d27fe88f1d 100644 (file)
--- a/simgear/scene/sky/newcloud.cxx
+++ b/simgear/scene/sky/newcloud.cxx
@@ -69,7 +69,6 @@ EffectMap effectMap;
 
 double SGNewCloud::sprite_density = 1.0;
 
-
 SGNewCloud::SGNewCloud(string type,
                        const SGPath &tex_path, 
                        string tex,
@@ -190,27 +189,19 @@ osg::ref_ptr<EffectGeode> SGNewCloud::genCloud() {
     // The value is squared as we use vector calculations.
     float cull_distance_squared = min_sprite_height * min_sprite_height * 0.1f;
     
-    // The number of sprites we actually used is a function of the (user-controlled) density
-    int n_sprites = num_sprites * sprite_density;
+    // The number of sprites we actually use is a function of the (user-controlled) density
+    int n_sprites = num_sprites * sprite_density * (0.5 + sg_random());
     
     for (int i = 0; i < n_sprites; i++)
     {
         // Determine the position of the sprite. Rather than being completely random,
         // we place them on the surface of a distorted sphere. However, we place
-        // the first and second sprites on the top and bottom, and the third in the
-        // center of the sphere (and at maximum size) to ensure good coverage and
-        // reduce the chance of there being "holes" in our cloud.
+        // the first sprite in the center of the sphere (and at maximum size) to
+       // ensure good coverage and reduce the chance of there being "holes" in our
+
         float x, y, z;
-        
+
         if (i == 0) {
-            x = 0;
-            y = 0;
-            z = height * 0.5f;
-        } else if (i == 1) {
-            x = 0;
-            y = 0;
-            z = - height * 0.5f;
-        } else if (i == 2) {
             x = 0;
             y = 0;
             z = 0;
@@ -219,29 +210,36 @@ osg::ref_ptr<EffectGeode> SGNewCloud::genCloud() {
             double elev  = sg_random() * SGD_PI;
             x = width * cos(theta) * 0.5f * sin(elev);
             y = width * sin(theta) * 0.5f * sin(elev);
-            z = height * cos(elev) * 0.5f; 
+            z = height * cos(elev) * 0.5f;
         }
         
-        SGVec3f *pos = new SGVec3f(x, y, z); 
-
-        // Determine the height and width as scaling factors on the minimum size (used to create the quad)
+        // Determine the height and width as scaling factors on the minimum size (used to create the quad).
         float sprite_width = 1.0f + sg_random() * (max_sprite_width - min_sprite_width) / min_sprite_width;
         float sprite_height = 1.0f + sg_random() * (max_sprite_height - min_sprite_height) / min_sprite_height;
-        
-        if (i == 2) {
+
+        // Sprites are never taller than square.
+        if (sprite_height * min_sprite_height > sprite_width * min_sprite_width)
+        {
+            sprite_height = sprite_width * min_sprite_width / min_sprite_height;
+        }
+
+        if (i == 0) {
             // The center sprite is always maximum size to fill up any holes.
             sprite_width = 1.0f + (max_sprite_width - min_sprite_width) / min_sprite_width;
             sprite_height = 1.0f + (max_sprite_height - min_sprite_height) / min_sprite_height;
         }
-        
-        // Determine the sprite texture indexes;
+
+        // Determine the sprite texture indexes.
         int index_x = (int) floor(sg_random() * num_textures_x);
         if (index_x == num_textures_x) { index_x--; }
-        
-        int index_y = (int) floor(sg_random() * num_textures_y);
+
+        // The y index depends on the positing of the sprite within the cloud.
+        // This allows cloud designers to have particular sprites for the base
+        // and tops of the cloud.
+        int index_y = (int) floor((z / height + 0.5f) * num_textures_y);
         if (index_y == num_textures_y) { index_y--; }
         
-        sg->addSprite(*pos, 
+        sg->addSprite(SGVec3f(x, y, z), 
                     index_x, 
                     index_y, 
                     sprite_width,