- geode = new Geode;
-
- CloudShaderGeometry* sg = new CloudShaderGeometry(num_textures_x, num_textures_y, max_width, max_height);
-
- // Determine how big this specific cloud instance is. Note that we subtract
- // the sprite size because the width/height is used to define the limits of
- // the center of the sprites, not their edges.
- float width = min_width + sg_random() * (max_width - min_width) - min_sprite_width;
- float height = min_height + sg_random() * (max_height - min_height) - min_sprite_height;
-
- // Determine the cull distance. This is used to remove sprites that are too close together.
- // 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;
-
- 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.
- 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;
- } else {
- double theta = sg_random() * SGD_2PI;
- 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;
- }
-
- SGVec3f *pos = new SGVec3f(x, y, z);
-
- // 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) {
- // 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;
- 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);
- if (index_y == num_textures_y) { index_y--; }
-
- sg->addSprite(*pos,
- index_x,
- index_y,
- sprite_width,
- sprite_height,
- bottom_shade,
- cull_distance_squared,
- height * 0.5f);