gamnit: move `Model::uv_sphere` to `UVSphere`

[nit.git] / lib / gamnit / depth / more_meshes.nit

diff --git a/lib/gamnit/depth/more_meshes.nit b/lib/gamnit/depth/more_meshes.nit
index 1c6edf4..699e831 100644 (file)
--- a/lib/gamnit/depth/more_meshes.nit
+++ b/lib/gamnit/depth/more_meshes.nit
@@ -17,6 +17,7 @@ module more_meshes
 
 import geometry
 import depth_core
+import model_dimensions
 
 # Simple flat mesh, sits on the axes X and Z, normal on Y
 class Plane
@@ -24,6 +25,22 @@ class Plane
 
        # TODO allow for complex rotation, either at creation or in Actor
 
+       # Modifier to `texture_coords` to repeat the texture on the X axis
+       #
+       # At 1.0, the texture is stretched to cover the whole plane.
+       # If greater than 1.0, the texture is repeated.
+       #
+       # This value must be set before using `texture_coords` or drawing this plane.
+       var repeat_x = 1.0 is writable
+
+       # Modifier to `texture_coords` to repeat the texture on the Y axis
+       #
+       # At 1.0, the texture is stretched to cover the whole plane.
+       # If greater than 1.0, the texture is repeated.
+       #
+       # This value must be set before using `texture_coords` or drawing this plane.
+       var repeat_y = 1.0 is writable
+
        redef var vertices is lazy do
                var a = [-0.5, 0.0, -0.5]
                var b = [ 0.5, 0.0, -0.5]
@@ -44,8 +61,8 @@ class Plane
        redef var texture_coords: Array[Float] is lazy do
                var offset_left = 0.0
                var offset_top = 0.0
-               var offset_right = 1.0
-               var offset_bottom = 1.0
+               var offset_right = 1.0*repeat_x
+               var offset_bottom = 1.0*repeat_y
                var a = [offset_left,  offset_bottom]
                var b = [offset_right, offset_bottom]
                var c = [offset_left,  offset_top]
@@ -101,5 +118,82 @@ class Cube
                return normals
        end
 
+       redef var texture_coords: Array[Float] is lazy do
+               var a = [0.0, 1.0]
+               var b = [1.0, 1.0]
+               var c = [0.0, 0.0]
+               var d = [1.0, 0.0]
+
+               var texture_coords = new Array[Float]
+               var face = [a, c, d, a, d, b]
+               for i in 6.times do for v in face do texture_coords.add_all v
+               return texture_coords
+       end
+
        redef var center = new Point3d[Float](0.0, 0.0, 0.0) is lazy
 end
+
+# Sphere with `radius` and a number of faces set by `n_meridians` and `n_parallels`
+class UVSphere
+       super Mesh
+
+       # Distance between the center and the vertices
+       var radius: Float
+
+       # Number of vertices on a full circle around the Z axis
+       var n_meridians: Int
+
+       # Number of vertices on an arc between both poles
+       var n_parallels: Int
+
+       init
+       do
+               var w = n_meridians
+               var h = n_parallels
+
+               var vertices = new Array[Float].with_capacity(w*h*3)
+               self.vertices = vertices
+
+               var texture_coords = new Array[Float].with_capacity(w*h*2)
+               self.texture_coords = texture_coords
+
+               var normals = new Array[Float].with_capacity(w*h*3)
+               self.normals = normals
+
+               # Build vertices
+               for m in [0..w[ do
+                       for p in [0..h[ do
+                               var u = m.to_f * 2.0 * pi / (w-1).to_f
+                               var v = p.to_f * pi / (h-1).to_f
+
+                               vertices.add radius * u.cos * v.sin
+                               vertices.add radius * v.cos
+                               vertices.add radius * u.sin * v.sin
+
+                               texture_coords.add (1.0 - m.to_f/(w-1).to_f)
+                               texture_coords.add(p.to_f/(h-1).to_f)
+
+                               normals.add u.cos * v.sin
+                               normals.add v.cos
+                               normals.add u.sin * v.sin
+                       end
+               end
+
+               # Build faces
+               var indices = new Array[Int].with_capacity((w-1)*(h-1)*6)
+               self.indices = indices
+               for m in [0..w-1[ do
+                       for p in [0..h-1[ do
+                               var a = m*h + p
+
+                               indices.add a
+                               indices.add a+h
+                               indices.add a+1
+
+                               indices.add a+h
+                               indices.add a+h+1
+                               indices.add a+1
+                       end
+               end
+       end
+end