Replace float with real_t, default Vectors, other misc C# improvements

Replace float with real_t in most files, defined at the top of each file via using. Objects such as Vector3 now accept doubles as inputs, and convert to real_t internally. I've added default Vectors such as Vector3.Zero. Other misc C# improvements such as Mathf.RoundToInt(). Color continues to use float only because high precision is not needed for 8-bit color math and to keep things simple. Everything seems to compile and work fine, but testing is requested, as this is the first time I've ever contributed to Godot.

modules/mono/glue/cs_files/Transform2D.cs

@@ -1,6 +1,12 @@
 using System;
 using System.Runtime.InteropServices;
 
+#if REAL_T_IS_DOUBLE
+using real_t = System.Double;
+#else
+using real_t = System.Single;
+#endif
+
 namespace Godot
 {
     [StructLayout(LayoutKind.Sequential)]
@@ -27,7 +33,7 @@ namespace Godot
             get { return o; }
         }
 
-        public float Rotation
+        public real_t Rotation
         {
             get { return Mathf.Atan2(y.x, o.y); }
         }
@@ -73,7 +79,7 @@ namespace Godot
         }
 
 
-        public float this[int index, int axis]
+        public real_t this[int index, int axis]
         {
             get
             {
@@ -107,7 +113,7 @@ namespace Godot
         {
             Transform2D inv = this;
 
-            float det = this[0, 0] * this[1, 1] - this[1, 0] * this[0, 1];
+            real_t det = this[0, 0] * this[1, 1] - this[1, 0] * this[0, 1];
 
             if (det == 0)
             {
@@ -119,9 +125,9 @@ namespace Godot
                 );
             }
 
-            float idet = 1.0f / det;
+            real_t idet = 1.0f / det;
 
-            float temp = this[0, 0];
+            real_t temp = this[0, 0];
             this[0, 0] = this[1, 1];
             this[1, 1] = temp;
 
@@ -143,10 +149,10 @@ namespace Godot
             return new Vector2(x.Dot(v), y.Dot(v));
         }
 
-        public Transform2D InterpolateWith(Transform2D m, float c)
+        public Transform2D InterpolateWith(Transform2D m, real_t c)
         {
-            float r1 = Rotation;
-            float r2 = m.Rotation;
+            real_t r1 = Rotation;
+            real_t r2 = m.Rotation;
 
             Vector2 s1 = Scale;
             Vector2 s2 = m.Scale;
@@ -155,7 +161,7 @@ namespace Godot
             Vector2 v1 = new Vector2(Mathf.Cos(r1), Mathf.Sin(r1));
             Vector2 v2 = new Vector2(Mathf.Cos(r2), Mathf.Sin(r2));
 
-            float dot = v1.Dot(v2);
+            real_t dot = v1.Dot(v2);
 
             // Clamp dot to [-1, 1]
             dot = (dot < -1.0f) ? -1.0f : ((dot > 1.0f) ? 1.0f : dot);
@@ -169,7 +175,7 @@ namespace Godot
             }
             else
             {
-                float angle = c * Mathf.Acos(dot);
+                real_t angle = c * Mathf.Acos(dot);
                 Vector2 v3 = (v2 - v1 * dot).Normalized();
                 v = v1 * Mathf.Cos(angle) + v3 * Mathf.Sin(angle);
             }
@@ -192,7 +198,7 @@ namespace Godot
             Transform2D inv = this;
 
             // Swap
-            float temp = inv.x.y;
+            real_t temp = inv.x.y;
             inv.x.y = inv.y.x;
             inv.y.x = temp;
 
@@ -218,7 +224,7 @@ namespace Godot
             return on;
         }
 
-        public Transform2D Rotated(float phi)
+        public Transform2D Rotated(real_t phi)
         {
             return this * new Transform2D(phi, new Vector2());
         }
@@ -232,12 +238,12 @@ namespace Godot
             return copy;
         }
 
-        private float Tdotx(Vector2 with)
+        private real_t Tdotx(Vector2 with)
         {
             return this[0, 0] * with[0] + this[1, 0] * with[1];
         }
 
-        private float Tdoty(Vector2 with)
+        private real_t Tdoty(Vector2 with)
         {
             return this[0, 1] * with[0] + this[1, 1] * with[1];
         }
@@ -259,24 +265,26 @@ namespace Godot
             Vector2 vInv = v - o;
             return new Vector2(x.Dot(vInv), y.Dot(vInv));
         }
-
+        
+        // Constructors 
         public Transform2D(Vector2 xAxis, Vector2 yAxis, Vector2 origin)
         {
             this.x = xAxis;
             this.y = yAxis;
             this.o = origin;
         }
-        public Transform2D(float xx, float xy, float yx, float yy, float ox, float oy)
+        
+        public Transform2D(real_t xx, real_t xy, real_t yx, real_t yy, real_t ox, real_t oy)
         {
             this.x = new Vector2(xx, xy);
             this.y = new Vector2(yx, yy);
             this.o = new Vector2(ox, oy);
         }
 
-        public Transform2D(float rot, Vector2 pos)
+        public Transform2D(real_t rot, Vector2 pos)
         {
-            float cr = Mathf.Cos(rot);
-            float sr = Mathf.Sin(rot);
+            real_t cr = Mathf.Cos( (real_t)rot);
+            real_t sr = Mathf.Sin( (real_t)rot);
             x.x = cr;
             y.y = cr;
             x.y = -sr;
@@ -288,7 +296,7 @@ namespace Godot
         {
             left.o = left.Xform(right.o);
 
-            float x0, x1, y0, y1;
+            real_t x0, x1, y0, y1;
 
             x0 = left.Tdotx(right.x);
             x1 = left.Tdoty(right.x);