populating Texel struct definition for textures

port/assimp_rs/src/structs/texel.rs

@@ -0,0 +1,19 @@
+#[derive(Clone, Debug, Copy)]
+struct Texel {
+    b: u32,
+    g: u32,
+    r: u32,
+    a: u32
+}
+
+impl Texel {
+    pub fn new(b_u32: u32, g_u32: u32,
+               r_u32: u32, a_u32: u32) -> Texel {
+        Texel {
+            b: b_u32,
+            g: g_u32,
+            r: r_u32,
+            a: a_u32
+        }
+    }
+}