-improved WASM compilation scripts

-added external bindbc.sdl import for WASM
-working on demos (WIP, working simple demo with ECS and SDL2)
-small change in ecs.std

demos/utils/source/ecs_utils/math/vector.d

@@ -0,0 +1,100 @@
+module ecs_utils.math.vector;
+
+struct vec2
+{
+    union
+    {
+        struct
+        {
+            float x;
+            float y;
+        }
+        float[2] data;
+    }
+
+    vec2 opBinary(string op)(vec2 v)
+    {
+        static if (op == "+") return vec2(x + v.x, y + v.y);
+        else static if (op == "-") return vec2(x - v.x, y - v.y);
+        else static if (op == "*") return vec2(x * v.x, y * v.y);
+        else static if (op == "/") return vec2(x / v.x, y / v.y);
+        else static assert(0, "Operator "~op~" not implemented");
+    }
+
+    vec2 opBinary(string op)(float v)
+    {
+        static if (op == "+") return vec2(x + v, y + v);
+        else static if (op == "-") return vec2(x - v, y - v);
+        else static if (op == "*") return vec2(x * v, y * v);
+        else static if (op == "/") return vec2(x / v, y / v);
+        else static assert(0, "Operator "~op~" not implemented");
+    }
+
+    void opOpAssign(string op)(vec2 v)
+    {
+        static if (op == "+")
+        {
+            x += v.x;
+            y += v.y;
+        }
+        else static if (op == "-")
+        {
+            x -= v.x;
+            y -= v.y;
+        }
+        else static if (op == "*")
+        {
+            x *= v.x;
+            y *= v.y;
+        }
+        else static if (op == "/")
+        {
+            x /= v.x;
+            y /= v.y;
+        }
+        else static assert(0, "Operator "~op~" not implemented");
+    }
+}
+
+struct vec4
+{
+    union
+    {
+        struct
+        {
+            float x;
+            float y;
+            float z;
+            float w;
+        }
+        float[4] data;
+    }
+}
+
+struct ivec2
+{
+    union
+    {
+        struct
+        {
+            int x;
+            int y;
+        }
+        int[2] data;
+    }
+}
+
+struct ivec4
+{
+    union
+    {
+        struct
+        {
+            int x;
+            int y;
+            int z;
+            int w;
+        }
+        int[4] data;
+    }
+}