Add more math utilities

Source/Shaders/Math.hlsl

@@ -54,6 +54,21 @@ float4 Square(float4 x)
 	return x * x;
 }
 
+float Min2(float2 x)
+{
+	return min(x.x, x.y);
+}
+
+float Min3(float3 x)
+{
+	return min(x.x, min(x.y, x.z));
+}
+
+float Min4(float4 x)
+{
+	return min(x.x, min(x.y, min(x.z, x.w)));
+}
+
 float Max2(float2 x)
 {
 	return max(x.x, x.y);