Add Rgb conversion functions

Author: adazem009

include/scratchcpp/iimageformat.h

@@ -10,6 +10,42 @@ namespace libscratchcpp
 /*! A typedef for unsigned int. Holds the RGBA values. */
 using Rgb = unsigned int;
 
+/*! Returns the red component of the quadruplet rgb. */
+inline constexpr int red(Rgb rgb)
+{
+    return ((rgb >> 16) & 0xff);
+}
+
+/*! Returns the green component of the quadruplet rgb. */
+inline constexpr int green(Rgb rgb)
+{
+    return ((rgb >> 8) & 0xff);
+}
+
+/*! Returns the blue component of the quadruplet rgb. */
+inline constexpr int blue(Rgb rgb)
+{
+    return (rgb & 0xff);
+}
+
+/*! Returns the alpha component of the quadruplet rgb. */
+inline constexpr int alpha(Rgb rgb)
+{
+    return rgb >> 24;
+}
+
+/*! Creates an RGB triplet from the given color components. */
+inline constexpr Rgb rgb(int r, int g, int b)
+{
+    return (0xffu << 24) | ((r & 0xffu) << 16) | ((g & 0xffu) << 8) | (b & 0xffu);
+}
+
+/*! Creates an RGBA quadruplet from the given color components. */
+inline constexpr Rgb rgba(int r, int g, int b, int a)
+{
+    return ((a & 0xffu) << 24) | ((r & 0xffu) << 16) | ((g & 0xffu) << 8) | (b & 0xffu);
+}
+
 /*! \brief The IImageFormat class is an interface for image format implementation. */
 class LIBSCRATCHCPP_EXPORT IImageFormat
 {