A C++ application running in another process passes in a char[] array of three-byte pixels (red, green, blue) to a go program. I've reconstructed this in go as a byte[] slice using cgo, but I'm unsure how to convert to an image. I can pass the width or height as well, if that is needed (I would imagine it would be).
I'm aware of the image.RGBA type, but the documentation seems to imply that those aren't just single-byte-per-color, and that assumes that there is an alpha channel, which my very simplistic bitmap does not have. Would converting the 3 byte values I have into something that works with image.RGBA be a solution? If so, how should I do that?
Alternatively, I could do the conversion in C/C++ before sending the values into a format that go recognizes (jpeg, gif, png). Either way works for my uses, but I don't know how to approach either.
The image package is based on interfaces. Just define a new type with those methods.
Your type's ColorModel would return color.RGBAModel, Bounds - your rectangle's borders, and At - the color at (x, y) that you can compute if you know the image's dimensions.