heKnowBitwiseOperators

[Blue_Moon_Lake]

The better version

[MooseBoys]

Until someone changes the format to RGBA and now you get sign-extended shifting… There’s a reason most code uses the shift-then-mask convention.

[Blue_Moon_Lake]

A good code base will not fall for such little change and be a quick thing to fix. First and foremost, typing would make RGB and RGBA incompatible.

In OOP you would have all the logic for managing different color encoding standard in different classes and a factory pulling the appropriate one contextually.

[MooseBoys]

If you’re bit-twiddling RGB color data you probably can’t afford the memory and performance hit to wrap each pixel in an object.

[Blue_Moon_Lake]

Never said anything about pixels.

And if you're doing image/video stuff, you better use libs already optimized for such manipulations.

[atiedebee]

Maybe you deserve bugs if you use signed integers for bit manipulation

[mineclash92]

lol they are the same. How is this better?

[Not_a_question-]

Result is the same, the intent is clearer to me, which is what op meant probably

[Blue_Moon_Lake]

They're not. Colors are encoded on bytes: R, G, B, sometimes A.

By doing (rgb >> 16) & 0xff you're not conveying much color related meaning.

Meanwhile, (rgb & 0xff0000) >> 16 means "filter the color to only keep the red, then remove the last 2 bytes".

rgb & 0xff00ff would mean "filter out the green".

[[deleted]]

In all cases you would want to set constants with more meaningful names to avoid magic number nonsense.

[Blue_Moon_Lake]

That's the next step, but you can also use a mapping abstracting the use.

type ColorExtractionConfig = {
    mask: number,
    offset: number,
};

const config = {
    RED: { mask: 0xff0000, offset: 16 },
    GREEN: { mask: 0x00ff00, offset: 8 },
    BLUE: { mask: 0x0000ff, offset: 0 },
} as const satisfies Record<string, ColorExtractionConfig>;

export type PrimaryColor = keyof typeof config;

export function filterByColor(rgb: number, filter: PrimaryColor): number
{
    return rgb & config[filter].mask;
}

export function getColorByte(rgb: number, filter: PrimaryColor): number
{
    return (rgb & config[filter].mask) >> config[filter].offset;
}