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Asked: 2026-06-05T18:31:15+00:00

With a method like glColor4f(0f, 0f, 0f, 0f); , it sets the values to

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With a method like glColor4f(0f, 0f, 0f, 0f);, it sets the values to whatever parameters one puts in. However, what I would like to do is only slightly change a color. Is there any existing OpenGL method that will add or subtract its parameters to the existing colors it has?

The only other way of doing this that I can come up with is first getting its color values, then editing those how I want to, and finally sending them back with glColor4f().

So, in closing, I would like to know if there is either a method for editing existing RGBA, or at least retrieving an existing RGBA.

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  1. Editorial Team

    Well, you can get the last value set with glColor4f by using glGet with GL_CURRENT_COLOR, but I wouldn’t recommend it; glGet operations are generally bad for your performance, so try not to do it too often.

    A better idea would be to maintain a local copy of the last value you sent to glColor4f, so that you have the data client-side instead of having to request it from the opengl driver.

    There’s no way to add or subtract from the current color that I’m aware of.

    Edit: Actually I just looked up and see this function called glSecondaryColor which may do what you want. You can supply a second RBG color, and then enable GL_COLOR_SUM, and the two colors get added together.

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