Changing pixel color in SDL

Question

I'm making a game that only uses PNG with black and white pixels. But there are some times where I would want to change the color of the white pixels to something different, like green (#00FF00).

How would I go about doing this exactly?

EDIT: Okay, I figured out a solution

Here is a simple function to do so:


    void setColor(SDL_Surface *surface, SDL_Color color) {
        Uint16 *pixels = (Uint16 *) surface->pixels;            // Get the pixels from the Surface

        // Iterrate through the pixels and chagne the color
        for (int i = 0; i w * surface->h); i++) {
            if (pixels[i] == SDL_MapRGB(surface->format, 0xFF, 0xFF, 0xFF))        // Search for white pixels
                pixels[i] = SDL_MapRGB(surface->format, color.r, color.b, color.g);
        }
    }

Something to keep in mind, change the "Uint16" to "Uint32" if you are using a 32-Bit surface, or "Uint8" for a 8-Bit surface.

I'm not sure on how fast this code is, but it gets the job done.

This is how it is done, works with all bit depths, alpha and so on. — Valmond

paulsm4 paulsm4 · Accepted Answer · 2011-07-24T04:20:15

That depends on exactly what you're trying to set the color of.

Without more information, two APIs that come immediately to mind are "SDL_SetColors()" and "SDL_SetPalette()".

But the real answer is "it depends".

Changing pixel color in SDL

1 Answers