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Joshnathan

RGB Color Code

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Hi all, I am trying to make the background of some of my images transparent and I thought I knew how to, but something must be missing. Here is the code:
void DrawPaddles(SDL_Surface *paddle1, SDL_Surface *paddle2, int x1, int y1, int x2, int y2)
{
    int r = 255;
    int g = 0;
    int b = 255;
    SDL_SetColorKey(paddle1, SDL_SRCCOLORKEY, SDL_MapRGB(paddle1->format, r, g, b));
    SDL_SetColorKey(paddle2, SDL_SRCCOLORKEY, SDL_MapRGB(paddle2->format, r, g, b));
    
    SDL_Rect rect1;
    rect1.x = x1;
    rect1.y = y2;
    
    SDL_Rect rect2;
    rect2.x = x2;
    rect2.y = y2;
    
    SDL_BlitSurface(paddle1, NULL, screen, &rect1);
    SDL_BlitSurface(paddle2, NULL, screen, &rect2);
} 



It draws the Paddles, but they are not transparent, I figured out that I need the r, g and be values to make white, but where can I find a table so I can manually change the I want to be transparent? [Edited by - Joshnathan on December 14, 2004 1:28:25 PM]

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a white RGB value is 255, 255, 255

I like to use MSPaint's color palette. I load an image and use the eyedropper tool to select the color from the image, and then I click on Colors->Edit Colors->Define Custom Colors and it tells me the exact RGB value. Or in picking a color I play around with the palette till I get a color I like, then just note the RGB values.

You might also want to look up the SDL_DisplayFormat function in the SDL docs, you should call it after your SDL_SetColorKey function calls.

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Here is a huge list of RGB values if this is what you are looking for. Link

When you are setting a transparent color, make sure that color is being used in your graphics file.

Also in your code, you are saying that Pinkish (255,0,255) is your transparent color, so your images must have a background of color. I'd suggust just making the background of all your images pure green (0,255,0) and then making the program use R=0,G=255,and B=0. I hope this helps!

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