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OpenGL, SDL RGB mapping
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Join Date: Jun 2006
Posts: 98
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Solved Threads: 7
Junior Poster in Training
Do anybody know about this mapping in the SDL_MapRGB
The screen is my SDL_Surface.
Does this define only a single color. The RGB are Uint8 type and I set them As I wish from 0-256.
i don't understand the -> operator exactly in this line??
SDL_MapRGB(screen->format, R, G, B)
The screen is my SDL_Surface.
Does this define only a single color. The RGB are Uint8 type and I set them As I wish from 0-256.
Uint32 color = SDL_MapRGB(screen->format, R, G, B);
i don't understand the -> operator exactly in this line??
Last edited by slacke; Apr 2nd, 2008 at 3:31 pm.
http://www.cplusplus.com/doc/tutorial/classes.html
Very bottom of page, second to last section. Basically screen is a pointer that points to a class and you directly access it through ->. Could be a struct instead of a class but you get the point.
Very bottom of page, second to last section. Basically screen is a pointer that points to a class and you directly access it through ->. Could be a struct instead of a class but you get the point.
Last edited by Grigor; Apr 4th, 2008 at 12:17 pm.
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Join Date: Jun 2006
Posts: 98
Reputation:
Solved Threads: 7
Junior Poster in Training
Yes thats exactly what I was looking for, how did you know that?? 
"in order to refer directly to a member of an object pointed by a pointer we can use the arrow operator (->) of indirection"
But I read the whole site again. I like this tutorial very much.
Thanks
If you can help me out with this:
bufp = (Uint32 *)screen->pixels + y*screen->pitch/4 + x;
Huuh.
I access a member in my screen object of SDL_Surface class called pixels. Add to it (y*pitch/4+x)?? And What is the (Uint32 *)
I know, maybe I am asking the irrelevant questions but I can't get no sleep until I find that out.
"in order to refer directly to a member of an object pointed by a pointer we can use the arrow operator (->) of indirection"
But I read the whole site again. I like this tutorial very much.
Thanks
If you can help me out with this:
bufp = (Uint32 *)screen->pixels + y*screen->pitch/4 + x;
Huuh.
I access a member in my screen object of SDL_Surface class called pixels. Add to it (y*pitch/4+x)?? And What is the (Uint32 *)
I know, maybe I am asking the irrelevant questions but I can't get no sleep until I find that out.
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