Inverting colors?
Blitz3D Forums/Blitz3D Programming/Inverting colors?
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| hi. I wonder if you could help me with this. First I'll explain what it is. In MSpaint, if you select something and then press CTRL+I you can invert the colors. I was wondering if anyone knew how to do this in Blitz3D? ie. The all the colors on the screen are inverted? Thanks in advance. |
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| I don't know of any built-in commands to do such a thing but you could write your own routine to do it although it most likely would not be a very fast routine. I think all you have to do is for R, G, and B each just subtract the current color from 255 for every pixel in the image. |
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| All pixel routines written in blitz will never get fast. That's because there are always many pixels to write (long loops). Like, if you have a screen at 800x600, then it have to loop 800*600 = 480 000 times a mainloop to invert them (which would result <2 frames a second). Anyway, if it's a onetime operation (like if you're coding some sort of image editor), then it should work out fine. |
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| yeh as your exspected to wait in things like taht |
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| If you want *all* the pixels on the screen inverted, then the answer is yes, you can, very easily and quickly - simply invert all the values in the gamma table. I haven't checked it but something along these lines: for lp=0 to 255 setgamma lp,lp,lp,255-lp,255-lp,255-lp next updategamma() |
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| now that's indeed an easy way to do it!!! ;-) |
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| Wow, thanks! |
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