[LaBodilsen]

Originally Posted by Master484

Could a system be used where the graphics of the previous frame are never cleared, but instead we preserve them, and when drawing a new frame we only draw those pixels that have been changed since the last frame, and therefore need to be updated.

And those pixels that remain the same color as they did last frame, are simply skipped.

So every frame we would go through the pixels one by one, and check the current color versus the color that it should be; and draw the pixel only in the case where the "should be color" is different from the current color.

I think in quite many cases the individual pixel colors in two consequtive frames would be the same, and also you would never need to totally "clear" the screen. So could this method work or boost the speed?

explained for a non-coder

what is currently happening:

copy TexturePixel1 to ScreenPixel1
copy TexturePixel2 to ScreenPixel2
copy TexturePixel3 to ScreenPixel3
etc

what you suggest would be

Read ScreenPixel1
Compare ScreenPixel1 to TexturePixel1
IF not equal:	Write TexturePixel1 to ScreenPixel1
If equal:	Read ScreenPixel2
Compare ScreenPixel2 to TexturePixel2
IF not equal:	Write TexturePixel2 to ScreenPixel2
If equal:	Read ScreenPixel3
Compare ScreenPixel3 to TexturePixel3
IF not equal:	Write TexturePixel3 to ScreenPixel3
If equal etc.....

So when the pixels are not equal, the current way is _MUCH_ faster than your suggestion. And if the pixel are equal, the current way is still faster, as you would have to read each screenpixel anyway to make a compare. Hope it makes sence.