PMG over GR8

[twh/f2]

Friends,

 

could please somebody point me in the right direction how this effect of the Forsaken Love demo can be realized? You see two rotating cubes, one is black, the other one is light gray. it is in hires mode, which normally only gives you one color. I suppose it is realized using overlapping PMG gfx. From my understanding the PMG is in it's horizontal resolution twice as large. So just using PMG graphics instead of the actual gr8 pixel does not seem to be the solution.

 

are there any "colorization" overlapping tricks for gr8? is that managed by GTIA somehow? Is there possibly a prio mode so that the player-background-colorization appears only when there is an actual gr8 pixel at the same position?

 

maybe they are also using hardware register changes within the line.

 

grtx,

\twh

[pseudografx]

The magic word is "inverse". While sprites in Gr.8 are only visible over playfield (color reg. 710) and pixels (color reg. 709) are in front of them, you can achieve more colours by making everything inverse - i.e. fill the whole screen with value 255 and then draw to it with playfield colour. This way, if you underlay sprites, your graphics will show with the colour of the sprite.

[twh/f2]

The magic word is "inverse". While sprites in Gr.8 are only visible over playfield (color reg. 710) and pixels (color reg. 709) are in front of them, you can achieve more colours by making everything inverse - i.e. fill the whole screen with value 255 and then draw to it with playfield colour. This way, if you underlay sprites, your graphics will show with the colour of the sprite.

 

indeed. that was easy. You are right. thank you!

 

\twh