Tinting Greyscale Sprite Sheets?

[diablothe2nd]

Is this possible?

instead of manually drawing out a red, blue and green tile from a spritesheet is it possible to just call the spritesheet and have either the blitter (or i guess the copper?) then add the colour on the fly?

[Thorham]

Originally Posted by diablothe2nd

Is this possible?

instead of manually drawing out a red, blue and green tile from a spritesheet is it possible to just call the spritesheet and have either the blitter (or i guess the copper?) then add the colour on the fly?

Sure, but not with the Copper.

Say each tile uses four shades. What you do is define your palette like this:

Color nr: 0   1   2   3   4   5   6   7   8   9   10  11  12  13  14  15
          x   x   x   x   red red red red gre gre gre gre blu blu blu blu

The uncolored tiles use two bitplanes, for four shades, so all you have to do now is have the blitter write two extra bitplanes like this:

Tile data:            0000111100001111 plane 0
	              1100110011001100 plane 1
Color select for red: 1111111111111111 plane 2
                      0000000000000000 plane 3

So basically the extra data you write combines with the tile data to create the full 16 color indexes.

Hope that made some sense

[diablothe2nd]

I think I get it.

I'm imagining it sort of like a Worms map, where the terrain uses only 4 colours, but instead of drawing the mud and rock for each "themed map" i could just adjust the colour of the tileset, needing less tile variations and thus, less tiles needing to be loaded in ram.

now the bigger question... using this technique, its it possible to tweak the tint on the fly? think of it like a downfall type digging game, but as you get deeper and deeper the colour hue of the tiles change?

[Thorham]

Originally Posted by diablothe2nd

I'm imagining it sort of like a Worms map, where the terrain uses only 4 colours, but instead of drawing the mud and rock for each "themed map" i could just adjust the colour of the tileset, needing less tile variations and thus, less tiles needing to be loaded in ram.

If you're not mixing tiles of different colors, you can just change the colors in the palette directly.

Originally Posted by diablothe2nd

now the bigger question... using this technique, its it possible to tweak the tint on the fly? think of it like a downfall type digging game, but as you get deeper and deeper the colour hue of the tiles change?

Sure. If you do it like in my example, you could have three different hue levels by defining them in the palette.

If you want very smooth hue transitions, you can use the Copper to change the four tile colors per scan line. But that only works for your 'going deeper and deeper' example.

[diablothe2nd]

Excellent! Thanks for the advice

I've yet another idea for a game ("lol! not ANOTHER one!?" I hear you guys cry). My problem is choosing a game type that's on par with my programming level, but will still offer a challenge as i learn more while making it. so if i made a digging game going deeper and deeper i could use a lot of cue's from Downfall to get me started then maybe work toward that colour change as a long term "for added polish" type of goal

so cheers!