character based graphics

[Thelen]

I was reading De Re Atari, about character graphics in antic mode 4 and 5, and they wrote space invaders have character graphics. What games have this also ?

 

Thelen

[DanBoris]

LOTS of games used these modes. They where quite popular since if used properly they could give you fairly detailed four color graphics without taking up a lot of memory which was a major consideration on these systems.

 

Dan

[Goochman]

Donkey Kong was another - An easy way to find out is to load an old version of ST XFormer which didnt have Sprite Collesions on it yet - games that worked were using character mode

[Jetboot Jack]

Donkey Kong does not use a character mapped mode - it uses a bitmapped mode - Antic E... (Donkey Kong Jnr is in character mode though - Antic 4)

 

But MANY 8bit games used character mode for their playfields, so to list which games used char mode would be a list of over 50% of Atari 8bit games

 

Start off looking at titles like Caverns of Mars or Eastern Front, or Donkey Kong Jnr - load the games up in Atari800win and then hit F8 for the monitor - type DLIST and you'll see what modes the screen is made from....

 

sTeVE

[Goochman]

What

Say it aint so!

 

Ok, so I didnt realize the difference between Bitmapped and Char mode - I know they aint Sprites!

 

Ill climb back into my cave now

[+Cafeman]

Donkey Kong is an amazing example of how to to program the 5200 (oops, I mean the Atari 8bit ) using the bitmap Antic E pixel mode! The game is closer to the coin-op than any other version I've seen from that era.

 

Jet Boot Jack, refresh my memory (I know you know) -- who coded it? He used Antic E, the high res pixel mode, and he uses background graphics for the 'sprites' of the barrels and (I believe) the fireballs. Which is rather clever IMHO. I wonder how he handles collision detection then -- the barrels' main brown color must be the only one checked for death collision? I never really studied the screen to determine it.

 

Anyway, had DK been done in Antic 4 with character gfx, is it true that the developer would have needed to use Player sprites for the barrels? Can you use bit masking in Antic 4 in the same way you'd use it in Antic E (I can't see how that's possible given Antic 4 Character mode uses blocks of 8 scanlines at a time).

[Jetboot Jack]

I would imagine that the collision with Mario is done on a co-ordinate rather than a collision register basis between teh hardware sprite (Mario) and teh software sprites, although I imagine hardware collision is used for the bonus items which are all PMG's...

 

As to doing it in Antic 4 - well it could done, but it would be hard - check out this Menace shot (Big thanx to Mark K for sending me my lost files!!!) - its all in Antic 4 - it scrolls smoothly, the red backdrop is a parallax layer behind the main scenery, the ship is PMG, the enemies are software sprites that move pixel increments, and at any pixel position - all done with redefined characters!!!

[+Cafeman]

I would imagine that the collision with Mario is done on a co-ordinate rather than a collision register basis between teh hardware sprite (Mario) and teh software sprites, although I imagine hardware collision is used for the bonus items which are all PMG's...

 

If the barrels have a unique color register, one that the ladders & bg floor both do not use, then you don't need to check coordinates. Any simple collision of your Player and that color register is definitely a barrel (or fireball). I don't have a screen shot to compare right now. Perhaps fireballs are sprites and barrels are bg gfx? Or do they both use the same color register, perhaps a reddish brown color that would suit both images?

[Jetboot Jack]

In Donkey Kong the harware collisions are not used in that way I would say - it would be far too restrictive given that Antic E has only 3 colors plus background to make one whole color register lethal...

 

Several elements of the game have all 3 foreground colors in them - so enemies do not use unique colors certainly - barrels are red and blue - same as platforms and ladders, and all objects that move EOR to the background rather than mask to produce other color combinations - so Mario can be hit by any color and be killed - but its the object itself that determines that...

 

sTeVE

[Goochman]

I had a brief email conversation with the DK developer a long time ago praising how great the game was - He mentioned the work he did to try and get all the girders on the first screen but nothing would look right. He was also proud of the algorithm he used for the 'jumping' to make it appear like gravity was play during the motion and last but not least he mentioned that the released version isnt 100% in the death scene (Mario appear munched) and he fixed it but it missed the production release.

 

DK on the 800 is def the best home conversion during its time.