Jump to content

Photo

Just for fun contest idea: "i can't believe it's not bitmap"


41 replies to this topic

#26 carlsson OFFLINE  

carlsson

    Metagalactic Mule

  • 5,243 posts
  • Location:Västerås, Sweden

Posted Thu Nov 30, 2017 4:14 AM

I also wonder... Even if the graphics are made with just the character set, are they not a bitmap graphic nonetheless? After all those characters are just bits mapped in a cell (8x8 or other depending on the system). So no modification to those stock character then? Maybe the OP should have asked for pure ASCII art then?

As far as I know, in graphics mode 1 you can redefine the character set with 256 symbols that you position freely on the screen and which can be repeated any number of times. If you would make a pseudo-bitmap screen, it would be 16x16 characters, 24x10 characters, 32x8 characters or something similar, while the total screen area still is 32x24 positions. Furthermore, these 256 symbols are divided into 32 colour sets with 8 symbols in each. Each colour set has its own combination of background and foreground colour, meaning that if you want both a blue ball on white background and a red ball on white background, you would need to define the ball twice in your character set and position those into different colour sets.

 

A real bitmap in graphics mode 2 takes up three character sets so you can get all 32x24 = 768 positions with unique patterns in each character. The colour tables also are arranged in such way that for each position, you have 8 lines of colour data: one background nybble and one foreground nybble meaning you can have two colours per line and character.

 

The real challenge then is to pick up to 256 custom symbols arranged in 32 sets of colour combinations, and make it look like a true bitmap image where each position on the screen has its own definition and own set of colours. Obviously the colour resolution in graphics mode 1 is nowhere near the bitmapped mode, but then again not all bitmap images utilize the colour resolution.

 

As a middle way, some kind of ASCII/ANSI/PETSCII/ATASCII art could be considered. It would involve a custom but fixed character set that probably is duplicated a number of times within the character generator to overcome the colour set limitation unless you want mostly monochrome images.



#27 ramidavis OFFLINE  

ramidavis

    Chopper Commander

  • Topic Starter
  • 108 posts

Posted Thu Nov 30, 2017 9:15 AM

 

 

As I understand, it's still just on the idea stage. Hence all the inputs, questions and changes. And your example input is appreciated. ;)

 

  

 

One question. Does it have to be something original, like something you draw yourself, or is it okay to bring in and manipulate graphics from different sources?
 

:)

Outsourcing is OK i suppose.

Once an original has been manipulated, its no longer the original.

Thats how i made the graphics in my two music programs. I took a nice clear picture of the character, and attempted to map it out into 8x8 characters, filling in the odd-places with sprites.

The picture below was the original i was working off for the frog

2a656df6128b729ac16d321e32355e0e.jpg

Giving credit to the original author in REM line if possible would probably be the right thing to do.

Basically, if there is a noticeable difference between the work you based yours on, and your finished entry, all fine and dandy i'd reckon :-)


Edited by ramidavis, Thu Nov 30, 2017 9:20 AM.


#28 Tursi OFFLINE  

Tursi

    River Patroller

  • 4,852 posts
  • HarmlessLion
  • Location:BUR

Posted Thu Nov 30, 2017 10:07 AM

There's also no entries. Other than mine. C'mon people - get your charset piccies in.  Let's see them.  I'm damn sure some will have better than mine (because I can't find my Mayan Temple pic) 

 

Some of us need to wait for at least one weekend to come around ;)



#29 --- Ω --- OFFLINE  

--- Ω ---

    TI-Runner

  • 10,731 posts

Posted Sat Dec 2, 2017 7:25 AM

There's also no entries. Other than mine. C'mon people - get your charset piccies in.  Let's see them.  I'm damn sure some will have better than mine (because I can't find my Mayan Temple pic) 

 

Considering the time of year, maybe we can kill two Partridges in a Pear tree with one contest?  I'm sure a Christmas theme could generate some flashy colors and neat images. (Just a thought.)



#30 Willsy OFFLINE  

Willsy

    River Patroller

  • 3,038 posts
  • Location:Uzbekistan (no, really!)

Posted Sat Dec 2, 2017 3:46 PM

Attached File  Alpiner3.png   1.68KB   0 downloadsAttached File  96969-alpiner-ti-99-4a-screenshot-game-over.png   4.07KB   0 downloads

#31 PeteE ONLINE  

PeteE

    Chopper Commander

  • 103 posts
  • Location:Beaverton, OR

Posted Sat Dec 2, 2017 4:19 PM

The ZX Spectrum has some pretty amazing art made on it, so I converted the best image I could find.  I ran out of 256 pattern space, so I used sprites for extra graphics, and then used gradients for the background.  Source of image

Attached Files



#32 Asmusr OFFLINE  

Asmusr

    River Patroller

  • 2,496 posts
  • Location:Denmark

Posted Sat Dec 2, 2017 4:20 PM

I can't believe it's not Alpiner.  :-o



#33 mizapf OFFLINE  

mizapf

    River Patroller

  • 2,623 posts
  • Location:Germany

Posted Sat Dec 2, 2017 4:31 PM

Nice! (Here's the RPK.)

Attached Files



#34 adamantyr ONLINE  

adamantyr

    Stargunner

  • 1,192 posts

Posted Sat Dec 2, 2017 6:29 PM

I think we have a winner, PeteE!

#35 Tursi OFFLINE  

Tursi

    River Patroller

  • 4,852 posts
  • HarmlessLion
  • Location:BUR

Posted Sat Dec 2, 2017 7:49 PM

That is pretty amazing, PeteE, it definitely fits the 'can't believe it's not bitmap' theme.



#36 --- Ω --- OFFLINE  

--- Ω ---

    TI-Runner

  • 10,731 posts

Posted Sat Dec 2, 2017 8:26 PM

Damn, PeteE!   :o

EXCELLENT JOB!!



#37 Retrospect OFFLINE  

Retrospect

    Dragonstomper

  • 879 posts
  • Location:Wakefield, England

Posted Sun Dec 3, 2017 4:22 AM

That's absolutely brilliant PeteE.  Very very well done.

 

Just goes to show , our TI-99's have always had the edge over the Speccy.



#38 Asmusr OFFLINE  

Asmusr

    River Patroller

  • 2,496 posts
  • Location:Denmark

Posted Sun Dec 3, 2017 5:44 AM

 

Just goes to show , our TI-99's have always had the edge over the Speccy.

 

How does an image with less graphics than on the Spectrum show that?  ;)

 

It would be interesting to see how much Spectrum art could be improved in bitmap mode.



#39 Retrospect OFFLINE  

Retrospect

    Dragonstomper

  • 879 posts
  • Location:Wakefield, England

Posted Sun Dec 3, 2017 6:39 AM

 

How does an image with less graphics than on the Spectrum show that?  ;)

 

It would be interesting to see how much Spectrum art could be improved in bitmap mode.

However many chars the Speccy can display, the TI can use sprites on top of it's 255 chars.  This can be used to create the effect of more than 2 colours per character cell.  At least with static screens, I would say the TI had the advantage.



#40 sometimes99er OFFLINE  

sometimes99er

    River Patroller

  • 3,993 posts
  • Location:Denmark

Posted Sun Dec 3, 2017 11:37 AM

http://pixeljoint.co...s.asp?TID=21399

http://zxart.ee/spa/.../mac/phantis11/

http://www.videoshoc...hment/azpiri-4/

 

;)


Edited by sometimes99er, Sun Dec 3, 2017 11:39 AM.


#41 PeteE ONLINE  

PeteE

    Chopper Commander

  • 103 posts
  • Location:Beaverton, OR

Posted Sun Dec 3, 2017 1:45 PM

However many chars the Speccy can display, the TI can use sprites on top of it's 255 chars.  This can be used to create the effect of more than 2 colours per character cell.  At least with static screens, I would say the TI had the advantage.

Even with sprites, the 256 char limit is still quite constraining.  In the phantis image above, using 32 16x16 pixel sprites added the equivalent of 128 extra characters. Fewer actually, since there needed to be solid color characters in the background, as I was not attempting to use 3 colors per cell.  The ZX Spectrum has 32x24 characters on screen, so 768 total character patterns -- and you can set the colors separately for each cell.  The TI Mode 1 only has 256 character patterns, and the colors must the same in groups of 8, a serious artistic limitation.



#42 carlsson OFFLINE  

carlsson

    Metagalactic Mule

  • 5,243 posts
  • Location:Västerås, Sweden

Posted Mon Dec 4, 2017 4:54 AM

Shouldn't the ZX Spectrum bitmap graphics be compared to graphics mode 2 rather than graphics mode 1? The Speccy pretty much works in bitmapped mode all the time, as it plots the ROM characters on screen and can combine those with your own lines, dots and circles. This is a problem when it comes to using UDG:s on the Speccy, as the BASIC routine to check which character is at a given position reads the bitmap pattern and compares to the ROM (or RAM if you relocated the entire character set instead of just using UDG). Any custom character not part of the current character set then is not recognized at all, which puts a certain challenge to BASIC programs, and I presume also machine code.






0 user(s) are browsing this forum

0 members, 0 guests, 0 anonymous users