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Forum Index : Microcontroller and PC projects : CMM2 graphics questions

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Macer_D
Newbie

Joined: 25/04/2026
Location: United Kingdom
Posts: 5
Posted: 04:18pm 02 May 2026
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Hi all, thank you for your responses to my questions about the paint program. I have two more questions I would like to ask with regards to the CMM2. Firstly, is there an extension for a PC paint program like libresprite or gimp that would allow me to draw using the 12 bit rgba scheme that is on the CMM2? And secondly, how do sprites work on the CMM2? Is there a good resource for that I could consult? Thank you.
 
LeoNicolas

Guru

Joined: 07/10/2020
Location: Canada
Posts: 574
Posted: 05:15pm 03 May 2026
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The CMM2 user manual has detailed explanation about sprites and other commands and functions.

https://geoffg.net/Downloads/Maximite/Colour_Maximite_2_User_Manual.pdf

The CMM2 graphics manual expands this material.

2021-04-05_114624_Graphics Programming on the CMM2-v3f.pdf

Usually I edit my images on Gimp and export them as PNG selecting the appropriate pixel format

 
hhtg1968
Senior Member

Joined: 25/05/2023
Location: Germany
Posts: 187
Posted: 10:49am 04 May 2026
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Earlier I posted questions about my paint program on my cmm2 (gen2). I hope, the questions are no to silly or annoying.

this is a link to youtube with 4 of my movies that show the screen memory error.

https://www.youtube.com/@heinrichhubbert8474

or

to the movies...


this is the basic sourcecode


2026-04-27_215913_hg.bas.zip


is it my bug or what is the reason for the memory/screen mistakes?

perhaps you or disco4now could read this. many thanks.
Edited 2026-05-04 20:50 by hhtg1968
 
LeoNicolas

Guru

Joined: 07/10/2020
Location: Canada
Posts: 574
Posted: 09:02pm 04 May 2026
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I can try to figure out what is happening. I will reply black to you soon
 
PhenixRising
Guru

Joined: 07/11/2023
Location: United Kingdom
Posts: 1886
Posted: 09:26pm 04 May 2026
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I experienced similar

Reported here

But I found that a different resolution was better for my needs and the flicker didn't occur.
 
disco4now

Guru

Joined: 18/12/2014
Location: Australia
Posts: 1120
Posted: 11:35pm 04 May 2026
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  LeoNicolas said  I can try to figure out what is happening. I will reply black to you soon

That would be good. I previously ran the code and can see the artifacts he is seeing.
I did not really get anywhere to resolve it. There is a memory leak with CURSOR ON/OFF that is fixed in latest CMM2 betas.
I was suspicious that the GUI controls and the drawing code where both trying to update the cursor.
Edited 2026-05-05 09:37 by disco4now
F4 H7FotSF4xGT
 
hhtg1968
Senior Member

Joined: 25/05/2023
Location: Germany
Posts: 187
Posted: 02:43pm 06 May 2026
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  LeoNicolas said  I can try to figure out what is happening. I will reply black to you soon


i wait with tension...

i think that disco4now could be right with his thought...
 
LeoNicolas

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Joined: 07/10/2020
Location: Canada
Posts: 574
Posted: 05:44pm 06 May 2026
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I only can work on it on the weekend.
I'm curious to know what is causing the issue.

Are you using double buffer?
 
hhtg1968
Senior Member

Joined: 25/05/2023
Location: Germany
Posts: 187
Posted: 07:02pm 06 May 2026
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  LeoNicolas said  I only can work on it on the weekend.
I'm curious to know what is causing the issue.

Are you using double buffer?


double buffer?
 
LeoNicolas

Guru

Joined: 07/10/2020
Location: Canada
Posts: 574
Posted: 04:02am 07 May 2026
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Yes
You can draw the elements on a memory page and blit them to page 0 or 1 depending on the screen mode you are using. This technique removes the flickering

From my game Knightmare:


page write 0
blit 0,TILE_SIZEx2, SCREEN_OFFSET,0, SCREEN_WIDTH,SCREEN_HEIGHT, SCREEN_BUFFER
page write 1
blit 0,TILE_SIZEx2, SCREEN_OFFSET,0, SCREEN_WIDTH,SCREEN_HEIGHT, SPRITES_BUFFER


In my case, it's a little more complex because I have a ton of sprites moving, and they were creating a lot of artifacts. I decided to use the two visible pages (zero and one) to render the screen elements and the sprites. I compose the frame in memory, by using two non visible pages, and I blit these two memory pages to the page 0 and 1, that are visible.
 
hhtg1968
Senior Member

Joined: 25/05/2023
Location: Germany
Posts: 187
Posted: 07:54am 07 May 2026
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I think I will need some time to follow your thoughts...

do you (LeoNicolas) know the reason for the artefacts?
 
LeoNicolas

Guru

Joined: 07/10/2020
Location: Canada
Posts: 574
Posted: 06:47pm 10 May 2026
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I made some changes. It looks good. Let me know if it is working for you

hg.bas.zip
 
hhtg1968
Senior Member

Joined: 25/05/2023
Location: Germany
Posts: 187
Posted: 05:50am 11 May 2026
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  LeoNicolas said  I made some changes. It looks good. Let me know if it is working for you

hg.bas.zip


many thanks... i think i can test it in a few days...
 
hhtg1968
Senior Member

Joined: 25/05/2023
Location: Germany
Posts: 187
Posted: 06:11am 11 May 2026
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@LeoNicolas:

my first check of the changed code (without running):

gui commands are not used (only gui cursor...). perhaps this is the solution... i will "create" the graphical menus "by hand". so i did it on other systems (i have a self constructed and built z80-system (8bit 64k ram!) with my own operatings system).

the mmbasic gui system leads to run some code in the backround with refreshing the menu texts or objects and so on. so i thounght earlier that this could lead to errors, because i do not exactly know what the gui commands do...

many thanks...
 
LeoNicolas

Guru

Joined: 07/10/2020
Location: Canada
Posts: 574
Posted: 02:40pm 11 May 2026
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I didn't change anything regarding commands or gui.
My updates were only on the render logic, creating a double buffering and removing flickering and artifacts. I drew lines, circles and rectangles and I didn't see any artifacts or flickering.

Let me know if you had the same result when running the modified code on you machine.
 
hhtg1968
Senior Member

Joined: 25/05/2023
Location: Germany
Posts: 187
Posted: 08:42pm 11 May 2026
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  LeoNicolas said  I didn't change anything regarding commands or gui.
My updates were only on the render logic, creating a double buffering and removing flickering and artifacts. I drew lines, circles and rectangles and I didn't see any artifacts or flickering.

Let me know if you had the same result when running the modified code on you machine.


yes and many thanks again.

one question

do you know the reason for the flickering?

is there an issue in the gui commands?
 
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