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Graphiocs Demo help! How can I cover the whole area of my 4 inch LCD ??? — Parallax Forums

Graphiocs Demo help! How can I cover the whole area of my 4 inch LCD ???

StratosStratos Posts: 15
edited 2007-11-15 00:14 in Propeller 1
· I am new to the propeller graphics "ability"·and·I am·trying to cover the whole are of my 4 inch LCD screen (479X234 NTSC)·using the Graphics _demo. How can I increase the screen buffer ? Increasing the number of tiles and adjusting the offset gives me weird results! It is displaying other page/s (?) data.·Has anyone has solved this problem ?

Comments

  • deSilvadeSilva Posts: 2,967
    edited 2007-11-11 23:03
    Yes.
    You have also to adjust the TV or VGA to the new size - the tiles must fit!
    But you will most likely run out of memory when using double buffering..
  • StratosStratos Posts: 15
    edited 2007-11-12 12:08
    ·Can you please clarify how to do this ? What kind of adjustments ?· How do I disable double buffrering etc. ··I would really appreciate your help... or just point to a source so I can read it and understand it !
  • RaymanRayman Posts: 14,793
    edited 2007-11-12 12:37
    I have some notes on the graphics demo here:
    http://www.rayslogic.com/propeller/Programming/GraphicsDemo.htm

    These are the buffers:
    bitmap_base = $2000
    display_base = $5000

    If you replace all instances of one with the other, you get rid of double buffering.
  • StratosStratos Posts: 15
    edited 2007-11-12 15:48
    OK, so I made the display_base=$2000...There was only once instance. Is this correct ? I got a lot of flikering ! So how would you avoid the flickering ? and how come the compiler says the I have 6333 long available ? It doesn't count the disp buffers ???etc...
  • Mike GreenMike Green Posts: 23,101
    edited 2007-11-12 16:02
    1) Double buffering is what prevents the flickering. If you disable the double buffering, you get the flicker. You're trading off appearance for memory.

    2) The compiler doesn't know how you're using the high end of memory (from $2000 to $7FFF) so it isn't included in the estimate of memory use.
  • StratosStratos Posts: 15
    edited 2007-11-12 16:09
    So how much actual memeory is left with DB ? Long time ago I did a little bit of programming on the Amiga 500. I remember the same problem but in order to avoid the flickering I would wait for the beam to reach the bottom of the screen and do what ever I could in the 1/50 of a sec left. This way I need not to use DB. Is this possible here ?
  • Mike GreenMike Green Posts: 23,101
    edited 2007-11-12 16:41
    It is possible since the underlying video driver indicates when it is in the active portion of the vertical scan cycle and you could update the buffer during the inactive portion of the scan. Look at the comments at the end of TV.spin at the description of tv_status.

    Make sure you understand how the "_stack =" statement works in graphics_demo.spin and make a drawing of how memory is laid out with the display buffer(s). Make sure you understand how the graphics double buffering was done (look at the "copy" method in graphics.spin).
  • StratosStratos Posts: 15
    edited 2007-11-12 22:09
    thanks, I'll give it a try...
  • krilliskrillis Posts: 6
    edited 2007-11-14 16:46
    I too am interested in this topic. I was using the VGA driver in a text mode, and was wanting for more capability with respect to graphics. So I looked at the forums and the object exchange but I don't see any full screen examples of graphics demo for VGA. There is an example for the TV driver though. Does anybody have the graphics example that runs on TV ported and running on VGA? Low REZ would be great, as I don't need more than 640x480.

    Thanks,

    Paul
  • RaymanRayman Posts: 14,793
    edited 2007-11-14 17:00
    It's fairly easy to go from basic TV to VGA... Only real trouble is getting the colors right... Anyway, I have a code that was first in TV then ported to VGA here:

    http://www.rayslogic.com/propeller/Programming/2BitBitmap.htm
  • Beau SchwabeBeau Schwabe Posts: 6,568
    edited 2007-11-14 17:41
    krillis,

    Take a look at this thread...

    http://forums.parallax.com/showthread.php?p=606957

    ...The functions are similar to the TV graphics.· Be sure to scroll down and get·the latest version... 1.2

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Beau Schwabe

    IC Layout Engineer
    Parallax, Inc.
  • krilliskrillis Posts: 6
    edited 2007-11-14 23:52
    Thanks Beau,

    I remember seeing a demo that was at the last Embedded systems conference where a bunch of text was on the screen at the same time there were some graphics objects on the screen. I wonder if you could post that demo you guys had running? The limitations of the block size and the color limits wont really work for me to try this full screen, even at reduced rez. I really need say 8 fore and 8 back colors, with scalable font. I think for my needs the vga text drivers will be good enough. I was just hoping for line drawing along with the text drawing. But then, there are font characters that are lines, right? Maybe I can make due with what I have.

    Thanks for pointing me to this code,

    Krillis (aka Paul)
  • Mike GreenMike Green Posts: 23,101
    edited 2007-11-15 00:14
    Chip posted several VGA drivers in different resolutions. Two of them are in the Propeller Object Exchange and one at 1024 x 768 was just attached to a forum message. Here's one from the Object Exchange: obex.parallax.com/objects/176/.
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