Could some one please tell me why this scrolling text box doesnt work?

Kaos Kidd · 2006-05-20 19:11

I'v tried everything I can think of, and I just can't see why the textbox doesnt scroll or work right when the text is less then the size of the box...

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Just tossing my two bits worth into the bit bucket

KK

Mike Green · 2006-05-20 19:47

Correct me if I'm wrong, but isn't this
VGA.STR(Text[noparse][[/noparse]Index])
supposed to be
VGA.STR(@Text[noparse][[/noparse]Index])
?
Also shouldn't
HoldChar := Text[noparse][[/noparse]Index + Size + 1]
be
HoldChar := Text[noparse][[/noparse]Index + Size]
?

Kaos Kidd · 2006-05-21 15:04

Hmmmm...
I had not thought of that... thanks for the insight and I'll give it whirl!

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Just tossing my two bits worth into the bit bucket

KK
·

Kaos Kidd · 2006-05-22 02:15

Well, that wasn't it...
It's printing trash...
I changed the ref's to include @Text[noparse][[/noparse]Index]
I think it's got something to do with what is acutally created with STRING command, or what VGA.OUT is expecting

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Just tossing my two bits worth into the bit bucket

KK
·

Mike Green · 2006-05-22 02:24

VGA.OUT expects a character value. VGA.STR expects the address of a null-terminated string. STRING constructs a null-terminated string constant and its value is the address of the string at run-time.

Kaos Kidd · 2006-05-22 15:24

Mike:
As I figured out. Hence the VGA.STR call, now follow this: If I remove the [noparse]/noparse from the call, it prints!
Yes, if I do VGA.STR(@Text), it prints it all out.
But, if I do VGA.STR(@Text[noparse][[/noparse]Index]), I get "trash" on the screen.
I understand about the null terminator, that's how I'm setting the length of the string to print.
HoldChar = the original char, then I set it to null, print it, then reset it.
The question is simply this: Why can't I start outputing from the middle of the screen?
Eventually this routine will be included in something that gets its data from a device (like the directory of a SD device or something), which may or may not be be bigger then the scrolling window.
Oh, and BTW, thanks for helpin me out here...

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Just tossing my two bits worth into the bit bucket

KK
·

Beau Schwabe · 2006-05-23 00:04

Kaos Kidd,

I modified your code a little bit, I believe this version is closer to what you are looking for.

Version 1:   - Initial scrolling solution of modified code

Version 2:   - Added automatic character padding on either side of main scrolling text
             - "Title" or non scrolling text can be a null string size.
             - The main scrolling text can range from 1 character to 255 characters.
               In other words it can be smaller than the available scrolling window and
               still scroll from right to left.

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Beau Schwabe

IC Layout Engineer
Parallax, Inc.

Post Edited (Beau Schwabe (Parallax)) : 5/23/2006 7:19:20 PM GMT

Kaos Kidd · 2006-05-23 03:21

Beau:
Thanks! I would have never thought of the byte command.
Slick..
THanks again all!

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Just tossing my two bits worth into the bit bucket

KK
·

Kaos Kidd · 2006-05-23 20:02

Beau:
THe new edits are much better... and slicker!
thanks again...

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Just tossing my two bits worth into the bit bucket

KK
·

Could some one please tell me why this scrolling text box doesnt work?

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