Help: Screenshotting program ends up screensh*tting

[DJ Omnimaga]

Ok so that french guy was asking how to make a program to store pics into programs, something that is impossible so far, but I decided to make an appvar version for now. However, I have problems. When I recall the pic, it's kinda glitchy. Some stuff shows fine, but other lines are garbage. I also got a crash once

Here's the code of my programs:

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.SCRNSHOT StoreGDB "vPIC"->Str1 GetCalc(Str1) GetCalc(Str1,768) conj(L6,Str1,768) DispGraph

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.SCRNVIEW "vPIC"->Str1 GetCalc(Str1)->M If M conj(Str1,L6,768) DispGraph End

Note: those two progs are launched from a TI-BASIC program so the graph screen is displayed prior launching them.

If anyone tries to debug this, please do not run on calc, or at least back up first, because my TI-Nspire froze once.

For french people, here's the original request: http://www.omnimaga.org/index.php?topic=2284.msg36767;topicseen#new

[Builderboy]

Ok in the first program, remove the first getcalc, add a '->M' to the end of the second getCalc statement and change the Str1 on the line after into an M

should work I'm on my itouch so sorry if I messed up

[Quigibo]

Yeah, Str1 is just a pointer to the name of the "vPIC" string it isn't the actual data.  You need to assign the getcalc result to a variable pointer (like M in builderboy's suggestion) becasue the appvars cannot be assigned static pointers like StrXX and PicXX since they move around a lot in ram and aren't in the same place every time you execute.

[DJ Omnimaga]

Ooh wow I didn't knew variables were actually pointers. I thought they could only be like one byte lenght each. I didn't knew you could use -> at the end of the GetCalc(PTR,BYTES) command.

It still doesn't work, though. Now I changed what Builderboy told me to change and I got

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.SCRNSHOT StoreGDB "vPIC"->Str1 GetCalc(Str1) GetCalc(Str1,768)->M conj(L6,M,768) DispGraph

And it's even worse it seems, cuz it no longer actually manages to store even a single byte of the screen data.

[calcdude84se]

I don't think you need the first "GetCalc" (did someone already say that?) and the "DispGraph" at the end seems superfluous, but it should work. Let me try...
Also, scrnview should have that last Str1 (the one in the conj( line) be M also.
As an afterthought, though I doubt this is your problem, just be aware that if there isn't enough free ram when you try to create vPIC, nothing will actually be created (since you are then proceeding to try to write to ROM, nothing bad will happen.)

[DJ Omnimaga]

didn't I need to use GetCalc(Str1) to point to the appvar name? Else IIRC it couldn't find the appvar

I definitively think someone needs to write a tutorial on how to use Getcalc. It is getting way too complicated and confusing

[calcdude84se]

no, calling GetCalc(Str1,768) creates vPIC it if it doesn't exist, deletes it and recreates it if it does, and then proceeds to return the pointer to the 768 bytes of data.
And yeah, variable management can be difficult. The "correct" way to create an appvar is a bit unwieldy, as this code that loads the value in an appvar demonstrates:

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"vSCORE"->Str1 GetCalc(Str1)->X .If it's non-zero, we're good, otherwise it's archived or non existent. !If     UnArchive Str1     .If 0, it failed. Try to create the appvar     !If         GetCalc(Str1,2)         .If it's 0, not enough RAM. Err and give up.         !If             "Not enough RAM"->Str2             Disp Str2,i             Return         End     End     GetCalc(Str1)->X     .This next If should never be reached     !If         "Serious Error"->Str3         Disp Str3,i         Return     End End .X should now contain the pointer to the data. Phew!

Even w/o comments and indents, it still looks like this:

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"vSCORE"->Str1 GetCalc(Str1)->X !If UnArchive Str1 !If GetCalc(Str1,2) !If "Not enough RAM"->Str2 Disp Str2,i Return End End GetCalc(Str1)->X !If "Serious Error"->Str3 Disp Str3,i Return End End

Oh, if an If has on condition following it, it's the condition on the previous line.

[DJ Omnimaga]

Is !If with nothing after the equivalent of If not(Ans) in BASIC?

[calcdude84se]

pretty much. and "If" is about the equivalent of "If Ans"

[DJ Omnimaga]

ooh that's good to know. I did not even know Axe supported some sort of Ans style feature (where the last value is stored after doing something). I guess that's why stuff like 1->A->B->C->D can be done

EDIT: Well I give up, I tried what you all told me to do and to no avail.

I think making a program to store pictures to appvars in Axe is impossible. It just starts reading the appvar content from the wrong location and that stuff is too much for me anyway.

If anyone wants to attempt at writing such program, feel free to do so. Kindermoumoute would appreciate very well.

EDIT: Example of what happens wrong. Both myself and him tried and we got similar results:

The image being stored to the appvar


The image being recalled


In my case it was more off, though.

[Quigibo]

I'm using minimal error testing, basically if there is a problem, the program will just exit.

Copy the drawing buffer to the appvar

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"vPIC"->Str1 Return!If GetCalc(Str1,768)->A conj(L6,A,768)

Or if you want the current LCD instead

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"vPIC"->Str1 StoreGDB Return!If GetCalc(Str1,768)->A conj(L6,A,768)

Copy the appvar to the buffer and then to the screen

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"vPIC"->Str1 Unarchive Str1 Return!If GetCalc(Str1)->A conj(A,L6,768) DispGraph

Or simply display it on the LCD directly

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"vPIC"->Str1 Unarchive Str1 Return!If GetCalc(Str1)->A A->DispGraph

[DJ Omnimaga]

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"vPIC"->Str1 StoreGDB Return!If GetCalc(Str1,768)->A conj(L6,A,768)

That gives an ERR:BAD SYMBOL error at 76%

[Quigibo]

You just found a new bug   I'll fix it later, just do this for now, it does the same thing and seems to work:

Replace:

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1	Return!If GetCalc(Str1,768)->A

With:

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1 2	GetCalc(Str1,768)->A Return!If

[DJ Omnimaga]

Ok that works, but now Quigibo I think I found a second bug, and I fear this might be the source of all my problems. Hold on I'll try my original program on another calc model...

[kindermoumoute]

This time there are two results, the first picture that displays whatever and another that displays a portion of the picture

The second picture uses "A => dispgraph" and third I do not know