Axe Q&A

[epic7]

I have a question: why doesn't this code work? (It compiles, but it glitches on me)
0→{S}→{S+5}→{S+15}
and S is the pointer to appvar.

(I just had this happen to me too and I spent a couple of hours before getting Runer's help and facepalming.)

Because of the way Axe optimizes, number→{pointer} returns the pointer instead of the number.  The code equivalent to what you are doing is actually this:
:0→{S} :S→{S+5} :S+5→{S+15}

Oh I think I've been doing that
I've noticed a few bugs in my game so I'll check for those

For that
and 0->
Is that supposed to be more optimized than
0->

[squidgetx]

Only if you are storing to a one-byte value.

I need to update my guide...lool

[Deep Thought]

For that
and 0->
Is that supposed to be more optimized than
0->

Explained right before you posted, but you probably didn't notice because it was the last post on the page. It's one byte smaller and three cycles faster (but it works only if you're doing something with one byte, as squidgetx said, such as for sin(), xor , or →{}).

You probably wouldn't notice if you just used 0, though

[epic7]

Only if you are storing to a one-byte value.

I need to update my guide...lool

Please do. Everything I know on optimizing is from that

[epic7]

Can Z-Test be used to go to subroutines?

Like doing
1->A
Z-Test(A,1
Disp "World" ;returns here after subroutine
Return
Lbl 1
Disp "Hello"
Return

And have it display Hello world?

[calc84maniac]

Try this:

Code: Select All | Copy To Clipboard

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0→A DO(A) Disp "World" Return Lbl DO Z-Test(r1,1) Return Lbl 1 Disp "Hello" Return

[Darl181]

Ok I'm trying to figure out how to do angles.
What I'm thinking of is if some value is, say, 64 (the 256-degree equivalent of 90 degrees), it sets the x-velocity to the max and y-velocity to 0.  If that value is 128 it should set the y-vel to the max, x-vel zero, etc.

How would I go about doing this?

EDIT: answered on IRC.
.A is angle, 256 degrees
.M is max velocity
cos(A)*2**M→(x-vel)
Then determine Y-velocity based on that.

[Builderboy]

Cos(angle) for the X velocity and Sin(angle) for the Y velocity?

[Darl181]

Hm that makes sense actually..I was thinking it might be something really simple like this but didn't know what it would be
tho I prolly should have known after taking algebra II...idk :\

[calc84maniac]

Rather than computing Y velocity based on X velocity, it might be better to just do sin(A)*2**M→(y-vel)

[jacobly]

Here is an example program that might help:

Code: Select All | Copy To Clipboard

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:.VELOCITY :192→θ .begin facing up :0.0→V .begin stationary :47.0→X .begin in the middle :31.0→Y :Repeat getKey(15) :getKey(4)-getKey(1)+V→V .press up/down to speed up/slow down :getKey(3)-getKey(2)+θ→θ .press left/right to turn left/turn right :cos(θ)*2**V+X^96.0→X .use V and θ to change position :sin(θ)*2**V+Y^64.0→Y :Pxl-On(X/256,Y/256) :DispGraphClrDraw :End

[Yeong]

is there a way to shift the portion of the buffer? (Rectangular region will be fine.)

[ztrumpet]

Are you talking at an arbitrary spot, or can it be in multiples of 8 pixels in the X direction?  It's quite easy if the X can be in multiples of 8, but a little more difficult if you need to mask off parts of bits.

[MGOS]

Another question about number input:

I need a function in my program that checks if a number key from 1 - 8 is pressed. It should return the a value between 1 and 8, or 0 if none of them is pressed. I already looked at the number input routine, but it isn't that what I need.
Would you recommend a LUT, a mathematical way or only some Ifs and Elses?

[ztrumpet]

I recommend using inData.  Yesterday I wrote some code to do the exact thing you talk about, only with the numbers 0 through 9, and it looks like this:

While 1
EndIf inData(getKey,Data(33,34,26,18,35,27,19,36,28,20,0))->r1

This gives you the number of the key pressed plus one, stored in r1.  If my condensed code doesn't make sense to you, here's an uncompressed version:

Data(33,34,26,18,35,27,19,36,28,20,0)->GDB0
While 1
getKey->K
inData(K,GDB0)->r1
EndIf r1

You could easily modify it to suit your needs, and while you do it I hope you figure out how it works.  InData is a very useful and powerful command, though it is a bit advanced. If you need more help with it, check out this post: http://www.omnimaga.org/index.php?topic=1532.msg60704#msg60704

Edit:  In response to your question, I am using a LUT, but accessing it through InData for some great space savings (assuming you use InData more than once or twice in your program).