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[i2amroy]

I am failing to understand a bit of found code that takes the aspect ratio and area of a rectangle and returns the width and height. I wondered if anyone else might be able to explain. I suspect this is a basic maths fail on my part.

Spoiler (click to show/hide)

For examples sake lets say the area = 150 and the ratio = 1.5.

Code: [Select]

height = sqrt(area / ratio)
       = sqrt(150 / 1.5)
       = sqrt(100)
       = 10

width = area / height
      = 150 / 10
      = 15
I don't understand why the above works. On paper I'd do it like:

Code: [Select]

width * height = area
3x * 2x = 150
   6x^2 = 150
    x^2 = 150/6
        = 25
      x = sqrt(25)
        = 5

width = 3x
      = 3 * 5
      = 15

height = 2x
       = 2 * 5
       = 10
For the curious I'm dividing a rectangle into a grid so that a given number of elements will fit one per cell. In the above I replace area with desired number of elements to fit and round up to make sure I always have space, even if it leaves some cells empty.

Think of it this way:
x = smaller side
a*x = a (ratio) * smaller side = larger side
(a*x)*(x) = larger side * smaller side = area
a*x^2 = area
x^2 = area / a
x = sqrt(area / a)
Therefore:
smaller side = sqrt(area / ratio)
larger side = ratio * smaller side OR larger side = area / smaller side     (The two are functionally equivalent in the amount of processing they do, one just risks decimal rounding error and the other integer overflow).

[Vattic]

Well explained i2amroy many thanks, and to you too TheBiggerFish for the hint. Crossed fingers this message will get through the gateway errors.

[TheBiggerFish]

It worked.

[Malus]

I've been dabbling around a bit with live code editing while I learn OpenGL. Basically, you have all of your main code built into a .dll, and then you have a helper executable that loads that .dll and calls it, reloading it if it changes. The result is pretty neat. Kind of makes scripting languages feel weak in comparison... I was going to implement some kind of lua but I don't think it'll be necessary now.

[Mephisto]

Kind of makes scripting languages feel weak in comparison...

Heh.

[cerapa]

Intellisense is officially the dumbest piece of crap ever devised by mankind.

It complained about the line "int SecondFaction;", which you might correctly deduce has no error and is literally just a goddamn int.

Being forced to use Visual Studio for writing C++ code for Unreal 4 is so goddamn annoying.

EDIT:

i is indeed unidentified you fucking idiot.

[Levi]

Any chance its currently set to the wrong language?  I vaguely remember intellisense was pretty good 10+ years ago when I used it.  A lot can change in that amount of time though.   

[cerapa]

I don't know if you even can set the language to be different than the project.

[itisnotlogical]

I looked in to writing programs for my TI-89 because I want to believe that there is a reason for me to have this thing once I'm finished with math classes. A lot of the things I've found are hobbyist resources, and those are for standard TI Basic anyway when I need 68k. Are there any official Texas Instruments manuals, aside from the physical one that probably came with the calculator and I don't have?

[i2amroy]

I can assure you that my TI-89 Titanium has been one of my most useful tools for rapidly prototyping math stuff; computers have calculator programs, true, but the speed which I can view, adjust, and change things on the calculator is just so much faster and easier to use that it's definitely been worth keeping it around, even without much customization.

And here's a guidebook published by Oregon state. To be honest for most calculators you can just google "calculator-name manual" and you'll find at least one pdf version of the official manual (and in fact a lot of more recent calculators, like the 89-Titanium, don't even have physical manual copies).

[Bumber]

i is indeed unidentified you fucking idiot.

This happens to me sometimes, too. I think something gets fudged in whatever parsing thing it has when you try to quickly edit typos and such. It usually goes away when I save and re-open. Sometimes it's also due to weird characters getting in (backquotes, etc.)

[Skyrunner]

On the other hand, Intellisense for C# is extremely good. But that's because C# was probably designed around the idea of Bisual studio.

[Telgin]

i is indeed unidentified you fucking idiot.

This happens to me sometimes, too. I think something gets fudged in whatever parsing thing it has when you try to quickly edit typos and such. It usually goes away when I save and re-open. Sometimes it's also due to weird characters getting in (backquotes, etc.)

Weird characters like smart quotes and unprintable things are great fun to fix in every programming language it seems.  I remember the first time I had one get pasted into a JavaScript source file once.  Trying to figure out why the browser was complaining about UNEXPECTED TOKEN: ILLEGAL took a while.

[alway]

Yeah, Intellisense is not only just bad, but reliably so. So reliably so, in fact, that companies like this both exist and rely upon it being terrible and continuing to be terrible into the future: http://www.wholetomato.com/
Just be glad it's only underlining the wrong thing instead of deciding it wants to parse something and locking up visual studio in the process. :v

As for live coding, I've posted it here before and will inevitably post it again in the future, but Shadertoy is great for learning about some graphics stuff, as it's doing a pixel-shader in your browser sorta thing: https://www.shadertoy.com/
Even has multi-buffer support now, so you can do compute stuff like this: https://www.shadertoy.com/view/Xd33Df

[Cryxis, Prince of Doom]

Started coding in Robotc for an elevator my friend and I have built for engineering class.

He is making the 3D model of the device on inventor while I get stuck with the code.
I think I know what I am doing.... maybe....