Programming Q & A

[Brett_val]

Originally Posted by ©reative

Thanks! Also, someone noted that drawing an image at less than 0,0 caused the player to crash, so I'm trying to get around it by drawing only the part of that image which is visible on screen. exampleImage:draw(0, 0, 40, 40, 80, 80), which is supposed to just draw part of an image, doesn't seem to do anything; when I use it, no image is drawn. Do we know that this function actually works?

Yes it works, but I thought the API is wrong about the usage.
The first four are screen coordinates and the last two are sizes:
First two are where the upper left corner of the pic would be on screen, next two are where you want to start drawing the snip, and last two are the sizes of the snip.
I used my incredible paint skills to visualize this:

exampleImage:draw(x1, y1, x2, y2, x3, y3)

[delirius]

i already wrote about this in another tread.
http://www.anythingbutipod.com/forum...3&postcount=17

[©reative]

Q: How do I get the opposite (negative) of a positive number? I've already tried using the NOT (~) operator, and also multiplying by -1:

print(10);
print(~10);
print(-1 * 10);

Using ~ did nothing, and multiplying by -1 caused the simulator to crash.

[Nohajc]

It shouldn't crash when you multiply.

try print(tostring(-1*10))

[©reative]

Q: Is there a switch statement for Lua? I googled it but wasn't convinced.

[Nohajc]

I googled the same thing some time ago, and the answer is no: there is no switch in Lua.
You'll have to use if/else...

[©reative]

Alright, here's another question: If you load and image as such:

test = image.load("test.jpg");

and then set a variable to that image:

myTable = {};
myTable.img = test;

is the image copied into the variable, or just a reference to it? When I tried print(myTable.imgName) I got image (0373BB80).
Thanks in advance!

[jbob182]

I would think it is copied, so just load it directly:

myTable.img = image.load("test.jpg");

[©reative]

So for the game I'm currently working on there's a variable that holds the amount of money the player has. At first it'll start out at around 500, but by the end of the game it may be in the millions. I assume I can just use an int for this (4,328,291), or should I avoid possible "max-size exceeded" issues by instead dividing the actual amount by a number and using a double (4,328.291) and converting to the actual number every time I needed to use it?

[jbob182]

I would just use an int. In pingus, we have some rather large variables as well, though I suppose in the end, it is a personal preference.