koobas.hobune.stream
Allocating 5MB for a single variable within a script
TL;DR below
Hi,
I'm trying to make an in-game screen, whose purpose is to show the contents of another window running on the computer (under Windows). For that matter, I had to get my hands dirty and play with that good ol' Windows legacy API, the one with external references and everything. After a couple days of struggle, I was able to make it work! The only problem is that Unity doesn't seem to support it...
I have a WindowOperation class which wraps all of the API calls into static methods, and also performs a few basic tasks. One of them consists in capturing the screen pixels and saving them in a System.Drawing.Bitmap:
public static Bitmap CaptureApplication(string procName)
{
// ...
var bmp = new Bitmap(width, height, PixelFormat.Format24bppRgb);
// ...
return bmp;
}
Unity fails declaring bmp and outputs the following message in the console:
ArgumentException: Parameter is not valid.
System.Drawing.Bitmap..ctor (Int32 width, Int32 height, PixelFormat format)
(wrapper remoting-invoke-with-check) System.Drawing.Bitmap:.ctor (int,int,System.Drawing.Imaging.PixelFormat)
[More info about the stack trace, which leads to the declaration of bmp in the above code]
According to MSDN and Stack Overflow, such exceptions are thrown when .NET is unable to allocate a single block of contiguous memory as big as requested.
Since I didn't have such problems when I tested my code outside of Unity, my best guess is that (correct me if I'm wrong) Unity sandboxes the execution of the script and somehow doesn't allow the allocation of the memory
bmpneeds.My screen dimension is 1600*900, and pixel depth is 3 bytes (
PixelFormat.Format24bppRgb), so the amount of memory needed is 4,320,000 bytes, or just a bit more than 4MB, which doesn't seem excessive to me.
EDIT: To capture the screen, I'm using .NET'sGraphics.CopyFromScreen()function. I don't know how it works, but let's say it uses the same amount of memory asbmp, so the biggest amount of memory being used at one point of time in this script according to a pessimistic estimation rounds up to 10MB. However, I don't think this changes the root of the problem, andbmpis declared before any usage ofCopyFromScreen()anyway.
TL;DR, is there a way I can tell Unity that it should let me allocate tons of memory in my scripts if I want to? Or maybe I'm completely off tracks and the problem lies somewhere else?
All answers are more than welcome!
Thank you in advance. :)
