How can you set the colour of a pixel on a form? | Tech Off

Pon

I'm creating a software renderer. Currently, for each and every frame, I use the SetPixel method of the Bitmap class to update the colour, then put that on the form. However, I dislike doing it this way for obvious reasons. How can I set the colour of a pixel on a Form?

Khamul
Death by Escape Key

In the OnPaint() event you could use e.Graphics.[whatever] to draw a one pixel rectangle or line.

Pon

To me, that seems a really inefficient method of doing it; wouldn't it have quite a lot of overhead in for loops etc?

Khamul
Death by Escape Key

Yes.

See, I'm a great lot of help, aren't I? Tongue Out

Sven Groot
My name has 9 letters. Coincidence? I think not...

The only really efficient way to draw to the screen in Windows is using DirectX.

Or you could try locking a bitmap and writing directly to its (unmanaged) memory, then displaying the bitmap.

Foxfire

Pon wrote:
I'm creating a software renderer. Currently, for each and every frame, I use the SetPixel method of the Bitmap class to update the colour, then put that on the form. However, I dislike doing it this way for obvious reasons. How can I set the colour of a pixel on a Form?

What are these obvious reasons? Speed?
If your program runs in full trust you can lock the image and directly paint to the memory using pointers. Besides using DirectX you will not find a faster way to do this:

Bitmap bm = new Bitmap (1000, 1000);
BitmapData data = bm.LockBits (new Rectangle (1000,1000), ImageLockmode.ReadWrite, PixelFormat.Format32bppRgb);

byte* firstByte = (byte*)data.Scan0.ToPointer ();

Don't forget to unlock once you are done...

Pon

Foxfire wrote:

Pon wrote: I'm creating a software renderer. Currently, for each and every frame, I use the SetPixel method of the Bitmap class to update the colour, then put that on the form. However, I dislike doing it this way for obvious rionseasons. How can I set the colour of a pixel on a Form?

What are these obvious reasons? Speed?
If your program runs in full trust you can lock the image and directly paint to the memory using pointers. Besides using DirectX you will not find a faster way to do this:

Bitmap bm = new Bitmap (1000, 1000);
BitmapData data = bm.LockBits (new Rectangle (1000,1000), ImageLockmode.ReadWrite, PixelFormat.Format32bppRgb);

byte* firstByte = (byte*)data.Scan0.ToPointer ();

Don't forget to unlock once you are done...