stb_image.h

About

StbImage.cs and StbImage.Generated.cs contain ported code of the stb_image.h. Right now, it can load images in JPG, PNG, BMP, TGA, PSD and GIF formats.

Loading Image

'ImageReader' class wraps the call to 'stbi_load_from_callbacks' method. It could be used following way:

ImageReader loader = new ImageReader();
using (Stream stream = File.Open(path, FileMode.Open)) 
{
	Image image = loader.Read(stream, StbImage.STBI_rgb_alpha);
}

Or 'LoadFromMemory' method wraps 'stbi_load_from_memory':

byte[] buffer = File.ReadAllBytes(path);
int x, y, comp;
Image image = StbImage.LoadFromMemory(buffer, Stb.STBI_rgb_alpha);

Both code samples will try to load an image (JPG/PNG/BMP/TGA/PSD/GIF) located at 'path'. It'll throw Exception on failure.

If you are writing MonoGame application and would like to convert that data to the Texture2D. It could be done following way:

Texture2D texture = new Texture2D(GraphicsDevice, image.Width, image.Height, false, SurfaceFormat.Color);
texture.SetData(image.Data);

Or if you are writing WinForms app and would like StbSharp resulting bytes to be converted to the Bitmap. The sample code is:

byte[] data = image.Data;
// Convert rgba to bgra
for (int i = 0; i < x*y; ++i)
{
	byte r = data[i*4];
	byte g = data[i*4 + 1];
	byte b = data[i*4 + 2];
	byte a = data[i*4 + 3];


	data[i*4] = b;
	data[i*4 + 1] = g;
	data[i*4 + 2] = r;
	data[i*4 + 3] = a;
}

// Create Bitmap
Bitmap bmp = new Bitmap(_loadedImage.Width, _loadedImage.Height, PixelFormat.Format32bppArgb);
BitmapData bmpData = bmp.LockBits(new Rectangle(0, 0, _loadedImage.Width, _loadedImage.Height), ImageLockMode.WriteOnly,
	bmp.PixelFormat);

Marshal.Copy(data, 0, bmpData.Scan0, bmpData.Stride*bmp.Height);
bmp.UnlockBits(bmpData);