public unsafe static Texture2DContent Build(Stream dataStream)
{
using (var rawImage = SixLabors.ImageSharp.Image.Load(dataStream))
using (var image = rawImage.CloneAs <Rgba32>())
{
var pixels = image.GetPixelSpan();
var imageData = new int[pixels.Length];
fixed(int *imageDataPointer = imageData)
{
var casted = new Span <Rgba32>(imageDataPointer, imageData.Length);
pixels.CopyTo(casted);
}
//We're only supporting R8G8B8A8 right now, so texel size in bytes is always 4.
//We don't compute mips during at content time. We could, but... there's not much reason to.
//The font builder does because it uses a nonstandard mip process, but this builder is expected to be used to with normal data.
var content = new Texture2DContent(image.Width, image.Height, 1, sizeof(Rgba32));
var data = (Rgba32 *)content.Pin();
//Copy the image data into the Texture2DContent.
for (int rowIndex = 0; rowIndex < image.Height; ++rowIndex)
{
var sourceRow = image.GetPixelRowSpan(rowIndex);
var targetRow = data + content.GetRowOffsetForMip0(rowIndex);
Unsafe.CopyBlockUnaligned(ref *(byte *)targetRow, ref Unsafe.As <Rgba32, byte>(ref sourceRow[0]), (uint)(sizeof(Rgba32) * image.Width));
}
content.Unpin();
return(content);
}
}
/// <summary>
/// Uploads the mip0 stored in the Content to the Texture2D and generates new mips.
/// </summary>
public unsafe void UploadContentToTexture()
{
GL.BindTexture(TextureTarget.Texture2D, Texture);
var data = Content.Pin();
GL.TexImage2D(TextureTarget.Texture2D, 0,
srgb ? PixelInternalFormat.Rgba8Snorm : PixelInternalFormat.Rgba8,
Content.Width, Content.Height, 0,
PixelFormat.Rgba, PixelType.UnsignedByte,
new IntPtr(data + Content.GetMipStartIndex(0))
);
Content.Unpin();
GL.GenerateMipmap(GenerateMipmapTarget.Texture2D);
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.LinearMipmapLinear);
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Linear);
GL.BindTexture(TextureTarget.Texture2D, 0);
}