totte/Texture.cs

using OpenTK.Graphics.OpenGL4;
using OpenTK.Mathematics;
using System.Runtime.CompilerServices;

namespace SemiColinGames;

public class Texture : IDisposable {
  public int Handle;
  public Vector2i Size;

  private static int maxHandle = -1;
  private bool disposedValue = false;

  public Texture(Image<Rgba32> image) {
    Size = new Vector2i(image.Width, image.Height);
    byte[] pixelBytes = new byte[Size.X * Size.Y * Unsafe.SizeOf<Rgba32>()];
    image.CopyPixelDataTo(pixelBytes);

    Handle = GL.GenTexture();
    if (Handle > maxHandle) {
      // Console.WriteLine("GL.GenTexture #" + Handle);
      maxHandle = Handle;
    }
    GL.ActiveTexture(TextureUnit.Texture0);
    GL.BindTexture(TextureTarget.Texture2D, Handle);
    GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba, Size.X, Size.Y, 0, PixelFormat.Rgba, PixelType.UnsignedByte, pixelBytes);
    //GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int) TextureMinFilter.LinearMipmapLinear);
    GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int) TextureMinFilter.Linear);
    GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int) TextureMagFilter.Nearest);
    GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapS, (int) TextureWrapMode.ClampToBorder);
    GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapT, (int) TextureWrapMode.ClampToBorder);
    float[] borderColor = { 0.0f, 0.0f, 0.0f, 1.0f };
    GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureBorderColor, borderColor);
    // FIXME: should we use mipmaps?
    //GL.GenerateMipmap(GenerateMipmapTarget.Texture2D);
  }

  protected virtual void Dispose(bool disposing) {
    if (!disposedValue) {
      GL.DeleteTexture(Handle);
      disposedValue = true;
    }
  }

  ~Texture() {
    if (!disposedValue) {
      Console.WriteLine("~Texture(): resource leak? Dispose() should be called manually.");
    }
  }

  public void Dispose() {
    Dispose(true);
    GC.SuppressFinalize(this);
  }
}