PCK-Studio/PCK-Studio/Rendering/Texture2D.cs

using System;
using System.Diagnostics;
using System.Drawing;
using System.Drawing.Imaging;
using OpenTK;
using OpenTK.Graphics.OpenGL;

namespace PckStudio.Rendering
{
    internal class Texture2D : IDisposable
    {
        private int _id;

        public Texture2D(string filepath)
            : this(Image.FromFile(filepath))
        {

        }

        public Texture2D(Image image)
            : this(new Bitmap(image))
        {

        }

        private Texture2D(Bitmap bitmap)
        {
            _id = GL.GenTexture();
            GL.BindTexture(TextureTarget.Texture2D, _id);

            GL.GenerateMipmap(GenerateMipmapTarget.Texture2D);
            GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Nearest);
            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);
            
            var data = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
            GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba8, bitmap.Width, bitmap.Height, 0, OpenTK.Graphics.OpenGL.PixelFormat.Bgra, PixelType.UnsignedByte, data.Scan0);
            bitmap.UnlockBits(data);

            GL.BindTexture(TextureTarget.Texture2D, 0);
        }

        public void Bind(int slot)
        {
            Debug.Assert(slot >= 0 || slot < 32, "Slot is out of range");
            slot = MathHelper.Clamp(slot, 0, 31);
            GL.ActiveTexture(TextureUnit.Texture0 + slot);
            GL.BindTexture(TextureTarget.Texture2D, _id);
        }

        [Conditional("DEBUG")]
        public void Unbind()
        {
            GL.BindTexture(TextureTarget.Texture2D, 0);
        }

        public void Dispose()
        {
            Unbind();
            GL.DeleteTexture(_id);
        }

    }
}