From d3e7718b5f29f84f4dd174d880d3cfbec481b336 Mon Sep 17 00:00:00 2001
From: Colin McMillen <colin@semicolin.games>
Date: Thu, 29 Jun 2023 15:51:42 -0400
Subject: [PATCH] make a Texture object

---
 Program.cs | 78 ++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 52 insertions(+), 26 deletions(-)

diff --git a/Program.cs b/Program.cs
index 24fa33b..8c65524 100644
--- a/Program.cs
+++ b/Program.cs
@@ -103,7 +103,7 @@ void main() {
 
   ~Shader() {
     if (disposedValue == false) {
-      Console.WriteLine("GPU Resource leak! Did you forget to call Dispose()?");
+      Console.WriteLine("~Shader(): resource leak? Dispose() should be called manually.");
     }
   }
 
@@ -122,6 +122,53 @@ void main() {
 
 }
 
+public class Texture : IDisposable {
+  public int Handle;
+
+  public Texture(string path) {
+    Image<Rgba32> image = Image.Load<Rgba32>(path);
+    Console.WriteLine($"{image.Width}x{image.Height}");
+    //foreach (IExifValue exif in image.Metadata.ExifProfile.Values) {
+    //  Console.WriteLine($"{exif.Tag} : {exif.GetValue()}");
+    //}
+    byte[] pixelBytes = new byte[image.Width * image.Height * Unsafe.SizeOf<Rgba32>()];
+    image.CopyPixelDataTo(pixelBytes);
+    image.Dispose();
+
+    Handle = GL.GenTexture();
+    GL.ActiveTexture(TextureUnit.Texture0);
+    GL.BindTexture(TextureTarget.Texture2D, Handle);
+    GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba, image.Width, image.Height, 0, PixelFormat.Rgba, PixelType.UnsignedByte, pixelBytes);
+    GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int) TextureMinFilter.LinearMipmapLinear); // FIXME: is this right?
+    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);
+    GL.GenerateMipmap(GenerateMipmapTarget.Texture2D);
+  }
+
+  private bool disposedValue = false;
+
+  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);
+  }
+}
+
 public class Game : GameWindow {
   public Game(GameWindowSettings gwSettings, NativeWindowSettings nwSettings) : base(gwSettings, nwSettings) { }
 
@@ -144,7 +191,7 @@ public class Game : GameWindow {
   int VertexBufferObject;
   int ElementBufferObject;
   int VertexArrayObject;
-  int texture;
+  Texture texture;
   Shader shader;
   Matrix4 projection;
 
@@ -191,29 +238,8 @@ public class Game : GameWindow {
     GL.EnableVertexAttribArray(texCoordLocation);
     GL.VertexAttribPointer(texCoordLocation, 2, VertexAttribPointerType.Float, false, 5 * sizeof(float), 3 * sizeof(float));
 
-    // Decode a JPEG image.
-    //Image<Rgba32> image = Image.Load<Rgba32>(@"c:\users\colin\pictures\texture.jpg");
-    Image<Rgba32> image = Image.Load<Rgba32>(@"c:\users\colin\pictures\photos\2023\06\27\DSC_0035.jpg");
-    Console.WriteLine($"{image.Width}x{image.Height}");
-    //foreach (IExifValue exif in image.Metadata.ExifProfile.Values) {
-    //  Console.WriteLine($"{exif.Tag} : {exif.GetValue()}");
-    //}
-    byte[] pixelBytes = new byte[image.Width * image.Height * Unsafe.SizeOf<Rgba32>()];
-    image.CopyPixelDataTo(pixelBytes);
-    image.Dispose();
-
-    // TODO: put the texture into an actual class.
-    texture = GL.GenTexture();
-    GL.ActiveTexture(TextureUnit.Texture0);
-    GL.BindTexture(TextureTarget.Texture2D, texture);
-    GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba, image.Width, image.Height, 0, PixelFormat.Rgba, PixelType.UnsignedByte, pixelBytes);
-    GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int) TextureMinFilter.LinearMipmapLinear); // FIXME: is this right?
-    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);
-    GL.GenerateMipmap(GenerateMipmapTarget.Texture2D);
+    // Load textures from JPEGs.
+    texture = new Texture(@"c:\users\colin\pictures\photos\2023\06\27\DSC_0035.jpg");
   }
 
   protected override void OnUnload() {
@@ -226,7 +252,7 @@ public class Game : GameWindow {
     GL.Clear(ClearBufferMask.ColorBufferBit);
     GL.BindVertexArray(VertexArrayObject);
     GL.ActiveTexture(TextureUnit.Texture0);
-    GL.BindTexture(TextureTarget.Texture2D, texture);
+    GL.BindTexture(TextureTarget.Texture2D, texture.Handle);
     shader.Use();
     GL.DrawElements(PrimitiveType.Triangles, indices.Length, DrawElementsType.UnsignedInt, 0);
     SwapBuffers();