From 2af773b421cd193e80a3aa78e3a7634e027a01e6 Mon Sep 17 00:00:00 2001
From: Nikos Kastellanos <nkastellanos@gmail.com>
Date: Wed, 1 Jan 2025 08:39:03 +0200
Subject: [PATCH] refactor GL graphics (#2164)

* whitespaces

* refactor DrawElementsBaseVertex

* clean up ConcreteSamplerState
---
 Platforms/Graphics/.GL/ConcreteGraphicsContext.cs     |  2 +-
 Platforms/Graphics/.GL/OpenGL.cs                      |  9 +++++++--
 Platforms/Graphics/.GL/States/ConcreteSamplerState.cs | 10 ++--------
 3 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/Platforms/Graphics/.GL/ConcreteGraphicsContext.cs b/Platforms/Graphics/.GL/ConcreteGraphicsContext.cs
index f961ba32141..bda8e5ba71f 100644
--- a/Platforms/Graphics/.GL/ConcreteGraphicsContext.cs
+++ b/Platforms/Graphics/.GL/ConcreteGraphicsContext.cs
@@ -91,7 +91,7 @@ public override void PlatformSetup()
             this._newEnabledVertexAttributes = new bool[base.Capabilities.MaxVertexBufferSlots];
 
             if (((ConcreteGraphicsCapabilities)base.Capabilities).SupportsFramebufferObjectARB
-            || ((ConcreteGraphicsCapabilities)base.Capabilities).SupportsFramebufferObjectEXT)
+            ||  ((ConcreteGraphicsCapabilities)base.Capabilities).SupportsFramebufferObjectEXT)
             {
                 this._supportsBlitFramebuffer = GL.BlitFramebuffer != null;
                 this._supportsInvalidateFramebuffer = GL.InvalidateFramebuffer != null;
diff --git a/Platforms/Graphics/.GL/OpenGL.cs b/Platforms/Graphics/.GL/OpenGL.cs
index dd5947f891c..4f68406365e 100644
--- a/Platforms/Graphics/.GL/OpenGL.cs
+++ b/Platforms/Graphics/.GL/OpenGL.cs
@@ -1492,8 +1492,13 @@ private void LoadEntryPoints()
             DrawElements = LoadFunctionOrNull<DrawElementsDelegate>("glDrawElements");
             DrawArrays = LoadFunctionOrNull<DrawArraysDelegate>("glDrawArrays");
 
+            // OpenGL >= 2.0, GLES >= 3.0
             DrawRangeElements = LoadFunctionOrNull<DrawRangeElementsDelegate>("glDrawRangeElements");
 
+            // OpenGL >= 3.2, GLES >= 3.2 or GL_ARB_draw_elements_base_vertex
+            DrawElementsBaseVertex = LoadFunctionOrNull<DrawElementsBaseVertexDelegate>("glDrawElementsBaseVertex");
+            DrawRangeElementsBaseVertex = LoadFunctionOrNull<DrawRangeElementsBaseVertexDelegate>("glDrawRangeElementsBaseVertex");
+
             // uniforms OpenGL Version >= 2.0
             Uniform1i = LoadFunctionOrNull<Uniform1iDelegate>("glUniform1i");
             Uniform1f = LoadFunctionOrNull<Uniform1fDelegate>("glUniform1f");
@@ -1719,9 +1724,9 @@ internal void InitExtensions()
             if (BlendEquationSeparatei == null && Extensions.Contains("GL_ARB_draw_buffers_blend"))
                 BlendEquationSeparatei = LoadFunctionOrNull<OGL.BlendEquationSeparateiDelegate>("BlendEquationSeparateiARB");
 
-            //if (Extensions.Contains("GL_ARB_draw_elements_base_vertex"))
+            if (DrawElementsBaseVertex == null && Extensions.Contains("GL_ARB_draw_elements_base_vertex"))
                 DrawElementsBaseVertex = LoadFunctionOrNull<DrawElementsBaseVertexDelegate>("glDrawElementsBaseVertex");
-            //if (Extensions.Contains("GL_ARB_draw_elements_base_vertex"))
+            if (DrawRangeElementsBaseVertex == null && Extensions.Contains("GL_ARB_draw_elements_base_vertex"))
                 DrawRangeElementsBaseVertex = LoadFunctionOrNull<DrawRangeElementsBaseVertexDelegate>("glDrawRangeElementsBaseVertex");
         }
 
diff --git a/Platforms/Graphics/.GL/States/ConcreteSamplerState.cs b/Platforms/Graphics/.GL/States/ConcreteSamplerState.cs
index cfe83de94e2..0fe7720385d 100644
--- a/Platforms/Graphics/.GL/States/ConcreteSamplerState.cs
+++ b/Platforms/Graphics/.GL/States/ConcreteSamplerState.cs
@@ -11,8 +11,6 @@
 using Microsoft.Xna.Framework;
 using Microsoft.Xna.Framework.Graphics;
 using Microsoft.Xna.Platform.Graphics.OpenGL;
-using ExtTextureFilterAnisotropic = Microsoft.Xna.Platform.Graphics.OpenGL.TextureParameterName;
-
 
 
 namespace Microsoft.Xna.Platform.Graphics
@@ -21,10 +19,6 @@ internal class ConcreteSamplerState : ResourceSamplerStateStrategy
     {
         private readonly float[] _openGLBorderColor = new float[4];
 
-        internal const TextureParameterName TextureParameterNameTextureMaxAnisotropy = (TextureParameterName)ExtTextureFilterAnisotropic.TextureMaxAnisotropyExt;
-        internal const TextureParameterName TextureParameterNameTextureMaxLevel = TextureParameterName.TextureMaxLevel;
-
-
         internal ConcreteSamplerState(GraphicsContextStrategy contextStrategy, ISamplerStateStrategy source)
             : base(contextStrategy, source)
         {
@@ -94,7 +88,7 @@ internal void PlatformApplyState(ConcreteGraphicsContextGL cgraphicsContext, Tex
             }
             if (cgraphicsContext.Capabilities.SupportsTextureFilterAnisotropic)
             {
-                GL.TexParameter(target, TextureParameterNameTextureMaxAnisotropy, textureMaxAnisotropy);
+                GL.TexParameter(target, TextureParameterName.TextureMaxAnisotropyExt, textureMaxAnisotropy);
                 GL.CheckGLError();
             }
             GL.TexParameter(target, TextureParameterName.TextureMinFilter, (int)textureMinFilter);
@@ -143,7 +137,7 @@ internal void PlatformApplyState(ConcreteGraphicsContextGL cgraphicsContext, Tex
                 int textureMaxLevel = 1000;
                 if (this.MaxMipLevel > 0)
                     textureMaxLevel = this.MaxMipLevel;
-                GL.TexParameter(TextureTarget.Texture2D, TextureParameterNameTextureMaxLevel, textureMaxLevel);
+                GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMaxLevel, textureMaxLevel);
                 GL.CheckGLError();
             }
         }