Fix multiple rendertargets (#427)

* Simplify render target bindings

* Implement multiple viewports

* Pack glViewportIndexed calls into a single glViewportArray

* Use ARB_viewport_array when available

* Cache framebuffer attachments

* Use get accessors in OGLExtension

* Address feedback

1 files changed, 7 insertions, 30 deletions

diff --git a/Ryujinx.Graphics/Gal/OpenGL/OGLExtension.cs b/Ryujinx.Graphics/Gal/OpenGL/OGLExtension.cs
index 5ad42298..11daeb59 100644
--- a/Ryujinx.Graphics/Gal/OpenGL/OGLExtension.cs
+++ b/Ryujinx.Graphics/Gal/OpenGL/OGLExtension.cs
@@ -1,40 +1,17 @@
 using OpenTK.Graphics.OpenGL;
+using System;
 
 namespace Ryujinx.Graphics.Gal.OpenGL
 {
     static class OGLExtension
     {
-        private static bool Initialized = false;
+        private static Lazy<bool> s_EnhancedLayouts    = new Lazy<bool>(() => HasExtension("GL_ARB_enhanced_layouts"));
+        private static Lazy<bool> s_TextureMirrorClamp = new Lazy<bool>(() => HasExtension("GL_EXT_texture_mirror_clamp"));
+        private static Lazy<bool> s_ViewportArray      = new Lazy<bool>(() => HasExtension("GL_ARB_viewport_array"));
 
-        private static bool EnhancedLayouts;
-
-        private static bool TextureMirrorClamp;
-
-        public static bool HasEnhancedLayouts()
-        {
-            EnsureInitialized();
-
-            return EnhancedLayouts;
-        }
-
-        public static bool HasTextureMirrorClamp()
-        {
-            EnsureInitialized();
-
-            return TextureMirrorClamp;
-        }
-
-        private static void EnsureInitialized()
-        {
-            if (Initialized)
-            {
-                return;
-            }
-
-            EnhancedLayouts = HasExtension("GL_ARB_enhanced_layouts");
-
-            TextureMirrorClamp = HasExtension("GL_EXT_texture_mirror_clamp");
-        }
+        public static bool EnhancedLayouts    => s_EnhancedLayouts.Value;
+        public static bool TextureMirrorClamp => s_TextureMirrorClamp.Value;
+        public static bool ViewportArray      => s_ViewportArray.Value;
 
         private static bool HasExtension(string Name)
         {