Apply ComparisonFunction in SamplerState.OpenGL

MonoGame · Mar 18, 2015 · 3624b2d · 3624b2d · mgbot · Mar 18, 2015
1 parent 59d6eb7
commit 3624b2d
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Showing 3 changed files with 38 additions and 30 deletions.
diff --git a/MonoGame.Framework/Graphics/GraphicsExtensions.cs b/MonoGame.Framework/Graphics/GraphicsExtensions.cs
@@ -438,6 +438,30 @@ public static BlendingFactorDest GetBlendFactorDest (this Blend blend)
 
 		}
 
+        public static DepthFunction GetDepthFunction(this CompareFunction compare)
+        {
+            switch (compare)
+            {
+                default:
+                case CompareFunction.Always:
+                    return DepthFunction.Always;
+                case CompareFunction.Equal:
+                    return DepthFunction.Equal;
+                case CompareFunction.Greater:
+                    return DepthFunction.Greater;
+                case CompareFunction.GreaterEqual:
+                    return DepthFunction.Gequal;
+                case CompareFunction.Less:
+                    return DepthFunction.Less;
+                case CompareFunction.LessEqual:
+                    return DepthFunction.Lequal;
+                case CompareFunction.Never:
+                    return DepthFunction.Never;
+                case CompareFunction.NotEqual:
+                    return DepthFunction.Notequal;
+            }
+        }
+
 #if WINDOWS || LINUX || ANGLE
         /// <summary>
         /// Convert a <see cref="SurfaceFormat"/> to an OpenTK.Graphics.ColorFormat.

diff --git a/MonoGame.Framework/Graphics/States/DepthStencilState.OpenGL.cs b/MonoGame.Framework/Graphics/States/DepthStencilState.OpenGL.cs
@@ -37,36 +37,7 @@ internal void PlatformApplyState(GraphicsDevice device, bool force = false)
 
             if (force || this.DepthBufferFunction != device._lastDepthStencilState.DepthBufferFunction)
             {
-                DepthFunction func;
-                switch (DepthBufferFunction)
-                {
-                    default:
-                    case CompareFunction.Always:
-                        func = DepthFunction.Always;
-                        break;
-                    case CompareFunction.Equal:
-                        func = DepthFunction.Equal;
-                        break;
-                    case CompareFunction.Greater:
-                        func = DepthFunction.Greater;
-                        break;
-                    case CompareFunction.GreaterEqual:
-                        func = DepthFunction.Gequal;
-                        break;
-                    case CompareFunction.Less:
-                        func = DepthFunction.Less;
-                        break;
-                    case CompareFunction.LessEqual:
-                        func = DepthFunction.Lequal;
-                        break;
-                    case CompareFunction.Never:
-                        func = DepthFunction.Never;
-                        break;
-                    case CompareFunction.NotEqual:
-                        func = DepthFunction.Notequal;
-                        break;
-                }
-                GL.DepthFunc(func);
+                GL.DepthFunc(DepthBufferFunction.GetDepthFunction());
                 GraphicsExtensions.CheckGLError();
                 device._lastDepthStencilState.DepthBufferFunction = this.DepthBufferFunction;
             }

diff --git a/MonoGame.Framework/Graphics/States/SamplerState.OpenGL.cs b/MonoGame.Framework/Graphics/States/SamplerState.OpenGL.cs
@@ -149,6 +149,19 @@ internal void Activate(GraphicsDevice device, TextureTarget target, bool useMipm
             // LOD bias is not supported by glTexParameter in OpenGL ES 2.0
             GL.TexParameter(target, TextureParameterName.TextureLodBias, MipMapLevelOfDetailBias);
             GraphicsExtensions.CheckGLError();
+            // Comparison samplers are not supported in OpenGL ES 2.0 (without an extension, anyway)
+            if (ComparisonFunction != CompareFunction.Never)
+            {
+                GL.TexParameter(target, TextureParameterName.TextureCompareMode, (int) TextureCompareMode.CompareRefToTexture);
+                GraphicsExtensions.CheckGLError();
+                GL.TexParameter(target, TextureParameterName.TextureCompareFunc, (int) ComparisonFunction.GetDepthFunction());
+                GraphicsExtensions.CheckGLError();
+            }
+            else
+            {
+                GL.TexParameter(target, TextureParameterName.TextureCompareMode, (int) TextureCompareMode.None);
+                GraphicsExtensions.CheckGLError();
+            }
 #endif
             if (GraphicsDevice.GraphicsCapabilities.SupportsTextureMaxLevel)
             {