Implementation of UBOs instead of uniform constant arrays (#186)

* Sort uniform binding to avoid possible failures in drivers fewer bindings

* Throw exception for Cbuf overflow

* Search for free bindings instead of using locked ones

* EnsureAllocated when binding buffers

* Fix uniform bindings

* Remove spaces

* Use 64 KiB UBOs when available

* Remove double colon

* Use IdentationStr and avoid division in Cbuf offset

* Add spaces

Ryujinx.Graphics/Gal/OpenGL/OGLShader.cs

@@ -69,6 +69,8 @@ namespace Ryujinx.Graphics.Gal.OpenGL
             public ShaderStage Fragment;
         }
 
+        const int ConstBuffersPerStage = 18;
+
         private ShaderProgram Current;
 
         private ConcurrentDictionary<long, ShaderStage> Stages;
@@ -77,11 +79,20 @@ namespace Ryujinx.Graphics.Gal.OpenGL
 
         public int CurrentProgramHandle { get; private set; }
 
+        private OGLStreamBuffer[][] ConstBuffers;
+
         public OGLShader()
         {
             Stages = new ConcurrentDictionary<long, ShaderStage>();
 
             Programs = new Dictionary<ShaderProgram, int>();
+
+            ConstBuffers = new OGLStreamBuffer[5][];
+
+            for (int i = 0; i < 5; i++)
+            {
+                ConstBuffers[i] = new OGLStreamBuffer[ConstBuffersPerStage];
+            }
         }
 
         public void Create(IGalMemory Memory, long Key, GalShaderType Type)
@@ -119,27 +130,19 @@ namespace Ryujinx.Graphics.Gal.OpenGL
 
         public void SetConstBuffer(long Key, int Cbuf, byte[] Data)
         {
-            BindProgram();
-
             if (Stages.TryGetValue(Key, out ShaderStage Stage))
             {
                 foreach (ShaderDeclInfo DeclInfo in Stage.UniformUsage.Where(x => x.Cbuf == Cbuf))
                 {
-                    int Location = GL.GetUniformLocation(CurrentProgramHandle, DeclInfo.Name);
+                    OGLStreamBuffer Buffer = GetConstBuffer(Stage.Type, Cbuf);
 
-                    int Count = Data.Length >> 2;
+                    int Size = Math.Min(Data.Length, Buffer.Size);
 
-                    //The Index is the index of the last element,
-                    //so we can add 1 to get the uniform array size.
-                    Count = Math.Min(Count, DeclInfo.Index + 1);
+                    byte[] Destiny = Buffer.Map(Size);
 
-                    unsafe
-                    {
-                        fixed (byte* Ptr = Data)
-                        {
-                            GL.Uniform1(Location, Count, (float*)Ptr);
-                        }
-                    }
+                    Array.Copy(Data, Destiny, Size);
+
+                    Buffer.Unmap(Size);
                 }
             }
         }
@@ -204,11 +207,15 @@ namespace Ryujinx.Graphics.Gal.OpenGL
 
                 CheckProgramLink(Handle);
 
+                BindUniformBlocks(Handle);
+
                 Programs.Add(Current, Handle);
             }
 
             GL.UseProgram(Handle);
 
+            BindUniformBuffers(Handle);
+
             CurrentProgramHandle = Handle;
         }
 
@@ -222,6 +229,87 @@ namespace Ryujinx.Graphics.Gal.OpenGL
             }
         }
 
+        private void BindUniformBlocks(int ProgramHandle)
+        {
+            int FreeBinding = 0;
+
+            int BindUniformBlocksIfNotNull(ShaderStage Stage)
+            {
+                if (Stage != null)
+                {
+                    foreach (ShaderDeclInfo DeclInfo in Stage.UniformUsage)
+                    {
+                        int BlockIndex = GL.GetUniformBlockIndex(ProgramHandle, DeclInfo.Name);
+
+                        if (BlockIndex < 0)
+                        {
+                            //It is expected that its found, if it's not then driver might be in a malfunction
+                            throw new InvalidOperationException();
+                        }
+
+                        GL.UniformBlockBinding(ProgramHandle, BlockIndex, FreeBinding);
+
+                        FreeBinding++;
+                    }
+                }
+
+                return FreeBinding;
+            }
+
+            BindUniformBlocksIfNotNull(Current.Vertex);
+            BindUniformBlocksIfNotNull(Current.TessControl);
+            BindUniformBlocksIfNotNull(Current.TessEvaluation);
+            BindUniformBlocksIfNotNull(Current.Geometry);
+            BindUniformBlocksIfNotNull(Current.Fragment);
+        }
+
+        private void BindUniformBuffers(int ProgramHandle)
+        {
+            int FreeBinding = 0;
+
+            int BindUniformBuffersIfNotNull(ShaderStage Stage)
+            {
+                if (Stage != null)
+                {
+                    foreach (ShaderDeclInfo DeclInfo in Stage.UniformUsage)
+                    {
+                        OGLStreamBuffer Buffer = GetConstBuffer(Stage.Type, DeclInfo.Cbuf);
+
+                        GL.BindBufferBase(BufferRangeTarget.UniformBuffer, FreeBinding, Buffer.Handle);
+
+                        FreeBinding++;
+                    }
+                }
+
+                return FreeBinding;
+            }
+            
+            BindUniformBuffersIfNotNull(Current.Vertex);
+            BindUniformBuffersIfNotNull(Current.TessControl);
+            BindUniformBuffersIfNotNull(Current.TessEvaluation);
+            BindUniformBuffersIfNotNull(Current.Geometry);
+            BindUniformBuffersIfNotNull(Current.Fragment);
+        }
+
+        private OGLStreamBuffer GetConstBuffer(GalShaderType StageType, int Cbuf)
+        {
+            int StageIndex = (int)StageType;
+
+            OGLStreamBuffer Buffer = ConstBuffers[StageIndex][Cbuf];
+
+            if (Buffer == null)
+            {
+                //Allocate a maximum of 64 KiB
+                int Size = Math.Min(GL.GetInteger(GetPName.MaxUniformBlockSize), 64 * 1024);
+
+                Buffer = OGLStreamBuffer.Create(BufferTarget.UniformBuffer, Size);
+
+                ConstBuffers[StageIndex][Cbuf] = Buffer;
+            }
+
+            return Buffer;
+        }
+
         public static void CompileAndCheck(int Handle, string Code)
         {
             GL.ShaderSource(Handle, Code);