Implement alpha test using legacy functions (#1426)

4 files changed, 39 insertions, 13 deletions

diff --git a/Ryujinx.Graphics.GAL/IPipeline.cs b/Ryujinx.Graphics.GAL/IPipeline.cs
index 83ccfc3d..8e8cd965 100644
--- a/Ryujinx.Graphics.GAL/IPipeline.cs
+++ b/Ryujinx.Graphics.GAL/IPipeline.cs
@@ -31,6 +31,8 @@ namespace Ryujinx.Graphics.GAL
 
         void EndTransformFeedback();
 
+        void SetAlphaTest(bool enable, float reference, CompareOp op);
+
         void SetBlendState(int index, BlendDescriptor blend);
 
         void SetDepthBias(PolygonModeMask enables, float factor, float units, float clamp);
@@ -61,9 +63,7 @@ namespace Ryujinx.Graphics.GAL
         void SetRasterizerDiscard(bool discard);
 
         void SetRenderTargetScale(float scale);
-
         void SetRenderTargetColorMasks(ReadOnlySpan<uint> componentMask);
-
         void SetRenderTargets(ITexture[] colors, ITexture depthStencil);
 
         void SetSampler(int index, ShaderStage stage, ISampler sampler);
diff --git a/Ryujinx.Graphics.Gpu/Engine/Methods.cs b/Ryujinx.Graphics.Gpu/Engine/Methods.cs
index fbde0f0a..f8b6e43f 100644
--- a/Ryujinx.Graphics.Gpu/Engine/Methods.cs
+++ b/Ryujinx.Graphics.Gpu/Engine/Methods.cs
@@ -164,6 +164,13 @@ namespace Ryujinx.Graphics.Gpu.Engine
                 UpdateDepthClampState(state);
             }
 
+            if (state.QueryModified(MethodOffset.AlphaTestEnable,
+                                    MethodOffset.AlphaTestRef,
+                                    MethodOffset.AlphaTestFunc))
+            {
+                UpdateAlphaTestState(state);
+            }
+
             if (state.QueryModified(MethodOffset.DepthTestEnable,
                                     MethodOffset.DepthWriteEnable,
                                     MethodOffset.DepthTestFunc))
@@ -372,7 +379,7 @@ namespace Ryujinx.Graphics.Gpu.Engine
             if (dsEnable)
             {
                 var dsState = state.Get<RtDepthStencilState>(MethodOffset.RtDepthStencilState);
-                var dsSize  = state.Get<Size3D>             (MethodOffset.RtDepthStencilSize);
+                var dsSize  = state.Get<Size3D>(MethodOffset.RtDepthStencilSize);
 
                 depthStencil = TextureManager.FindOrCreateTexture(dsState, dsSize, samplesInX, samplesInY);
             }
@@ -451,6 +458,18 @@ namespace Ryujinx.Graphics.Gpu.Engine
         }
 
         /// <summary>
+        /// Updates host alpha test state based on current GPU state.
+        /// </summary>
+        /// <param name="state">Current GPU state</param>
+        private void UpdateAlphaTestState(GpuState state)
+        {
+            _context.Renderer.Pipeline.SetAlphaTest(
+                state.Get<Boolean32>(MethodOffset.AlphaTestEnable),
+                state.Get<float>(MethodOffset.AlphaTestRef),
+                state.Get<CompareOp>(MethodOffset.AlphaTestFunc));
+        }
+
+        /// <summary>
         /// Updates host depth test state based on current GPU state.
         /// </summary>
         /// <param name="state">Current GPU state</param>
@@ -577,8 +596,8 @@ namespace Ryujinx.Graphics.Gpu.Engine
         /// <param name="state">Current GPU state</param>
         private void UpdateStencilTestState(GpuState state)
         {
-            var backMasks = state.Get<StencilBackMasks>    (MethodOffset.StencilBackMasks);
-            var test      = state.Get<StencilTestState>    (MethodOffset.StencilTestState);
+            var backMasks = state.Get<StencilBackMasks>(MethodOffset.StencilBackMasks);
+            var test      = state.Get<StencilTestState>(MethodOffset.StencilTestState);
             var backTest  = state.Get<StencilBackTestState>(MethodOffset.StencilBackTestState);
 
             CompareOp backFunc;
diff --git a/Ryujinx.Graphics.Gpu/State/MethodOffset.cs b/Ryujinx.Graphics.Gpu/State/MethodOffset.cs
index 505e3d89..13b699f3 100644
--- a/Ryujinx.Graphics.Gpu/State/MethodOffset.cs
+++ b/Ryujinx.Graphics.Gpu/State/MethodOffset.cs
@@ -52,8 +52,11 @@ namespace Ryujinx.Graphics.Gpu.State
         DepthTestEnable                 = 0x4b3,
         BlendIndependent                = 0x4b9,
         DepthWriteEnable                = 0x4ba,
+        AlphaTestEnable                 = 0x4bb,
         VbElementU8                     = 0x4c1,
         DepthTestFunc                   = 0x4c3,
+        AlphaTestRef                    = 0x4c4,
+        AlphaTestFunc                   = 0x4c5,
         BlendConstant                   = 0x4c7,
         BlendStateCommon                = 0x4cf,
         BlendEnableCommon               = 0x4d7,
diff --git a/Ryujinx.Graphics.OpenGL/Pipeline.cs b/Ryujinx.Graphics.OpenGL/Pipeline.cs
index 4f3c2a29..69bd7844 100644
--- a/Ryujinx.Graphics.OpenGL/Pipeline.cs
+++ b/Ryujinx.Graphics.OpenGL/Pipeline.cs
@@ -157,7 +157,6 @@ namespace Ryujinx.Graphics.OpenGL
             if (!_program.IsLinked)
             {
                 Logger.PrintDebug(LogClass.Gpu, "Dispatch error, shader not linked.");
-
                 return;
             }
 
@@ -171,7 +170,6 @@ namespace Ryujinx.Graphics.OpenGL
             if (!_program.IsLinked)
             {
                 Logger.PrintDebug(LogClass.Gpu, "Draw error, shader not linked.");
-
                 return;
             }
 
@@ -290,7 +288,6 @@ namespace Ryujinx.Graphics.OpenGL
             if (!_program.IsLinked)
             {
                 Logger.PrintDebug(LogClass.Gpu, "Draw error, shader not linked.");
-
                 return;
             }
 
@@ -527,12 +524,23 @@ namespace Ryujinx.Graphics.OpenGL
             _tfEnabled = false;
         }
 
+        public void SetAlphaTest(bool enable, float reference, CompareOp op)
+        {
+            if (!enable)
+            {
+                GL.Disable(EnableCap.AlphaTest);
+                return;
+            }
+
+            GL.AlphaFunc((AlphaFunction)op.Convert(), reference);
+            GL.Enable(EnableCap.AlphaTest);
+        }
+
         public void SetBlendState(int index, BlendDescriptor blend)
         {
             if (!blend.Enable)
             {
                 GL.Disable(IndexedEnableCap.Blend, index);
-
                 return;
             }
 
@@ -658,7 +666,6 @@ namespace Ryujinx.Graphics.OpenGL
             if (!enable)
             {
                 GL.Disable(EnableCap.CullFace);
-
                 return;
             }
 
@@ -742,7 +749,6 @@ namespace Ryujinx.Graphics.OpenGL
             if (!enable)
             {
                 GL.Disable(EnableCap.PrimitiveRestart);
-
                 return;
             }
 
@@ -874,7 +880,6 @@ namespace Ryujinx.Graphics.OpenGL
             if (!stencilTest.TestEnable)
             {
                 GL.Disable(EnableCap.StencilTest);
-
                 return;
             }
 
@@ -1077,7 +1082,6 @@ namespace Ryujinx.Graphics.OpenGL
             if (buffer.Handle == null)
             {
                 GL.BindBufferRange(target, bindingPoint, 0, IntPtr.Zero, 0);
-
                 return;
             }