Implement GPU scissors (#1058)

* Implement GPU scissors

* Remove unused using

* Add missing changes for Clear

Ryujinx.Graphics.Gpu/Engine/MethodClear.cs

@@ -13,6 +13,12 @@ namespace Ryujinx.Graphics.Gpu.Engine
         /// <param name="argument">Method call argument</param>
         private void Clear(GpuState state, int argument)
         {
+            // Scissor affects clears aswell.
+            if (state.QueryModified(MethodOffset.ScissorState))
+            {
+                UpdateScissorState(state);
+            }
+
             UpdateRenderTargetState(state, useControl: false);
 
             TextureManager.CommitGraphicsBindings();

Ryujinx.Graphics.Gpu/Engine/Methods.cs

@@ -117,6 +117,11 @@ namespace Ryujinx.Graphics.Gpu.Engine
                 UpdateRenderTargetState(state, useControl: true);
             }
 
+            if (state.QueryModified(MethodOffset.ScissorState))
+            {
+                UpdateScissorState(state);
+            }
+
             if (state.QueryModified(MethodOffset.DepthTestEnable,
                                     MethodOffset.DepthWriteEnable,
                                     MethodOffset.DepthTestFunc))
@@ -321,6 +326,27 @@ namespace Ryujinx.Graphics.Gpu.Engine
             return colorState.Format != 0 && colorState.WidthOrStride != 0;
         }
 
+        /// <summary>
+        /// Updates host scissor test state based on current GPU state.
+        /// </summary>
+        /// <param name="state">Current GPU state</param>
+        private void UpdateScissorState(GpuState state)
+        {
+            for (int index = 0; index < Constants.TotalViewports; index++)
+            {
+                ScissorState scissor = state.Get<ScissorState>(MethodOffset.ScissorState, index);
+
+                bool enable = scissor.Enable && (scissor.X1 != 0 || scissor.Y1 != 0 || scissor.X2 != 0xffff || scissor.Y2 != 0xffff);
+
+                _context.Renderer.Pipeline.SetScissorEnable(index, enable);
+
+                if (enable)
+                {
+                    _context.Renderer.Pipeline.SetScissor(index, scissor.X1, scissor.Y1, scissor.X2 - scissor.X1, scissor.Y2 - scissor.Y1);
+                }
+            }
+        }
+
         /// <summary>
         /// Updates host depth test state based on current GPU state.
         /// </summary>

Ryujinx.Graphics.Gpu/State/GpuStateTable.cs

@@ -57,6 +57,7 @@ namespace Ryujinx.Graphics.Gpu.State
             new TableItem(MethodOffset.ViewportExtents,        typeof(ViewportExtents),       8),
             new TableItem(MethodOffset.VertexBufferDrawState,  typeof(VertexBufferDrawState), 1),
             new TableItem(MethodOffset.DepthBiasState,         typeof(DepthBiasState),        1),
+            new TableItem(MethodOffset.ScissorState,           typeof(ScissorState),          8),
             new TableItem(MethodOffset.StencilBackMasks,       typeof(StencilBackMasks),      1),
             new TableItem(MethodOffset.RtDepthStencilState,    typeof(RtDepthStencilState),   1),
             new TableItem(MethodOffset.VertexAttribState,      typeof(VertexAttribState),     16),

Ryujinx.Graphics.Gpu/State/MethodOffset.cs

@@ -33,6 +33,7 @@ namespace Ryujinx.Graphics.Gpu.State
         ClearStencilValue               = 0x368,
         DepthBiasState                  = 0x370,
         TextureBarrier                  = 0x378,
+        ScissorState                    = 0x380,
         StencilBackMasks                = 0x3d5,
         InvalidateTextures              = 0x3dd,
         TextureBarrierTiled             = 0x3df,

Ryujinx.Graphics.Gpu/State/ScissorState.cs

@@ -0,0 +1,12 @@
+namespace Ryujinx.Graphics.Gpu.State
+{
+    struct ScissorState
+    {
+        public Boolean32 Enable;
+        public ushort X1;
+        public ushort X2;
+        public ushort Y1;
+        public ushort Y2;
+        public uint Padding;
+    }
+}