Reworked scissor tests to remove fixme and handle issues with intel gpu's

Ryujinx.Graphics/Gal/OpenGL/OGLPipeline.cs

@@ -270,39 +270,35 @@ namespace Ryujinx.Graphics.Gal.OpenGL
 
 
             // Scissor Test
-            bool forceUpdate;
+            // All scissor test are disabled before drawing final framebuffer to screen so we don't need to handle disabling
-
+            // Skip if there are no scissor tests to enable
-            for (int Index = 0; Index < New.ScissorTestCount; Index++)
+            if (New.ScissorTestCount != 0)
             {
-                forceUpdate = false;
+                int  scissorsApplied = 0;
+                bool applyToAll      = false;
 
+                for (int Index = 0; Index < GalPipelineState.RenderTargetsCount; Index++)
+                {
                     if (New.ScissorTestEnabled[Index])
                     {
-                    // If there is only 1 scissor test, geometry shaders are disabled so the scissor test applies to all viewports
+                        // If there is only 1 scissor test, and it's the first, the scissor test applies to all viewports
-                    if (New.ScissorTestCount == 1)
+                        if (Index == 0 && New.ScissorTestCount == 1)
                         {
                             GL.Enable(EnableCap.ScissorTest);
+                            applyToAll = true;
                         }
                         else
                         {
                             GL.Enable(IndexedEnableCap.ScissorTest, Index);
                         }
-                    forceUpdate = true;
-                }
-                else
-                {
-                    GL.Disable(IndexedEnableCap.ScissorTest, Index);
-                }
 
-                if (New.ScissorTestEnabled[Index] &&
+                        if (New.ScissorTestEnabled[Index] != Old.ScissorTestEnabled[Index] ||
-                   (New.ScissorTestX[Index]      != Old.ScissorTestX[Index]      ||
+                            New.ScissorTestX[Index]       != Old.ScissorTestX[Index]       ||
                             New.ScissorTestY[Index]       != Old.ScissorTestY[Index]       ||
                             New.ScissorTestWidth[Index]   != Old.ScissorTestWidth[Index]   ||
-                    New.ScissorTestHeight[Index] != Old.ScissorTestHeight[Index] ||
+                            New.ScissorTestHeight[Index]  != Old.ScissorTestHeight[Index])
-                    forceUpdate)) // Force update intentionally last to reduce if comparisons
                         {
-                    // If there is only 1 scissor test geometry shaders are disables so the scissor test applies to all viewports
+                            if (applyToAll)
-                    if (New.ScissorTestCount == 1)
                             {
                                 GL.Scissor(New.ScissorTestX[Index],     New.ScissorTestY[Index],
                                            New.ScissorTestWidth[Index], New.ScissorTestHeight[Index]);
@@ -313,6 +309,14 @@ namespace Ryujinx.Graphics.Gal.OpenGL
                                                          New.ScissorTestWidth[Index], New.ScissorTestHeight[Index]);
                             }
                         }
+
+                        // If all scissor tests have been applied so we can skip remaining itterations
+                        if (++scissorsApplied == New.ScissorTestCount)
+                        {
+                            break;
+                        }
+                    }
+                }
             }
 
 

Ryujinx.Graphics/Graphics3d/NvGpuEngine3d.cs

@@ -24,7 +24,12 @@ namespace Ryujinx.Graphics.Graphics3d
 
         private ConstBuffer[][] ConstBuffers;
 
-        // Height kept for flipping y axis
+        // Viewport dimensions kept for scissor test limits
+        private int ViewportX0 = 0;
+        private int ViewportY0 = 0;
+        private int ViewportX1 = 0;
+        private int ViewportY1 = 0;
+        private int ViewportWidth = 0;
         private int ViewportHeight = 0;
 
         private int CurrentInstance = 0;
@@ -200,11 +205,11 @@ namespace Ryujinx.Graphics.Graphics3d
             float SX = ReadRegisterFloat(NvGpuEngine3dReg.ViewportNScaleX + FbIndex * 8);
             float SY = ReadRegisterFloat(NvGpuEngine3dReg.ViewportNScaleY + FbIndex * 8);
 
-            int VpX = (int)MathF.Max(0, TX - MathF.Abs(SX));
+            ViewportX0 = (int)MathF.Max(0, TX - MathF.Abs(SX));
-            int VpY = (int)MathF.Max(0, TY - MathF.Abs(SY));
+            ViewportY0 = (int)MathF.Max(0, TY - MathF.Abs(SY));
 
-            int VpW = (int)(TX + MathF.Abs(SX)) - VpX;
+            ViewportX1 = (int)(TX + MathF.Abs(SX));
-            int VpH = (int)(TY + MathF.Abs(SY)) - VpY;
+            ViewportY1 = (int)(TY + MathF.Abs(SY));
 
             GalImageFormat Format = ImageUtils.ConvertSurface((GalSurfaceFormat)SurfFormat);
 
@@ -212,9 +217,7 @@ namespace Ryujinx.Graphics.Graphics3d
 
             Gpu.ResourceManager.SendColorBuffer(Vmm, Key, FbIndex, Image);
 
-            ViewportHeight = VpH;
+            Gpu.Renderer.RenderTarget.SetViewport(FbIndex, ViewportX0, ViewportY0, ViewportX1 - ViewportX0, ViewportY1 - ViewportY0);
-
-            Gpu.Renderer.RenderTarget.SetViewport(FbIndex, VpX, VpY, VpW, VpH);
         }
 
         private void SetFrameBuffer(GalPipelineState State)
@@ -415,11 +418,9 @@ namespace Ryujinx.Graphics.Graphics3d
 
         private void SetScissor(GalPipelineState State)
         {
-            // FIXME: Stubbed, only the first scissor test is valid without a geometry shader loaded. At time of writing geometry shaders are also stubbed.
+            int count = 0;
-            // Once geometry shaders are fixed it should be equal to GalPipelineState.RenderTargetCount when shader loaded, otherwise equal to 1
-            State.ScissorTestCount = 1;
 
-            for (int Index = 0; Index < State.ScissorTestCount; Index++)
+            for (int Index = 0; Index < GalPipelineState.RenderTargetsCount; Index++)
             {
                 State.ScissorTestEnabled[Index] = ReadRegisterBool(NvGpuEngine3dReg.ScissorEnable + Index * 4);
 
@@ -428,25 +429,107 @@ namespace Ryujinx.Graphics.Graphics3d
                     uint ScissorHorizontal = (uint)ReadRegister(NvGpuEngine3dReg.ScissorHorizontal + Index * 4);
                     uint ScissorVertical   = (uint)ReadRegister(NvGpuEngine3dReg.ScissorVertical   + Index * 4);
 
-                    State.ScissorTestX[Index]     = (int)((ScissorHorizontal & 0xFFFF) * State.FlipX);                          // X, lower 16 bits
+                    int left  = (int)(ScissorHorizontal & 0xFFFF); // Left, lower 16 bits
-                    State.ScissorTestWidth[Index] = (int)((ScissorHorizontal >> 16) * State.FlipX) - State.ScissorTestX[Index]; // Width, right side is upper 16 bits
+                    int right = (int)(ScissorHorizontal >> 16);    // Right, upper 16 bits
 
-                    State.ScissorTestY[Index]      = (int)((ScissorVertical & 0xFFFF));                                         // Y, lower 16 bits
+                    int bottom = (int)(ScissorVertical & 0xFFFF); // Bottom, lower 16 bits
-                    State.ScissorTestHeight[Index] = (int)((ScissorVertical >> 16)) - State.ScissorTestY[Index];                // Height, top side is upper 16 bits
+                    int top    = (int)(ScissorVertical >> 16);    // Top, upper 16 bits
 
-                    // Y coordinates may have to be flipped
+                    int width  = Math.Abs(right - left);
-                    if ((int)State.FlipY == -1)
+                    int height = Math.Abs(top   - bottom);
+
+                    // If the scissor test covers the whole possible viewport, i.e. uninititalized, disable scissor test
+                    if ((width > 16383 && height > 16383) || width <= 0 || height <= 0)
                     {
-                        State.ScissorTestY[Index] = ViewportHeight - State.ScissorTestY[Index] - State.ScissorTestHeight[Index];
+                        State.ScissorTestEnabled[Index] = false;
+                        continue;
+                    }
 
-                        // Handle negative viewpont coordinate
+                    // Keep track of how many scissor tests are active.
-                        if (State.ScissorTestY[Index] < 0)
+                    // If only 1, and it's the first user should apply to all viewports
+                    count++;
+
+                    // Flip X
+                    if (State.FlipX == -1)
                     {
-                            State.ScissorTestY[Index] = 0;
+                        left  = ViewportX1 - (left  - ViewportX0);
-                        }
+                        right = ViewportX1 - (right - ViewportX0);
-                    }
+                    }
+                    
+                    // Ensure X is in the right order
+                    if (left > right)
+                    {
+                        int temp = left;
+                        left     = right;
+                        right    = temp;
+                    }
+
+                    // Flip Y
+                    if (State.FlipY == -1)
+                    {
+                        bottom = ViewportY1 - (bottom - ViewportY0);
+                        top    = ViewportY1 - (top - ViewportY0);
+                    }
+
+                    // Ensure Y is in the right order
+                    if (bottom > top)
+                    {
+                        int temp = top;
+                        top      = bottom;
+                        bottom   = temp;
+                    }
+
+                    // Handle out of active viewport dimensions
+                    // Left
+                    if (left < ViewportX0)
+                    {
+                        left = ViewportX0;
+                    }
+                    else if (left > ViewportX1)
+                    {
+                        left = ViewportX1;
+                    }
+
+                    // Right
+                    if (right < ViewportX0)
+                    {
+                        right = ViewportX0;
+                    }
+                    else if (right > ViewportX1)
+                    {
+                        right = ViewportX1;
+                    }
+
+                    // Bottom
+                    if (bottom < ViewportY0)
+                    {
+                        bottom = ViewportY0;
+                    }
+                    else if (bottom > ViewportY1)
+                    {
+                        bottom = ViewportY1;
+                    }
+
+                    // Top
+                    if (top < ViewportX0)
+                    {
+                        top = ViewportX0;
+                    }
+                    else if (top > ViewportX1)
+                    {
+                        top = ViewportX1;
+                    }
+
+                    // Save values to state
+                    State.ScissorTestX[Index] = left;
+                    State.ScissorTestY[Index] = bottom;
+
+                    State.ScissorTestWidth[Index]  = right - left;
+                    State.ScissorTestHeight[Index] = top - bottom;
                 }
             }
+
+            State.ScissorTestCount = count;
         }
 
         private void SetBlending(GalPipelineState State)