VideoCommon: Better logic op invert approximation

1 files changed, 20 insertions, 0 deletions

diff --git a/Source/Core/VideoCommon/UberShaderPixel.cpp b/Source/Core/VideoCommon/UberShaderPixel.cpp
index d625ce9c42..21309bc8b3 100644
--- a/Source/Core/VideoCommon/UberShaderPixel.cpp
+++ b/Source/Core/VideoCommon/UberShaderPixel.cpp
@@ -1092,6 +1092,26 @@ ShaderCode GenPixelShader(APIType api_type, const ShaderHostConfig& host_config,
               "    TevResult &= 0xff;\n"
               "  }}\n");
   }
+  else if (!host_config.backend_logic_op)
+  {
+    out.Write("  // Helpers for logic op blending approximations\n"
+              "  if (logic_op_enable) {{\n"
+              "    switch (logic_op_mode) {{\n");
+    out.Write("      case {}: // Clear\n", static_cast<u32>(LogicOp::Clear));
+    out.Write("        TevResult = int4(0, 0, 0, 0);\n"
+              "        break;\n");
+    out.Write("      case {}: // Copy Inverted\n", static_cast<u32>(LogicOp::CopyInverted));
+    out.Write("        TevResult ^= 0xff;\n"
+              "        break;\n");
+    out.Write("      case {}: // Set\n", static_cast<u32>(LogicOp::Set));
+    out.Write("      case {}: // Invert\n", static_cast<u32>(LogicOp::Invert));
+    out.Write("        TevResult = int4(255, 255, 255, 255);\n"
+              "        break;\n");
+    out.Write("      default:\n"
+              "        break;\n"
+              "    }}\n"
+              "  }}\n");
+  }
 
   // Some backends require that the shader outputs be uint when writing to a uint render target for
   // logic op.