shader: Rework varyings and implement passthrough geometry shaders

Put all varyings into a single std::bitset with helpers to access it.

Implement passthrough geometry shaders using host's.

1 files changed, 69 insertions, 0 deletions

diff --git a/src/shader_recompiler/varying_state.h b/src/shader_recompiler/varying_state.h
new file mode 100644
index 000000000..9d7b24a76
--- /dev/null
+++ b/src/shader_recompiler/varying_state.h
@@ -0,0 +1,69 @@
+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <bitset>
+#include <cstddef>
+
+#include "shader_recompiler/frontend/ir/attribute.h"
+
+namespace Shader {
+
+struct VaryingState {
+    std::bitset<256> mask{};
+
+    void Set(IR::Attribute attribute, bool state = true) {
+        mask[static_cast<size_t>(attribute)] = state;
+    }
+
+    [[nodiscard]] bool operator[](IR::Attribute attribute) const noexcept {
+        return mask[static_cast<size_t>(attribute)];
+    }
+
+    [[nodiscard]] bool AnyComponent(IR::Attribute base) const noexcept {
+        return mask[static_cast<size_t>(base) + 0] || mask[static_cast<size_t>(base) + 1] ||
+               mask[static_cast<size_t>(base) + 2] || mask[static_cast<size_t>(base) + 3];
+    }
+
+    [[nodiscard]] bool AllComponents(IR::Attribute base) const noexcept {
+        return mask[static_cast<size_t>(base) + 0] && mask[static_cast<size_t>(base) + 1] &&
+               mask[static_cast<size_t>(base) + 2] && mask[static_cast<size_t>(base) + 3];
+    }
+
+    [[nodiscard]] bool IsUniform(IR::Attribute base) const noexcept {
+        return AnyComponent(base) == AllComponents(base);
+    }
+
+    [[nodiscard]] bool Generic(size_t index, size_t component) const noexcept {
+        return mask[static_cast<size_t>(IR::Attribute::Generic0X) + index * 4 + component];
+    }
+
+    [[nodiscard]] bool Generic(size_t index) const noexcept {
+        return Generic(index, 0) || Generic(index, 1) || Generic(index, 2) || Generic(index, 3);
+    }
+
+    [[nodiscard]] bool ClipDistances() const noexcept {
+        return AnyComponent(IR::Attribute::ClipDistance0) ||
+               AnyComponent(IR::Attribute::ClipDistance4);
+    }
+
+    [[nodiscard]] bool Legacy() const noexcept {
+        return AnyComponent(IR::Attribute::ColorFrontDiffuseR) ||
+               AnyComponent(IR::Attribute::ColorFrontSpecularR) ||
+               AnyComponent(IR::Attribute::ColorBackDiffuseR) ||
+               AnyComponent(IR::Attribute::ColorBackSpecularR) || FixedFunctionTexture();
+    }
+
+    [[nodiscard]] bool FixedFunctionTexture() const noexcept {
+        for (size_t index = 0; index < 10; ++index) {
+            if (AnyComponent(IR::Attribute::FixedFncTexture0S + index * 4)) {
+                return true;
+            }
+        }
+        return false;
+    }
+};
+
+} // namespace Shader