1 files changed, 111 insertions, 0 deletions

diff --git a/src/shader_recompiler/backend/glsl/emit_glsl_special.cpp b/src/shader_recompiler/backend/glsl/emit_glsl_special.cpp
new file mode 100644
index 000000000..9b866f889
--- /dev/null
+++ b/src/shader_recompiler/backend/glsl/emit_glsl_special.cpp
@@ -0,0 +1,111 @@
+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <string_view>
+
+#include "shader_recompiler/backend/glsl/emit_context.h"
+#include "shader_recompiler/backend/glsl/emit_glsl_instructions.h"
+#include "shader_recompiler/frontend/ir/program.h"
+#include "shader_recompiler/frontend/ir/value.h"
+#include "shader_recompiler/profile.h"
+
+namespace Shader::Backend::GLSL {
+namespace {
+std::string_view OutputVertexIndex(EmitContext& ctx) {
+    return ctx.stage == Stage::TessellationControl ? "[gl_InvocationID]" : "";
+}
+
+void InitializeOutputVaryings(EmitContext& ctx) {
+    if (ctx.uses_geometry_passthrough) {
+        return;
+    }
+    if (ctx.stage == Stage::VertexB || ctx.stage == Stage::Geometry) {
+        ctx.Add("gl_Position=vec4(0,0,0,1);");
+    }
+    for (size_t index = 0; index < IR::NUM_GENERICS; ++index) {
+        if (!ctx.info.stores.Generic(index)) {
+            continue;
+        }
+        const auto& info_array{ctx.output_generics.at(index)};
+        const auto output_decorator{OutputVertexIndex(ctx)};
+        size_t element{};
+        while (element < info_array.size()) {
+            const auto& info{info_array.at(element)};
+            const auto varying_name{fmt::format("{}{}", info.name, output_decorator)};
+            switch (info.num_components) {
+            case 1: {
+                const char value{element == 3 ? '1' : '0'};
+                ctx.Add("{}={}.f;", varying_name, value);
+                break;
+            }
+            case 2:
+            case 3:
+                if (element + info.num_components < 4) {
+                    ctx.Add("{}=vec{}(0);", varying_name, info.num_components);
+                } else {
+                    // last element is the w component, must be initialized to 1
+                    const auto zeros{info.num_components == 3 ? "0,0," : "0,"};
+                    ctx.Add("{}=vec{}({}1);", varying_name, info.num_components, zeros);
+                }
+                break;
+            case 4:
+                ctx.Add("{}=vec4(0,0,0,1);", varying_name);
+                break;
+            default:
+                break;
+            }
+            element += info.num_components;
+        }
+    }
+}
+} // Anonymous namespace
+
+void EmitPhi(EmitContext& ctx, IR::Inst& phi) {
+    const size_t num_args{phi.NumArgs()};
+    for (size_t i = 0; i < num_args; ++i) {
+        ctx.var_alloc.Consume(phi.Arg(i));
+    }
+    if (!phi.Definition<Id>().is_valid) {
+        // The phi node wasn't forward defined
+        ctx.var_alloc.PhiDefine(phi, phi.Arg(0).Type());
+    }
+}
+
+void EmitVoid(EmitContext&) {}
+
+void EmitReference(EmitContext& ctx, const IR::Value& value) {
+    ctx.var_alloc.Consume(value);
+}
+
+void EmitPhiMove(EmitContext& ctx, const IR::Value& phi_value, const IR::Value& value) {
+    IR::Inst& phi{*phi_value.InstRecursive()};
+    const auto phi_type{phi.Arg(0).Type()};
+    if (!phi.Definition<Id>().is_valid) {
+        // The phi node wasn't forward defined
+        ctx.var_alloc.PhiDefine(phi, phi_type);
+    }
+    const auto phi_reg{ctx.var_alloc.Consume(IR::Value{&phi})};
+    const auto val_reg{ctx.var_alloc.Consume(value)};
+    if (phi_reg == val_reg) {
+        return;
+    }
+    ctx.Add("{}={};", phi_reg, val_reg);
+}
+
+void EmitPrologue(EmitContext& ctx) {
+    InitializeOutputVaryings(ctx);
+}
+
+void EmitEpilogue(EmitContext&) {}
+
+void EmitEmitVertex(EmitContext& ctx, const IR::Value& stream) {
+    ctx.Add("EmitStreamVertex(int({}));", ctx.var_alloc.Consume(stream));
+    InitializeOutputVaryings(ctx);
+}
+
+void EmitEndPrimitive(EmitContext& ctx, const IR::Value& stream) {
+    ctx.Add("EndStreamPrimitive(int({}));", ctx.var_alloc.Consume(stream));
+}
+
+} // namespace Shader::Backend::GLSL