1 files changed, 35 insertions, 0 deletions

diff --git a/src/shader_recompiler/backend/spirv/emit_spirv_special.cpp b/src/shader_recompiler/backend/spirv/emit_spirv_special.cpp
new file mode 100644
index 000000000..70ae7b51e
--- /dev/null
+++ b/src/shader_recompiler/backend/spirv/emit_spirv_special.cpp
@@ -0,0 +1,35 @@
+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "shader_recompiler/backend/spirv/emit_spirv.h"
+
+namespace Shader::Backend::SPIRV {
+
+void EmitPrologue(EmitContext& ctx) {
+    if (ctx.stage == Stage::VertexB) {
+        const Id zero{ctx.Constant(ctx.F32[1], 0.0f)};
+        const Id one{ctx.Constant(ctx.F32[1], 1.0f)};
+        const Id null_vector{ctx.ConstantComposite(ctx.F32[4], zero, zero, zero, zero)};
+        ctx.OpStore(ctx.output_position, ctx.ConstantComposite(ctx.F32[4], zero, zero, zero, one));
+        for (const Id generic_id : ctx.output_generics) {
+            if (Sirit::ValidId(generic_id)) {
+                ctx.OpStore(generic_id, null_vector);
+            }
+        }
+    }
+}
+
+void EmitEpilogue(EmitContext& ctx) {
+    if (ctx.profile.convert_depth_mode) {
+        const Id type{ctx.F32[1]};
+        const Id position{ctx.OpLoad(ctx.F32[4], ctx.output_position)};
+        const Id z{ctx.OpCompositeExtract(type, position, 2u)};
+        const Id w{ctx.OpCompositeExtract(type, position, 3u)};
+        const Id screen_depth{ctx.OpFMul(type, ctx.OpFAdd(type, z, w), ctx.Constant(type, 0.5f))};
+        const Id vector{ctx.OpCompositeInsert(ctx.F32[4], screen_depth, position, 2u)};
+        ctx.OpStore(ctx.output_position, vector);
+    }
+}
+
+} // namespace Shader::Backend::SPIRV