shader: Implement geometry shaders

1 files changed, 36 insertions, 7 deletions

diff --git a/src/shader_recompiler/backend/spirv/emit_context.cpp b/src/shader_recompiler/backend/spirv/emit_context.cpp
index bf2210899..01b77a7d1 100644
--- a/src/shader_recompiler/backend/spirv/emit_context.cpp
+++ b/src/shader_recompiler/backend/spirv/emit_context.cpp
@@ -140,7 +140,27 @@ Id DefineVariable(EmitContext& ctx, Id type, std::optional<spv::BuiltIn> builtin
     return id;
 }
 
+u32 NumVertices(InputTopology input_topology) {
+    switch (input_topology) {
+    case InputTopology::Points:
+        return 1;
+    case InputTopology::Lines:
+        return 2;
+    case InputTopology::LinesAdjacency:
+        return 4;
+    case InputTopology::Triangles:
+        return 3;
+    case InputTopology::TrianglesAdjacency:
+        return 6;
+    }
+    throw InvalidArgument("Invalid input topology {}", input_topology);
+}
+
 Id DefineInput(EmitContext& ctx, Id type, std::optional<spv::BuiltIn> builtin = std::nullopt) {
+    if (ctx.stage == Stage::Geometry) {
+        const u32 num_vertices{NumVertices(ctx.profile.input_topology)};
+        type = ctx.TypeArray(type, ctx.Constant(ctx.U32[1], num_vertices));
+    }
     return DefineVariable(ctx, type, builtin, spv::StorageClass::Input);
 }
 
@@ -455,12 +475,16 @@ void EmitContext::DefineSharedMemory(const IR::Program& program) {
 
 void EmitContext::DefineAttributeMemAccess(const Info& info) {
     const auto make_load{[&] {
+        const bool is_array{stage == Stage::Geometry};
         const Id end_block{OpLabel()};
         const Id default_label{OpLabel()};
 
-        const Id func_type_load{TypeFunction(F32[1], U32[1])};
+        const Id func_type_load{is_array ? TypeFunction(F32[1], U32[1], U32[1])
+                                         : TypeFunction(F32[1], U32[1])};
         const Id func{OpFunction(F32[1], spv::FunctionControlMask::MaskNone, func_type_load)};
         const Id offset{OpFunctionParameter(U32[1])};
+        const Id vertex{is_array ? OpFunctionParameter(U32[1]) : Id{}};
+
         AddLabel();
         const Id base_index{OpShiftRightArithmetic(U32[1], offset, Constant(U32[1], 2U))};
         const Id masked_index{OpBitwiseAnd(U32[1], base_index, Constant(U32[1], 3U))};
@@ -472,7 +496,7 @@ void EmitContext::DefineAttributeMemAccess(const Info& info) {
             labels.push_back(OpLabel());
         }
         const u32 base_attribute_value = static_cast<u32>(IR::Attribute::Generic0X) >> 2;
-        for (u32 i = 0; i < info.input_generics.size(); i++) {
+        for (u32 i = 0; i < info.input_generics.size(); ++i) {
             if (!info.input_generics[i].used) {
                 continue;
             }
@@ -486,7 +510,10 @@ void EmitContext::DefineAttributeMemAccess(const Info& info) {
         size_t label_index{0};
         if (info.loads_position) {
             AddLabel(labels[label_index]);
-            const Id result{OpLoad(F32[1], OpAccessChain(input_f32, input_position, masked_index))};
+            const Id pointer{is_array
+                                 ? OpAccessChain(input_f32, input_position, vertex, masked_index)
+                                 : OpAccessChain(input_f32, input_position, masked_index)};
+            const Id result{OpLoad(F32[1], pointer)};
             OpReturnValue(result);
             ++label_index;
         }
@@ -502,7 +529,9 @@ void EmitContext::DefineAttributeMemAccess(const Info& info) {
                 continue;
             }
             const Id generic_id{input_generics.at(i)};
-            const Id pointer{OpAccessChain(type->pointer, generic_id, masked_index)};
+            const Id pointer{is_array
+                                 ? OpAccessChain(type->pointer, generic_id, vertex, masked_index)
+                                 : OpAccessChain(type->pointer, generic_id, masked_index)};
             const Id value{OpLoad(type->id, pointer)};
             const Id result{type->needs_cast ? OpBitcast(F32[1], value) : value};
             OpReturnValue(result);
@@ -910,13 +939,13 @@ void EmitContext::DefineOutputs(const Info& info) {
     }
     if (info.stores_point_size || profile.fixed_state_point_size) {
         if (stage == Stage::Fragment) {
-            throw NotImplementedException("Storing PointSize in Fragment stage");
+            throw NotImplementedException("Storing PointSize in fragment stage");
         }
         output_point_size = DefineOutput(*this, F32[1], spv::BuiltIn::PointSize);
     }
     if (info.stores_clip_distance) {
         if (stage == Stage::Fragment) {
-            throw NotImplementedException("Storing PointSize in Fragment stage");
+            throw NotImplementedException("Storing ClipDistance in fragment stage");
         }
         const Id type{TypeArray(F32[1], Constant(U32[1], 8U))};
         clip_distances = DefineOutput(*this, type, spv::BuiltIn::ClipDistance);
@@ -924,7 +953,7 @@ void EmitContext::DefineOutputs(const Info& info) {
     if (info.stores_viewport_index &&
         (profile.support_viewport_index_layer_non_geometry || stage == Shader::Stage::Geometry)) {
         if (stage == Stage::Fragment) {
-            throw NotImplementedException("Storing ViewportIndex in Fragment stage");
+            throw NotImplementedException("Storing ViewportIndex in fragment stage");
         }
         viewport_index = DefineOutput(*this, U32[1], spv::BuiltIn::ViewportIndex);
     }