Support reflecting builtins.

They were ignored in input/output variables.

1 files changed, 24 insertions, 1 deletions

diff --git a/spirv_cross.hpp b/spirv_cross.hpp
index 84e23ca3..d818bb66 100644
--- a/spirv_cross.hpp
+++ b/spirv_cross.hpp
@@ -59,6 +59,26 @@ struct Resource
 	std::string name;
 };
 
+struct BuiltInResource
+{
+	// This is mostly here to support reflection of builtins such as Position/PointSize/CullDistance/ClipDistance.
+	// This needs to be different from Resource since we can collect builtins from blocks.
+	// A builtin present here does not necessarily mean it's considered an active builtin,
+	// since variable ID "activeness" is only tracked on OpVariable level, not Block members.
+	// For that, update_active_builtins() -> has_active_builtin() can be used to further refine the reflection.
+	spv::BuiltIn builtin;
+
+	// This is the actual value type of the builtin.
+	// Typically float4, float, array<float, N> for the gl_PerVertex builtins.
+	TypeID value_type_id;
+
+	// This refers to the base resource which contains the builtin.
+	// If resource is a Block, it can hold multiple builtins, or it might not be a block.
+	// For advanced reflection scenarios, all information in builtin/value_type_id can be deduced,
+	// it's just more convenient this way.
+	Resource resource;
+};
+
 struct ShaderResources
 {
 	SmallVector<Resource> uniform_buffers;
@@ -79,6 +99,9 @@ struct ShaderResources
 	// these correspond to separate texture2D and samplers respectively.
 	SmallVector<Resource> separate_images;
 	SmallVector<Resource> separate_samplers;
+
+	SmallVector<BuiltInResource> builtin_inputs;
+	SmallVector<BuiltInResource> builtin_outputs;
 };
 
 struct CombinedImageSampler
@@ -324,7 +347,7 @@ public:
 
 	// Traverses all reachable opcodes and sets active_builtins to a bitmask of all builtin variables which are accessed in the shader.
 	void update_active_builtins();
-	bool has_active_builtin(spv::BuiltIn builtin, spv::StorageClass storage);
+	bool has_active_builtin(spv::BuiltIn builtin, spv::StorageClass storage) const;
 
 	// Query and modify OpExecutionMode.
 	const Bitset &get_execution_mode_bitset() const;