Add Shader compile groups to RD Shader system

This allows us to specify a subset of variants to compile at load time and conditionally other variants later.

This works seamlessly with shader caching.

Needed to ensure that users only pay the cost for variants they use

2 files changed, 14 insertions, 4 deletions

diff --git a/drivers/vulkan/rendering_device_vulkan.cpp b/drivers/vulkan/rendering_device_vulkan.cpp
index 6cf8f2dfac..6f6e9ddfb7 100644
--- a/drivers/vulkan/rendering_device_vulkan.cpp
+++ b/drivers/vulkan/rendering_device_vulkan.cpp
@@ -4835,7 +4835,7 @@ Vector<uint8_t> RenderingDeviceVulkan::shader_compile_binary_from_spirv(const Ve
 	return ret;
 }
 
-RID RenderingDeviceVulkan::shader_create_from_bytecode(const Vector<uint8_t> &p_shader_binary) {
+RID RenderingDeviceVulkan::shader_create_from_bytecode(const Vector<uint8_t> &p_shader_binary, RID p_placeholder) {
 	const uint8_t *binptr = p_shader_binary.ptr();
 	uint32_t binsize = p_shader_binary.size();
 
@@ -5161,14 +5161,23 @@ RID RenderingDeviceVulkan::shader_create_from_bytecode(const Vector<uint8_t> &p_
 
 		ERR_FAIL_V_MSG(RID(), error_text);
 	}
-
-	RID id = shader_owner.make_rid(shader);
+	RID id;
+	if (p_placeholder.is_null()) {
+		id = shader_owner.make_rid(shader);
+	} else {
+		shader_owner.initialize_rid(p_placeholder, shader);
+		id = p_placeholder;
+	}
 #ifdef DEV_ENABLED
 	set_resource_name(id, "RID:" + itos(id.get_id()));
 #endif
 	return id;
 }
 
+RID RenderingDeviceVulkan::shader_create_placeholder() {
+	return shader_owner.allocate_rid();
+}
+
 uint32_t RenderingDeviceVulkan::shader_get_vertex_input_attribute_mask(RID p_shader) {
 	_THREAD_SAFE_METHOD_
 
diff --git a/drivers/vulkan/rendering_device_vulkan.h b/drivers/vulkan/rendering_device_vulkan.h
index 9c621c1d44..8004368b63 100644
--- a/drivers/vulkan/rendering_device_vulkan.h
+++ b/drivers/vulkan/rendering_device_vulkan.h
@@ -1134,7 +1134,8 @@ public:
 	virtual String shader_get_binary_cache_key() const;
 	virtual Vector<uint8_t> shader_compile_binary_from_spirv(const Vector<ShaderStageSPIRVData> &p_spirv, const String &p_shader_name = "");
 
-	virtual RID shader_create_from_bytecode(const Vector<uint8_t> &p_shader_binary);
+	virtual RID shader_create_from_bytecode(const Vector<uint8_t> &p_shader_binary, RID p_placeholder = RID());
+	virtual RID shader_create_placeholder();
 
 	virtual uint32_t shader_get_vertex_input_attribute_mask(RID p_shader);