Support array of images and samplers in MSL.

spirv_msl.cpp

@@ -2292,7 +2292,11 @@ void CompilerMSL::emit_function_prototype(SPIRFunction &func, const Bitset &)
 		// Manufacture automatic sampler arg for SampledImage texture
 		auto &arg_type = get<SPIRType>(arg.type);
 		if (arg_type.basetype == SPIRType::SampledImage && arg_type.image.dim != DimBuffer)
-			decl += ", thread const sampler& " + to_sampler_expression(arg.id);
+		{
+			//const char *reference = arg_type.array.empty() ? "& " : " ";
+			const char *reference = " ";
+			decl += join(", thread const ", sampler_type(arg_type), reference, to_sampler_expression(arg.id));
+		}
 
 		if (&arg != &func.arguments.back())
 			decl += ", ";
@@ -2594,14 +2598,9 @@ string CompilerMSL::to_func_call_arg(uint32_t id)
 	string arg_str = CompilerGLSL::to_func_call_arg(id);
 
 	// Manufacture automatic sampler arg if the arg is a SampledImage texture.
-	Variant &id_v = ids[id];
+	auto &type = expression_type(id);
-	if (id_v.get_type() == TypeVariable)
+	if (type.basetype == SPIRType::SampledImage && type.image.dim != DimBuffer)
-	{
+		arg_str += ", " + to_sampler_expression(id);
-		auto &var = id_v.get<SPIRVariable>();
-		auto &type = get<SPIRType>(var.basetype);
-		if (type.basetype == SPIRType::SampledImage && type.image.dim != DimBuffer)
-			arg_str += ", " + to_sampler_expression(id);
-	}
 
 	return arg_str;
 }
@@ -2611,8 +2610,18 @@ string CompilerMSL::to_func_call_arg(uint32_t id)
 // by appending a suffix to the expression constructed from the ID.
 string CompilerMSL::to_sampler_expression(uint32_t id)
 {
+	auto expr = to_expression(id);
+	auto index = expr.find_first_of('[');
 	uint32_t samp_id = meta[id].sampler;
-	return samp_id ? to_expression(samp_id) : to_expression(id) + sampler_name_suffix;
+
+	if (index == string::npos)
+		return samp_id ? to_expression(samp_id) : expr + sampler_name_suffix;
+	else
+	{
+		auto image_expr = expr.substr(0, index);
+		auto array_expr = expr.substr(index);
+		return samp_id ? to_expression(samp_id) : (image_expr + sampler_name_suffix + array_expr);
+	}
 }
 
 // Checks whether the ID is a row_major matrix that requires conversion before use
@@ -3110,7 +3119,7 @@ string CompilerMSL::entry_point_args(bool append_comma)
 		case SPIRType::Sampler:
 			if (!ep_args.empty())
 				ep_args += ", ";
-			ep_args += "sampler " + r.name;
+			ep_args += type_to_glsl(type) + " " + r.name;
 			ep_args += " [[sampler(" + convert_to_string(r.index) + ")]]";
 			break;
 		case SPIRType::Image:
@@ -3215,6 +3224,15 @@ string CompilerMSL::argument_decl(const SPIRFunction::Parameter &arg)
 	auto &type = expression_type(arg.id);
 	bool constref = !arg.alias_global_variable && (!type.pointer || arg.write_count == 0);
 
+	bool type_is_image =
+			type.basetype == SPIRType::Image ||
+			type.basetype == SPIRType::SampledImage ||
+			type.basetype == SPIRType::Sampler;
+
+	// Arrays of images/samplers in MSL are always const.
+	if (!type.array.empty() && type_is_image)
+		constref = true;
+
 	// TODO: Check if this arg is an uniform pointer
 	bool pointer = type.storage == StorageClassUniformConstant;
 
@@ -3227,7 +3245,8 @@ string CompilerMSL::argument_decl(const SPIRFunction::Parameter &arg)
 	else
 		decl += type_to_glsl(type, arg.id);
 
-	if (is_array(type))
+	// Arrays of images and samplers are special cased.
+	if (is_array(type) && !type_is_image)
 	{
 		decl += " (&";
 		decl += to_expression(var.self);
@@ -3383,7 +3402,7 @@ string CompilerMSL::type_to_glsl(const SPIRType &type, uint32_t id)
 		return image_type_glsl(type, id);
 
 	case SPIRType::Sampler:
-		return "sampler";
+		return sampler_type(type);
 
 	case SPIRType::Void:
 		return "void";
@@ -3435,9 +3454,44 @@ string CompilerMSL::type_to_glsl(const SPIRType &type, uint32_t id)
 	return type_name;
 }
 
+std::string CompilerMSL::sampler_type(const SPIRType &type)
+{
+	if (!type.array.empty())
+	{
+		// Arrays of samplers in MSL must be declared with a special array<T, N> syntax ala C++11 std::array.
+		auto *parent = &type;
+		while (parent->pointer)
+			parent = &get<SPIRType>(parent->parent_type);
+		parent = &get<SPIRType>(parent->parent_type);
+
+		uint32_t array_size = type.array_size_literal.back() ?
+		                      type.array.back() : get<SPIRConstant>(type.array.back()).scalar();
+
+		if (array_size == 0)
+			SPIRV_CROSS_THROW("Unsized array of samplers is not supported in MSL.");
+		return join("array<", sampler_type(*parent), ", ", array_size, ">");
+	}
+	else
+		return "sampler";
+}
+
 // Returns an MSL string describing  the SPIR-V image type
 string CompilerMSL::image_type_glsl(const SPIRType &type, uint32_t id)
 {
+	if (!type.array.empty())
+	{
+		// Arrays of images in MSL must be declared with a special array<T, N> syntax ala C++11 std::array.
+		auto *parent = &type;
+		while (parent->pointer)
+			parent = &get<SPIRType>(parent->parent_type);
+		parent = &get<SPIRType>(parent->parent_type);
+
+		uint32_t array_size = type.array_size_literal.back() ? type.array.back() : get<SPIRConstant>(type.array.back()).scalar();
+		if (array_size == 0)
+			SPIRV_CROSS_THROW("Unsized array of images is not supported in MSL.");
+		return join("array<", image_type_glsl(*parent, id), ", ", array_size, ">");
+	}
+
 	string img_type_name;
 
 	// Bypass pointers because we need the real image struct

spirv_msl.hpp

@@ -202,6 +202,7 @@ protected:
 	                        const std::string &qualifier = "", uint32_t base_offset = 0) override;
 	std::string type_to_glsl(const SPIRType &type, uint32_t id = 0) override;
 	std::string image_type_glsl(const SPIRType &type, uint32_t id = 0) override;
+	std::string sampler_type(const SPIRType &type);
 	std::string builtin_to_glsl(spv::BuiltIn builtin, spv::StorageClass storage) override;
 	std::string constant_expression(const SPIRConstant &c) override;
 	size_t get_declared_struct_member_size(const SPIRType &struct_type, uint32_t index) const override;