Support passing implicit frag_coord arguments down to functions.

reference/opt/shaders-msl/frag/input-attachment-ms.frag

@@ -0,0 +1,17 @@
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct main0_out
+{
+    float4 FragColor [[color(0)]];
+};
+
+fragment main0_out main0(texture2d_ms<float> uSubpass0 [[texture(0)]], texture2d_ms<float> uSubpass1 [[texture(1)]], uint gl_SampleID [[sample_id]], float4 gl_FragCoord [[position]])
+{
+    main0_out out = {};
+    out.FragColor = (uSubpass0.read(uint2(gl_FragCoord.xy), 1) + uSubpass1.read(uint2(gl_FragCoord.xy), 2)) + uSubpass0.read(uint2(gl_FragCoord.xy), gl_SampleID);
+    return out;
+}
+

reference/opt/shaders-msl/frag/input-attachment.frag

@@ -0,0 +1,17 @@
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct main0_out
+{
+    float4 FragColor [[color(0)]];
+};
+
+fragment main0_out main0(texture2d<float> uSubpass0 [[texture(0)]], texture2d<float> uSubpass1 [[texture(1)]], float4 gl_FragCoord [[position]])
+{
+    main0_out out = {};
+    out.FragColor = uSubpass0.read(uint2(gl_FragCoord.xy), 0) + uSubpass1.read(uint2(gl_FragCoord.xy), 0);
+    return out;
+}
+

reference/shaders-msl/frag/input-attachment-ms.frag

@@ -0,0 +1,24 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct main0_out
+{
+    float4 FragColor [[color(0)]];
+};
+
+float4 load_subpasses(thread const texture2d_ms<float> uInput, thread uint& gl_SampleID, thread float4& gl_FragCoord)
+{
+    return uInput.read(uint2(gl_FragCoord.xy), gl_SampleID);
+}
+
+fragment main0_out main0(texture2d_ms<float> uSubpass0 [[texture(0)]], texture2d_ms<float> uSubpass1 [[texture(1)]], uint gl_SampleID [[sample_id]], float4 gl_FragCoord [[position]])
+{
+    main0_out out = {};
+    out.FragColor = (uSubpass0.read(uint2(gl_FragCoord.xy), 1) + uSubpass1.read(uint2(gl_FragCoord.xy), 2)) + load_subpasses(uSubpass0, gl_SampleID, gl_FragCoord);
+    return out;
+}
+

reference/shaders-msl/frag/input-attachment.frag

@@ -0,0 +1,24 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct main0_out
+{
+    float4 FragColor [[color(0)]];
+};
+
+float4 load_subpasses(thread const texture2d<float> uInput, thread float4& gl_FragCoord)
+{
+    return uInput.read(uint2(gl_FragCoord.xy), 0);
+}
+
+fragment main0_out main0(texture2d<float> uSubpass0 [[texture(0)]], texture2d<float> uSubpass1 [[texture(1)]], float4 gl_FragCoord [[position]])
+{
+    main0_out out = {};
+    out.FragColor = uSubpass0.read(uint2(gl_FragCoord.xy), 0) + load_subpasses(uSubpass1, gl_FragCoord);
+    return out;
+}
+

shaders-msl/frag/input-attachment-ms.frag

@@ -0,0 +1,15 @@
+#version 450
+
+layout(input_attachment_index = 0, set = 0, binding = 0) uniform subpassInputMS uSubpass0;
+layout(input_attachment_index = 1, set = 0, binding = 1) uniform subpassInputMS uSubpass1;
+layout(location = 0) out vec4 FragColor;
+
+vec4 load_subpasses(mediump subpassInputMS uInput)
+{
+	return subpassLoad(uInput, gl_SampleID);
+}
+
+void main()
+{
+    FragColor = subpassLoad(uSubpass0, 1) + subpassLoad(uSubpass1, 2) + load_subpasses(uSubpass0);
+}

shaders-msl/frag/input-attachment.frag

@@ -0,0 +1,16 @@
+#version 310 es
+precision mediump float;
+
+layout(input_attachment_index = 0, set = 0, binding = 0) uniform mediump subpassInput uSubpass0;
+layout(input_attachment_index = 1, set = 0, binding = 1) uniform mediump subpassInput uSubpass1;
+layout(location = 0) out vec4 FragColor;
+
+vec4 load_subpasses(mediump subpassInput uInput)
+{
+	return subpassLoad(uInput);
+}
+
+void main()
+{
+    FragColor = subpassLoad(uSubpass0) + load_subpasses(uSubpass1);
+}

spirv_msl.cpp

@@ -19,6 +19,7 @@
 
 #include <algorithm>
 #include <numeric>
+#include <assert.h>
 
 using namespace spv;
 using namespace spirv_cross;
@@ -69,6 +70,7 @@ void CompilerMSL::build_implicit_builtins()
 			    meta[var.self].decoration.builtin &&
 			    meta[var.self].decoration.builtin_type == BuiltInFragCoord)
 			{
+				builtin_frag_coord_id = var.self;
 				has_frag_coord = true;
 				break;
 			}
@@ -93,10 +95,11 @@ void CompilerMSL::build_implicit_builtins()
 			vec4_type_ptr.parent_type = type_id;
 			vec4_type_ptr.storage = StorageClassInput;
 			auto &ptr_type = set<SPIRType>(type_ptr_id, vec4_type_ptr);
-			ptr_type.self = offset;
+			ptr_type.self = type_id;
 
 			set<SPIRVariable>(var_id, type_ptr_id, StorageClassInput);
 			set_decoration(var_id, DecorationBuiltIn, BuiltInFragCoord);
+			builtin_frag_coord_id = var_id;
 		}
 	}
 }
@@ -123,6 +126,7 @@ string CompilerMSL::compile()
 	backend.flexible_member_array_supported = false;
 	backend.can_declare_arrays_inline = false;
 	backend.can_return_array = false;
+	backend.boolean_mix_support = false;
 
 	replace_illegal_names();
 
@@ -332,6 +336,14 @@ void CompilerMSL::extract_global_variables_from_function(uint32_t func_id, std::
 				if (global_var_ids.find(base_id) != global_var_ids.end())
 					added_arg_ids.insert(base_id);
 
+				auto &type = get<SPIRType>(ops[0]);
+				if (type.image.dim == DimSubpassData)
+				{
+					// Implicitly reads gl_FragCoord.
+					assert(builtin_frag_coord_id != 0);
+					added_arg_ids.insert(builtin_frag_coord_id);
+				}
+
 				break;
 			}
 			case OpFunctionCall:
@@ -3023,7 +3035,7 @@ string CompilerMSL::argument_decl(const SPIRFunction::Parameter &arg)
 	if (is_array(type))
 	{
 		decl += " (&";
-		decl += to_name(var.self);
+		decl += to_expression(var.self);
 		decl += ")";
 		decl += type_to_array_glsl(type);
 	}
@@ -3031,12 +3043,12 @@ string CompilerMSL::argument_decl(const SPIRFunction::Parameter &arg)
 	{
 		decl += "&";
 		decl += " ";
-		decl += to_name(var.self);
+		decl += to_expression(var.self);
 	}
 	else
 	{
 		decl += " ";
-		decl += to_name(var.self);
+		decl += to_expression(var.self);
 	}
 
 	return decl;

spirv_msl.hpp

@@ -268,6 +268,7 @@ protected:
 	void emit_barrier(uint32_t id_exe_scope, uint32_t id_mem_scope, uint32_t id_mem_sem);
 	void emit_array_copy(const std::string &lhs, uint32_t rhs_id) override;
 	void build_implicit_builtins();
+	uint32_t builtin_frag_coord_id = 0;
 
 	Options options;
 	std::set<SPVFuncImpl> spv_function_implementations;