Fix depth image usage in MSL for separate image/samplers.

reference/opt/shaders-msl/frag/sample-depth-separate-image-sampler.frag

@@ -0,0 +1,17 @@
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct main0_out
+{
+    float FragColor [[color(0)]];
+};
+
+fragment main0_out main0(depth2d<float> uDepth [[texture(0)]], texture2d<float> uColor [[texture(1)]], sampler uSamplerShadow [[sampler(0)]], sampler uSampler [[sampler(1)]])
+{
+    main0_out out = {};
+    out.FragColor = uDepth.sample_compare(uSamplerShadow, float3(0.5).xy, 0.5) + uColor.sample(uSampler, float2(0.5)).x;
+    return out;
+}
+

reference/shaders-msl/frag/sample-depth-separate-image-sampler.frag

@@ -0,0 +1,29 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct main0_out
+{
+    float FragColor [[color(0)]];
+};
+
+float sample_depth_from_function(thread const depth2d<float> uT, thread const sampler uS)
+{
+    return uT.sample_compare(uS, float3(0.5).xy, float3(0.5).z);
+}
+
+float sample_color_from_function(thread const texture2d<float> uT, thread const sampler uS)
+{
+    return uT.sample(uS, float2(0.5)).x;
+}
+
+fragment main0_out main0(depth2d<float> uDepth [[texture(0)]], texture2d<float> uColor [[texture(1)]], sampler uSamplerShadow [[sampler(0)]], sampler uSampler [[sampler(1)]])
+{
+    main0_out out = {};
+    out.FragColor = sample_depth_from_function(uDepth, uSamplerShadow) + sample_color_from_function(uColor, uSampler);
+    return out;
+}
+

shaders-msl/frag/sample-depth-separate-image-sampler.frag

@@ -0,0 +1,22 @@
+#version 450
+
+layout(set = 0, binding = 0) uniform texture2D uDepth;
+layout(set = 0, binding = 1) uniform texture2D uColor;
+layout(set = 0, binding = 2) uniform sampler uSampler;
+layout(set = 0, binding = 3) uniform samplerShadow uSamplerShadow;
+layout(location = 0) out float FragColor;
+
+float sample_depth_from_function(texture2D uT, samplerShadow uS)
+{
+	return texture(sampler2DShadow(uT, uS), vec3(0.5));
+}
+
+float sample_color_from_function(texture2D uT, sampler uS)
+{
+	return texture(sampler2D(uT, uS), vec2(0.5)).x;
+}
+
+void main()
+{
+	FragColor = sample_depth_from_function(uDepth, uSamplerShadow) + sample_color_from_function(uColor, uSampler);
+}

spirv_cross.cpp

@@ -3781,10 +3781,10 @@ bool Compiler::CombinedImageSamplerUsageHandler::begin_function_scope(const uint
 
 void Compiler::CombinedImageSamplerUsageHandler::add_hierarchy_to_comparison_images(uint32_t image)
 {
-	// Traverse the variable dependency hierarchy and tag everything in its path with comparison samplers.
+	// Traverse the variable dependency hierarchy and tag everything in its path with comparison images.
 	comparison_images.insert(image);
 	for (auto &img : dependency_hierarchy[image])
-		add_hierarchy_to_comparison_samplers(img);
+		add_hierarchy_to_comparison_images(img);
 }
 
 void Compiler::CombinedImageSamplerUsageHandler::add_hierarchy_to_comparison_samplers(uint32_t sampler)

spirv_glsl.cpp

@@ -7419,7 +7419,9 @@ string CompilerGLSL::image_type_glsl(const SPIRType &type, uint32_t /* id */)
 			require_extension("GL_EXT_texture_array");
 		res += "Array";
 	}
-	if (type.image.depth)
+
+	// "Shadow" state in GLSL only exists for samplers and combined image samplers.
+	if (((type.basetype == SPIRType::SampledImage) || (type.basetype == SPIRType::Sampler)) && type.image.depth)
 		res += "Shadow";
 
 	return res;

spirv_msl.cpp

@@ -3237,8 +3237,9 @@ string CompilerMSL::image_type_glsl(const SPIRType &type, uint32_t id)
 
 	// Bypass pointers because we need the real image struct
 	auto &img_type = get<SPIRType>(type.self).image;
+	bool shadow_image = comparison_images.count(id) != 0;
 
-	if (img_type.depth)
+	if (img_type.depth || shadow_image)
 	{
 		switch (img_type.dim)
 		{