From 16c02e4dc3c9a10df15d4ddca2afd29cf3be8d73 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 11 Mar 2021 23:39:59 +0200
Subject: [PATCH] Avoid generating invalid interfaces in geometry shader

Geometry inputs need an extra array dimension compared to vertex shader
outputs, but multi-dimensional arrays currently can't be properly
represented.
---
 source/glsl/generate.cpp                      | 13 +++-
 .../ignore_array_in_geometry_passthrough.glsl | 71 +++++++++++++++++++
 2 files changed, 82 insertions(+), 2 deletions(-)
 create mode 100644 tests/glsl/ignore_array_in_geometry_passthrough.glsl

diff --git a/source/glsl/generate.cpp b/source/glsl/generate.cpp
index 158bb4cc..01d34c63 100644
--- a/source/glsl/generate.cpp
+++ b/source/glsl/generate.cpp
@@ -1040,6 +1040,9 @@ VariableDeclaration *InterfaceGenerator::generate_interface(VariableDeclaration
 	if(stage->content.variables.count(name))
 		return 0;
 
+	if(stage->type==Stage::GEOMETRY && !copy_block && var.interface=="out" && var.array)
+		return 0;
+
 	VariableDeclaration* iface_var = new VariableDeclaration;
 	iface_var->sampling = var.sampling;
 	iface_var->interface = iface;
@@ -1137,8 +1140,14 @@ void InterfaceGenerator::visit(VariableReference &var)
 		i = prev_vars.find(in_prefix+var.name);
 	if(i!=prev_vars.end() && i->second->interface=="out")
 	{
-		generate_interface(*i->second, "in", i->second->name);
-		var.name = i->second->name;
+		if(stage->type==Stage::GEOMETRY && i->second->array)
+			stage->diagnostics.push_back(Diagnostic(Diagnostic::WARN, var.source, var.line,
+				format("Can't access '%s' through automatic interface because it's an array", var.name)));
+		else
+		{
+			generate_interface(*i->second, "in", i->second->name);
+			var.name = i->second->name;
+		}
 		return;
 	}
 
diff --git a/tests/glsl/ignore_array_in_geometry_passthrough.glsl b/tests/glsl/ignore_array_in_geometry_passthrough.glsl
new file mode 100644
index 00000000..2b3eea26
--- /dev/null
+++ b/tests/glsl/ignore_array_in_geometry_passthrough.glsl
@@ -0,0 +1,71 @@
+uniform mat4 vp_matrix;
+uniform sampler2D tex;
+
+#pragma MSP stage(vertex)
+layout(location=0) in vec4 position;
+layout(location=1) in vec2 texcoord;
+layout(location=2) in vec4 instance_transform[3];
+void main()
+{
+	passthrough;
+	mat4 model_matrix = transpose(mat4(instance_transform[0], instance_transform[1], instance_transform[2], vec4(0.0, 0.0, 0.0, 1.0)));
+	gl_Position = vp_matrix*model_matrix*position;
+}
+
+#pragma MSP stage(geometry)
+layout(triangles) in;
+layout(triangles, max_vertices=3) out;
+void main()
+{
+	for(int i=0; i<3; ++i)
+	{
+		passthrough[i];
+		EmitVertex();
+	}
+}
+
+#pragma MSP stage(fragment)
+layout(location=0) out vec4 frag_color;
+void main()
+{
+	frag_color = texture(tex, texcoord);
+}
+
+/* Expected output: vertex
+uniform mat4 vp_matrix;
+layout(location=0) in vec4 position;
+layout(location=1) in vec2 texcoord;
+layout(location=2) in vec4 instance_transform[3];
+out vec2 _vs_out_texcoord;
+void main()
+{
+  _vs_out_texcoord = texcoord;
+  gl_Position = vp_matrix*transpose(mat4(instance_transform[0], instance_transform[1], instance_transform[2], vec4(0.0, 0.0, 0.0, 1.0)))*position;
+}
+*/
+
+/* Expected output: geometry
+layout(triangles) in;
+layout(triangles, max_vertices=3) out;
+in vec2 _vs_out_texcoord[];
+out vec2 _gs_out_texcoord;
+void main()
+{
+	for(int i = 0; i<3; ++i)
+	{
+		gl_Position = gl_in[i].gl_Position;
+		_gs_out_texcoord = _vs_out_texcoord[i];
+		EmitVertex();
+	}
+}
+*/
+
+/* Expected output: fragment
+uniform sampler2D tex;
+layout(location=0) out vec4 frag_color;
+in vec2 _gs_out_texcoord;
+void main()
+{
+	frag_color = texture(tex, _gs_out_texcoord);
+}
+*/
-- 
2.45.2