Merge pull request #1233 from KhronosGroup/fix-1231

GLSL: Fix EmitStreamVertex/Primitive.

Author: HansKristian-Work

reference/opt/shaders/geom/multi-stream.geom

@@ -0,0 +1,14 @@
+#version 450
+layout(triangles) in;
+layout(max_vertices = 2, points) out;
+
+void main()
+{
+    gl_Position = gl_in[0].gl_Position;
+    EmitStreamVertex(0);
+    EndStreamPrimitive(0);
+    gl_Position = gl_in[0].gl_Position + vec4(2.0);
+    EmitStreamVertex(1);
+    EndStreamPrimitive(1);
+}
+

reference/shaders/geom/multi-stream.geom

@@ -0,0 +1,14 @@
+#version 450
+layout(triangles) in;
+layout(max_vertices = 2, points) out;
+
+void main()
+{
+    gl_Position = gl_in[0].gl_Position;
+    EmitStreamVertex(0);
+    EndStreamPrimitive(0);
+    gl_Position = gl_in[0].gl_Position + vec4(2.0);
+    EmitStreamVertex(1);
+    EndStreamPrimitive(1);
+}
+

shaders/geom/multi-stream.geom

@@ -0,0 +1,15 @@
+#version 450
+
+layout(triangles) in;
+layout(points, max_vertices = 2) out;
+
+void main()
+{
+	gl_Position = gl_in[0].gl_Position;
+	EmitStreamVertex(0);
+	EndStreamPrimitive(0);
+	gl_Position = gl_in[0].gl_Position + 2;
+	EmitStreamVertex(1);
+	EndStreamPrimitive(1);
+}
+

spirv_glsl.cpp

@@ -9464,12 +9464,32 @@ void CompilerGLSL::emit_instruction(const Instruction &instruction)
 		break;
 
 	case OpEmitStreamVertex:
-		statement("EmitStreamVertex();");
+	{
+		if (options.es)
+			SPIRV_CROSS_THROW("Multi-stream geometry shaders not supported in ES.");
+		else if (!options.es && options.version < 400)
+			SPIRV_CROSS_THROW("Multi-stream geometry shaders only supported in GLSL 400.");
+
+		auto stream_expr = to_expression(ops[0]);
+		if (expression_type(ops[0]).basetype != SPIRType::Int)
+			stream_expr = join("int(", stream_expr, ")");
+		statement("EmitStreamVertex(", stream_expr, ");");
 		break;
+	}
 
 	case OpEndStreamPrimitive:
-		statement("EndStreamPrimitive();");
+	{
+		if (options.es)
+			SPIRV_CROSS_THROW("Multi-stream geometry shaders not supported in ES.");
+		else if (!options.es && options.version < 400)
+			SPIRV_CROSS_THROW("Multi-stream geometry shaders only supported in GLSL 400.");
+
+		auto stream_expr = to_expression(ops[0]);
+		if (expression_type(ops[0]).basetype != SPIRType::Int)
+			stream_expr = join("int(", stream_expr, ")");
+		statement("EndStreamPrimitive(", stream_expr, ");");
 		break;
+	}
 
 	// Textures
 	case OpImageSampleExplicitLod: