+uniform mat4 mvp;
+uniform int mask_index;
+
+#pragma MSP stage(vertex)
+layout(location=0) in vec4 position;
+layout(location=1) in vec4 color;
+out VertexOut
+{
+ vec4 color;
+ vec4 mask_color;
+} vs_out;
+void main()
+{
+ int index = mask_index%4;
+ vs_out.color = color;
+ vs_out.color[index] = 0.0;
+ vs_out.mask_color = vec4(1.0);
+ vs_out.mask_color[index] = 1.0;
+ gl_Position = mvp*position;
+}
+
+#pragma MSP stage(fragment)
+layout(location=0) out vec4 frag_color;
+void main()
+{
+ frag_color = vs_out.color+vs_out.mask_color;
+}
+
+/* Expected output: vertex
+uniform mat4 mvp;
+uniform int mask_index;
+layout(location=0) in vec4 position;
+layout(location=1) in vec4 color;
+out VertexOut
+{
+ vec4 color;
+ vec4 mask_color;
+} vs_out;
+void main()
+{
+ int index = mask_index%4;
+ vs_out.color = color;
+ vs_out.color[index] = 0.0;
+ vs_out.mask_color = vec4(1.0);
+ vs_out.mask_color[index] = 1.0;
+ gl_Position = mvp*position;
+}
+/*
+
+/* Expected output: fragment
+layout(location=0) out vec4 frag_color;
+in VertexOut
+{
+ vec4 color;
+ vec4 mask_color;
+} vs_out;
+void main()
+{
+ frag_color = vs_out.color+vs_out.mask_color;
+}
+*/