/* Expected output: vertex
layout(location=0) in vec4 position;
layout(location=1) in vec4 color;
-out vec4 _vs_out_color;
+layout(location=0) out vec4 _vs_out_color;
void main()
{
gl_Position = position;
/* Expected output: fragment
layout(location=0) out vec4 frag_color;
-in vec4 _vs_out_color;
+layout(location=0) in vec4 _vs_out_color;
void main()
{
frag_color = _vs_out_color;