Greetings,
I'm currently playing with OpenGL ES 3.0 and I'm wondering if Mali (>= T6xx) drivers can perform interesting optimisations based on the chosen layout qualifier applied to Interface Blocks ? (shared, packed, std140, row_major, column_major)
The fact that Std140 avoids pinging the OpenGL implementation, about the data layout, makes me wonder if there's any reason to choose another layout qualifier.
The explicit locations set in the shader define the bind point name used for each symbol; without this explicit setting they can be set arbitrarily by the driver and different drivers will do different things with them. All the explicit location support means is that if you set the location in the shader you no longer need to call glGetUniformLocation at run-time, you can just use the pre-defined location value set in the shader source code.
glGetUniformLocation
HTH, Pete