shaders-msl/comp/image.comp

#version 310 es
layout(local_size_x = 1) in;

layout(rgba8, binding = 0) uniform readonly mediump image2D uImageIn;
layout(rgba8, binding = 1) uniform writeonly mediump image2D uImageOut;

void main()
{
    vec4 v = imageLoad(uImageIn, ivec2(gl_GlobalInvocationID.xy) + imageSize(uImageIn));
    imageStore(uImageOut, ivec2(gl_GlobalInvocationID.xy), v);
}