shared.earth

<!--
Demo of shared layers. This will render the earth imagery without the oceans.
It will work with either GL3 or NVGL terrain rendering.
Note the use of the oe_use_shared_layer pragma to call out the shared names.
-->
<map>
    <TMSImage name="ocean_mask" visible="false" shared="true">
        <url>https://readymap.org/readymap/tiles/1.0.0/2/</url>
        <shared_sampler>mask_tex</shared_sampler>
        <shared_matrix>mask_mat</shared_matrix>
    </TMSImage>
    <TMSImage name="imagery">
        <url>https://readymap.org/readymap/tiles/1.0.0/7/</url>
        <shader>
            <![CDATA[
            #pragma vp_function mask_me, fragment    
            #pragma oe_use_shared_layer(mask_tex, mask_mat)
            in vec4 oe_layer_tilec;
            
            void mask_me(inout vec4 color)
            {
                vec4 mask = texture(mask_tex, (mask_mat*oe_layer_tilec).st);
                if (mask.a > 0.75)
                    discard;
            }
        ]]></shader>
    </TMSImage>
</map>