vert = vg_shader_subshader( shader->src_vert, GL_VERTEX_SHADER );
frag = vg_shader_subshader( shader->src_frag, GL_FRAGMENT_SHADER );
vert = vg_shader_subshader( shader->src_vert, GL_VERTEX_SHADER );
frag = vg_shader_subshader( shader->src_frag, GL_FRAGMENT_SHADER );