UNIFORM-TUPLE: fixed-uniforms
    { "light_dir" vec4-uniform f }
    { "dcolor"    vec4-uniform f }
    { "acolor"    vec4-uniform f }
    { "light"     float-uniform f } ;

: fixed-uniforms ( -- uniforms )
  { 0.0   1.0   0.0   1.0 }  ! light position
  { 0.7   0.7   0.7   1.0 }  ! diffuse color
  { 0.3   0.3   0.3   1.0 }  ! ambient color
    1.0  ! light
  fixed-uniforms boa ;