/* Texture format tokens -- Type explictness required by other Graphics APIs. */
#define depth2D sampler2D
#define depth2DArray sampler2DArray
#define depth2DMS sampler2DMS
#define depth2DMSArray sampler2DMSArray
#define depthCube samplerCube
#define depthCubeArray samplerCubeArray
#define depth2DArrayShadow sampler2DArrayShadow

/* Backend Functions. */
#define select(A, B, mask) mix(A, B, mask)

bool is_zero(vec2 A)
{
  return all(equal(A, vec2(0.0)));
}

bool is_zero(vec3 A)
{
  return all(equal(A, vec3(0.0)));
}

bool is_zero(vec4 A)
{
  return all(equal(A, vec4(0.0)));
}