11. GLSL elements of vectors and matrices

• Individual elements of vectors and matrices can be accessed via name component accessors

  • xyzw – typically for positions

  • rgba – usually for colors

  • stpq – usually for texture coordinates

• For example,

  
      my_vec.x = 4.0f;
      my_vec.xy = vec2( 1.0f, 5.0f );
      my_vec.xyz = another_vec.xyz;
      float pos_z = pos.z;
      color = color.abgr; // components reversed in color (vec4)
      color.abgr = color; // the same resuilt
  
  

• The last example is called component swizzling