src/gallium/docs/source/cso/dsa.rst

   1 .. _depth,stencil,&alpha:
   2
   3 Depth, Stencil, & Alpha
   4 =======================
   5
   6 These three states control the depth, stencil, and alpha tests, used to
   7 discard fragments that have passed through the fragment shader.
   8
   9 Traditionally, these three tests have been clumped together in hardware, so
  10 they are all stored in one structure.
  11
  12 During actual execution, the order of operations done on fragments is always:
  13
  14 * Stencil
  15 * Depth
  16 * Alpha
  17
  18 Depth Members
  19 -------------
  20
  21 enabled
  22     Whether the depth test is enabled.
  23 writemask
  24     Whether the depth buffer receives depth writes.
  25 func
  26     The depth test function. One of PIPE_FUNC.
  27
  28 Stencil Members
  29 ---------------
  30
  31 XXX document valuemask, writemask
  32
  33 enabled
  34     Whether the stencil test is enabled. For the second stencil, whether the
  35     two-sided stencil is enabled.
  36 func
  37     The stencil test function. One of PIPE_FUNC.
  38 ref_value
  39     Stencil test reference value; used for certain functions.
  40 fail_op
  41     The operation to carry out if the stencil test fails. One of
  42     PIPE_STENCIL_OP.
  43 zfail_op
  44     The operation to carry out if the stencil test passes but the depth test
  45     fails. One of PIPE_STENCIL_OP.
  46 zpass_op
  47     The operation to carry out if the stencil test and depth test both pass.
  48     One of PIPE_STENCIL_OP.
  49
  50 Alpha Members
  51 -------------
  52
  53 enabled
  54     Whether the alpha test is enabled.
  55 func
  56     The alpha test function. One of PIPE_FUNC.
  57 ref_value
  58     Alpha test reference value; used for certain functions.