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

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