operator op::math1::abs {
    section transform math unary

    note Applies the unary function `abs(I)`.

    input

    simplify for   src/type @self   returns src
    simplify for   constant abs

    state -setup {
    #define IN_GEOM aktive_image_get_geometry (srcs->v[0])
	aktive_geometry_copy (domain, IN_GEOM);
    }

    pixels {
    #define FETCH aktive_region_fetch_area (srcs->v[0], request)
	aktive_blit_unary0 (block, dst, fabs, FETCH);
    }
}
      

proc aktive::op::math1::abs {src} {
    ::aktive simplify do \
        src/type op::math1::abs \
        /src
    ::aktive simplify do \
        src/type image::from::value \
        /fold/constant/0 abs 
    Iabs $src
}
      

critcl::cproc aktive::op::math1::Iabs {
  Tcl_Interp*  ip 
  aktive_image src
} aktive_image {
  /* src :: keep */
  /* no parameters */
  aktive_image _r = aktive_image_check (ip,
        aktive_op_math1_abs_new (ip, src));
  return _r;
}
      

extern aktive_image
aktive_op_math1_abs_new (Tcl_Interp* ip, aktive_image src) {
  TRACE_FUNC("", 0);

  static aktive_image_type aktive_op_math1_abs_opspec = {
    .name         = "op::math1::abs"
  , .sz_param     = 0
  , .setup        = (aktive_image_setup)  aktive_op_math1_abs_setup
  , .region_fetch = (aktive_region_fetch) aktive_op_math1_abs_region_fetch
  };

  aktive_image_vector srcs = {
      .c = 1, .v = &src
  };

  aktive_image r = aktive_image_new (&aktive_op_math1_abs_opspec,
                                     NULL, &srcs);
  TRACE_RETURN ("(aktive_image) %p", r);
}
      

static int
aktive_op_math1_abs_setup (
  aktive_image_info* info
, Tcl_Obj**          meta
) {
  TRACE_FUNC("((aktive_image_info*) %p)", info);
  aktive_image_vector* srcs   = &info->srcs;
  aktive_geometry*     domain = &info->domain;
#define                state  (info->state)
  // - - -- --- ----- -------- ------------- ----------------

  #define IN_GEOM aktive_image_get_geometry (srcs->v[0])
  aktive_geometry_copy (domain, IN_GEOM);

  // - - -- --- ----- -------- ------------- ----------------
  TRACE_GEOMETRY (domain);
#undef state
  TRACE_RETURN ("(ok) %d", 1);
}
      

static void
aktive_op_math1_abs_region_fetch (
  aktive_region_info* info    // Params, inputs, (image) state
, aktive_rectangle*   request // Area to fetch
, aktive_rectangle*   dst     // Destination in `block`
, aktive_block*       block   // Pixel storage
) {
  [...]
  aktive_region_vector* srcs    = &info->srcs;
  aktive_geometry*      idomain = info->domain;
  [...]
  // - - -- --- ----- -------- ------------- ----------------

  #define FETCH aktive_region_fetch_area (srcs->v[0], request)
  aktive_blit_unary0 (block, dst, fabs, FETCH);

  // - - -- --- ----- -------- ------------- ----------------
  TRACE_RETURN_VOID;
}