2: /*
  3:        Provides the calling sequences for all the basic PetscDraw routines.
  4: */
  5: #include <petsc-private/drawimpl.h>  /*I "petscdraw.h" I*/

  9: /*@
 10:    PetscDrawIsNull - Returns PETSC_TRUE if draw is a null draw object.

 12:    Not collective

 14:    Input Parameter:
 15: .  draw - the draw context

 17:    Output Parameter:
 18: .  yes - PETSC_TRUE if it is a null draw object; otherwise PETSC_FALSE

 20:    Level: advanced

 22: @*/
 23: PetscErrorCode  PetscDrawIsNull(PetscDraw draw,PetscBool  *yes)
 24: {
 26:   PetscBool      isdrawnull;

 31:   PetscObjectTypeCompare((PetscObject)draw,PETSC_DRAW_NULL,&isdrawnull);
 32:   if (isdrawnull) *yes = PETSC_TRUE;
 33:   else            *yes = PETSC_FALSE;
 34:   return(0);
 35: }

 39: /*@
 40:    PetscDrawSetDoubleBuffer - Sets a window to be double buffered.

 42:    Logically Collective on PetscDraw

 44:    Input Parameter:
 45: .  draw - the drawing context

 47:    Level: intermediate

 49:    Concepts: drawing^double buffer
 50:    Concepts: graphics^double buffer
 51:    Concepts: double buffer

 53: @*/
 54: PetscErrorCode  PetscDrawSetDoubleBuffer(PetscDraw draw)
 55: {

 60:   if (draw->ops->setdoublebuffer) {
 61:     (*draw->ops->setdoublebuffer)(draw);
 62:   }
 63:   return(0);
 64: }