impls/draw/drawv.c

#include <../src/sys/classes/viewer/impls/draw/vdraw.h> /*I "petscdraw.h" I*/
#include <petscviewer.h>                                /*I "petscviewer.h" I*/

#undef __FUNCT__
#define __FUNCT__ "PetscViewerDestroy_Draw"
PetscErrorCode PetscViewerDestroy_Draw(PetscViewer v)
{
  PetscErrorCode   ierr;
  PetscInt         i;
  PetscViewer_Draw *vdraw = (PetscViewer_Draw*)v->data;

  PetscFunctionBegin;
  if (vdraw->singleton_made) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ORDER,"Destroying PetscViewer without first restoring singleton");
  for (i=0; i<vdraw->draw_max; i++) {
    ierr = PetscDrawAxisDestroy(&vdraw->drawaxis[i]);CHKERRQ(ierr);
    ierr = PetscDrawLGDestroy(&vdraw->drawlg[i]);CHKERRQ(ierr);
    ierr = PetscDrawDestroy(&vdraw->draw[i]);CHKERRQ(ierr);
  }

  ierr = PetscFree(vdraw->display);CHKERRQ(ierr);
  ierr = PetscFree(vdraw->title);CHKERRQ(ierr);
  ierr = PetscFree3(vdraw->draw,vdraw->drawlg,vdraw->drawaxis);CHKERRQ(ierr);
  ierr = PetscFree(vdraw->bounds);CHKERRQ(ierr);
  ierr = PetscFree(vdraw->drawtype);CHKERRQ(ierr);
  ierr = PetscFree(vdraw);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerFlush_Draw"
PetscErrorCode PetscViewerFlush_Draw(PetscViewer v)
{
  PetscErrorCode   ierr;
  PetscInt         i;
  PetscViewer_Draw *vdraw = (PetscViewer_Draw*)v->data;

  PetscFunctionBegin;
  for (i=0; i<vdraw->draw_max; i++) {
    if (vdraw->draw[i]) {ierr = PetscDrawSynchronizedFlush(vdraw->draw[i]);CHKERRQ(ierr);}
  }
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerDrawGetDraw"
/*@C
    PetscViewerDrawGetDraw - Returns PetscDraw object from PetscViewer object.
    This PetscDraw object may then be used to perform graphics using
    PetscDrawXXX() commands.

    Not collective (but PetscDraw returned will be parallel object if PetscViewer is)

    Input Parameters:
+  viewer - the PetscViewer (created with PetscViewerDrawOpen())
-   windownumber - indicates which subwindow (usually 0)

    Ouput Parameter:
.   draw - the draw object

    Level: intermediate

   Concepts: drawing^accessing PetscDraw context from PetscViewer
   Concepts: graphics

.seealso: PetscViewerDrawGetLG(), PetscViewerDrawGetAxis(), PetscViewerDrawOpen()
@*/
PetscErrorCode  PetscViewerDrawGetDraw(PetscViewer viewer,PetscInt windownumber,PetscDraw *draw)
{
  PetscViewer_Draw *vdraw = (PetscViewer_Draw*)viewer->data;
  PetscErrorCode   ierr;
  PetscBool        isdraw;
  char             *title;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,1);
  if (draw) PetscValidPointer(draw,3);
  ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
  if (!isdraw) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Must be draw type PetscViewer");
  if (windownumber < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Window number cannot be negative");
  windownumber += vdraw->draw_base;
  if (windownumber >= vdraw->draw_max) {
    /* allocate twice as many slots as needed */
    PetscInt      draw_max  = vdraw->draw_max;
    PetscDraw     *tdraw    = vdraw->draw;
    PetscDrawLG   *drawlg   = vdraw->drawlg;
    PetscDrawAxis *drawaxis = vdraw->drawaxis;

    vdraw->draw_max = 2*windownumber;

    ierr = PetscCalloc3(vdraw->draw_max,&vdraw->draw,vdraw->draw_max,&vdraw->drawlg,vdraw->draw_max,&vdraw->drawaxis);CHKERRQ(ierr);

    ierr = PetscMemcpy(vdraw->draw,tdraw,draw_max*sizeof(PetscDraw));CHKERRQ(ierr);
    ierr = PetscMemcpy(vdraw->drawlg,drawlg,draw_max*sizeof(PetscDrawLG));CHKERRQ(ierr);
    ierr = PetscMemcpy(vdraw->drawaxis,drawaxis,draw_max*sizeof(PetscDrawAxis));CHKERRQ(ierr);

    ierr = PetscFree3(tdraw,drawlg,drawaxis);CHKERRQ(ierr);
  }

  if (!vdraw->draw[windownumber]) {
    if (!windownumber) title = vdraw->title;
    else {
      char tmp_str[128];
      ierr  = PetscSNPrintf(tmp_str, 128, "%s:%d", vdraw->title,windownumber);CHKERRQ(ierr);
      title = tmp_str;
    }
    ierr = PetscDrawCreate(PetscObjectComm((PetscObject)viewer),vdraw->display,title,PETSC_DECIDE,PETSC_DECIDE,vdraw->w,vdraw->h,&vdraw->draw[windownumber]);CHKERRQ(ierr);
    if (vdraw->drawtype) {
      ierr = PetscDrawSetType(vdraw->draw[windownumber],vdraw->drawtype);CHKERRQ(ierr);
    }
    ierr = PetscDrawSetPause(vdraw->draw[windownumber],vdraw->pause);CHKERRQ(ierr);
    ierr = PetscDrawSetFromOptions(vdraw->draw[windownumber]);CHKERRQ(ierr);
  }
  if (draw) *draw = vdraw->draw[windownumber];
  if (draw) PetscValidHeaderSpecific(*draw,PETSC_DRAW_CLASSID,-1);
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerDrawBaseAdd"
/*@C
    PetscViewerDrawBaseAdd - add to the base integer that is added to the windownumber passed to PetscViewerDrawGetDraw()

    Not collective (but PetscDraw returned will be parallel object if PetscViewer is)

    Input Parameters:
+  viewer - the PetscViewer (created with PetscViewerDrawOpen())
-   windownumber - how much to add to the base

    Level: developer

   Concepts: drawing^accessing PetscDraw context from PetscViewer
   Concepts: graphics

.seealso: PetscViewerDrawGetLG(), PetscViewerDrawGetAxis(), PetscViewerDrawOpen(), PetscViewerDrawGetDraw(), PetscViewerDrawBaseSet()
@*/
PetscErrorCode  PetscViewerDrawBaseAdd(PetscViewer viewer,PetscInt windownumber)
{
  PetscViewer_Draw *vdraw = (PetscViewer_Draw*)viewer->data;
  PetscErrorCode   ierr;
  PetscBool        isdraw;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,1);
  ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
  if (!isdraw) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Must be draw type PetscViewer");
  if (windownumber + vdraw->draw_base < 0) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Resulting base %D cannot be negative",windownumber+vdraw->draw_base);
  vdraw->draw_base += windownumber;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerDrawBaseSet"
/*@C
    PetscViewerDrawBaseSet - sets the base integer that is added to the windownumber passed to PetscViewerDrawGetDraw()

    Not collective (but PetscDraw returned will be parallel object if PetscViewer is)

    Input Parameters:
+  viewer - the PetscViewer (created with PetscViewerDrawOpen())
-   windownumber - value to set the base

    Level: developer

   Concepts: drawing^accessing PetscDraw context from PetscViewer
   Concepts: graphics

.seealso: PetscViewerDrawGetLG(), PetscViewerDrawGetAxis(), PetscViewerDrawOpen(), PetscViewerDrawGetDraw(), PetscViewerDrawBaseAdd()
@*/
PetscErrorCode  PetscViewerDrawBaseSet(PetscViewer viewer,PetscInt windownumber)
{
  PetscViewer_Draw *vdraw = (PetscViewer_Draw*)viewer->data;
  PetscErrorCode   ierr;
  PetscBool        isdraw;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,1);
  ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
  if (!isdraw) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Must be draw type PetscViewer");
  if (windownumber < 0) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Resulting base %D cannot be negative",windownumber);
  vdraw->draw_base = windownumber;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerDrawGetDrawLG"
/*@C
    PetscViewerDrawGetDrawLG - Returns PetscDrawLG object from PetscViewer object.
    This PetscDrawLG object may then be used to perform graphics using
    PetscDrawLGXXX() commands.

    Not Collective (but PetscDrawLG object will be parallel if PetscViewer is)

    Input Parameter:
+   PetscViewer - the PetscViewer (created with PetscViewerDrawOpen())
-   windownumber - indicates which subwindow (usually 0)

    Ouput Parameter:
.   draw - the draw line graph object

    Level: intermediate

  Concepts: line graph^accessing context

.seealso: PetscViewerDrawGetDraw(), PetscViewerDrawGetAxis(), PetscViewerDrawOpen()
@*/
PetscErrorCode  PetscViewerDrawGetDrawLG(PetscViewer viewer,PetscInt windownumber,PetscDrawLG *drawlg)
{
  PetscErrorCode   ierr;
  PetscBool        isdraw;
  PetscViewer_Draw *vdraw = (PetscViewer_Draw*)viewer->data;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,1);
  PetscValidPointer(drawlg,3);
  ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
  if (!isdraw) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Must be draw type PetscViewer");
  if (windownumber < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Window number cannot be negative");

  if (windownumber+vdraw->draw_base >= vdraw->draw_max || !vdraw->draw[windownumber+vdraw->draw_base]) {
    ierr = PetscViewerDrawGetDraw(viewer,windownumber,NULL);CHKERRQ(ierr);
  }
  if (!vdraw->drawlg[windownumber+vdraw->draw_base]) {
    ierr = PetscDrawLGCreate(vdraw->draw[windownumber+vdraw->draw_base],1,&vdraw->drawlg[windownumber+vdraw->draw_base]);CHKERRQ(ierr);
    ierr = PetscLogObjectParent((PetscObject)viewer,(PetscObject)vdraw->drawlg[windownumber+vdraw->draw_base]);CHKERRQ(ierr);
  }
  *drawlg = vdraw->drawlg[windownumber+vdraw->draw_base];
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerDrawGetDrawAxis"
/*@C
    PetscViewerDrawGetDrawAxis - Returns PetscDrawAxis object from PetscViewer object.
    This PetscDrawAxis object may then be used to perform graphics using
    PetscDrawAxisXXX() commands.

    Not Collective (but PetscDrawAxis object will be parallel if PetscViewer is)

    Input Parameter:
+   viewer - the PetscViewer (created with PetscViewerDrawOpen()
-   windownumber - indicates which subwindow (usually 0)

    Ouput Parameter:
.   drawaxis - the draw axis object

    Level: advanced

  Concepts: line graph^accessing context

.seealso: PetscViewerDrawGetDraw(), PetscViewerDrawGetLG(), PetscViewerDrawOpen()
@*/
PetscErrorCode  PetscViewerDrawGetDrawAxis(PetscViewer viewer,PetscInt windownumber,PetscDrawAxis *drawaxis)
{
  PetscErrorCode   ierr;
  PetscBool        isdraw;
  PetscViewer_Draw *vdraw = (PetscViewer_Draw*)viewer->data;;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,1);
  PetscValidPointer(drawaxis,3);
  ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
  if (!isdraw) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Must be draw type PetscViewer");
  if (windownumber < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Window number cannot be negative");

  if (windownumber+vdraw->draw_base >= vdraw->draw_max || !vdraw->draw[windownumber+vdraw->draw_base]) {
    ierr = PetscViewerDrawGetDraw(viewer,windownumber,NULL);CHKERRQ(ierr);
  }
  if (!vdraw->drawaxis[windownumber+vdraw->draw_base]) {
    ierr = PetscDrawAxisCreate(vdraw->draw[windownumber+vdraw->draw_base],&vdraw->drawaxis[windownumber+vdraw->draw_base]);CHKERRQ(ierr);
    ierr = PetscLogObjectParent((PetscObject)viewer,(PetscObject)vdraw->drawaxis[windownumber+vdraw->draw_base]);CHKERRQ(ierr);
  }
  *drawaxis = vdraw->drawaxis[windownumber+vdraw->draw_base];
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerDrawResize"
PetscErrorCode  PetscViewerDrawResize(PetscViewer v,int w,int h)
{
  PetscViewer_Draw *vdraw = (PetscViewer_Draw*)v->data;

  PetscFunctionBegin;
  vdraw->h = h;
  vdraw->w = w;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerDrawSetInfo"
PetscErrorCode  PetscViewerDrawSetInfo(PetscViewer v,const char display[],const char title[],int x,int y,int w,int h)
{
  PetscErrorCode   ierr;
  PetscViewer_Draw *vdraw = (PetscViewer_Draw*)v->data;

  PetscFunctionBegin;
  vdraw->h = h;
  vdraw->w = w;
  ierr     = PetscStrallocpy(display,&vdraw->display);CHKERRQ(ierr);
  ierr     = PetscStrallocpy(title,&vdraw->title);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerDrawSetDrawType"
PetscErrorCode  PetscViewerDrawSetDrawType(PetscViewer v,PetscDrawType drawtype)
{
  PetscErrorCode   ierr;
  PetscViewer_Draw *vdraw = (PetscViewer_Draw*)v->data;
  PetscBool        flg;

  PetscFunctionBegin;
  ierr = PetscObjectTypeCompare((PetscObject)v,PETSCVIEWERDRAW,&flg);CHKERRQ(ierr);
  if (flg) {
    ierr = PetscFree(vdraw->drawtype);CHKERRQ(ierr);
    ierr = PetscStrallocpy(drawtype,(char**)&vdraw->drawtype);CHKERRQ(ierr);
  }
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerDrawOpen"
/*@C
   PetscViewerDrawOpen - Opens a window for use as a PetscViewer. If you want to
   do graphics in this window, you must call PetscViewerDrawGetDraw() and
   perform the graphics on the PetscDraw object.

   Collective on MPI_Comm

   Input Parameters:
+  comm - communicator that will share window
.  display - the X display on which to open, or null for the local machine
.  title - the title to put in the title bar, or null for no title
.  x, y - the screen coordinates of the upper left corner of window, or use PETSC_DECIDE
-  w, h - window width and height in pixels, or may use PETSC_DECIDE or PETSC_DRAW_FULL_SIZE, PETSC_DRAW_HALF_SIZE,
          PETSC_DRAW_THIRD_SIZE, PETSC_DRAW_QUARTER_SIZE

   Output Parameters:
. viewer - the PetscViewer

   Format Options:
+  PETSC_VIEWER_DRAW_BASIC - displays with basic format
-  PETSC_VIEWER_DRAW_LG    - displays using a line graph

   Options Database Keys:
   PetscViewerDrawOpen() calls PetscDrawCreate(), so see the manual page for
   PetscDrawCreate() for runtime options, including
+  -draw_type x or null
.  -nox - Disables all x-windows output
.  -display <name> - Specifies name of machine for the X display
.  -geometry <x,y,w,h> - allows setting the window location and size
-  -draw_pause <pause> - Sets time (in seconds) that the
     program pauses after PetscDrawPause() has been called
     (0 is default, -1 implies until user input).

   Level: beginner

   Note for Fortran Programmers:
   Whenever indicating null character data in a Fortran code,
   NULL_CHARACTER must be employed; using NULL is not
   correct for character data!  Thus, NULL_CHARACTER can be
   used for the display and title input parameters.

  Concepts: graphics^opening PetscViewer
  Concepts: drawing^opening PetscViewer


.seealso: PetscDrawCreate(), PetscViewerDestroy(), PetscViewerDrawGetDraw(), PetscViewerCreate(), PETSC_VIEWER_DRAW_,
          PETSC_VIEWER_DRAW_WORLD, PETSC_VIEWER_DRAW_SELF
@*/
PetscErrorCode  PetscViewerDrawOpen(MPI_Comm comm,const char display[],const char title[],int x,int y,int w,int h,PetscViewer *viewer)
{
  PetscErrorCode ierr;

  PetscFunctionBegin;
  ierr = PetscViewerCreate(comm,viewer);CHKERRQ(ierr);
  ierr = PetscViewerSetType(*viewer,PETSCVIEWERDRAW);CHKERRQ(ierr);
  ierr = PetscViewerDrawSetInfo(*viewer,display,title,x,y,w,h);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerGetSingleton_Draw"
PetscErrorCode PetscViewerGetSingleton_Draw(PetscViewer viewer,PetscViewer *sviewer)
{
  PetscErrorCode   ierr;
  PetscMPIInt      rank;
  PetscInt         i;
  PetscViewer_Draw *vdraw = (PetscViewer_Draw*)viewer->data,*vsdraw;

  PetscFunctionBegin;
  if (vdraw->singleton_made) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ORDER,"Trying to get singleton without first restoring previous");

  /* only processor zero can use the PetscViewer draw singleton */
  ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)viewer),&rank);CHKERRQ(ierr);
  if (!rank) {
    ierr   = PetscViewerCreate(PETSC_COMM_SELF,sviewer);CHKERRQ(ierr);
    ierr   = PetscViewerSetType(*sviewer,PETSCVIEWERDRAW);CHKERRQ(ierr);
    vsdraw = (PetscViewer_Draw*)(*sviewer)->data;
    for (i=0; i<vdraw->draw_max; i++) {
      if (vdraw->draw[i]) {
        ierr = PetscDrawGetSingleton(vdraw->draw[i],&vsdraw->draw[i]);CHKERRQ(ierr);
      }
    }
  }
  vdraw->singleton_made = PETSC_TRUE;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerRestoreSingleton_Draw"
PetscErrorCode PetscViewerRestoreSingleton_Draw(PetscViewer viewer,PetscViewer *sviewer)
{
  PetscErrorCode   ierr;
  PetscMPIInt      rank;
  PetscInt         i;
  PetscViewer_Draw *vdraw = (PetscViewer_Draw*)viewer->data,*vsdraw;

  PetscFunctionBegin;
  if (!vdraw->singleton_made) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ORDER,"Trying to restore a singleton that was not gotten");
  ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)viewer),&rank);CHKERRQ(ierr);
  if (!rank) {
    vsdraw = (PetscViewer_Draw*)(*sviewer)->data;
    for (i=0; i<vdraw->draw_max; i++) {
      if (vdraw->draw[i] && vsdraw->draw[i]) {
        ierr = PetscDrawRestoreSingleton(vdraw->draw[i],&vsdraw->draw[i]);CHKERRQ(ierr);
      }
    }
    ierr = PetscFree3(vsdraw->draw,vsdraw->drawlg,vsdraw->drawaxis);CHKERRQ(ierr);
    ierr = PetscFree((*sviewer)->data);CHKERRQ(ierr);
    ierr = PetscHeaderDestroy(sviewer);CHKERRQ(ierr);
  }
  vdraw->singleton_made = PETSC_FALSE;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerSetFromOptions_Draw"
PetscErrorCode PetscViewerSetFromOptions_Draw(PetscViewer v)
{
  PetscErrorCode ierr;
  PetscReal      bounds[16];
  PetscInt       nbounds = 16;
  PetscBool      flg;

  PetscFunctionBegin;
  ierr = PetscOptionsHead("Draw PetscViewer Options");CHKERRQ(ierr);
  ierr = PetscOptionsRealArray("-draw_bounds","Bounds to put on plots axis","PetscViewerDrawSetBounds",bounds,&nbounds,&flg);CHKERRQ(ierr);
  if (flg) {
    ierr = PetscViewerDrawSetBounds(v,nbounds/2,bounds);CHKERRQ(ierr);
  }

  ierr = PetscOptionsTail();CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerView_Draw"
PetscErrorCode PetscViewerView_Draw(PetscViewer viewer,PetscViewer v)
{
  PetscErrorCode   ierr;
  PetscDraw        draw;
  PetscInt         i;
  PetscViewer_Draw *vdraw = (PetscViewer_Draw*)viewer->data;

  PetscFunctionBegin;
  /*  If the PetscViewer has just been created then no vdraw->draw yet
      exists so this will not actually call the viewer on any draws. */
  for (i=0; i<vdraw->draw_base; i++) {
    if (vdraw->draw[i]) {
      ierr = PetscViewerDrawGetDraw(viewer,i,&draw);CHKERRQ(ierr);
      ierr = PetscDrawView(draw,v);CHKERRQ(ierr);
    }
  }
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerCreate_Draw"
PETSC_EXTERN PetscErrorCode PetscViewerCreate_Draw(PetscViewer viewer)
{
  PetscErrorCode   ierr;
  PetscViewer_Draw *vdraw;

  PetscFunctionBegin;
  ierr         = PetscNewLog(viewer,&vdraw);CHKERRQ(ierr);
  viewer->data = (void*)vdraw;

  viewer->ops->flush            = PetscViewerFlush_Draw;
  viewer->ops->view             = PetscViewerView_Draw;
  viewer->ops->destroy          = PetscViewerDestroy_Draw;
  viewer->ops->setfromoptions   = PetscViewerSetFromOptions_Draw;
  viewer->ops->getsingleton     = PetscViewerGetSingleton_Draw;
  viewer->ops->restoresingleton = PetscViewerRestoreSingleton_Draw;

  /* these are created on the fly if requested */
  vdraw->draw_max  = 5;
  vdraw->draw_base = 0;
  vdraw->w         = PETSC_DECIDE;
  vdraw->h         = PETSC_DECIDE;

  ierr = PetscCalloc3(vdraw->draw_max,&vdraw->draw,vdraw->draw_max,&vdraw->drawlg,vdraw->draw_max,&vdraw->drawaxis);CHKERRQ(ierr);
  vdraw->singleton_made = PETSC_FALSE;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerDrawClear"
/*@
    PetscViewerDrawClear - Clears a PetscDraw graphic associated with a PetscViewer.

    Not Collective

    Input Parameter:
.  viewer - the PetscViewer

    Level: intermediate

.seealso: PetscViewerDrawOpen(), PetscViewerDrawGetDraw(),

@*/
PetscErrorCode  PetscViewerDrawClear(PetscViewer viewer)
{
  PetscErrorCode   ierr;
  PetscInt         i;
  PetscBool        isdraw;
  PetscViewer_Draw *vdraw;

  PetscFunctionBegin;
  ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
  if (isdraw) {
    vdraw = (PetscViewer_Draw*)viewer->data;
    for (i=0; i<vdraw->draw_max; i++) {
      if (vdraw->draw[i]) {ierr = PetscDrawClear(vdraw->draw[i]);CHKERRQ(ierr);}
    }
  }
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerDrawGetPause"
/*@
    PetscViewerDrawGetPause - Gets a pause for the first present draw

    Not Collective

    Input Parameter:
.  viewer - the PetscViewer

    Output Parameter:
.  pause - the pause value

    Level: intermediate

.seealso: PetscViewerDrawOpen(), PetscViewerDrawGetDraw(),

@*/
PetscErrorCode  PetscViewerDrawGetPause(PetscViewer viewer,PetscReal *pause)
{
  PetscErrorCode   ierr;
  PetscInt         i;
  PetscBool        isdraw;
  PetscViewer_Draw *vdraw;
  PetscDraw        draw;

  PetscFunctionBegin;
  ierr   = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
  *pause = 0.0;
  if (isdraw) {
    vdraw = (PetscViewer_Draw*)viewer->data;
    for (i=0; i<vdraw->draw_max; i++) {
      if (vdraw->draw[i]) {
        ierr = PetscDrawGetPause(vdraw->draw[i],pause);CHKERRQ(ierr);
        PetscFunctionReturn(0);
      }
    }
    /* none exist yet so create one and get its pause */
    ierr = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr);
    ierr = PetscDrawGetPause(vdraw->draw[0],pause);CHKERRQ(ierr);
  }
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerDrawSetPause"
/*@
    PetscViewerDrawSetPause - Sets a pause for each PetscDraw in the viewer

    Not Collective

    Input Parameters:
+  viewer - the PetscViewer
-  pause - the pause value

    Level: intermediate

.seealso: PetscViewerDrawOpen(), PetscViewerDrawGetDraw(),

@*/
PetscErrorCode  PetscViewerDrawSetPause(PetscViewer viewer,PetscReal pause)
{
  PetscErrorCode   ierr;
  PetscInt         i;
  PetscBool        isdraw;

  PetscFunctionBegin;
  ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
  if (isdraw) {
    PetscViewer_Draw *vdraw = (PetscViewer_Draw*)viewer->data;

    vdraw->pause = pause;
    for (i=0; i<vdraw->draw_max; i++) {
      if (vdraw->draw[i]) {ierr = PetscDrawSetPause(vdraw->draw[i],pause);CHKERRQ(ierr);}
    }
  }
  PetscFunctionReturn(0);
}


#undef __FUNCT__
#define __FUNCT__ "PetscViewerDrawSetHold"
/*@
    PetscViewerDrawSetHold - Holds previous image when drawing new image

    Not Collective

    Input Parameters:
+  viewer - the PetscViewer
-  hold - indicates to hold or not

    Level: intermediate

.seealso: PetscViewerDrawOpen(), PetscViewerDrawGetDraw(),

@*/
PetscErrorCode  PetscViewerDrawSetHold(PetscViewer viewer,PetscBool hold)
{
  PetscErrorCode   ierr;
  PetscViewer_Draw *vdraw;
  PetscBool        isdraw;

  PetscFunctionBegin;
  ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
  if (isdraw) {
    vdraw       = (PetscViewer_Draw*)viewer->data;
    vdraw->hold = hold;
  }
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerDrawGetHold"
/*@
    PetscViewerDrawGetHold - Holds previous image when drawing new image

    Not Collective

    Input Parameter:
.  viewer - the PetscViewer

    Output Parameter:
.  hold - indicates to hold or not

    Level: intermediate

.seealso: PetscViewerDrawOpen(), PetscViewerDrawGetDraw(),

@*/
PetscErrorCode  PetscViewerDrawGetHold(PetscViewer viewer,PetscBool *hold)
{
  PetscErrorCode   ierr;
  PetscViewer_Draw *vdraw;
  PetscBool        isdraw;

  PetscFunctionBegin;
  ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);CHKERRQ(ierr);
  if (isdraw) {
    vdraw = (PetscViewer_Draw*)viewer->data;
    *hold = vdraw->hold;
  }
  PetscFunctionReturn(0);
}

/* ---------------------------------------------------------------------*/
/*
    The variable Petsc_Viewer_Draw_keyval is used to indicate an MPI attribute that
  is attached to a communicator, in this case the attribute is a PetscViewer.
*/
static PetscMPIInt Petsc_Viewer_Draw_keyval = MPI_KEYVAL_INVALID;

#undef __FUNCT__
#define __FUNCT__ "PETSC_VIEWER_DRAW_"
/*@C
    PETSC_VIEWER_DRAW_ - Creates a window PetscViewer shared by all processors
                     in a communicator.

     Collective on MPI_Comm

     Input Parameter:
.    comm - the MPI communicator to share the window PetscViewer

     Level: intermediate

     Notes:
     Unlike almost all other PETSc routines, PETSC_VIEWER_DRAW_ does not return
     an error code.  The window is usually used in the form
$       XXXView(XXX object,PETSC_VIEWER_DRAW_(comm));

.seealso: PETSC_VIEWER_DRAW_WORLD, PETSC_VIEWER_DRAW_SELF, PetscViewerDrawOpen(),
@*/
PetscViewer  PETSC_VIEWER_DRAW_(MPI_Comm comm)
{
  PetscErrorCode ierr;
  PetscMPIInt    flag;
  PetscViewer    viewer;
  MPI_Comm       ncomm;

  PetscFunctionBegin;
  ierr = PetscCommDuplicate(comm,&ncomm,NULL);if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_VIEWER_DRAW_",__FILE__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," ");PetscFunctionReturn(0);}
  if (Petsc_Viewer_Draw_keyval == MPI_KEYVAL_INVALID) {
    ierr = MPI_Keyval_create(MPI_NULL_COPY_FN,MPI_NULL_DELETE_FN,&Petsc_Viewer_Draw_keyval,0);
    if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_VIEWER_DRAW_",__FILE__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," ");PetscFunctionReturn(0);}
  }
  ierr = MPI_Attr_get(ncomm,Petsc_Viewer_Draw_keyval,(void**)&viewer,&flag);
  if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_VIEWER_DRAW_",__FILE__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," ");PetscFunctionReturn(0);}
  if (!flag) { /* PetscViewer not yet created */
    ierr = PetscViewerDrawOpen(ncomm,0,0,PETSC_DECIDE,PETSC_DECIDE,300,300,&viewer);
    if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_VIEWER_DRAW_",__FILE__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," ");PetscFunctionReturn(0);}
    ierr = PetscObjectRegisterDestroy((PetscObject)viewer);
    if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_VIEWER_DRAW_",__FILE__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," ");PetscFunctionReturn(0);}
    ierr = MPI_Attr_put(ncomm,Petsc_Viewer_Draw_keyval,(void*)viewer);
    if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_VIEWER_DRAW_",__FILE__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," ");PetscFunctionReturn(0);}
  }
  ierr = PetscCommDestroy(&ncomm);
  if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_VIEWER_DRAW_",__FILE__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," ");PetscFunctionReturn(0);}
  PetscFunctionReturn(viewer);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerDrawSetBounds"
/*@
    PetscViewerDrawSetBounds - sets the upper and lower bounds to be used in plotting

    Collective on PetscViewer

    Input Parameters:
+   viewer - the PetscViewer (created with PetscViewerDrawOpen())
.   nbounds - number of plots that can be made with this viewer, for example the dof passed to DMDACreate()
-   bounds - the actual bounds, the size of this is 2*nbounds, the values are stored in the order min F_0, max F_0, min F_1, max F_1, .....


    Options Database:
.   -draw_bounds  minF0,maxF0,minF1,maxF1

    Level: intermediate

    Notes: this determines the colors used in 2d contour plots generated with VecView() for DMDA in 2d. Any values in the vector below or above the
      bounds are moved to the bound value before plotting. In this way the color index from color to physical value remains the same for all plots generated with
      this viewer. Otherwise the color to physical value meaning changes with each new image if this is not set.

   Concepts: drawing^accessing PetscDraw context from PetscViewer
   Concepts: graphics

.seealso: PetscViewerDrawGetLG(), PetscViewerDrawGetAxis(), PetscViewerDrawOpen()
@*/
PetscErrorCode  PetscViewerDrawSetBounds(PetscViewer viewer,PetscInt nbounds,const PetscReal *bounds)
{
  PetscViewer_Draw *vdraw = (PetscViewer_Draw*)viewer->data;
  PetscErrorCode   ierr;


  PetscFunctionBegin;
  PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,1);
  vdraw->nbounds = nbounds;

  ierr = PetscMalloc1(2*nbounds,&vdraw->bounds);CHKERRQ(ierr);
  ierr = PetscMemcpy(vdraw->bounds,bounds,2*nbounds*sizeof(PetscReal));CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerDrawGetBounds"
/*@C
    PetscViewerDrawGetBounds - gets the upper and lower bounds to be used in plotting set with PetscViewerDrawSetBounds()

    Collective on PetscViewer

    Input Parameter:
.   viewer - the PetscViewer (created with PetscViewerDrawOpen())

    Output Paramters:
+   nbounds - number of plots that can be made with this viewer, for example the dof passed to DMDACreate()
-   bounds - the actual bounds, the size of this is 2*nbounds, the values are stored in the order min F_0, max F_0, min F_1, max F_1, .....

    Level: intermediate

   Concepts: drawing^accessing PetscDraw context from PetscViewer
   Concepts: graphics

.seealso: PetscViewerDrawGetLG(), PetscViewerDrawGetAxis(), PetscViewerDrawOpen(), PetscViewerDrawSetBounds()
@*/
PetscErrorCode  PetscViewerDrawGetBounds(PetscViewer viewer,PetscInt *nbounds,const PetscReal **bounds)
{
  PetscViewer_Draw *vdraw = (PetscViewer_Draw*)viewer->data;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,1);
  *nbounds = vdraw->nbounds;
  *bounds  = vdraw->bounds;
  PetscFunctionReturn(0);
}