1 2 #include <petscdraw.h> /*I "petscdraw.h" I*/ 3 4 /*@C 5 PetscDrawZoom - Allows one to create a graphic that users may zoom into. 6 7 Collective on PetscDraw 8 9 Input Parameters: 10 + draw - the window where the graph will be made. 11 . func - users function that draws the graphic 12 - ctx - pointer to any user required data 13 14 Level: advanced 15 16 Concepts: graphics^zooming 17 Concepts: drawing^zooming 18 Concepts: zooming^in graphics 19 20 .seealso: 21 @*/ 22 PetscErrorCode PetscDrawZoom(PetscDraw draw,PetscErrorCode (*func)(PetscDraw,void*),void *ctx) 23 { 24 PetscErrorCode ierr; 25 PetscDrawButton button; 26 PetscReal dpause,xc,yc,scale = 1.0,w,h,xr,xl,yr,yl,xmin,xmax,ymin,ymax; 27 PetscBool isnull; 28 29 PetscFunctionBegin; 30 ierr = PetscDrawIsNull(draw,&isnull);CHKERRQ(ierr); 31 if (isnull) PetscFunctionReturn(0); 32 33 ierr = PetscDrawCheckResizedWindow(draw);CHKERRQ(ierr); 34 ierr = PetscDrawClear(draw);CHKERRQ(ierr); 35 ierr = PetscDrawCollectiveBegin(draw);CHKERRQ(ierr); 36 ierr = (*func)(draw,ctx);CHKERRQ(ierr); 37 ierr = PetscDrawCollectiveEnd(draw);CHKERRQ(ierr); 38 ierr = PetscDrawFlush(draw);CHKERRQ(ierr); 39 40 ierr = PetscDrawGetPause(draw,&dpause);CHKERRQ(ierr); 41 if (dpause >= 0) { 42 ierr = PetscSleep(dpause);CHKERRQ(ierr); 43 goto theend; 44 } 45 if (dpause != -1) goto theend; 46 47 ierr = PetscDrawGetMouseButton(draw,&button,&xc,&yc,NULL,NULL);CHKERRQ(ierr); 48 ierr = PetscDrawGetCoordinates(draw,&xl,&yl,&xr,&yr);CHKERRQ(ierr); 49 xmin = xl; xmax = xr; w = xr - xl; 50 ymin = yl; ymax = yr; h = yr - yl; 51 52 while (button != PETSC_BUTTON_NONE && button != PETSC_BUTTON_RIGHT) { 53 switch (button) { 54 case PETSC_BUTTON_LEFT: scale = 0.5; break; 55 case PETSC_BUTTON_CENTER: scale = 2.0; break; 56 case PETSC_BUTTON_WHEEL_UP: scale = 8/10.; break; 57 case PETSC_BUTTON_WHEEL_DOWN: scale = 10/8.; break; 58 default: scale = 1.0; 59 } 60 xl = scale*(xl + w - xc) + xc - w*scale; 61 xr = scale*(xr - w - xc) + xc + w*scale; 62 yl = scale*(yl + h - yc) + yc - h*scale; 63 yr = scale*(yr - h - yc) + yc + h*scale; 64 w *= scale; h *= scale; 65 ierr = PetscDrawClear(draw);CHKERRQ(ierr); 66 ierr = PetscDrawSetCoordinates(draw,xl,yl,xr,yr);CHKERRQ(ierr); 67 ierr = PetscDrawCollectiveBegin(draw);CHKERRQ(ierr); 68 ierr = (*func)(draw,ctx);CHKERRQ(ierr); 69 ierr = PetscDrawCollectiveEnd(draw);CHKERRQ(ierr); 70 ierr = PetscDrawFlush(draw);CHKERRQ(ierr); 71 ierr = PetscDrawGetMouseButton(draw,&button,&xc,&yc,NULL,NULL);CHKERRQ(ierr); 72 } 73 ierr = PetscDrawSetCoordinates(draw,xmin,ymin,xmax,ymax);CHKERRQ(ierr); 74 theend: 75 PetscFunctionReturn(0); 76 } 77 78