;+ ; NAME: ; MRK_RECT ; ; PURPOSE: ; Allows the USER to interactively position and size a rectangle ; on an existing plot. ; ; CATEGORY: ; Graphics. ; ; CALLING SEQUENCE: ; ; Result = MRK_RECT( [Window] ) ; ; OPTIONAL INPUTS: ; ; Window: Index of the plot window that the rectangle is to be drawn in. ; ; OPTIONAL INPUT KEYWORD PARAMETERS: ; ; STATUS: Set this keyword to display the coordinates of the current ; cursor position in the lower left-hand corner of the plot ; window. (0=Default) ; ; ERASE: Set this keyword to erase the rectangle and status ; coordinates after the position and size of the rectangle ; has been selected. (0=Default) ; ; HELP: Set this keyword to display a instruction window on how ; to interactively position the rectangle on the plot. ; (0=Default) ; ; DATA: Set this keyword to display and return rectangle position ; in data coordinates. (1=Default) ; ; NORMAL: Set this keyword to display and return rectangle position ; in normalized coordinates. (0=Default) ; ; DEVICE: Set this keyword to display and return rectangle position ; in device coordinates. (0=Default) ; ; COLOR: Set this to the color index of the line. (0=Default) ; ; OUTPUTS: ; Returns the position of the rectanlge in the coordinates specified ; USER (DATA=Default). Result(*,0) = [X0,Y0] is the position of the ; first corner. Result(*,1) = [X1,Y1] is the position of the ; diagonally opposite corner. ; ; EXAMPLE: ; plot,indgen(100) ; rect_position = MRK_LINE(/HELP) ; ; MODIFICATION HISTORY: ; Written by: Han Wen, June 1995. ; 17-JUN-1995 Small bug-fix, TITLE of instructions incorrect (Mrk_Line) ; 10-SEP-1996 Display status before setting point. ; 03-OCT-1996 Added COLOR keyword. ;- function MRK_RECT, Window, STATUS=Status, ERASE=Erase, HELP=Help, $ NORMAL=NORMAL_, DEVICE=DEVICE_, DATA=DATA_, COLOR=Color NP=N_PARAMS() if !D.WINDOW eq -1 then message,'No existing plot.' if NP eq 0 then Window=!D.WINDOW wset, Window wshow, Window if (NOT keyword_set(NORMAL_)) and $ (NOT keyword_set(DEVICE_)) and $ (NOT keyword_set(DATA_)) then DATA_ = 1 LINESTYLE = 0 ; solid line if (N_ELEMENTS(Color) eq 0) then $ COLOR = !D.N_COLORS-1 ; white (B-W Linear) statline = '' ; Save original window orig_plot = tvrd() ; Display HELP instructions if keyword_set( HELP ) then begin object = 'rectangle' instr = ['1. Place the mouse pointer within the plot',$ 'area and then press and hold mouse button 1',$ 'to mark a corner of the '+object+'.',$ '',$ '2. Move the mouse until the '+object+' is at',$ 'the desired size.',$ '',$ '3. Release the mouse button.'] xmsg, instr, TITLE='Mrk_Rect Instruction',/NOBUTTON, $ /LEFT, /TOP, MSG_ID=Msg_ID, /ALIGN endif ; Define active plot region Xleft = !X.MARGIN(0)*!D.X_CH_SIZE Xright = !D.X_SIZE - !X.MARGIN(1)*!D.X_CH_SIZE Ybottom = !Y.MARGIN(0)*!D.Y_CH_SIZE Ytop = !D.Y_SIZE - !Y.MARGIN(1)*!D.Y_CH_SIZE Rmargin = [[Xleft,Ybottom],[Xright,Ytop]] Rmargin = CONVERT_COORD( Rmargin, /DEVICE, TO_DATA=DATA_, $ TO_DEVICE=DEVICE_, TO_NORMAL=NORMAL_ ) DEVICE, GET_GRAPHICS_FUNCTION=GXsave, $ SET_GRAPHICS_FUNCTION=6 ; Exclusive OR existing pixels ; Make sure first point is within the plot region repeat begin repeat begin CURSOR,X0,Y0,/CHANGE,DATA=DATA_,DEVICE=DEVICE_,NORMAL=NORMAL_ DX = (X0 - Rmargin(0,0))*(Rmargin(0,1) - X0) DY = (Y0 - Rmargin(1,0))*(Rmargin(1,1) - Y0) if KEYWORD_SET(STATUS) then begin XYOUTS,0,0,/NORMAL,statline ; erase old status line statline = '('+arr2str(X0,4)+','+arr2str(Y0,4)+')' XYOUTS,0,0,/NORMAL,statline endif endrep until (!ERR eq 1) endrep until (DX gt 0) and (DY gt 0) ; Draw first rectangle R = [X0,Y0] plots,R,DATA=DATA_,DEVICE=DEVICE_,NORMAL=NORMAL_,$ LINESTYLE=LINESTYLE,COLOR=COLOR if keyword_set(STATUS) then begin XYOUTS,0,0,/NORMAL,statline ; erase old status line statline = '('+arr2str(X0,4)+','+arr2str(Y0,4)+')' XYOUTS,0,0,/NORMAL,statline endif Rlast = CONVERT_COORD( X0,Y0, DATA=DATA_, DEVICE=DEVICE_,$ NORMAL=NORMAL_, /TO_DEVICE) Rsign = SIGN(Rlast(0)) or SIGN(Rlast(1)) ; Loop until USER releases mouse button 1 while (!err) or (Rsign lt 0) do begin CURSOR, X1,Y1, /CHANGE, DATA=DATA_,DEVICE=DEVICE_,NORMAL=NORMAL_ Rcurr = CONVERT_COORD( X1,Y1, DATA=DATA_, $ DEVICE=DEVICE_, NORMAL=NORMAL_, /TO_DEVICE) Rcurr = ROUND(Rcurr) ; Round to nearest pixel dR = TOTAL(ABS(Rcurr - Rlast)) Rsign = SIGN(Rcurr(0)) or SIGN(Rcurr(1)) if (dR gt 0) and (Rsign gt 0) then begin ; Make sure coordinates are within plot region X1 = X1 > Rmargin(0,0) X1 = X1 < Rmargin(0,1) Y1 = Y1 > Rmargin(1,0) Y1 = Y1 < Rmargin(1,1) ; erase previous rectangle plots,R,DATA=DATA_,DEVICE=DEVICE_,NORMAL=NORMAL_,$ LINESTYLE=LINESTYLE,COLOR=COLOR ; draw new rectangle R = [ [X0,Y0], [X1,Y0], [X1,Y1], [X0,Y1], [X0,Y0] ] plots,R,DATA=DATA_,DEVICE=DEVICE_,NORMAL=NORMAL_,$ LINESTYLE=LINESTYLE,COLOR=COLOR if keyword_set(STATUS) then begin XYOUTS,0,0,/NORMAL,statline ; erase old status line statline = '('+arr2str(X1,4)+$ ','+arr2str(Y1,4)+')' XYOUTS,0,0,/NORMAL,statline ; draw new status line endif Rlast = Rcurr endif endwhile ; Restore plot window DEVICE,SET_GRAPHICS_FUNCTION=GXsave ; OVERWRITE existing pixels tv, orig_plot if NOT keyword_set(ERASE) then $ plots,R,DATA=DATA_,DEVICE=DEVICE_,NORMAL=NORMAL_,$ LINESTYLE=LINESTYLE,COLOR=COLOR if keyword_set(HELP) then WIDGET_CONTROL,Msg_ID, /DESTROY wshow,Window ; Return position of rectangle return, [[X0,Y0],[X1,Y1]] end