PostScriptMakeDash

Syntax

struct PostScriptDash *PostScriptMakeDash(float *p,float phase,int sze);

Header

base/rps.h

Library

rps

Description

The PostScriptMakeDash function makes a dash pattern for an PostScript plot.

The array pointed to by the argument p is interpreted as distances along the line that alternately specify dashes and gaps. The argument sze give the number of elements in the array.

When a dashed line is plotted an element is read from the array and a dash of length equal to that value is drawn. A gap equal to the value of the next element is then left and the process is repeated until the end of the line is reached, cycling through the array as necessary.

The argument phase specifies the initial element to use from the array.

Returns

Returns a pointer to the dash structure on success. On error, a NULL pointer is returned.

Errors

On error, a NULL pointer is returned.

Example

PostScriptMakeDash
Source Code: PostScriptMakeDash.c

/* PostScriptMakeDash
   ==================
   Author: R.J.Barnes
 Copyright (c) 2012 The Johns Hopkins University/Applied Physics Laboratory

This file is part of the Radar Software Toolkit (RST).

RST is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.

Modifications:




#include <stdio.h>
#include <stdlib.h>
#include "rfbuffer.h"
#include "rps.h"

int stream(char *buf,int sze,void *data) {
  FILE *fp;
  fp=(FILE *) data;
  fwrite(buf,sze,1,stdout);
  return 0;
} 


int main(int argc,char *argv[]) {

  struct PostScript *ps=NULL;
  struct PostScriptDash *dash=NULL;

  float p[3]={10,5,20};

  float wdt=400,hgt=400;
  float xoff=50,yoff=50;

  unsigned int fgcol=0xff000000;

  ps=PostScriptMake();
  PostScriptSetText(ps,stream,stdout);   
  PostScriptMakeDocument(ps,xoff,yoff,wdt,hgt,0);
  PostScriptMakePlot(ps);

  dash=PostScriptMakeDash(p,0,3);

  PostScriptRectangle(ps,NULL,10,10,wdt-20,hgt-20,
                 0,fgcol,1.0,dash,NULL);

  PostScriptFreeDash(dash);

  PostScriptEndPlot(ps);
  PostScriptEndDocument(ps);
  return 0;
}