"Strange output of 'text' within text"

[JimJoyce]

I have some javascript  which generates SVG code
to produces a spectrum of colours within a honeycomb of hexagons.
It works OK. I now trying to re-code it in 'C'

It's simply text generation, but I have often to include quotes within strings.
E.g. "Some text,  id='txt', and continue"

Quite often, in the generated code, the trailing single quote is omitted,
or, strangely, replaced with a hash (#);

In my code, lines 221-222, produces the central hexagon:
   fprintf ( fp, "  <use xlink:href='#hxg' x='0' y='0' " );
   fprintf ( fp, " style='fill: rgb(%d,%d,%d);' />\n",  r, g, b );

Then, in several loops, lines 234-237 produce the outer 'rings'.
  calcXY (ring,sector,segmnt);                   // calculate the x,y position of hexagon
  calcRGB (R,G,B,ring,sector,segmnt,stp); // calculate the rgb colour of the hexagon
   fprintf ( fp, "<use xlink:href='#hxg' x='%d' y='%d' ", r, g, b );
   fprintf ( fp, "style='fill: rgb(%d,%d,%d);' />\n", r, g, b );

In the output:
  221-222 correctly produces line 18:
    <use xlink:href='#hxg' x='0' y='0'  style='fill: rgb(200,200,200);' />
'#hxg' correctly refers to a hexagon defined earlier,
and 'x, y': '0,0'  is the correct location.

  but the loop produces: lines 20 ....
   <use xlink:href='#hx# x='0'   y='-52   style='rgb(208,196,196)' />
   <use xlink:href='#hx# x='45' y='-26   style='rgb(204,204,192)' />
   <use xlink:href='#hx# x='45' y='26    style='rgb(196,208,196)' />
   <use xlink:href='#hx# x='0'   y='52    style='rgb(192,204,204)' />
   etc.etc.
The xlink@href:  '#hx# is complete gibberish
and the trailing quote is missing from the 'y' coordinate

Has anyone else had similar problems?
Is it just a problem of text within text strings?

[frankie]

Could you post a small code snippet to reproduce the problem?
Maybe you have a mishandled pointer that overwrites the format string.

[JimJoyce]

I thing I have already shown the critical code.
But here is a larger chunk.
I had already commented out the inner loop from drawHcmb()
and replaced it with the doLoops().

My abbreviated arguments!!!
shd = shade =r =g =b = rgb(shd,shd,shd)
rng = ring number ( the hexagonal 'rings' around the central ring
stp = step, the rgb colour adjustment between neighbouring hexagons
sc  = scale  NOT USED.

Note the central hexagon is generated in the 'drawHcmb' function
All the surrounding hexagons are produced by doLoops.

Code Select Expand


/* * * * * * * * * * * * * * * * * * */

int doLoops ( FILE *fp, int shd, int rng, int stp )
  {
  int   i, j, k;
  char use[] = "  <use xlink:href='#hx# x='%d' y='%d ";
  char styl[] = "  style='rgb(%d,%d,%d)' />\n";
  for ( i=0 ; i<rng ; i++ )
    {
    for ( j=0 ; j<6 ; j++ )
      {
      for ( k=0 ; k<i ; k++ )
        {
        calcXY (i, j, k);                // calculate the x,y position of hexagon
        calcRGB (R, G, B, i, j, k, stp); // calculate the rgb colour of the hexagon
        fprintf ( fp, use, hx, hy );
        fprintf ( fp, styl, r, g, b );
        labelHex( fp, hx, hy, r, g, b);  // Label the individual hexagon with its R,G,B values
        }
      }
    }
  return 1;
  }

/* * * * * * * * * * * * * * * * * * */

int    drawHcmb ( FILE* fp, int W, int H, int shd, int rng, int sc )
  {
  fprintf ( fp, "<g id='BG' transform='rotate(0)'>\n" );
                  // Draw Central hexagon, centred on x=0, y=0
  fprintf ( fp, "  <use xlink:href='#hxg' x='0' y='0' " );
  fprintf ( fp, " style='fill: rgb(%d,%d,%d);' />\n", r, g, b );
  labelDec( fp, 0, 0, R, G, B);  // Label the Central Hexagon
                        // Calculate the rgb(), and the x,y location
                        // for each individual hexagon
/*
  for ( ring=1 ; ring<=rng ; ring++ )   // Count the 'Rings' in the Honeycomb
    {
    fputs ( "\n", fp );
    for ( sector=0 ; sector<6 ; sector++ )      // Count the 6 Sectors in each Ring
      {
      for ( segmnt=0 ; segmnt<ring ; segmnt++ ) // Count the Segments within the Sector
        {
        calcXY (ring,sector,segmnt);            // calculate the hx,hy position of hexagon
        calcRGB (R,G,B,ring,sector,segmnt,stp); // calculate the rgb colour of the hexagon
        fprintf ( fp, "<use xlink:href='#hxg' x='%d' y='%d' ", r, g, b );
        fprintf ( fp, "style='fill: rgb(%d,%d,%d);' />\n", r, g, b );
        labelHex( fp,x,y,r,g,b);   // Label the individual hexagon with its R,G,B values
        }
      }
    }
*/
  doLoops ( fp, shd, rng, stp );

  fprintf ( fp, "</g>\n" );
  return 1;
  }


[JimJoyce]

APOLOGIES
I now see the error of my ways.
I generated the stray hash in doLoops.
char use[] = "  <use xlink:href='#hx# x='%d' y='%d ";
I mistyped '#' for the trailing quote.
I'm very sorry.
JJ

[frankie]

JJ don't worry, it happen often that the error is under our eyes, but we don't see it.
Maybe if you have not posted the larger chunk you will have never seen it 

[Bitbeisser]

Just as a general note, when posting code snippets, please put "code" tags around it (the

• button above the smiles of the forum text entry box), thanks.
  
  Ralf

[riya20]

I had already commented out the inner loop from drawHcmb I mistyped '#' for the trailing quote.