path: root/generator/pbmtext.c

/* pbmtext.c - render text into a bitmap
**
** Copyright (C) 1991 by Jef Poskanzer.
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation.  This software is provided "as is" without express or
** implied warranty.
*/

#define _BSD_SOURCE 1      /* Make sure strdup() is in string.h */
#define _XOPEN_SOURCE 500  /* Make sure strdup() is in string.h */

#include <string.h>
#include <math.h>
#include <limits.h>
#include <assert.h>

#include "pm_c_util.h"
#include "mallocvar.h"
#include "shhopt.h"
#include "pbm.h"
#include "pbmfont.h"

#define  MAXLINECHARS 5000

struct CmdlineInfo {
    /* All the information the user supplied in the command line,
       in a form easy for the program to use.
    */
    const char * text;    /* text from command line or NULL if none */
    const char * font;    /* -font option value or NULL if none */
    const char * builtin; /* -builtin option value or NULL if none */
    unsigned int dump;   
        /* undocumented dump option for installing a new built-in font */
    float space;   /* -space option value or default */
    unsigned int width;     /* -width option value or zero */
    int lspace;    /* lspace option value or default */
    unsigned int nomargins;     /* -nomargins */
    unsigned int verbose;
};



static void
parseCommandLine(int argc, const char ** argv,
                 struct CmdlineInfo * const cmdlineP) {
/*----------------------------------------------------------------------------
   Note that the file spec array we return is stored in the storage that
   was passed to us as the argv array.
-----------------------------------------------------------------------------*/
    optEntry * option_def;
        /* Instructions to OptParseOptions3 on how to parse our options.
         */
    optStruct3 opt;

    unsigned int option_def_index;

    MALLOCARRAY_NOFAIL(option_def, 100);

    option_def_index = 0;   /* incremented by OPTENTRY */
    OPTENT3(0, "font",      OPT_STRING, &cmdlineP->font, NULL,        0);
    OPTENT3(0, "builtin",   OPT_STRING, &cmdlineP->builtin, NULL,     0);
    OPTENT3(0, "dump",      OPT_FLAG,   NULL, &cmdlineP->dump,        0);
    OPTENT3(0, "space",     OPT_FLOAT,  &cmdlineP->space, NULL,       0);
    OPTENT3(0, "width",     OPT_UINT,   &cmdlineP->width, NULL,       0);
    OPTENT3(0, "lspace",    OPT_INT,    &cmdlineP->lspace, NULL,      0);
    OPTENT3(0, "nomargins", OPT_FLAG,   NULL, &cmdlineP->nomargins,   0);
    OPTENT3(0, "verbose",   OPT_FLAG,   NULL, &cmdlineP->verbose,     0);

    /* Set the defaults */
    cmdlineP->font = NULL;
    cmdlineP->builtin = NULL;
    cmdlineP->space = 0.0;
    cmdlineP->width = 0;
    cmdlineP->lspace = 0;

    opt.opt_table = option_def;
    opt.short_allowed = FALSE;  /* We have no short (old-fashioned) options */
    opt.allowNegNum = FALSE;  /* We have no parms that are negative numbers */

    pm_optParseOptions3(&argc, (char **)argv, opt, sizeof(opt), 0);
    /* Uses and sets argc, argv, and some of *cmdlineP and others. */

    if (cmdlineP->width > 0 && cmdlineP->nomargins == TRUE) {
        pm_message("-nomargins has no effect when -width is specified");
        cmdlineP->nomargins = FALSE;
    } else if (cmdlineP->width > INT_MAX-10)
        pm_error("-width value too large");

    if (cmdlineP->space > pbm_maxfontwidth())
        pm_error("-space value too large");
    else if (cmdlineP->space < -pbm_maxfontwidth())
        pm_error("negative -space value too large");

    if (cmdlineP->lspace > pbm_maxfontheight())
        pm_error("-lspace value too large");
    else if (cmdlineP->lspace < -pbm_maxfontheight())
        pm_error("negative -lspace value too large");

    if (argc-1 == 0)
        cmdlineP->text = NULL;
    else {
        char *text;
        int i;
        int totaltextsize;

        totaltextsize = 1;  /* initial value */

        MALLOCARRAY(text, MAXLINECHARS+1);        

        if (!text)
            pm_error("Unable to allocate memory for a buffer of up to %u "
                     "characters of text", MAXLINECHARS);

        text[0] = '\0';
        
        for (i = 1; i < argc; ++i) {
            if (i > 1) {
                strcat(text, " ");
            } 
            totaltextsize += strlen(argv[i]) + 1;
            if (totaltextsize > MAXLINECHARS)
                pm_error("input text too long");
            strcat(text, argv[i]);
        }
        cmdlineP->text = text;
    }
}



static void
reportFont(struct font * const fontP) {

    unsigned int n;
    unsigned int c;

    pm_message("FONT:");
    pm_message("  character dimensions: %uw x %uh",
               fontP->maxwidth, fontP->maxheight);
    pm_message("  Additional vert white space: %d pixels", fontP->y);

    for (c = 0, n = 0; c < ARRAY_SIZE(fontP->glyph); ++c)
        if (fontP->glyph[c])
            ++n;

    pm_message("  # characters: %u", n);
}



static void
computeFont(struct CmdlineInfo const cmdline,
            struct font **     const fontPP) {

    struct font * fontP;

    if (cmdline.font)
        fontP = pbm_loadfont(cmdline.font);
    else {
        if (cmdline.builtin)
            fontP = pbm_defaultfont(cmdline.builtin);
        else
            fontP = pbm_defaultfont("bdf");
    }

    if (cmdline.verbose)
        reportFont(fontP);

    if (cmdline.dump) {
        pbm_dumpfont(fontP);
        exit(0);
    }
    *fontPP = fontP;
}



struct text {
    char **      textArray;  /* malloc'ed */
    unsigned int allocatedLineCount;
    unsigned int lineCount;
};



static void
allocTextArray(struct text * const textP,
               unsigned int  const maxLineCount,
               unsigned int  const maxColumnCount) {

    unsigned int line;

    textP->allocatedLineCount = maxColumnCount > 0 ? maxLineCount : 0;
    MALLOCARRAY_NOFAIL(textP->textArray, maxLineCount);

    for (line = 0; line < maxLineCount; ++line) {
        if(maxColumnCount > 0)
            MALLOCARRAY_NOFAIL(textP->textArray[line], maxColumnCount+1);
    else
        textP->textArray[line] = NULL;
    }
    textP->lineCount = 0;
}



static void
freeTextArray(struct text const text) {

    unsigned int line;

    for (line = 0; line < text.allocatedLineCount; ++line)
        free((char **)text.textArray[line]);

    free(text.textArray);
}



static void
fixControlChars(const char *  const input,
                struct font * const fontP,
                const char ** const outputP) {
/*----------------------------------------------------------------------------
   Return a translation of input[] that can be rendered as glyphs in
   the font 'fontP'.  Return it as newly malloced *outputP.

   Expand tabs to spaces.

   Remove any trailing newline.  (But leave intermediate ones as line
   delimiters).

   Turn anything that isn't a code point in the font to a single space
   (which isn't guaranteed to be in the font either, of course).
-----------------------------------------------------------------------------*/
    /* We don't know in advance how big the output will be because of the
       tab expansions.  So we make sure before processing each input
       character that there is space in the output buffer for a worst
       case tab expansion, plus a terminating NUL, reallocating as
       necessary.  And we originally allocate enough for the entire line
       assuming no tabs.
    */

    unsigned int const tabSize = 8;

    unsigned int inCursor, outCursor;
    char * output;      /* Output buffer.  Malloced */
    size_t outputSize;  /* Currently allocated size of 'output' */

    outputSize = strlen(input) + 1 + tabSize;
        /* Leave room for one worst case tab expansion and NUL terminator */
    MALLOCARRAY(output, outputSize);

    if (output == NULL)
        pm_error("Couldn't allocate %u bytes for a line of text.",
                 (unsigned)outputSize);

    for (inCursor = 0, outCursor = 0; input[inCursor] != '\0'; ++inCursor) {
        if (outCursor + 1 + tabSize > outputSize) {
            outputSize = outCursor + 1 + 4 * tabSize;
            REALLOCARRAY(output, outputSize);
            if (output == NULL)
                pm_error("Couldn't allocate %u bytes for a line of text.",
                         (unsigned)outputSize);
        }
        if (input[inCursor] == '\n' && input[inCursor+1] == '\0') {
            /* This is a terminating newline.  We don't do those. */
        } else if (input[inCursor] == '\t') { 
            /* Expand this tab into the right number of spaces. */
            unsigned int const nextTabStop =
                (outCursor + tabSize) / tabSize * tabSize;

        if (fontP->glyph[(unsigned char)' '] == NULL)
            pm_error("space character not defined in font");

            while (outCursor < nextTabStop)
                output[outCursor++] = ' ';
        } else if (!fontP->glyph[(unsigned char)input[inCursor]]) {
            /* Turn this unknown char into a single space. */
            if(fontP->glyph[(unsigned char) ' '] == NULL)
                pm_error("space character not defined in font");
            else
                output[outCursor++] = ' ';
        } else
            output[outCursor++] = input[inCursor];

        assert(outCursor <= outputSize);
    }
    output[outCursor++] = '\0';

    assert(outCursor <= outputSize);

    *outputP = output;
}



static void
fillRect(bit** const bits, 
         int   const height, 
         int   const width, 
         bit   const color) {

    unsigned int row;

    for (row = 0; row < height; ++row) {
        unsigned int col;
        for (col = 0; col < width; ++col)
            bits[row][col] = color;
    }
}



static void
getEdges(double               const currentPosition,
         char                 const currentChar,
         const struct glyph * const glyphP, 
         int                  const currLeftEdge,
         double               const currRightEdge,
         int                * const newLeftEdgeP,
         double             * const newRightEdgeP) {

    int leftEdge;
    double rightEdge;
  
    if (glyphP == NULL)
        pm_error("Unrenderable char: %c", currentChar);
    else {
        leftEdge  =  (int) MIN(currentPosition + glyphP->x, currLeftEdge);
        rightEdge =  MAX(currentPosition + glyphP->x + glyphP->width,
                         currRightEdge);
    }
    *newLeftEdgeP  = leftEdge;
    *newRightEdgeP = rightEdge;
}



static void
advancePosition(double               const currentPosition,
                char                 const currentChar,
                const struct glyph * const glyphP,
                float                const space,
                double               const accumulatedSpace,
                double             * const newPositionP,
                double             * const newAccumulatedSpaceP) {
/*----------------------------------------------------------------------------
  Advance position according to value for glyph.
  Add extra intercharacter space if -space option was used.

  The advance value must be zero or positive.
----------------------------------------------------------------------------*/

    /* Start position of next character */
    /* Must not move left from current position */
    int const fullPixels = (int) (accumulatedSpace + space);
        /* round toward 0 */
    int const advance    = (int) glyphP->xadd + fullPixels;
    
    if (advance < 0) {
        if (space < 0)
            pm_error("Negative -space value too large"); 
        else
            pm_error("Abnormal horizontal advance value %d "
                     "for char '%c' 0x%x.",
                     glyphP->xadd, currentChar, (unsigned int) currentChar);
    }
    else if (currentPosition + advance > INT_MAX)
        pm_error("Image is too wide");
    else {
        *newPositionP = currentPosition + advance;
        *newAccumulatedSpaceP = accumulatedSpace + space
            - (double) fullPixels;
    }
}



static void
getLineDimensions(char                const line[],
                  const struct font * const fontP, 
                  float               const intercharacterSpace,
                  double *            const rightEdgeP,
                  int    *            const leftEdgeP) {
/*----------------------------------------------------------------------------
   Determine the left edge and right edge in pixels of the line of text
   line[] in the font *fontP, and return them as *leftEdgeP and *rightEdgeP.
   *leftEdgeP will be negative if the leftmost character in the line has a
   "backup" distance.

   Note that the right (left) edge may not belong to the last (first)
   character in the text line.  This happens when the font is slanted
   (xadd is smaller than width) and/or intercharacter space is negative.
   This is illustrated by the following:

     pbmtext -nomargin "ART." | pnmshear -30 -noantialias

   Also note that there may be no black pixels on what is reported as an edge.
   This often happens with fixed-width font in which the white areas on the
   sides are not trimmed.
-----------------------------------------------------------------------------*/
    int cursor;  /* cursor into the line of text */
    double currentPosition;
        /* sum of xadd values and intercharacter space so far in line.  this
           is never negative.
        */
    double accumulatedIcs;
        /* accumulated intercharacter space so far in the line we are stepping
           through.  Because the intercharacter space might not be an integer,
           we accumulate it here and realize full pixels whenever we have more
           than one pixel.  Note that this can be negative (which means were
           crowding, rather than spreading, text).
        */
    int leftEdge;
    double rightEdge;

    currentPosition = 0;  /* initial value */
    accumulatedIcs  = 0.0;  /* initial value */

    leftEdge  = INT_MAX;  /* initial value */
    rightEdge = INT_MIN;  /* initial value */
    
    for (cursor = 0; line[cursor] != '\0'; ++cursor) {
        char const currentChar = line[cursor];
        struct glyph * const glyphP = 
            fontP->glyph[(unsigned char) currentChar];

        getEdges(currentPosition, currentChar, glyphP, leftEdge, rightEdge,
                 &leftEdge, &rightEdge);

        advancePosition(currentPosition, currentChar, glyphP,
                        intercharacterSpace, accumulatedIcs,
                        &currentPosition, &accumulatedIcs);
    }

    if (line[0] == '\0') {     /* Empty line */
        leftEdge  = 0;
        rightEdge = 0.0;
    }

    *leftEdgeP  = leftEdge;
    *rightEdgeP = rightEdge;
}



static void
getCharsWithinWidth(char                const line[],
                    const struct font * const fontP, 
                    float               const intercharacter_space,
                    unsigned int        const targetWidth,
                    unsigned int      * const charCountP,
                    int               * const leftEdgeP) {
/*----------------------------------------------------------------------------
   Determine how many characters of text line[] fit into an image of target
   width targetWidth.

   *leftEdgeP will be negative if the leftmost character in the line has a
   "backup" distance and zero if it does not.
-----------------------------------------------------------------------------*/
    if (line[0] == '\0') {
        /* Empty line */
        *leftEdgeP = 0;
        *charCountP = 0;
    } else {
        unsigned int cursor;  /* cursor into the line of text */
        double currentPosition;
        double accumulatedIcs;
        int leftEdge;
        double rightEdge;
        unsigned int currentWidth;

        currentPosition = 0;    /* initial value */
        accumulatedIcs  = 0.0;  /* initial value */

        leftEdge     = INT_MAX;  /* initial value */
        rightEdge    = INT_MIN;  /* initial value */
    
        for (cursor = 0, currentWidth = 0;
             currentWidth <= targetWidth && line[cursor] != '\0';
             ++cursor) {
            char const currentChar = line[cursor];
            struct glyph * const glyphP = 
                fontP->glyph[(unsigned char) currentChar];

            getEdges(currentPosition, currentChar, glyphP, leftEdge, rightEdge,
                     &leftEdge, &rightEdge);

            advancePosition(currentPosition, currentChar, glyphP,
                            intercharacter_space, accumulatedIcs,
                            &currentPosition, &accumulatedIcs);

            currentWidth = rightEdge - ((leftEdge > 0 ) ? 0 : leftEdge);
        }

        if (currentWidth > targetWidth) {
            if (cursor == 1)
                pm_error("-width value too small "
                         "to accomodate single character");
            else
                *charCountP = cursor - 1;
        } else
            *charCountP = cursor;

        *leftEdgeP  = leftEdge;
    }
}



static void
insertCharacter(const struct glyph * const glyph, 
                int                  const toprow, 
                int                  const leftcol,
                unsigned int         const cols,
                unsigned int         const rows,
                bit **               const bits) {
/*----------------------------------------------------------------------------
   Insert one character (whose glyph is 'glyph') into the image bits[].
   Its top left corner shall be row 'toprow', column 'leftcol'.
-----------------------------------------------------------------------------*/
    unsigned int glyph_y;  /* Y position within the glyph */

    if (leftcol + glyph->x < 0 ||
        leftcol + glyph->x + glyph->width > cols ||
        toprow < 0 ||
        toprow + glyph->height >rows )
        pm_error("internal error.  Rendering out of bounds");

    for (glyph_y = 0; glyph_y < glyph->height; ++glyph_y) {
        unsigned int glyph_x;  /* position within the glyph */

        for (glyph_x = 0; glyph_x < glyph->width; ++glyph_x) {
            if (glyph->bmap[glyph_y * glyph->width + glyph_x])
                bits[toprow + glyph_y][leftcol + glyph->x + glyph_x] = 
                    PBM_BLACK;
        }
    }
}    



static void
insertCharacters(bit **        const bits, 
                 struct text   const lp,
                 struct font * const fontP, 
                 int           const topmargin, 
                 int           const leftmargin,
                 float         const intercharacter_space,
                 unsigned int  const cols,
                 unsigned int  const rows,
                 int           const lspace) {
/*----------------------------------------------------------------------------
   Render the text 'lp' into the image 'bits' using font *fontP and
   putting 'intercharacter_space' pixels between characters and
   'lspace' pixels between the lines.
-----------------------------------------------------------------------------*/
    unsigned int line;  /* Line number in input text */

    for (line = 0; line < lp.lineCount; ++line) {
        unsigned int row;  /* row in image of top of current typeline */
        double leftcol;  /* Column in image of left edge of current glyph */
        unsigned int cursor;  /* cursor into a line of input text */
        double accumulatedIcs;
            /* accumulated intercharacter space so far in the line we
               are building.  Because the intercharacter space might
               not be an integer, we accumulate it here and realize
               full pixels whenever we have more than one pixel. 
            */

        row = topmargin + line * (fontP->maxheight + lspace);
        leftcol = leftmargin;
        accumulatedIcs = 0.0;  /* initial value */
    
        for (cursor = 0; lp.textArray[line][cursor] != '\0'; ++cursor) {
            char const currentChar = lp.textArray[line][cursor];
            unsigned int const glyphIndex = (unsigned int) currentChar;
            struct glyph * const glyphP = fontP->glyph[glyphIndex];
            int const toprow = row + fontP->maxheight + fontP->y 
                - glyphP->height - glyphP->y;
                /* row number in image of top row in glyph */

            assert(glyphP != NULL);
            
            insertCharacter(glyphP, toprow, leftcol, cols, rows, bits);

            advancePosition(leftcol, currentChar, glyphP,
                            intercharacter_space, accumulatedIcs,
                            &leftcol, &accumulatedIcs);
        }
    }
}



static void
flowText(struct text    const inputText,
         int            const targetWidth, 
         struct font  * const fontP, 
         float          const intercharacterSpace,
         struct text  * const outputTextP,
         unsigned int * const maxleftbP) {
    
    unsigned int outputLineNum;
    unsigned int incursor;   /* cursor into the line we are reading */
    unsigned int const maxLineCount = 50; /* max output lines */
    int leftEdge;
    int leftExtreme = 0;
    unsigned int charCount;

    allocTextArray(outputTextP, maxLineCount, 0);

    for (incursor = 0, outputLineNum = 0;
         inputText.textArray[0][incursor] != '\0'; ) {

        unsigned int outcursor;

        getCharsWithinWidth(&inputText.textArray[0][incursor], fontP, 
                            intercharacterSpace, targetWidth,
                            &charCount, &leftEdge);

        MALLOCARRAY(outputTextP->textArray[outputLineNum], charCount+1);

        if (!outputTextP->textArray[outputLineNum])
            pm_error("Unable to allocate memory for the text of line %u, "
                     "%u characters long", outputLineNum, charCount);

        ++outputTextP->allocatedLineCount;

        for (outcursor = 0; outcursor < charCount; ++outcursor, ++incursor) 
            outputTextP->textArray[outputLineNum][outcursor] = 
                inputText.textArray[0][incursor];

        outputTextP->textArray[outputLineNum][charCount] = '\0'; 
        ++outputLineNum;
        if (outputLineNum >= maxLineCount)
            pm_error("-width too small.  too many output lines");

        leftExtreme = MIN(leftEdge, leftExtreme);
    }
    outputTextP->lineCount = outputLineNum;
    *maxleftbP = (unsigned int) -leftExtreme;
}



static void
truncateText(struct text    const inputText, 
             unsigned int   const targetWidth, 
             struct font  * const fontP, 
             float          const intercharacterSpace,
             unsigned int * const maxleftbP) {

    unsigned int lineNum;  /* Line number on which we are currently working */
    int leftEdge;
    int leftExtreme = 0;

    for (lineNum = 0; lineNum < inputText.lineCount; ++lineNum) {
        char * const currentLine = inputText.textArray[lineNum];

        unsigned int charCount;

        getCharsWithinWidth(currentLine, fontP, 
                            intercharacterSpace, targetWidth,
                            &charCount, &leftEdge);

        if (currentLine[charCount] != '\0') {
            pm_message("truncating line %u from %u to %u characters",
                       lineNum, (unsigned) strlen(currentLine), charCount); 
            currentLine[charCount] = '\0';
        }

        leftExtreme = MIN(leftEdge, leftExtreme);
    }
    *maxleftbP = (unsigned int) - leftExtreme;
}



static void
getText(char          const cmdlineText[], 
        struct font * const fontP,
        struct text * const inputTextP) {

    struct text inputText;

    if (cmdlineText) {
        MALLOCARRAY_NOFAIL(inputText.textArray, 1);
        inputText.allocatedLineCount = 1;
        inputText.lineCount = 1;
        fixControlChars(cmdlineText, fontP,
                        (const char**)&inputText.textArray[0]);
    } else {
        /* Read text from stdin. */

        unsigned int maxlines;
            /* Maximum number of lines for which we presently have space in
               the text array
            */
        char * buf;
        char ** textArray;
        unsigned int lineCount;

        MALLOCARRAY(buf, MAXLINECHARS+1);

        if (!buf)
            pm_error("Unable to allocate memory for up to %u characters of "
                     "text", MAXLINECHARS);

        maxlines = 50;  /* initial value */
        MALLOCARRAY(textArray, maxlines);
        
        if (!textArray)
            pm_error("Unable to allocate memory for a buffer for up to %u "
                     "lines of text", maxlines);

        lineCount = 0;  /* initial value */
        while (fgets(buf, MAXLINECHARS, stdin) != NULL) {
            if (strlen(buf) + 1 >= MAXLINECHARS)
                pm_error("A line of input text is longer than %u characters."
                         "Cannot process", (unsigned int) MAXLINECHARS-1);
            if (lineCount >= maxlines) {
                maxlines *= 2;
                REALLOCARRAY(textArray, maxlines);
                if (textArray == NULL)
                    pm_error("out of memory");
            }
            fixControlChars(buf, fontP, (const char **)&textArray[lineCount]);
            if (textArray[lineCount] == NULL)
                pm_error("out of memory");
            ++lineCount;
        }
        inputText.textArray = textArray;
        inputText.lineCount = lineCount;
        inputText.allocatedLineCount = lineCount;
    }
    *inputTextP = inputText;
}



static void
computeImageHeight(struct text         const formattedText, 
                   const struct font * const fontP,
                   int                 const interlineSpace,
                   unsigned int        const vmargin,
                   unsigned int      * const rowsP) {

    if (interlineSpace < 0 && fontP->maxheight < -interlineSpace)
        pm_error("-lspace value (%d) negative and exceeds font height.",
                 interlineSpace);     
    else {
        double const rowsD = 2 * (double) vmargin + 
            (double) formattedText.lineCount * fontP->maxheight + 
            (double) (formattedText.lineCount-1) * interlineSpace;
        
        if (rowsD > INT_MAX-10)
            pm_error("Image height too large.");
        else
            *rowsP = (unsigned int) rowsD;
    }
}



static void
computeImageWidth(struct text         const formattedText, 
                  const struct font * const fontP,
                  float               const intercharacterSpace,
                  unsigned int        const hmargin,
                  unsigned int *      const colsP,
                  unsigned int *      const maxleftbP) {

    if (intercharacterSpace < 0 && fontP->maxwidth < -intercharacterSpace)
        pm_error("negative -space value %.2f exceeds font width",
                 intercharacterSpace);     
    else {
        /* Find the widest line, and the one that backs up the most past
           the nominal start of the line.
        */
    
        unsigned int lineNum;
        double rightExtreme;
        int leftExtreme;
        double colsD;

        rightExtreme = 0.0;  /* initial value */
        leftExtreme = 0;     /* initial value */

        for (lineNum = 0; lineNum < formattedText.lineCount;  ++lineNum) {
            double rightEdge;
            int leftEdge;
            
            getLineDimensions(formattedText.textArray[lineNum], fontP,
                              intercharacterSpace,
                              &rightEdge, &leftEdge);
            rightExtreme = MAX(rightExtreme, rightEdge);
            leftExtreme  = MIN(leftExtreme,  leftEdge);
        }
        leftExtreme = MIN(leftExtreme, 0);

        colsD = (double) (-leftExtreme) + rightExtreme + 2 * hmargin;

        if (colsD > INT_MAX-10)
            pm_error("Image width too large.");
        else
            *colsP = (unsigned int) colsD;
    
        *maxleftbP = (unsigned int) - leftExtreme;
    }
}



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

    struct CmdlineInfo cmdline;
    bit ** bits;
    unsigned int rows, cols;
    struct font * fontP;
    unsigned int vmargin, hmargin, fontMargin;
    struct text inputText;
    struct text formattedText;
    unsigned int maxleftb, maxleftb0;

    pm_proginit(&argc, argv);

    parseCommandLine(argc, argv, &cmdline);
    
    computeFont(cmdline, &fontP);

    getText(cmdline.text, fontP, &inputText);
       
    if (cmdline.nomargins) {
        vmargin = 0;
        hmargin = 0;
    } else {
        if (inputText.lineCount == 1) {
            vmargin = fontP->maxheight / 2;
            hmargin = fontP->maxwidth;
        } else {
            vmargin = fontP->maxheight;
            hmargin = 2 * fontP->maxwidth;
        }
    }
    
    if (cmdline.width > 0) {
        fontMargin = fontP->x < 0 ? -fontP->x : 0;

        if (cmdline.width > INT_MAX -10)
            pm_error("-width value too large: %u", cmdline.width);
        else if (cmdline.width < 2 * hmargin)
            pm_error("-width value too small: %u", cmdline.width);
        /* Flow or truncate lines to meet user's width request */
        else if (inputText.lineCount == 1) {
            flowText(inputText, cmdline.width - fontMargin,
                     fontP, cmdline.space, &formattedText, &maxleftb0);
            freeTextArray(inputText);
        } else {
            truncateText(inputText, cmdline.width - fontMargin,
                         fontP, cmdline.space, &maxleftb0);
            formattedText = inputText;
        }
    } else
        formattedText = inputText;
        
    if (formattedText.lineCount == 0)
        pm_error("No input text");
    
    computeImageHeight(formattedText, fontP, cmdline.lspace, vmargin,
                       &rows);

    computeImageWidth(formattedText, fontP, cmdline.space,
              cmdline.width > 0 ? 0 : hmargin, &cols, &maxleftb);

    if (cols == 0 || rows == 0)
        pm_error("Input is all whitespace and/or non-renderable characters.");

    if (cmdline.width > 0) {
      if(cmdline.width < cols)
      pm_error("internal error: calculated image width (%u) exceeds "
                   "specified -width value: %u",
                   cols, cmdline.width);
      else if(maxleftb0 != maxleftb)
      pm_error("internal error: contradicting backup values");
      else {
      hmargin = MIN(hmargin, (cmdline.width - cols) / 2);
          cols = cmdline.width;
      }
    }

    bits = pbm_allocarray(cols, rows);

    /* Fill background with white */
    fillRect(bits, rows, cols, PBM_WHITE);

    /* Put the text in  */
    insertCharacters(bits, formattedText, fontP, vmargin, hmargin + maxleftb, 
                     cmdline.space, cols, rows, cmdline.lspace);

    pbm_writepbm(stdout, bits, cols, rows, 0);

    pbm_freearray(bits, rows);

    freeTextArray(formattedText);
    pm_close(stdout);

    return 0;
}