<?php
/** PHP Weathermap 0.97a
 * Copyright Howard Jones, 2005-2010 howie@thingy.com
 * http://www.network-weathermap.com/
 * Released under the GNU Public License
 *
 * Utility Functions
 */

/**
 * Check for GD & PNG support This is just in here so that both the editor
 * and CLI can use it without the need for another file
 *
 * @return boolean If it's OK to run or not
 */
function WM_module_checks()
{
    if (false === extension_loaded('gd')) {
        warn(
            "\n\nNo image (gd) extension is loaded. This is required by weathermap. [WMWARN20]\n\n");
        warn("\nrun check.php to check PHP requirements.\n\n");

        return (false);
    }

    if (false === function_exists('imagecreatefrompng')) {
        warn("Your GD php module doesn't support PNG format. [WMWARN21]\n");
        warn("\nrun check.php to check PHP requirements.\n\n");
        return (false);
    }

    if (false === function_exists('imagecreatetruecolor')) {
        warn("Your GD php module doesn't support truecolor. [WMWARN22]\n");
        warn("\nrun check.php to check PHP requirements.\n\n");
        return (false);
    }

    if (false === function_exists('imagecopyresampled')) {
        warn(
            "Your GD php module doesn't support thumbnail creation (imagecopyresampled). [WMWARN23]\n");
    }
    return (true);
}

    function string_or_null($input)
    {
    	return ($input === null ? 'NULL' : $input);
    }

/**
 * central point for all debug logging, whether in the
 * standalone or Cacti parts of the tool.
 *
 * @global boolean $weathermap_debugging
 * @global string $weathermap_map
 * @global boolean $weathermap_debug_suppress
 * @param string $string The actual message to be logged
  */

function debug($string)
{
    global $weathermap_debugging;
    global $weathermap_map;
    global $weathermap_debug_suppress;

    if (true === $weathermap_debugging) {
        $calling_fn = '';

        if (true === function_exists('debug_backtrace')) {
            $bt = debug_backtrace();
            $index = 1;
            
            $function = '';
            $file = '';
            $line = '';
            
            $function = (true === isset($bt[$index]['function']) ? $bt[$index]['function'] : '');
            $index = 0;
            $file = (true === isset($bt[$index]['file']) ? basename($bt[$index]['file']) : '');
            $line = (true === isset($bt[$index]['line']) ? $bt[$index]['line'] : '');

            $calling_fn = sprintf(' [%s@%s:%d]', $function, $file, $line);

            if ( (true === is_array($weathermap_debug_suppress))
                && ( true === in_array(strtolower($function), $weathermap_debug_suppress))) {
                return;
            }
        }

        // use Cacti's debug log, if we are running from the poller
        if (true === function_exists('debug_log_insert')
            && (false === function_exists('show_editor_startpage'))) {
            cacti_log('DEBUG:'.$calling_fn 
                . ($weathermap_map === '' ? '' : $weathermap_map . ': ') . rtrim($string),
                true, 'WEATHERMAP');
        } else {
            $stderr = fopen('php://stderr', 'w');
            fwrite($stderr, 'DEBUG:'.$calling_fn 
                . ($weathermap_map === '' ? '' : $weathermap_map . ': ') . $string);
            fclose($stderr);

            // mostly this is overkill, but it's sometimes useful (mainly in the editor)
            if (1 == 0) {
                $log = fopen('debug.log', 'a');
                fwrite($log, "DEBUG:$calling_fn "
                    . ($weathermap_map == '' ? '' : $weathermap_map . ": ") . $string);
                fclose($log);
            }
        }
    }
}

/**
 * central point for all warnings, whether in the
 * standalone or Cacti parts of the tool.
 * Either dumps to stderr, or logs appropriately.
 *
 * @global string $weathermap_map
 * @global integer $weathermap_warncount
 * @param string $string
 * @param boolean $notice_only Whether or not to prefix the string with WARNING
 */
function warn($string, $notice_only = false)
{
    global $weathermap_map;
    global $weathermap_warncount;

    $message = '';

    if (false === $notice_only) {
        $weathermap_warncount++;
        $message .= 'WARNING: ';
    }

    $message .= ($weathermap_map === '' ? '' : $weathermap_map . ': ') . rtrim($string);

    // use Cacti's debug log, if we are running from the poller
    if (true === function_exists('cacti_log') && (false === function_exists('show_editor_startpage'))) {
        cacti_log($message, true, 'WEATHERMAP');
    } else {
        $stderr = fopen('php://stderr', 'w');
        fwrite($stderr, $message . "\n");
        fclose($stderr);
    }
}


/**
 * Prepare a string to be embedded in JS code or JSON
 *
 * @param string $str String to be escaped
 * @param boolean $wrap Should it also wrap it in quotes?
 * @return string
 */
function js_escape($str, $wrap = true)
{
    $str = str_replace('\\', '\\\\', $str);
    $str = str_replace('"', '\\"', $str);

    if (true === $wrap) {
        $str = '"' . $str . '"';
    }

    return ($str);
}

/**
 * Format a single number using a printf()-style format string.
 * Adds extra options for KGMT-suffixes
 *
 * @param string $format
 * @param int $value
 * @param int $kilo
 * @return string
 *
 */
function mysprintf($format, $value, $kilo = 1000)
{
    $output = '';

    debug("mysprintf: $format $value\n");

    if (1 === preg_match('/%(\d*\.?\d*)k/', $format, $matches)) {
        $spec = $matches[1];
        $places = 2;

        if ($spec !== '') {
            preg_match('/(\d*)\.?(\d*)/', $spec, $matches);

            if ($matches[2] !== '') {
                $places = $matches[2];
            }
        // we don't really need the justification (pre-.) part...
        }
        debug("KMGT formatting $value with $spec.\n");
        $result = nice_scalar($value, $kilo, $places);
        $output = preg_replace('/%' . $spec . 'k/', $format, $result);
    } else {
        debug("Falling through to standard sprintf\n");
        $output = sprintf($format, $value);
    }
    return $output;
}

/**
 * Simple tokenizer for strings, producing a list of 'words'
 * taking into account quote-enclosed single-word phrases. *
 *
 * Based on code from:
 * http://www.webscriptexpert.com/Php/Space-Separated%20Tag%20Parser/
 *
 * @param string $input
 * @return string[]
 */
function ParseString($input)
{
    $output = array ();   // Array of Output
    $cPhraseQuote = null; // Record of the quote that opened the current phrase
    $sPhrase = null;      // Temp storage for the current phrase we are building

    // Define some constants
    $sTokens = " \t"; // Space, Tab
    $sQuotes = "'\""; // Single and Double Quotes

    // Start the State Machine
    do {
        // Get the next token, which may be the first
        $sToken = isset($sToken) ? strtok($sTokens) : strtok($input, $sTokens);

        // Are there more tokens?
        if ($sToken === false) {
            // Ensure that the last phrase is marked as ended
            $cPhraseQuote = null;
        } else {
            // Are we within a phrase or not?
            if ($cPhraseQuote !== null) {
                // Will the current token end the phrase?
                if (substr($sToken, -1, 1) === $cPhraseQuote) {
// Trim the last character and add to the current phrase, with a single leading space if necessary
                    if (strlen($sToken) > 1) {
                        $sPhrase .= ((strlen($sPhrase) > 0) ? ' ' : null)
                            . substr($sToken, 0, -1);
                    }
                    $cPhraseQuote = null;
                } else {
// If not, add the token to the phrase, with a single leading space if necessary
                    $sPhrase .= ((strlen($sPhrase) > 0) ? ' ' : null) . $sToken;
                }
            } else {
                // Will the current token start a phrase?
                if (strpos($sQuotes, $sToken[0]) !== false) {
                    // Will the current token end the phrase?
                    if ((strlen($sToken) > 1) && ($sToken[0] === substr($sToken, -1, 1)))
                        {
                        // The current token begins AND ends the phrase, trim the quotes
                        $sPhrase = substr($sToken, 1, -1);
                    } else {
                        // Remove the leading quote
                        $sPhrase = substr($sToken, 1);
                        $cPhraseQuote = $sToken[0];
                    }
                } else {
                    $sPhrase = $sToken;
                }
            }
        }

// If, at this point, we are not within a phrase, the prepared phrase is complete and can be added to the array
        if (($cPhraseQuote === null) && ($sPhrase != null)) {
            $output[] = $sPhrase;
            $sPhrase = null;
        }
    } while ($sToken !== false); // Stop when we receive FALSE from strtok()

    return $output;
}

/**
 * wrapper around imagecolorallocate to try and re-use palette slots where possible
 *
 * @param gdimageref $image
 * @param int $red
 * @param int $green
 * @param int $blue
 * @return gdcolorref
 */
function myimagecolorallocate($image, $red, $green, $blue)
{
// it's possible that we're being called early - just return straight away, in that case
    if (!isset($image)) {
        return (-1);
    }

    $existing = imagecolorexact($image, $red, $green, $blue);

    // XXX - check if this function is doing any good!
    if ($existing > -1) {
        return $existing;
    }

    return (imagecolorallocate($image, $red, $green, $blue));
}

/**
 * Take a string and anonymise it by replacing any run of 3 or more
 * letters with an X, and any IP address with 127.0.0.1
 *
 * @param string $input
 * @return string
 */
function screenshotify($input)
{
    $tmp = $input;

    $tmp = preg_replace("/\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b/", "127.0.0.1", $tmp);
    $tmp = preg_replace("/([A-Za-z]{3,})/e", "str_repeat('x',strlen('\\1'))", $tmp);

    return ($tmp);
}

/**
 * Turn a colour tuple into a string for a config file
 *
 * @param int[] $col
 * @return string
 *
 */
function render_colour($col)
{
    if (($col[0] == -1) && ($col[1] == -1) && ($col[1] == -1)) {
        return 'none';
    } else if (($col[0] == -2) && ($col[1] == -2) && ($col[1] == -2)) {
        return 'copy';
    } else if (($col[0] == -3) && ($col[1] == -3) && ($col[1] == -3)) {
        return 'contrast';
    } else {
        return sprintf("%d %d %d", $col[0], $col[1], $col[2]);
    }
}

/**
 * take the same set of points that imagepolygon does, but don't close the shape
 *
 * @param gdimageref $image
 * @param int[] $points
 * @param int $npoints
 * @param gdcolorref $color
 *
 */
function imagepolyline($image, $points, $npoints, $color)
{
    for ($i = 0; $i < ($npoints - 1); $i++) {
        imageline($image, $points[$i * 2], $points[$i * 2 + 1], $points[$i * 2 + 2],
            $points[$i * 2 + 3], $color);
    }
}

/**
 * draw a filled round-cornered rectangle
 *
 * @param gdimageref $image
 * @param int $x1
 * @param int $y1
 * @param int $x2
 * @param int $y2
 * @param int $radius
 * @param gdcolorref $color
 *
 */
function imagefilledroundedrectangle($image, $x1, $y1, $x2, $y2, $radius, $color)
{
    imagefilledrectangle($image, $x1, $y1 + $radius, $x2, $y2 - $radius, $color);
    imagefilledrectangle($image, $x1 + $radius, $y1, $x2 - $radius, $y2, $color);

    imagefilledarc($image, $x1 + $radius, $y1 + $radius, $radius * 2, $radius * 2, 0, 360,
        $color, IMG_ARC_PIE);
    imagefilledarc($image, $x2 - $radius, $y1 + $radius, $radius * 2, $radius * 2, 0, 360,
        $color, IMG_ARC_PIE);

    imagefilledarc($image, $x1 + $radius, $y2 - $radius, $radius * 2, $radius * 2, 0, 360,
        $color, IMG_ARC_PIE);
    imagefilledarc($image, $x2 - $radius, $y2 - $radius, $radius * 2, $radius * 2, 0, 360,
        $color, IMG_ARC_PIE);

# bool imagefilledarc  ( resource $image  , int $cx  , int $cy  , int $width  , int $height  , int $start  , int $end  , int $color  , int $style  )
}

// draw a round-cornered rectangle

/**
 *
 * draw a round-cornered rectangle outline
 *
 * @param gdimageref $image
 * @param int $x1
 * @param int $y1
 * @param int $x2
 * @param int $y2
 * @param int $radius
 * @param gdcolorref $color
 *
 */
function imageroundedrectangle($image, $x1, $y1, $x2, $y2, $radius, $color)
{

    imageline($image, $x1 + $radius, $y1, $x2 - $radius, $y1, $color);
    imageline($image, $x1 + $radius, $y2, $x2 - $radius, $y2, $color);
    imageline($image, $x1, $y1 + $radius, $x1, $y2 - $radius, $color);
    imageline($image, $x2, $y1 + $radius, $x2, $y2 - $radius, $color);

    imagearc($image, $x1 + $radius, $y1 + $radius, $radius * 2, $radius * 2, 180, 270,
        $color);
    imagearc($image, $x2 - $radius, $y1 + $radius, $radius * 2, $radius * 2, 270, 360,
        $color);
    imagearc($image, $x1 + $radius, $y2 - $radius, $radius * 2, $radius * 2, 90, 180,
        $color);
    imagearc($image, $x2 - $radius, $y2 - $radius, $radius * 2, $radius * 2, 0, 90,
        $color);
}

/**
 * Load an image file, and return a gdimageref to it.
 * Figures out for itself what format the image file is in
 * (between JPEG, PNG, and GIF as long as you have the libraries)
 *
 * @param string $filename
 * @return gdimageref
 *
 */
function imagecreatefromfile($filename)
{
    $bgimage = null;
    $formats = imagetypes();

    if (false === is_readable($filename)) {
        warn('Image file '.$filename." is unreadable. Check permissions. [WMIMG05]\n");
        return null;
    }
    
        list($width, $height, $type, $attr) = getimagesize($filename);

        switch ($type) {
            case IMAGETYPE_GIF:
                if ((imagetypes() & IMG_GIF) === IMG_GIF) {
                    $bgimage = imagecreatefromgif($filename);
                } else {
                    warn(
                        'Image file '.$filename." is GIF, but GIF is not supported by your GD library. [WMIMG01]\n");
                }
                break;

            case IMAGETYPE_JPEG:
                if ((imagetypes() & IMG_JPEG) === IMG_JPEG) {
                    $bgimage = imagecreatefromjpeg($filename);
                } else {
                    warn(
                        'Image file '.$filename." is JPEG, but JPEG is not supported by your GD library. [WMIMG02]\n");
                }
                break;

            case IMAGETYPE_PNG:
                if ((imagetypes() & IMG_PNG) === IMG_PNG) {
                    $bgimage = imagecreatefrompng($filename);
                } else {
                    warn(
                        'Image file '.$filename." is PNG, but PNG is not supported by your GD library. [WMIMG03]\n");
                }
                break;

            default:
                warn('Image file '.$filename." wasn't recognised (type=".$type."). Check format is supported by your GD library. [WMIMG04]\n");
                break;
        }
        
    return $bgimage;
}

/**
 * Much nicer colorization than imagefilter does, AND no special requirements.
 * Preserves white, black and transparency.
 *
 * taken from here:
 * http://www.php.net/manual/en/function.imagefilter.php#62395
 * ( with some bugfixes and changes)
 *
 * @param gdimageref $im
 * @param int $r
 * @param int $g
 * @param int $b
 * @return gdimageref
 */
function imagecolorize($im, $r, $g, $b)
{
    // We will create a monochromatic palette based on the input color
    // which will go from black to white
    //
    // Input color luminosity: this is equivalent to the
    // position of the input color in the monochromatic palette
    $lum_inp = round(255 * ($r + $g + $b) / 765); //765=255*3

    //We fill the palette entry with the input color at its
    //corresponding position

    $pal[$lum_inp]['r'] = $r;
    $pal[$lum_inp]['g'] = $g;
    $pal[$lum_inp]['b'] = $b;

    //Now we complete the palette, first we'll do it to
    //the black,and then to the white.

    //FROM input to black
    //how many colors between black and input
    $steps_to_black = $lum_inp;

    //The step size for each component
    if ($steps_to_black > 0) {
        $step_size_red = $r / $steps_to_black;
        $step_size_green = $g / $steps_to_black;
        $step_size_blue = $b / $steps_to_black;
    }

    for ($i = $steps_to_black; $i >= 0; $i--) {
        $pal[$steps_to_black - $i]['r'] = $r - round($step_size_red * $i);
        $pal[$steps_to_black - $i]['g'] = $g - round($step_size_green * $i);
        $pal[$steps_to_black - $i]['b'] = $b - round($step_size_blue * $i);
    }

    //From input to white:
    //how many colors between input and white
    $steps_to_white = 255 - $lum_inp;

    if ($steps_to_white > 0) {
        $step_size_red = (255 - $r) / $steps_to_white;
        $step_size_green = (255 - $g) / $steps_to_white;
        $step_size_blue = (255 - $b) / $steps_to_white;
    } else {
        $step_size_red = $step_size_green = $step_size_blue = 0;
    }

    //The step size for each component
    for ($i = ($lum_inp + 1); $i <= 255; $i++) {
        $pal[$i]['r'] = $r + round($step_size_red * ($i - $lum_inp));
        $pal[$i]['g'] = $g + round($step_size_green * ($i - $lum_inp));
        $pal[$i]['b'] = $b + round($step_size_blue * ($i - $lum_inp));
    }

    //--- End of palette creation

    //Now, let's change the original palette into the one we created
    for ($c = 0; $c < imagecolorstotal($im); $c++) {
        $col = imagecolorsforindex($im, $c);
        $lum_src = round(255 * ($col['red'] + $col['green'] + $col['blue']) / 765);
        $col_out = $pal[$lum_src];

        imagecolorset($im, $c, $col_out['r'], $col_out['g'], $col_out['b']);
    }

    return ($im);
}

/**
 * find the point where a line from x1,y1 through x2,y2 crosses another line through x3,y3 and x4,y4
 * (the point might not be between those points, but beyond them)
 * - doesn't handle parallel lines. In our case we will never get them.
 * - make sure we remove colinear points, or this will not be true!
 *
 * @param float $x1
 * @param float $y1
 * @param float $x2
 * @param float $y2
 * @param float $x3
 * @param float $y3
 * @param float $x4
 * @param float $y4
 * @return float[]
 */
function line_crossing($x1, $y1, $x2, $y2, $x3, $y3, $x4, $y4)
{

    // First, check that the slope isn't infinite.
    // if it is, tweak it to be merely huge
    if ($x1 !== $x2) {
        $slope1 = ($y2 - $y1) / ($x2 - $x1);
    } else {
        $slope1 = 1e10;
        debug("Slope1 is infinite.\n");
    }

    if ($x3 !== $x4) {
        $slope2 = ($y4 - $y3) / ($x4 - $x3);
    } else {
        $slope2 = 1e10;
        debug("Slope2 is infinite.\n");
    }

    $a1 = $slope1;
    $a2 = $slope2;
    $b1 = -1;
    $b2 = -1;
    $c1 = ($y1 - $slope1 * $x1);
    $c2 = ($y3 - $slope2 * $x3);

    $det_inv = 1 / ($a1 * $b2 - $a2 * $b1);

    $xi = (($b1 * $c2 - $b2 * $c1) * $det_inv);
    $yi = (($a2 * $c1 - $a1 * $c2) * $det_inv);

    return (array (
        $xi,
        $yi
    ));
}


/**
 * rotate a list of points around cx,cy by an angle in radians, IN PLACE
 *
 * @param &float[] $points
 * @param float $cx
 * @param float $cy
 * @param float $angle
 *
 */
function RotateAboutPoint(&$points, $cx, $cy, $angle = 0)
{
    $npoints = count($points) / 2;

    for ($i = 0; $i < $npoints; $i++) {
        $ox = $points[$i * 2] - $cx;
        $oy = $points[$i * 2 + 1] - $cy;
        $rx = $ox * cos($angle) - $oy * sin($angle);
        $ry = $oy * cos($angle) + $ox * sin($angle);

        $points[$i * 2] = $rx + $cx;
        $points[$i * 2 + 1] = $ry + $cy;
    }
}

// calculate the points for a span of the curve. We pass in the distance so far, and the array index, so that
// the chunk of array generated by this function can be array_merged with existing points from before.
// Considering how many array functions there are, PHP has horrible list support
// Each point is a 3-tuple - x,y,distance - which is used later to figure out where the 25%, 50% marks are on the curve
function calculate_catmull_rom_span($startn, $startdistance, $numsteps, $x0, $y0, $x1,
    $y1, $x2, $y2, $x3, $y3)
{
    $Ap_x = -$x0 + 3 * $x1 - 3 * $x2 + $x3;
    $Bp_x = 2 * $x0 - 5 * $x1 + 4 * $x2 - $x3;
    $Cp_x = -$x0 + $x2;
    $Dp_x = 2 * $x1;

    $Ap_y = -$y0 + 3 * $y1 - 3 * $y2 + $y3;
    $Bp_y = 2 * $y0 - 5 * $y1 + 4 * $y2 - $y3;
    $Cp_y = -$y0 + $y2;
    $Dp_y = 2 * $y1;

    $d = 2;
    $n = $startn;
    $distance = $startdistance;

    $lx = $x0;
    $ly = $y0;

    $allpoints[] = array (
        $x0,
        $y0,
        $distance
    );

    for ($i = 0; $i <= $numsteps; $i++) {
        $t = $i / $numsteps;
        $t2 = $t * $t;
        $t3 = $t2 * $t;
        $x = (($Ap_x * $t3) + ($Bp_x * $t2) + ($Cp_x * $t) + $Dp_x) / $d;
        $y = (($Ap_y * $t3) + ($Bp_y * $t2) + ($Cp_y * $t) + $Dp_y) / $d;

        if ($i > 0) {
            $step = sqrt((($x - $lx) * ($x - $lx)) + (($y - $ly) * ($y - $ly)));
            $distance = $distance + $step;
            $allpoints[$n] = array (
                $x,
                $y,
                $distance
            );

            $n++;
        }

        $lx = $x;
        $ly = $y;
    }

    return array (
        $allpoints,
        $distance,
        $n
    );
}


/**
 * Given a spine array, find the point that is a given distance from the
 * beginning, in pixels. Finds the known point before the distance is passed,
 * and then interpolates to the exact distance, if necessary.
 *
 * @param &float[][] $pointarray
 * @return float[]
 */
function find_distance_coords(&$pointarray, $distance)
{
    // We find the nearest lower point for each distance,
    // then linearly interpolate to get a more accurate point
    // this saves having quite so many points-per-curve

    $index = find_distance($pointarray, $distance);

    $ratio = ($distance - $pointarray[$index][2])
        / ($pointarray[$index + 1][2] - $pointarray[$index][2]);
    $x = $pointarray[$index][0]
        + $ratio * ($pointarray[$index + 1][0] - $pointarray[$index][0]);
    $y = $pointarray[$index][1]
        + $ratio * ($pointarray[$index + 1][1] - $pointarray[$index][1]);

    return (array (
        $x,
        $y,
        $index
    ));
}

function find_distance_coords_angle(&$pointarray, $distance)
{
    // This is the point we need
    list($x, $y, $index) = find_distance_coords($pointarray, $distance);

    // now to find one either side of it, to get a line to find the angle of
    $left = $index;
    $right = $left + 1;
    $max = count($pointarray) - 1;

    // if we're right up against the last point, then step backwards one
    if ($right >= $max) {
        $left--;
        $right--;
    }

    $x1 = $pointarray[$left][0];
    $y1 = $pointarray[$left][1];

    $x2 = $pointarray[$right][0];
    $y2 = $pointarray[$right][1];

    $dx = $x2 - $x1;
    $dy = $y2 - $y1;

    $angle = rad2deg(atan2(-$dy, $dx));

    return (array (
        $x,
        $y,
        $index,
        $angle
    ));
}

// return the index of the point either at (unlikely) or just before the target distance
// we will linearly interpolate afterwards to get a true point - pointarray is an array of 3-tuples produced by the function above
function find_distance(&$pointarray, $distance)
{
    $left = 0;
    $right = count($pointarray) - 1;

    if ($left === $right) {
        return ($left);
    }

    // if the distance is zero, there's no need to search (and it doesn't work anyway)
    if ($distance === 0) {
        return ($left);
    }

    // if it's a point past the end of the line, then just return the end of the line
    // Weathermap should *never* ask for this, anyway
    if ($pointarray[$right][2] < $distance) {
        return ($right);
    }

    // if somehow we have a 0-length curve, then don't try and search, just give up
    // in a somewhat predictable manner
    if ($pointarray[$left][2] === $pointarray[$right][2]) {
        return ($left);
    }

    while ($left <= $right) {
        $mid = floor(($left + $right) / 2);

        if (($pointarray[$mid][2] < $distance) && ($pointarray[$mid + 1][2] >= $distance))
            {
            return $mid;
        }

        if ($distance <= $pointarray[$mid][2]) {
            $right = $mid - 1;
        } else {
            $left = $mid + 1;
        }
    }

    print "FELL THROUGH\n";
    die("Howie's crappy binary search is wrong after all.\n");
}

// Give a list of key points, calculate a curve through them
// return value is an array of triples (x,y,distance)
function calc_curve(&$in_xarray, &$in_yarray, $pointsperspan = 32)
{
// search through the point list, for consecutive duplicate points
// (most common case will be a straight link with both NODEs at the same place, I think)
// strip those out, because they'll break the binary search/centre-point stuff

    $last_x = null;
    $last_y = null;

    for ($i = 0; $i < count($in_xarray); $i++) {
        if (($in_xarray[$i] === $last_x) && ($in_yarray[$i] === $last_y)) {
            debug("Dumping useless duplicate point on curve\n");
        } else {
            $xarray[] = $in_xarray[$i];
            $yarray[] = $in_yarray[$i];
        }

        $last_x = $in_xarray[$i];
        $last_y = $in_yarray[$i];
    }

    // only proceed if we still have at least two points!
    if (count($xarray) <= 1) {
        warn("Arrow not drawn, as it's 1-dimensional.\n");
        return (array (
            null,
            null,
            null,
            null
        ));
    }

    // duplicate the first and last points, so that all points are drawn
    // (C-R normally would draw from x[1] to x[n-1]
    array_unshift($xarray, $xarray[0]);
    array_unshift($yarray, $yarray[0]);

    $x = array_pop($xarray);
    $y = array_pop($yarray);
    array_push($xarray, $x);
    array_push($xarray, $x);
    array_push($yarray, $y);
    array_push($yarray, $y);

    $npoints = count($xarray);

    $curvepoints = array ();

// add in the very first point manually (the calc function skips this one to avoid duplicates, which mess up the distance stuff)
    $curvepoints[] = array (
        $xarray[0],
        $yarray[0],
        0
    );

    $np = 0;
    $distance = 0;

    for ($i = 0; $i < ($npoints - 3); $i++) {
        list($newpoints, $distance, $np) =
            calculate_catmull_rom_span($np, $distance, $pointsperspan, $xarray[$i],
                $yarray[$i], $xarray[$i + 1], $yarray[$i + 1], $xarray[$i + 2],
                $yarray[$i + 2], $xarray[$i + 3], $yarray[$i + 3]);
        $curvepoints = $curvepoints + $newpoints;
    }

    return ($curvepoints);
}

// Give a list of key points, calculate a "curve" through them
// return value is an array of triples (x,y,distance)
// this is here to mirror the real 'curve' version when we're using angled VIAs
// it means that all the stuff that expects an array of points with distances won't be upset.
function calc_straight(&$in_xarray, &$in_yarray, $pointsperspan = 12)
{
// search through the point list, for consecutive duplicate points
// (most common case will be a straight link with both NODEs at the same place, I think)
// strip those out, because they'll break the binary search/centre-point stuff
    $last_x = null;
    $last_y = null;

    for ($i = 0; $i < count($in_xarray); $i++) {
        if (($in_xarray[$i] === $last_x) && ($in_yarray[$i] === $last_y)) {
            debug("Dumping useless duplicate point on curve\n");
        } else {
            $xarray[] = $in_xarray[$i];
            $yarray[] = $in_yarray[$i];
        }

        $last_x = $in_xarray[$i];
        $last_y = $in_yarray[$i];
    }

    // only proceed if we still have at least two points!
    if (count($xarray) <= 1) {
        warn("Arrow not drawn, as it's 1-dimensional.\n");
        return (array (
            null,
            null,
            null,
            null
        ));
    }

    $npoints = count($xarray);

    $curvepoints = array ();

    $np = 0;
    $distance = 0;

    for ($i = 0; $i < ($npoints - 1); $i++) {
        // still subdivide the straight line, becuase other stuff makes assumptions about
        // how often there is a point - at least find_distance_coords_angle breaks
        $newdistance = sqrt(pow($xarray[$i + 1] - $xarray[$i], 2)
            + pow($yarray[$i + 1] - $yarray[$i], 2));
        $dx = ($xarray[$i + 1] - $xarray[$i]) / $pointsperspan;
        $dy = ($yarray[$i + 1] - $yarray[$i]) / $pointsperspan;
        $dd = $newdistance / $pointsperspan;

        for ($j = 0; $j < $pointsperspan; $j++) {
            $x = $xarray[$i] + $j * $dx;
            $y = $yarray[$i] + $j * $dy;
            $d = $distance + $j * $dd;

            $curvepoints[] = array (
                $x,
                $y,
                $d
            );

            $np++;
        }
        $distance += $newdistance;
    }
    $curvepoints[] = array (
        $xarray[$npoints - 1],
        $yarray[$npoints - 1],
        $distance
    );

    #	print_r($curvepoints);

    return ($curvepoints);
}

function calc_arrowsize($width, &$map, $linkname)
{
    $arrowlengthfactor = 4;
    $arrowwidthfactor = 2;

    // this is so I can use it in some test code - sorry!
    if ($map !== null) {
        if ($map->links[$linkname]->arrowstyle === 'compact') {
            $arrowlengthfactor = 1;
            $arrowwidthfactor = 1;
        }

        if (1 === preg_match('/(\d+) (\d+)/', $map->links[$linkname]->arrowstyle, $matches)) {
            $arrowlengthfactor = $matches[1];
            $arrowwidthfactor = $matches[2];
        }
    }

    $arrowsize = $width * $arrowlengthfactor;
    $arrowwidth = $width * $arrowwidthfactor;

    return (array (
        $arrowsize,
        $arrowwidth
    ));
}

function draw_straight($image, &$curvepoints, $widths, $outlinecolour, $fillcolours,
    $linkname, &$map, $q2_percent = 50, $unidirectional = false)
{
    $totaldistance = $curvepoints[count($curvepoints) - 1][DISTANCE];

    if (true === $unidirectional) {
        $halfway = $totaldistance;
        $dirs = array (OUT);
        $q2_percent = 100;
        $halfway = $totaldistance * ($q2_percent / 100);
        list($halfway_x, $halfway_y, $halfwayindex) =
            find_distance_coords($curvepoints, $halfway);

        $spine[OUT] = $curvepoints;
    } else {
        // we'll split the spine in half here.
        $halfway = $totaldistance * ($q2_percent / 100);

        $dirs = array (
            OUT,
            IN
        );

        list($halfway_x, $halfway_y, $halfwayindex) =
            find_distance_coords($curvepoints, $halfway);

        $spine[OUT] = array ();
        $spine[IN] = array ();
        $npoints = count($curvepoints) - 1;

        for ($i = 0; $i <= $halfwayindex; $i++) {
            $spine[OUT][] = $curvepoints[$i];
        }
        // finally, add the actual midpoint
        $spine[OUT][] = array (
            $halfway_x,
            $halfway_y,
            $halfway
        );

        // and then from the end to the middle for the other arrow
        for ($i = $npoints; $i > $halfwayindex; $i--) {
            // copy the original spine, but reversing the distance calculation
            $spine[IN][] = array (
                $curvepoints[$i][X],
                $curvepoints[$i][Y],
                $totaldistance - $curvepoints[$i][DISTANCE]
            );
        }

        // finally, add the actual midpoint
        $spine[IN][] = array (
            $halfway_x,
            $halfway_y,
            $totaldistance - $halfway
        );
    }


// now we have two seperate spines, with distances, so that the arrowhead is the end of each.
// (or one, if it's unidir)

// so we can loop along the spine for each one as a seperate entity

// we calculate the arrow size up here, so that we can decide on the
// minimum length for a link. The arrowheads are the limiting factor.
    list($arrowsize[IN], $arrowwidth[IN]) = calc_arrowsize($widths[IN], $map, $linkname);
    list($arrowsize[OUT], $arrowwidth[OUT]) =
        calc_arrowsize($widths[OUT], $map, $linkname);

    // the 1.2 here is empirical. It ought to be 1 in theory.
    // in practice, a link this short is useless anyway, especially with bwlabels.
    $minimumlength = 1.2 * ($arrowsize[IN] + $arrowsize[OUT]);

    foreach ($dirs as $dir) {
        $n = count($spine[$dir]) - 1;
        $l = $spine[$dir][$n][DISTANCE];

// loop increment, start point, width, labelpos, fillcolour, outlinecolour, commentpos
        $arrowsettings = array (
            +1,
            0,
            $widths[$dir],
            0,
            $fillcolours[$dir],
            $outlinecolour,
            5
        );

        if ($l < $minimumlength) {
            warn("Skipping too-short line.\n");
        } else {
            $arrow_d = $l - $arrowsize[$dir];

            list($pre_mid_x, $pre_mid_y, $pre_midindex) =
                find_distance_coords($spine[$dir], $arrow_d);

            $out = array_slice($spine[$dir], 0, $pre_midindex);
            $out[] = array (
                $pre_mid_x,
                $pre_mid_y,
                $arrow_d
            );

            $spine[$dir] = $out;

            $adx = ($halfway_x - $pre_mid_x);
            $ady = ($halfway_y - $pre_mid_y);
            $ll = sqrt(($adx * $adx) + ($ady * $ady));

            $anx = $ady / $ll;
            $any = -$adx / $ll;

            $ax1 = $pre_mid_x + $widths[$dir] * $anx;
            $ay1 = $pre_mid_y + $widths[$dir] * $any;

            $ax2 = $pre_mid_x + $arrowwidth[$dir] * $anx;
            $ay2 = $pre_mid_y + $arrowwidth[$dir] * $any;

            $ax3 = $halfway_x;
            $ay3 = $halfway_y;

            $ax5 = $pre_mid_x - $widths[$dir] * $anx;
            $ay5 = $pre_mid_y - $widths[$dir] * $any;

            $ax4 = $pre_mid_x - $arrowwidth[$dir] * $anx;
            $ay4 = $pre_mid_y - $arrowwidth[$dir] * $any;

            $simple = simplify_spine($spine[$dir]);
            $newn = count($simple);

            // now do the actual drawing....

            $numpoints = 0;
            $numrpoints = 0;

            $finalpoints = array ();
            $reversepoints = array ();

            $finalpoints[] = $simple[0][X];
            $finalpoints[] = $simple[0][Y];
            $numpoints++;

            $reversepoints[] = $simple[0][X];
            $reversepoints[] = $simple[0][Y];
            $numrpoints++;

// before the main loop, add in the jump out to the corners
// if this is the first step, then we need to go from the middle to the outside edge first
// ( the loop may not run, but these corners are required)
            $i = 0;
            $v1 = new Vector($simple[$i + 1][X] - $simple[$i][X],
                $simple[$i + 1][Y] - $simple[$i][Y]);
            $n1 = $v1->get_normal();

            $finalpoints[] = $simple[$i][X] + $n1->dx * $widths[$dir];
            $finalpoints[] = $simple[$i][Y] + $n1->dy * $widths[$dir];
            $numpoints++;

            $reversepoints[] = $simple[$i][X] - $n1->dx * $widths[$dir];
            $reversepoints[] = $simple[$i][Y] - $n1->dy * $widths[$dir];
            $numrpoints++;

            $max_start = count($simple) - 2;


            for ($i = 0; $i < $max_start; $i++) {
                $v1 = new Vector($simple[$i + 1][X] - $simple[$i][X],
                    $simple[$i + 1][Y] - $simple[$i][Y]);
                $v2 = new Vector($simple[$i + 2][X] - $simple[$i + 1][X],
                    $simple[$i + 2][Y] - $simple[$i + 1][Y]);
                $n1 = $v1->get_normal();
                $n2 = $v2->get_normal();

                $capping = false;
// figure out the angle between the lines - for very sharp turns, we should do something special
// (actually, their normals, but the angle is the same and we need the normals later)
                $angle = rad2deg(atan2($n2->dy, $n2->dx) - atan2($n1->dy, $n1->dx));

                if ($angle > 180) {
                    $angle -= 360;
                }

                if ($angle < -180) {
                    $angle += 360;
                }

                if (abs($angle) > 169) {
                    $capping = true;
                }

                // now figure out the geometry for where the next corners are

                list($xi1, $yi1) = line_crossing($simple[$i][X] + $n1->dx * $widths[$dir],
                    $simple[$i][Y] + $n1->dy * $widths[$dir],
                    $simple[$i + 1][X] + $n1->dx * $widths[$dir],
                    $simple[$i + 1][Y] + $n1->dy * $widths[$dir],
                    $simple[$i + 1][X] + $n2->dx * $widths[$dir],
                    $simple[$i + 1][Y] + $n2->dy * $widths[$dir],
                    $simple[$i + 2][X] + $n2->dx * $widths[$dir],
                    $simple[$i + 2][Y] + $n2->dy * $widths[$dir]);

                list($xi2, $yi2) = line_crossing($simple[$i][X] - $n1->dx * $widths[$dir],
                    $simple[$i][Y] - $n1->dy * $widths[$dir],
                    $simple[$i + 1][X] - $n1->dx * $widths[$dir],
                    $simple[$i + 1][Y] - $n1->dy * $widths[$dir],
                    $simple[$i + 1][X] - $n2->dx * $widths[$dir],
                    $simple[$i + 1][Y] - $n2->dy * $widths[$dir],
                    $simple[$i + 2][X] - $n2->dx * $widths[$dir],
                    $simple[$i + 2][Y] - $n2->dy * $widths[$dir]);

                if (false === $capping) {
                    $finalpoints[] = $xi1;
                    $finalpoints[] = $yi1;
                    $numpoints++;

                    $reversepoints[] = $xi2;
                    $reversepoints[] = $yi2;
                    $numrpoints++;
                } else {
// in here, we need to decide which is the 'outside' of the corner,
// because that's what we flatten. The inside of the corner is left alone.
// - depending on the relative angle between the two segments, it could
//   be either one of these points.

                    list($xi3, $yi3) =
                        line_crossing($simple[$i][X] + $n1->dx * $widths[$dir],
                            $simple[$i][Y] + $n1->dy * $widths[$dir],
                            $simple[$i + 1][X] + $n1->dx * $widths[$dir],
                            $simple[$i + 1][Y] + $n1->dy * $widths[$dir],
                            $simple[$i + 1][X] - $n2->dx * $widths[$dir],
                            $simple[$i + 1][Y] - $n2->dy * $widths[$dir],
                            $simple[$i + 2][X] - $n2->dx * $widths[$dir],
                            $simple[$i + 2][Y] - $n2->dy * $widths[$dir]);

                    list($xi4, $yi4) =
                        line_crossing($simple[$i][X] - $n1->dx * $widths[$dir],
                            $simple[$i][Y] - $n1->dy * $widths[$dir],
                            $simple[$i + 1][X] - $n1->dx * $widths[$dir],
                            $simple[$i + 1][Y] - $n1->dy * $widths[$dir],
                            $simple[$i + 1][X] + $n2->dx * $widths[$dir],
                            $simple[$i + 1][Y] + $n2->dy * $widths[$dir],
                            $simple[$i + 2][X] + $n2->dx * $widths[$dir],
                            $simple[$i + 2][Y] + $n2->dy * $widths[$dir]);

                    if ($angle < 0) {
                        $finalpoints[] = $xi3;
                        $finalpoints[] = $yi3;
                        $numpoints++;

                        $finalpoints[] = $xi4;
                        $finalpoints[] = $yi4;
                        $numpoints++;

                        $reversepoints[] = $xi2;
                        $reversepoints[] = $yi2;
                        $numrpoints++;
                    } else {
                        $reversepoints[] = $xi4;
                        $reversepoints[] = $yi4;
                        $numrpoints++;

                        $reversepoints[] = $xi3;
                        $reversepoints[] = $yi3;
                        $numrpoints++;

                        $finalpoints[] = $xi1;
                        $finalpoints[] = $yi1;
                        $numpoints++;
                    }
                }
            }

            // at this end, we add the arrowhead

            $finalpoints[] = $ax1;
            $finalpoints[] = $ay1;
            $finalpoints[] = $ax2;
            $finalpoints[] = $ay2;
            $finalpoints[] = $ax3;
            $finalpoints[] = $ay3;
            $finalpoints[] = $ax4;
            $finalpoints[] = $ay4;
            $finalpoints[] = $ax5;
            $finalpoints[] = $ay5;

            $numpoints += 5;

            // combine the forwards and backwards paths, to make a complete loop
            for ($i = ($numrpoints - 1) * 2; $i >= 0; $i -= 2) {
                $x = $reversepoints[$i];
                $y = $reversepoints[$i + 1];

                $finalpoints[] = $x;
                $finalpoints[] = $y;
                $numpoints++;
            }
            // $finalpoints[] contains a complete outline of the line at this stage

            if (false === is_null($fillcolours[$dir])) {
                wimagefilledpolygon($image, $finalpoints, count($finalpoints) / 2,
                    $arrowsettings[4]);
            } else {
                debug(
                    "Not drawing $linkname ($dir) fill because there is no fill colour\n");
            }

            $areaname = "LINK:L" . $map->links[$linkname]->id . ":$dir";
            $map->imap->addArea("Polygon", $areaname, '', $finalpoints);
            debug('Adding Poly imagemap for '.$areaname."\n");

            if (false === is_null($outlinecolour)) {
                wimagepolygon($image, $finalpoints, count($finalpoints) / 2,
                    $arrowsettings[5]);
            } else {
                debug(
                    "Not drawing $linkname ($dir) outline because there is no outline colour\n");
            }
        }
    }
}

// top-level function that takes a two lists to define some points, and draws a weathermap link
// - this takes care of all the extras, like arrowheads, and where to put the bandwidth labels
//    curvepoints is an array of the points the curve passes through
//    width is the link width (the actual width is twice this)
//    outlinecolour is a GD colour reference
//    fillcolours is an array of two more colour references, one for the out, and one for the in spans
function draw_curve($image, &$curvepoints, $widths, $outlinecolour, $fillcolours,
    $linkname, &$map, $q2_percent = 50, $unidirectional = false)
{
// now we have a 'spine' - all the central points for this curve.
// time to flesh it out to the right width, and figure out where to draw arrows and bandwidth boxes...

// get the full length of the curve from the last point
    $totaldistance = $curvepoints[count($curvepoints) - 1][2];
    // find where the in and out arrows will join (normally halfway point)
    $halfway = $totaldistance * ($q2_percent / 100);

    $dirs = array (
        OUT,
        IN
    );

    // for a unidirectional map, we just ignore the second half (direction = -1)
    if (true === $unidirectional) {
        $halfway = $totaldistance;
        $dirs = array (OUT);
    }

    // loop increment, start point, width, labelpos, fillcolour, outlinecolour, commentpos
    $arrowsettings[OUT] = array (
        +1,
        0,
        $widths[OUT],
        0,
        $fillcolours[OUT],
        $outlinecolour,
        5
    );

    $arrowsettings[IN] = array (
        -1,
        count($curvepoints) - 1,
        $widths[IN],
        0,
        $fillcolours[IN],
        $outlinecolour,
        95
    );

    // we calculate the arrow size up here, so that we can decide on the
    // minimum length for a link. The arrowheads are the limiting factor.
    list($arrowsize[IN], $arrowwidth[IN]) = calc_arrowsize($widths[IN], $map, $linkname);
    list($arrowsize[OUT], $arrowwidth[OUT]) =
        calc_arrowsize($widths[OUT], $map, $linkname);

    // the 1.2 here is empirical. It ought to be 1 in theory.
    // in practice, a link this short is useless anyway, especially with bwlabels.
    $minimumlength = 1.2 * ($arrowsize[IN] + $arrowsize[OUT]);

    if ($totaldistance <= $minimumlength) {
        warn(
            "Skipping drawing very short link ($linkname). Impossible to draw! Try changing WIDTH or ARROWSTYLE? [WMWARN01]\n");
        return;
    }

    list($halfway_x, $halfway_y, $halfwayindex) =
        find_distance_coords($curvepoints, $halfway);

// loop over direction here
// direction is 1.0 for the first half (forwards through the pointlist), and -1.0 for the second half (backwards from the end)
//  - used as a multiplier on anything that looks forwards or backwards through the list

    foreach ($dirs as $dir) {
        $direction = $arrowsettings[$dir][0];

        // this is the last index before the arrowhead starts
        list($pre_mid_x, $pre_mid_y, $pre_midindex) =
            find_distance_coords($curvepoints, $halfway - $direction * $arrowsize[$dir]);

        $there_points = array ();
        $back_points = array ();
        $arrowpoints = array ();

        $start = $arrowsettings[$dir][1];

        for ($i = $start; $i != $pre_midindex; $i += $direction) {
// for each point on the spine, produce two points normal to it's direction,
// each is $width away from the spine, but we build up the two lists in the opposite order,
// so that when they are joined together, we get one continuous line

            $dx = $curvepoints[$i + $direction][0] - $curvepoints[$i][0];
            $dy = $curvepoints[$i + $direction][1] - $curvepoints[$i][1];
            $l = sqrt(($dx * $dx) + ($dy * $dy));
            $nx = $dy / $l;
            $ny = -$dx / $l;

            $there_points[] = $curvepoints[$i][0] + $direction * $widths[$dir] * $nx;
            $there_points[] = $curvepoints[$i][1] + $direction * $widths[$dir] * $ny;

            $back_points[] = $curvepoints[$i][0] - $direction * $widths[$dir] * $nx;
            $back_points[] = $curvepoints[$i][1] - $direction * $widths[$dir] * $ny;
        }

        // all the normal line is done, now lets add an arrowhead on

        $adx = ($halfway_x - $pre_mid_x);
        $ady = ($halfway_y - $pre_mid_y);
        $l = sqrt(($adx * $adx) + ($ady * $ady));

        $anx = $ady / $l;
        $any = -$adx / $l;

        $there_points[] = $pre_mid_x + $direction * $widths[$dir] * $anx;
        $there_points[] = $pre_mid_y + $direction * $widths[$dir] * $any;

        $there_points[] = $pre_mid_x + $direction * $arrowwidth[$dir] * $anx;
        $there_points[] = $pre_mid_y + $direction * $arrowwidth[$dir] * $any;

        $there_points[] = $halfway_x;
        $there_points[] = $halfway_y;

        $there_points[] = $pre_mid_x - $direction * $arrowwidth[$dir] * $anx;
        $there_points[] = $pre_mid_y - $direction * $arrowwidth[$dir] * $any;

        $there_points[] = $pre_mid_x - $direction * $widths[$dir] * $anx;
        $there_points[] = $pre_mid_y - $direction * $widths[$dir] * $any;

        // all points done, now combine the lists, and produce the final result.
        $metapts = '';
        $y = array_pop($back_points);
        $x = array_pop($back_points);

        do {
            $metapts .= " $x $y";
            $there_points[] = $x;
            $there_points[] = $y;
            $y = array_pop($back_points);
            $x = array_pop($back_points);
        } while (!is_null($y));

        $arrayindex = 1;

        if ($direction < 0) {
            $arrayindex = 0;
        }

        if (false === is_null($fillcolours[$arrayindex])) {
            wimagefilledpolygon($image, $there_points, count($there_points) / 2,
                $arrowsettings[$dir][4]);
        } else {
            debug("Not drawing $linkname ($dir) fill because there is no fill colour\n");
        }

        $areaname = 'LINK:L' . $map->links[$linkname]->id . ':'.$dir;
        $map->imap->addArea('Polygon', $areaname, '', $there_points);
        debug("Adding Poly imagemap for $areaname\n");

        if (false === is_null($outlinecolour)) {
            wimagepolygon($image, $there_points, count($there_points) / 2,
                $arrowsettings[$dir][5]);
        } else {
            debug(
                "Not drawing $linkname ($dir) outline because there is no outline colour\n");
        }
    }
}

/**
 * Take a spine, and strip out all the points that are co-linear
 * with the points either side of them
 *
 * @param &float[][] $input  the spine array to remove points from
 * @param float $epsilon     the 'fudge factor' of how close is considered equal
 * @return float[][]         the new reduced spine array
 */
function simplify_spine(&$input, $epsilon = 1e-10)
{
    $output = array ();

    $output[] = $input[0];
    $n = 1;
    $c = count($input) - 2;
    $skip = 0;

    for ($n = 1; $n <= $c; $n++) {
        $x = $input[$n][X];
        $y = $input[$n][Y];

// figure out the area of the triangle formed by this point, and the one before and after
        $a = abs($input[$n - 1][X] * ($input[$n][Y] - $input[$n + 1][Y])
            + $input[$n][X] * ($input[$n + 1][Y] - $input[$n - 1][Y])
            + $input[$n + 1][X] * ($input[$n - 1][Y] - $input[$n][Y]));

        if ($a > $epsilon)
        {
            $output[] = $input[$n];
        } else {
            // ignore n
            $skip++;
        }
    }

    debug("Skipped $skip points of $c\n");

    $output[] = $input[$c + 1];
    return $output;
}

/**
 * Take a formatted number (1.2K, 55M) and produce a regular number from it
 *
 * @param string $instring
 * @param int $kilo
 * @return float
 */
function unformat_number($instring, $kilo = 1000)
{
    $matches = 0;
    $number = 0;

    if (1 === preg_match('/([0-9\.]+)(M|G|K|T|m|u)/', $instring, $matches)) {
        $number = floatval($matches[1]);

        if ($matches[2] === 'K') {
            $number = $number * $kilo;
        }

        if ($matches[2] === 'M') {
            $number = $number * $kilo * $kilo;
        }

        if ($matches[2] === 'G') {
            $number = $number * $kilo * $kilo * $kilo;
        }

        if ($matches[2] === 'T') {
            $number = $number * $kilo * $kilo * $kilo * $kilo;
        }

        // new, for absolute datastyle. Think seconds.
        if ($matches[2] === 'm') {
            $number = $number / $kilo;
        }

        if ($matches[2] === 'u') {
            $number = $number / ($kilo * $kilo);
        }
    } else {
        $number = floatval($instring);
    }

    return ($number);
}

/**
 * given an offset string, and a width & height, return a tuple of the x,y offsets
 *
 * 'offset string' can be a compass point, an actual offset, or a couple
 * of other polar coordinate formats.
 *
 * @param string $offsetstring
 * @param float $width
 * @param float $height
 * @return float[]
 */
function calc_offset($offsetstring, $width, $height)
{
    if (1 === preg_match('/^([-+]?\d+):([-+]?\d+)$/', $offsetstring, $matches)) {
        debug("Numeric Offset found\n");
        return (array (
            $matches[1],
            $matches[2]
        ));
    } elseif (1 === preg_match('/(NE|SE|NW|SW|N|S|E|W|C)(\d+)?$/i', $offsetstring, $matches)) {
        $multiply = 1;

        if (isset($matches[2])) {
            $multiply = intval($matches[2]) / 100;
            debug("Percentage compass offset: multiply by $multiply");
        }

        $height = $height * $multiply;
        $width = $width * $multiply;

        switch (strtoupper($matches[1])) {
            case 'N':
                return (array (
                    0,
                    -$height / 2
                ));

                break;

            case 'S':
                return (array (
                    0,
                    $height / 2
                ));

                break;

            case 'E':
                return (array (
                    +$width / 2,
                    0
                ));

                break;

            case 'W':
                return (array (
                    -$width / 2,
                    0
                ));

                break;

            case 'NW':
                return (array (
                    -$width / 2,
                    -$height / 2
                ));

                break;

            case 'NE':
                return (array (
                    $width / 2,
                    -$height / 2
                ));

                break;

            case 'SW':
                return (array (
                    -$width / 2,
                    $height / 2
                ));

                break;

            case 'SE':
                return (array (
                    $width / 2,
                    $height / 2
                ));

                break;

            case 'C':
            default:
                return (array (
                    0,
                    0
                ));

                break;
        }
    } elseif (1 === preg_match('/(-?\d+)r(\d+)$/i', $offsetstring, $matches)) {
        $angle = intval($matches[1]);
        $distance = intval($matches[2]);

        $x = $distance * sin(deg2rad($angle));
        $y = -$distance * cos(deg2rad($angle));

        return (array (
            $x,
            $y
        ));
    } else {
        warn("Got a position offset that didn't make sense ($offsetstring).");
        return (array (
            0,
            0
        ));
    }
}

// These next two are based on perl's Number::Format module
// by William R. Ward, chopped down to just what I needed

function format_number($number, $precision = 2, $trailing_zeroes = 0)
{
    $sign = 1;

    if ($number < 0) {
        $number = abs($number);
        $sign = -1;
    }

    $number = round($number, $precision);
    $integer = intval($number);

    if (strlen($integer) < strlen($number)) {
        $decimal = substr($number, strlen($integer) + 1);
    }

    if (false === isset($decimal)) {
        $decimal = '';
    }

    $integer = $sign * $integer;

    if ($decimal === '') {
        return ($integer);
    } else {
        return ($integer . '.' . $decimal);
    }
}

/**
 * Make a nice number out of a raw number.
 * Use kilo, mega etc to make it nicer.
 *
 * @param float $number
 * @param int $kilo           whether kilo is 1000, 1024 or something else
 * @param int $decimals       how many decimal places to show?
 * @param <type> $below_one   use the micro, nano, etc?
 * @return string
 */
function nice_bandwidth($number, $kilo = 1000, $decimals = 1, $below_one = true)
{
    $suffix = '';

    if ($number === 0) {
        return '0';
    }

    $mega = $kilo * $kilo;
    $giga = $mega * $kilo;
    $tera = $giga * $kilo;

    $milli = 1 / $kilo;
    $micro = 1 / $mega;
    $nano = 1 / $giga;

    if ($number >= $tera) {
        $number /= $tera;
        $suffix = 'T';
    } elseif ($number >= $giga) {
        $number /= $giga;
        $suffix = 'G';
    } elseif ($number >= $mega) {
        $number /= $mega;
        $suffix = 'M';
    } elseif ($number >= $kilo) {
        $number /= $kilo;
        $suffix = 'K';
    } elseif ($number >= 1) {
        $number = $number;
        $suffix = '';
    } elseif (($below_one == true) && ($number >= $milli)) {
        $number /= $milli;
        $suffix = 'm';
    } elseif (($below_one == true) && ($number >= $micro)) {
        $number /= $micro;
        $suffix = 'u';
    } elseif (($below_one == true) && ($number >= $nano)) {
        $number /= $nano;
        $suffix = 'n';
    }

    $result = format_number($number, $decimals) . $suffix;
    return ($result);
}

// XXX why are there two nearly-identical functions here?

/**
 * Make a nice number out of a raw number.
 * Use kilo, mega etc to make it nicer.
 *
 * @param float $number  the number to format
 * @param int $kilo      whether kilo is 1000, 1024 or something else
 * @param int $decimals  how many decimal places to show?
 * @return string
 */
function nice_scalar($number, $kilo = 1000, $decimals = 1)
{
    $suffix = '';
    $prefix = '';

    if ($number === 0) {
        return '0';
    }

    if ($number < 0) {
        $number = -$number;
        $prefix = '-';
    }

    $mega = $kilo * $kilo;
    $giga = $mega * $kilo;
    $tera = $giga * $kilo;

    if ($number > $tera) {
        $number /= $tera;
        $suffix = 'T';
    } elseif ($number > $giga) {
        $number /= $giga;
        $suffix = 'G';
    } elseif ($number > $mega) {
        $number /= $mega;
        $suffix = 'M';
    } elseif ($number > $kilo) {
        $number /= $kilo;
        $suffix = 'K';
    } elseif ($number > 1) {
        $number = $number;
        $suffix = '';
    } elseif ($number < (1 / ($kilo))) {
        $number = $number * $mega;
        $suffix = 'u';
    } elseif ($number < 1) {
        $number = $number * $kilo;
        $suffix = 'm';
    }

    $result = $prefix . format_number($number, $decimals) . $suffix;
    return ($result);
}


/**
 * Utility 'class' for 2D points.
 *
 * we use enough points in various places to make it worth a small class to
 * save some variable-pairs.
 *
 */
class Point
{
    var $x, $y;

    function Point($x = 0, $y = 0)
    {
        $this->x = $x;
        $this->y = $y;
    }
}

/**
 * Utility class for 2D vectors. Mostly used in the VIA calculations
 */
class Vector
{
    var $dx, $dy;

    function Vector($dx = 0, $dy = 0)
    {
        $this->dx = $dx;
        $this->dy = $dy;
    }

    function get_normal()
    {
        $len = $this->length();

        $nx1 = $this->dy / $len;
        $ny1 = -$this->dx / $len;

        return (new Vector($nx1, $ny1));
    }

    function normalise()
    {
        $len = $this->length();
        $this->dx = $this->dx / $len;
        $this->dy = $this->dy / $len;
    }

    function length()
    {
        return (sqrt(($this->dx) * ($this->dx)+($this->dy) * ($this->dy)));
    }
}

/**
 * Utility class used for colour calculations in Weathermap.
 *
 * Allows representation of any RGB colour, plus some special
 * pseudocolours.
 *
 */
class Colour
{
    var $r, $g, $b, $alpha;


    // take in an existing value and create a Colour object for it
    function Colour()
    {
        if (func_num_args() === 3)       # a set of 3 colours
        {
            $this->r = func_get_arg(0); # r
            $this->g = func_get_arg(1); # g
            $this->b = func_get_arg(2); # b        
        }

        if ((func_num_args() === 1)
            && gettype(func_get_arg(0)) === 'array') # an array of 3 colours
        {
            $ary = func_get_arg(0);
            $this->r = $ary[0];
            $this->g = $ary[1];
            $this->b = $ary[2];
        }
    }

    // Is this a transparent/none colour?
    function is_real()
    {
        if ($this->r >= 0 && $this->g >= 0 && $this->b >= 0) {
            return true;
        } else {
            return false;
        }
    }

    // Is this a transparent/none colour?
    function is_none()
    {
        if ($this->r === -1 && $this->g === -1 && $this->b === -1) {
            return true;
        } else {
            return false;
        }
    }

    // Is this a contrast colour?
    function is_contrast()
    {
        if ($this->r === -3 && $this->g === -3 && $this->b === -3) {
            return true;
        } else {
            return false;
        }
    }

    // Is this a copy colour?
    function is_copy()
    {
        if ($this->r === -2 && $this->g === -2 && $this->b === -2) {
            return true;
        } else {
            return false;
        }
    }

// allocate a colour in the appropriate image context
// - things like scale colours are used in multiple images now (the scale, several nodes, the main map...)
    function gdallocate($image_ref)
    {
        if (true === $this->is_none()) {
            return null;
        } else {
            return (myimagecolorallocate($image_ref, $this->r, $this->g, $this->b));
        }
    }

    // based on an idea from: http://www.bennadel.com/index.cfm?dax=blog:902.view
    function contrast_ary()
    {
        if ((($this->r + $this->g + $this->b) > 500) || ($this->g > 140)) {
            return (array (
                0,
                0,
                0
            ));
        } else {
            return (array (
                255,
                255,
                255
            ));
        }
    }

    function contrast()
    {
        return (new Colour($this->contrast_ary()));
    }

// make a printable version, for debugging
// - optionally take a format string, so we can use it for other things (like WriteConfig, or hex in stylesheets)
    function as_string($format = 'RGB(%d,%d,%d)')
    {
        return (sprintf($format, $this->r, $this->g, $this->b));
    }

    function as_config()
    {
        return $this->as_string('%d %d %d');
    }

    function as_html()
    {
        if (true === $this->is_real()) {
            return $this->as_string('#%02x%02x%02x');
        } else {
            return '';
        }
    }
}

/**
 *
 * A series of wrapper functions around all the GD function calls
 * - I added these in so I could make a 'metafile' easily of all the
 * drawing commands for a map. I have a basic Perl-Cairo script that makes
 * anti-aliased maps from these, using Cairo instead of GD.
 *
 */

/**
 * Add a line to the metadump file.
 * Used by all the wimage* functions
 *
 * @param string $string String to add to file
 * @param boolean $truncate Is this to start a new file, or continue one?
 */
function metadump($string, $truncate = false)
{
    // comment this line to get a metafile for this map
    return;

    if (true === $truncate) {
        $fd = fopen('metadump.txt', 'w+');
    } else {
        $fd = fopen('metadump.txt', 'a');
    }
    fputs($fd, $string . "\n");
    fclose($fd);
}

function metacolour(&$col)
{
    return ($col['red1'] . ' ' . $col['green1'] . ' ' . $col['blue1']);
}

/**
 * Create an image structure.
 * Log the parameters to the metafile.
 *
 * @param int $width
 * @param int $height
 * @return gdimageref
 */
function wimagecreate($width, $height)
{
    metadump('NEWIMAGE '.$width.' '.$height);
    return (imagecreate($width, $height));
}

function wimagefilledrectangle($image, $x1, $y1, $x2, $y2, $color)
{
    if ($color === null) {
        return;
    }

    $col = imagecolorsforindex($image, $color);
    $r = $col['red'];
    $g = $col['green'];
    $b = $col['blue'];
    $a = $col['alpha'];
    $r = $r / 255;
    $g = $g / 255;
    $b = $b / 255;
    $a = (127 - $a) / 127;

    metadump( sprintf('FRECT %f %f %f %f %f %f %f %f',
        $x1, $y1, $x2, $y2, $r, $g, $b, $a));
    
    return (imagefilledrectangle($image, $x1, $y1, $x2, $y2, $color));
}

function wimagerectangle($image, $x1, $y1, $x2, $y2, $color)
{
    if ($color === null) {
        return;
    }

    $col = imagecolorsforindex($image, $color);
    $r = $col['red'];
    $g = $col['green'];
    $b = $col['blue'];
    $a = $col['alpha'];
    $r = $r / 255;
    $g = $g / 255;
    $b = $b / 255;
    $a = (127 - $a) / 127;
    
    metadump( sprintf('RECT %f %f %f %f %f %f %f %f',
        $x1, $y1, $x2, $y2, $r, $g, $b, $a));
    
    return (imagerectangle($image, $x1, $y1, $x2, $y2, $color));
}

function wimagepolygon($image, $points, $num_points, $color)
{
    if ($color === null) {
        return;
    }

    $col = imagecolorsforindex($image, $color);
    $r = $col['red'];
    $g = $col['green'];
    $b = $col['blue'];
    $a = $col['alpha'];
    $r = $r / 255;
    $g = $g / 255;
    $b = $b / 255;
    $a = (127 - $a) / 127;

    $pts = '';

    for ($i = 0; $i < $num_points; $i++) {
        $pts .= $points[$i * 2] . ' ';
        $pts .= $points[$i * 2 + 1] . ' ';
    }

    metadump( sprintf('POLY %d %s %f %f %f %f',
        $num_points, $pts, $r, $g, $b, $a));
    
    return (imagepolygon($image, $points, $num_points, $color));
}

function wimagefilledpolygon($image, $points, $num_points, $color)
{
    if ($color === null) {
        return;
    }

    $col = imagecolorsforindex($image, $color);
    $r = $col['red'];
    $g = $col['green'];
    $b = $col['blue'];
    $a = $col['alpha'];
    $r = $r / 255;
    $g = $g / 255;
    $b = $b / 255;
    $a = (127 - $a) / 127;

    $pts = '';

    for ($i = 0; $i < $num_points; $i++) {
        $pts .= $points[$i * 2] . ' ';
        $pts .= $points[$i * 2 + 1] . ' ';
    }
    
    metadump( sprintf('FPOLY %d %s %f %f %f %f',
        $num_points, $pts, $r, $g, $b, $a));

    return (imagefilledpolygon($image, $points, $num_points, $color));
}

function wimagecreatetruecolor($width, $height)
{
    metadump('BLANKIMAGE '.$width.' '.$height);

    return imagecreatetruecolor($width, $height);
}

function wimagettftext($image, $size, $angle, $x, $y, $color, $file, $string)
{
    if ($color === null) {
        return;
    }        

    $col = imagecolorsforindex($image, $color);
    $r = $col['red'];
    $g = $col['green'];
    $b = $col['blue'];
    $a = $col['alpha'];
    $r = $r / 255;
    $g = $g / 255;
    $b = $b / 255;
    $a = (127 - $a) / 127;

    metadump( sprintf('TEXT %f %f %f %f %s %f %f %f %f %s',
        $x, $y, $angle, $size, $file, $r, $g, $b, $a, $string
    ));

    return (imagettftext($image, $size, $angle, $x, $y, $color, $file, $string));
}

function wm_draw_marker_diamond($im, $col, $x, $y, $size = 10)
{
    $points = array ();

    $points[] = $x - $size;
    $points[] = $y;

    $points[] = $x;
    $points[] = $y - $size;

    $points[] = $x + $size;
    $points[] = $y;

    $points[] = $x;
    $points[] = $y + $size;

    $num_points = 4;

    imagepolygon($im, $points, $num_points, $col);
}

function wm_draw_marker_box($im, $col, $x, $y, $size = 10)
{
    $points = array ();

    $points[] = $x - $size;
    $points[] = $y - $size;

    $points[] = $x + $size;
    $points[] = $y - $size;

    $points[] = $x + $size;
    $points[] = $y + $size;

    $points[] = $x - $size;
    $points[] = $y + $size;

    $num_points = 4;

    imagepolygon($im, $points, $num_points, $col);
}

function wm_draw_marker_circle($im, $col, $x, $y, $size = 10)
{
    imagearc($im, $x, $y, $size, $size, 0, 360, $col);
}

/**
 * Draw a spine array - not used in the main code, just for debugging
 *
 * @param gdimageref $im
 * @param float[][] $spine
 * @param gdcolorref $col
 * @param int $size
 */
function draw_spine_chain($im, $spine, $col, $size = 10)
{
    $newn = count($spine);

    for ($i = 0; $i < $newn; $i++) {
        imagearc($im, $spine[$i][X], $spine[$i][Y], $size, $size, 0, 360, $col);
    }
}

/**
 * Dump a spine array as text - not used in the main code, just for debugging
 *
 * @param float[][] $spine
 */
function dump_spine($spine)
{
    print "===============\n";

    for ($i = 0; $i < count($spine); $i++) {
        printf("  %3d: %d,%d (%d)\n", $i, $spine[$i][X], $spine[$i][Y],
            $spine[$i][DISTANCE]);
    }
    print "===============\n";
}


/**
 * Draw a spine array - not used in the main code, just for debugging
 *
 * @param gdimageref $im
 * @param float[][] $spine
 * @param gdcolorref $col
 */
function draw_spine($im, $spine, $col)
{
    $max_i = count($spine) - 1;

    for ($i = 0; $i < $max_i; $i++) {
        imageline($im, $spine[$i][X], $spine[$i][Y], $spine[$i + 1][X], $spine[$i + 1][Y],
            $col);
    }
}

// vim:ts=4:sw=4:
?>