Chamilo is a learning management system focused on ease of use and accessibility
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chamilo-lms/main/inc/lib/geometry.lib.php

336 lines
11 KiB

<?php
/* For licensing terms, see /license.txt */
/**
* @author Arnaud Ligot (CBlue SPRL) <arnaud@cblue.be>
* @package chamilo.include.geometry
*/
/**
* Code
*/
DEFINE('DEBUG', false);
/**
* poly_init - build the array which will store the image of the polygone
* @param max[x] X resolution
* @param max[y] Y resolution
* @returns an array such as: for all i in [0..max[x][ : for all j in [0..max[y][ : array[i][j] = FALSE
*/
function poly_init($max) {
return array_fill(0, $max["x"]-1,
array_fill(0, $max["y"]-1, FALSE));
}
/**
* poly_compile - return an array which holds the image of the polygone
* FALSE = blank pixel
* TRUE = black pixel
*
* @param poly points from the polygone
* example:
* poly[0]['x'] = ...
* poly[0]['y'] = ...
* poly[1]['x'] = ...
* poly[1]['y'] = ...
* ...
* poly[n]['x'] = <empty>
* poly[n]['y'] = <empty>
* poly[n+1]['x'] = <empty>
* poly[n+1]['y'] = <empty>
* ...
* @param max see poly_init
* @param boolean print or not a debug
*
* @returns an array such as: for all i in [0..max[x][ : for all j in [0..max[y][ : array[i][j] = in_poly(poly, i,j)
* in_poly(poly,i,j) = true iff (i,j) is inside the polygon defined by poly
*/
function poly_compile($poly, $max, $test = false) {
$res = poly_init($max);
// looking for EDGES
// may be optimized by a dynamic choice
// between Y and X based on max[y]<max[x]
/*
* bords cointains the edges of the polygone
* it is an array of array,
* there are an array for each collon of the image
*
* for all j in [O..max[y][ : for all i in bords[$j] :
* (i,j) is a point inside an edge of the polygone
*/
$bord_lenght = $max['x'];
if ($max['y'] > $bord_lenght) {
$bord_lenght = $max['y'];
}
//$bords = array_fill(0, $bord_lenght-1, array()); // building this array
$bords = array_fill(0, $bord_lenght, array()); // building this array
/* adding the first point of the polygone */
if (is_array($bords[$poly[0]['y']])) //avoid warning
array_push($bords[$poly[0]['y']], $poly[0]['x']);
$i = 1; // we re-use $i and $old_pente bellow the loop
$old_pente=0;
for ( ; // for each points of the polygon but the first
$i<sizeof($poly) && (!empty($poly[$i]['x']) && !empty($poly[$i]['y'])); $i++) {
/* special cases */
if ($poly[$i-1]['y'] == $poly[$i]['y']) {
if ($poly[$i-1]['x'] == $poly[$i]['x'])
continue; // twice the same point
else { // infinite elevation of the edge
if (is_array($bords[$poly[$i]['y']]))
array_push($bords[$poly[$i]['y']],$poly[$i]['x']);
$old_pente=0;
continue;
}
}
//echo 'point:'.$poly[$i]['y']; bug here
// adding the point as a part of an edge
if (is_array($bords[$poly[$i]['y']])) //avoid warning
array_push($bords[$poly[$i]['y']], $poly[$i]['x']);
if (DEBUG) echo '('.$poly[$i]['x'].';'.$poly[$i]['y'].') ';
/* computing the elevation of the edge going */
// from $poly[$i-1] to $poly[$i]
$pente = ($poly[$i-1]['x']-$poly[$i]['x'])/
($poly[$i-1]['y']-$poly[$i]['y']);
// if the sign of the elevation change from the one of the
// previous edge, the point must be added a second time inside
// $bords
if ($i>1)
if (($old_pente<0 && $pente>0)
|| ($old_pente>0 && $pente<0)) {
if (is_array($bords[$poly[$i]['y']])) //avoid warning
array_push($bords[$poly[$i]['y']],$poly[$i]['x']);
if (DEBUG)
echo '*('.$poly[$i]['x'].
';'.$poly[$i]['y'].') ';
}
/* detect the direction of the elevation in Y */
$dy_inc = ($poly[$i]['y']-$poly[$i-1]['y']) > 0 ? 1 : -1;
$x = $poly[$i-1]['x'];
// if (DEBUG) echo "init: ".$poly[$i-1]['y']." dy_inc: ".$dy_inc.
// " end: ".$poly[$i]['y']." pente:".$pente;
/* computing points between $poly[$i-1]['y'] and $poly[$i-1]['y'] */
// we iterate w/ $dy in ]$poly[$i-1]['y'],$poly[$i-1]['y'][
// w/ $dy_inc as increment
for ($dy = $poly[$i-1]['y']+$dy_inc;
$dy != $poly[$i]['y'];
$dy += $dy_inc) {
$x += $pente*$dy_inc;
array_push($bords[$dy], $x);
// if (DEBUG) echo '/('.$x.';'.$dy.') ';
}
$old_pente = $pente;
}
// closing the polygone (the edge between $poly[$i-1] and $poly[0])
if ($poly[$i-1]['y']!=$poly[0]['y']) {// droite--> rien à faire
// elevation between $poly[0]['x'] and $poly[1]['x'])
$rest = $poly[0]['y']-$poly[1]['y'];
if ($rest!=0)
$pente1 = ($poly[0]['x']-$poly[1]['x'])/($rest);
else
$pente1 = 0;
// elevation between $poly[$i-1]['x'] and $poly[0]['x'])
$pente = ($poly[$i-1]['x']-$poly[0]['x'])/
($poly[$i-1]['y']-$poly[0]['y']);
// if (DEBUG) echo 'start('.$poly[$i-1]['x'].','.$poly[$i-1]['y'].
// ')-end('.$poly[0]['x'].','.$poly[0]['y'].
// ')-pente'.$pente;
// doubling the first point if needed (see above)
if (($pente1<0 && $pente>0) || ($pente1>0 && $pente<0)) {
if (is_array($bords[$poly[$i]['y']]))
array_push($bords[$poly[$i]['y']], round($poly[$i]['x']));
//if (DEBUG) echo '('.$poly[$i-1]['x'].';'.$poly[$i-1]['y'].') ';
}
// doubling the last point if neededd
if (($old_pente<0 && $pente>0) || ($old_pente>0 && $pente<0)) {
if (is_array($bords[$poly[$i-1]['y']])) //avoid warning
array_push($bords[$poly[$i-1]['y']], round($poly[$i-1]['x']));
//if (DEBUG) echo '*('.$poly[$i-1]['x'].';'.$poly[$i-1]['y'].') ';
}
$dy_inc = ($poly[0]['y']-$poly[$i-1]['y']) > 0 ? 1 : -1;
$x = $poly[$i-1]['x'];
// if (DEBUG) echo "init: ".$poly[$i-1]['y']." dy_inc: ".$dy_inc.
// " end: ".$poly[0]['y'];
for ($dy = $poly[$i-1]['y']+$dy_inc;
$dy != $poly[0]['y'];
$dy += $dy_inc)
{
$x += $pente*$dy_inc;
array_push($bords[$dy], round($x));
// if (DEBUG) echo '/('.$x.';'.$dy.') ';
}
}
/* filling the polygon */
/* basic idea: we sort a column of edges.
For each pair of point, we color the points in between */
$n = count($bords);
for ($i = 0; $i<$n; $i++) { // Y
//error_log(__FILE__.' - Border Num '.$i,0);
if (is_array($bords[$i])) {
sort($bords[$i]);
}
for ($j = 0; $j<sizeof($bords[$i]);$j+=2) // bords
for ($k = round($bords[$i][$j]); $k<=$bords[$i][$j+1];$k++) {
$res[$k][$i] = true; //filling the array with trues
if ($test == 1) {
/*how to draw the polygon in a human way:
In ubuntu : sudo apt-get install gnuplot
Create an empty file with all points with the result of this echos (No commas, no point, no headers)
In gnuplot:
For 1 polygon: plot "/home/jmontoya/test"
For 2 polygons: plot "/home/jmontoya/test", "/home/jmontoya/test2"
A new window will appear with the plot
*/
echo $k.' '.$i; echo '<br />';
}
}
}
return $res;
}
/**
* poly_dump - dump an image on the screen
*
* @param array the polygone as output by poly_compile()
* @param array see above (poly_init)
* @param string Format ('raw' text or 'html')
*
* @return string html code of the representation of the polygone image
*/
function poly_dump(&$poly, $max, $format='raw') {
if ($format == 'html') {
$s = "<div style='font-size: 8px; line-height:3px'><pre>\n";
}
for ($i=0; $i<$max['y']; $i++) {
for($j=0; $j<$max['x']; $j++)
if($poly[$j][$i] == TRUE)
$s .= ($format=='html'?"<b>1</b>":'1');
else
$s .= "0";
$s .= ($format=='html'?"<br />\n":"\n");
}
$s .= ($format=='html'?"</pre></div>\n":"\n");
return $s;
}
/**
* poly_result - compute statis for two polygones
*
* @param poly1 first polygone as returned by poly_compile
* @param poly2 second ....
* @param max resolution as specified for poly_init
*
* @returns (see below, UTSL)
*/
function poly_result(&$poly1, &$poly2, $max) {
$onlyIn1 = 0;
$surfaceOf1 = 0;
$surfaceOf2 = 0;
for ($i=0; $i<$max['x']; $i++)
for($j=0; $j<$max['y']; $j++) {
if (isset($poly1[$i][$j]) && ($poly1[$i][$j] == TRUE)) {
$surfaceOf1++;
if (isset($poly2[$i][$j]) && ($poly2[$i][$j] == FALSE))
$onlyIn1++;
}
if (isset($poly2[$i][$j]) && ($poly2[$i][$j] == TRUE))
$surfaceOf2++;
}
return array (
"s1" => $surfaceOf1,
"s2" => $surfaceOf2,
"both" => $surfaceOf1 - $onlyIn1,
"s1Only" => $onlyIn1,
"s2Only" => $surfaceOf2 - ($surfaceOf1 - $onlyIn1));
}
/**
* poly_touch - compute statis for two polygones
*
* @param poly1 first polygone as returned by poly_compile
* @param poly2 second ....
* @param max resolution as specified for poly_init
*
* @returns (see below, UTSL)
*/
function poly_touch(&$poly1, &$poly2, $max) {
for ($i=0; $i<$max['x']; $i++) {
for($j=0; $j<$max['y']; $j++) {
if (isset($poly1[$i][$j]) && ($poly1[$i][$j] == true)
&& isset($poly2[$i][$j]) && ($poly2[$i][$j] == true)) {
return true;
}
}
}
return FALSE;
}
/**
* Convert a list of points in x1;y1|x2;y2|x3;y3 or x1;y1/x2;y2 format to
* the format in which the functions in this library are expecting their data
* @param string List of points in x1;y1|... format (or /)
* @param string The points separator for the list (| or /)
* @return array An array of points in the right format to use with the
* local functions
*/
function convert_coordinates($coords,$sep='|') {
$points = array();
$pairs = explode($sep,$coords);
foreach ($pairs as $idx => $pcoord) {
list($x,$y) = explode(';',$pcoord);
$points[] = array('x'=>$x,'y'=>$y);
}
return $points;
}
/**
* Returns the maximum coordinates in x,y (from 0,0) that the geometrical form
* can reach
* @param array Coordinates of one polygon
* @return array ('x'=>val,'y'=>val)
*/
function poly_get_max(&$coords1, &$coords2) {
$mx = 0;
$my = 0;
foreach ($coords1 as $coord) {
if ($coord['x'] > $mx) {
$mx = $coord['x'];
}
if ($coord['y'] > $my) {
$my = $coord['y'];
}
}
foreach ($coords2 as $coord) {
if ($coord['x'] > $mx) {
$mx = $coord['x'];
}
if ($coord['y'] > $my) {
$my = $coord['y'];
}
}
return array('x'=>$mx,'y'=>$my);
}