testcases/phpCairo/random-intersections.php

   1 <?
   2 function uniform_random($minval, $maxval)
   3 {
   4         global $state;
   5         $poly = 0x9a795537;
   6         $n=32;
   7         $state = 2*$state < $state ? (2*$state ^ $poly) : 2*$state;
   8         return floor($minval + $state * ($maxval - $minval) / 4294967296.0);
   9 }
  10
  11 $size = 512;
  12 $numseg = 128;
  13 $width = $size+3;
  14 $height = $size + 3;
  15 $sur = new CairoImageSurface(FORMAT_ARGB32, $size+3, $size + 3);
  16 $con = new CairoContext($sur);
  17
  18 $con->set_source_rgb(0,0,0);
  19 $con->paint();
  20
  21 $state = 0x123456;
  22
  23 $con->translate(1,1);
  24 $con->set_fill_rule(FILL_RULE_EVEN_ODD);
  25 $con->move_to(0,0);
  26
  27 for($i=0; $i<$numseg;$i++) {
  28 $x = uniform_random(0,$width);
  29 $y = uniform_random(0,$height);
  30 $con->line_to($x,$y);
  31 //echo "x = $x";
  32 //echo "y = $y";
  33 }
  34
  35 $con->close_path();
  36 $con->set_source_rgb(1,0,0);
  37 $con->fill_preserve();
  38 $con->set_source_rgb(0,1,0);
  39 $con->set_line_width(0.5);
  40 $con->stroke();
  41
  42 $sur->write_to_png("random-intersection-php.png");
  43 ?>