I made a simple .php file that should 'draw' a line for me, for which the user gives the start and end points using a form. And by 'draw', I mean tell you the pixels it's coloring. And yes, I know this only works with very specific lines.
This is my entire file:
<html>
<head>
<title>Thing</title>
<?php
function positiveLowLine($x,$y,$x0,$x1,$y0,$y1){
return (($x1–$x0)*$y – ($y1–$y0)*$x – $x1*$y0 + $x0*$y1);
}
?>
</head>
<body>
<form name="Q1" method="post" action="<?php $_SERVER["PHP_SELF"] ?>">
<table>
<tr>
<td align="right">x0</td>
<td><input type="number" name="x0" value="<?php echo $_POST["x0"]; ?>"></td>
</tr>
<tr>
<td align="right">x1</td>
<td><input type="number" name="x1" value="<?php echo $_POST["x1"]; ?>"></td>
</tr>
<tr>
<td align="right">y0</td>
<td><input type="number" name="y0" value="<?php echo $_POST["y0"]; ?>"></td>
</tr>
<tr>
<td align="right">y1</td>
<td><input type="number" name="y1" value="<?php echo $_POST["y1"]; ?>"></td>
</tr>
</table>
</form>
<?php
if (!empty($_POST)){
$x0 = $_POST["x0"];
$x1 = $_POST["x1"];
$y0 = $_POST["y0"];
$y1 = $_POST["y1"];
$y = $y0;
for($x = $x0;$x <= $x1; $x++){
echo "Step $x | x=$x | y=$y"
if (positiveLowLine($x,$y,$x0,$x1,$y0,$y1) < 0){
$y++;
}
}
}
?>
</body>
I'm getting and error that says syntax error, unexpected '$x0' (T_VARIABLE) in /file.php on line 6 (which is the return line)
But I don't understand what's the problem.
EDIT I have indeed taken a look at this post ("PHP Parse/Syntax Errors; and How to solve them?") but the answer wasn't there for me. At least I couldn't find it.
