src/includes/imageSmoothArc.php ➔ imageSmoothArc()

Complexity

Conditions	11
Paths	112

Size

Total Lines	82
Code Lines	36

Duplication

Lines	0
Ratio	0 %

Importance

Changes

0

<?php
function imageSmoothArc(&$img, $cx, $cy, $w, $h, $color, $start, $stop)
{
    // Originally written from scratch by Ulrich Mierendorff, 06/2006
    // Rewritten and improved, 04/2007, 07/2007

44% of this comment could be valid code. Did you maybe forget this after debugging?

    // compared to old version:
    // + Support for transparency added
    // + Improved quality of edges & antialiasing
    
    // note: This function does not represent the fastest way to draw elliptical
    // arcs. It was written without reading any papers on that subject. Better
    // algorithms may be twice as fast or even more.
    
    // what it cannot do: It does not support outlined arcs, only filled
    
    // Parameters:
    // $cx      - Center of ellipse, X-coord
    // $cy      - Center of ellipse, Y-coord
    // $w       - Width of ellipse ($w >= 2)
    // $h       - Height of ellipse ($h >= 2 )
    // $color   - Color of ellipse as a four component array with RGBA
    // $start   - Starting angle of the arc, no limited range!
    // $stop    - Stop     angle of the arc, no limited range!
    // $start _can_ be greater than $stop!
    // If any value is not in the given range, results are undefined!
    
    // This script does not use any special algorithms, everything is completely
    // written from scratch; see http://de.wikipedia.org/wiki/Ellipse for formulas.
    
    while ($start < 0) {
        $start += 2 * M_PI;
    }
    while ($stop < 0) {
        $stop += 2 * M_PI;
    }
    
    while ($start > 2 * M_PI) {
        $start -= 2 * M_PI;
    }
    
    while ($stop > 2 * M_PI) {
        $stop -= 2 * M_PI;
    }
    
    
    if ($start > $stop) {
        imageSmoothArc($img, $cx, $cy, $w, $h, $color, $start, 2 * M_PI);
        imageSmoothArc($img, $cx, $cy, $w, $h, $color, 0, $stop);
        return;
    }
    
    $a  = 1.0 * round($w / 2);
    $b  = 1.0 * round($h / 2);
    $cx = 1.0 * round($cx);
    $cy = 1.0 * round($cy);
    
    $aaAngle  = atan(($b * $b) / ($a * $a) * tan(0.25 * M_PI));
    $aaAngleX = $a * cos($aaAngle);
    $aaAngleY = $b * sin($aaAngle);
    
    $a -= 0.5; // looks better...
    $b -= 0.5;
    
    for ($i=0; $i < 4;$i++) {
        if ($start < ($i + 1) * M_PI / 2) {
            if ($start > $i * M_PI / 2) {
                if ($stop > ($i + 1) * M_PI / 2) {
                    imageSmoothArcDrawSegment($img, $cx, $cy, $a, $b, $aaAngleX, $aaAngleY, $color, $start, ($i + 1) * M_PI / 2, $i);
                } else {
                    imageSmoothArcDrawSegment($img, $cx, $cy, $a, $b, $aaAngleX, $aaAngleY, $color, $start, $stop, $i);
                    break;
                }
            } else {
                if ($stop > ($i + 1) * M_PI / 2) {
                    imageSmoothArcDrawSegment($img, $cx, $cy, $a, $b, $aaAngleX, $aaAngleY, $color, $i * M_PI / 2, ($i + 1) * M_PI / 2, $i);
                } else {
                    imageSmoothArcDrawSegment($img, $cx, $cy, $a, $b, $aaAngleX, $aaAngleY, $color, $i * M_PI / 2, $stop, $i);
                    break;
                }
            }
        }
    }
}