function image_distance_pixel($xo, $yo, $x0, $y0)
{
include_spip('filtres/images_lib');
return _image_distance_pixel($xo, $yo, $x0, $y0);
}
function image_RotateBicubic($src_img, $angle, $bicubic = 0)
{
include_spip('filtres/images_lib');
if (round($angle / 90) * 90 == $angle) {
$droit = true;
if (round($angle / 180) * 180 == $angle) {
$rot = 180;
} else {
$rot = 90;
}
} else {
$droit = false;
}
// convert degrees to radians
$angle = $angle + 180;
$angle = deg2rad($angle);
$src_x = imagesx($src_img);
$src_y = imagesy($src_img);
$center_x = floor(($src_x - 1) / 2);
$center_y = floor(($src_y - 1) / 2);
$cosangle = cos($angle);
$sinangle = sin($angle);
// calculer dimensions en simplifiant angles droits, ce qui evite "floutage"
// des rotations a angle droit
if (!$droit) {
$corners = array(array(0, 0), array($src_x, 0), array($src_x, $src_y), array(0, $src_y));
foreach ($corners as $key => $value) {
$value[0] -= $center_x;
//Translate coords to center for rotation
$value[1] -= $center_y;
$temp = array();
$temp[0] = $value[0] * $cosangle + $value[1] * $sinangle;
$temp[1] = $value[1] * $cosangle - $value[0] * $sinangle;
$corners[$key] = $temp;
}
$min_x = 1000000000000000;
$max_x = -1000000000000000;
$min_y = 1000000000000000;
$max_y = -1000000000000000;
foreach ($corners as $key => $value) {
if ($value[0] < $min_x) {
$min_x = $value[0];
}
if ($value[0] > $max_x) {
$max_x = $value[0];
}
if ($value[1] < $min_y) {
$min_y = $value[1];
}
if ($value[1] > $max_y) {
$max_y = $value[1];
}
}
$rotate_width = ceil($max_x - $min_x);
$rotate_height = ceil($max_y - $min_y);
} else {
if ($rot == 180) {
$rotate_height = $src_y;
$rotate_width = $src_x;
} else {
$rotate_height = $src_x;
$rotate_width = $src_y;
}
$bicubic = false;
}
$rotate = imagecreatetruecolor($rotate_width, $rotate_height);
imagealphablending($rotate, false);
imagesavealpha($rotate, true);
$cosangle = cos($angle);
$sinangle = sin($angle);
// arrondir pour rotations angle droit (car cos et sin dans {-1,0,1})
if ($droit) {
$cosangle = round($cosangle);
$sinangle = round($sinangle);
}
$newcenter_x = ($rotate_width - 1) / 2;
$newcenter_y = ($rotate_height - 1) / 2;
for ($y = 0; $y < $rotate_height; $y++) {
for ($x = 0; $x < $rotate_width; $x++) {
// rotate...
$old_x = ($newcenter_x - $x) * $cosangle + ($newcenter_y - $y) * $sinangle + $center_x;
$old_y = ($newcenter_y - $y) * $cosangle - ($newcenter_x - $x) * $sinangle + $center_y;
$old_x = ceil($old_x);
$old_y = ceil($old_y);
if ($old_x >= 0 && $old_x < $src_x && $old_y >= 0 && $old_y < $src_y) {
if ($bicubic == true) {
$xo = $old_x;
$x0 = floor($xo);
$x1 = ceil($xo);
$yo = $old_y;
$y0 = floor($yo);
$y1 = ceil($yo);
// on prend chaque point, mais on pondere en fonction de la distance
$rgb = ImageColorAt($src_img, $x0, $y0);
$a1 = $rgb >> 24 & 0xff;
$r1 = $rgb >> 16 & 0xff;
$g1 = $rgb >> 8 & 0xff;
$b1 = $rgb & 0xff;
$d1 = _image_distance_pixel($xo, $yo, $x0, $y0);
$rgb = ImageColorAt($src_img, $x1, $y0);
$a2 = $rgb >> 24 & 0xff;
$r2 = $rgb >> 16 & 0xff;
$g2 = $rgb >> 8 & 0xff;
$b2 = $rgb & 0xff;
$d2 = _image_distance_pixel($xo, $yo, $x1, $y0);
$rgb = ImageColorAt($src_img, $x0, $y1);
$a3 = $rgb >> 24 & 0xff;
$r3 = $rgb >> 16 & 0xff;
$g3 = $rgb >> 8 & 0xff;
$b3 = $rgb & 0xff;
$d3 = _image_distance_pixel($xo, $yo, $x0, $y1);
$rgb = ImageColorAt($src_img, $x1, $y1);
$a4 = $rgb >> 24 & 0xff;
$r4 = $rgb >> 16 & 0xff;
$g4 = $rgb >> 8 & 0xff;
$b4 = $rgb & 0xff;
$d4 = _image_distance_pixel($xo, $yo, $x1, $y1);
$ac1 = (127 - $a1) / 127;
$ac2 = (127 - $a2) / 127;
$ac3 = (127 - $a3) / 127;
$ac4 = (127 - $a4) / 127;
// limiter impact des couleurs transparentes,
// mais attention tout transp: division par 0
if ($ac1 * $d1 + $ac2 * $d2 + $ac3 + $d3 + $ac4 + $d4 > 0) {
if ($ac1 > 0) {
$d1 = $d1 * $ac1;
}
if ($ac2 > 0) {
$d2 = $d2 * $ac2;
}
if ($ac3 > 0) {
$d3 = $d3 * $ac3;
}
if ($ac4 > 0) {
$d4 = $d4 * $ac4;
}
}
$tot = $d1 + $d2 + $d3 + $d4;
$r = round(($d1 * $r1 + $d2 * $r2 + $d3 * $r3 + $d4 * $r4) / $tot);
$g = round(($d1 * $g1 + $d2 * $g2 + $d3 * $g3 + $d4 * $g4) / $tot);
$b = round(($d1 * $b1 + $d2 * $b2 + $d3 * $b3 + $d4 * $b4) / $tot);
$a = round(($d1 * $a1 + $d2 * $a2 + $d3 * $a3 + $d4 * $a4) / $tot);
$color = imagecolorallocatealpha($src_img, $r, $g, $b, $a);
} else {
$color = imagecolorat($src_img, round($old_x), round($old_y));
}
} else {
// this line sets the background colour
$color = imagecolorallocatealpha($src_img, 255, 255, 255, 127);
}
@imagesetpixel($rotate, $x, $y, $color);
}
}
return $rotate;
}
