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PHP 一定程度内缩放图像的简单示例,
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这是比在网络上的例子做的更简洁的方式。我看到的每个例子,在涉及到输入时,好像都依赖于方向,水平的垂直的或者两者都有,这忽略了水平和垂直映射“长边”和“短边”,然后在最后重新映射变量到$h / $w,
PHP 一定限度内缩放图像
/**
* PHP 一定限度内缩放图像的简单示例
*
* @param
* @author 编程之家 jb51.cc jb51.cc
**/
function scale_dimensions_within_limits($w,$h,$max_w,$max_h){
// $w is the width of the current rectangle
// $h is the height of the current rectangle
// $max_w is the maximum width that an image can be sized
// $max_h is the maximum height that an image can be sized
// **** Here's where the magic is starts ****
// Switch the concept of horiz/vertical/square to long/short side
$short_side_len = ($w < $h ? $w : $h);
$long_side_len = ($w > $h ? $w : $h);
// Set a variable to the variable name of the output variable
$ssvar = ($w > $h ? 'h':'w');
$lsvar = ($w > $h ? 'w':'h');
$maxLSvar = "max_".$lsvar;
$maxSSvar = "max_".$ssvar;
// Do the first pass on the long side
$ratio = $$maxLSvar/$long_side_len;
$newSS = round($short_side_len * $ratio);
$newLS = round($long_side_len * $ratio);
// *** Note - the only coditional block!
// If short side is still out of limit,limit the short side and adjust
if($newSS > $$maxSSvar){
$ratio = $$maxSSvar/$newSS;
$newLS = round($ratio*$newLS);
$newSS = $$maxSSvar;
}
// **** Here's where the magic ends ****
// Re-couple the h/w (or w/h) with the long/shortside counterparts
// $$ means it's a variable variable (dynamic assignment)
$$ssvar = $newSS;
$$lsvar = $newLS;
// Prep the return array
$dimensions['w'] = $w; // this is derived from either $ssvar or $lsvar
$dimensions['h'] = $h; return $dimensions;
}
/*** 来自编程之家 jb51.cc(jb51.cc) ***/