Question

我如何生成一个包含四个项目的列表，这些项目都应具有相同的宽高比，这取决于480x360的原始分辨率？原始宽高比480x360也属于列表。

Youtube上有一个示例，打开任何视频点击分享然后嵌入

现在，您可以看到我想要的列表与此处描述的相同。

*编辑我希望你现在明白我的问题

Answer 1

900/1600 = 0.5625 得到一半 800 * 0.5625 = 450

获得aspectratio，宽度* 0.5625 =高度

代码

$width = 640;
$height = 480;
$ratio = $height / $width;

function ratio($width){
   return $width * $ratio;
}

echo ratio(1280);

Answer 2

<?php

// create class to easily add and store resolutions
class Resolution
{
public $x;
public $y;
}

// create our original resolution and calculate its aspect ratio
$origRes = new Resolution();
$origRes->x = 640;
$origRes->y = 480;
$originalRatio = ($origRes->x / $origRes->y);

// create valid resolution
$firstRes = new Resolution();
$firstRes->x = 1280;
$firstRes->y = 720;

// create another resolution
$secondRes = new Resolution();
$secondRes->x = 320;
$secondRes->y = 240;

// ...and so on; two are enough for the example
// you must learn about arrays and came up with proper solution how to populate them

// create array of resolutions from existing resolutions
$arrayOfRes = array($firstRes, $secondRes);

// another way of adding could be: $arrayOfRes[] = $thirdRes

// because floating point values aren't perfect on computers,
// we need some range value to check if the values are "close enough"
// in other words: it's our precision
$epsilon = 0.00001;

// iterate over all elements in array
foreach ($arrayOfRes as $res)
{
// calculate ratio
$ratio = $res->x / $res->y;

// abs - absolute value, thus always positive
// we check if difference is precise enough and print some text
if(abs($ratio - $originalRatio) < $epsilon)
echo'print it here or do something';
}
?>

这是我作为非PHP程序员的十分钟答案代码。我假设此代码有效，但可能存在一些错误。

<强> [编辑]

使用ideone.com检查，修复了小错误，现在它可以正常工作。 https://ideone.com/lpW9DM

Calc具有相同宽高比的不同视频大小

2 个答案: