本文介绍了计算Facebook封面偏移y的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在使用Facebook SDK获取用户封面照片。我有通往img和偏移量y的路径。
I'm getting the user cover photo using Facebook SDK. I have the path to the img and the offset y.
"source": "http://a5.sphotos.ak.fbcdn.net/hphotos-ak-ash3/526114_459046674110601_992101492_n.jpg",
"offset_y": 19
我放置图像的div有300px高度;右边的背景位置是 center -146px;
。当我有300和19岁时,如何计算顶值
The div where i put the image have 300px height; and right background position is center -146px;
. How to calculate the top value
when I have 300 and 19 ?
推荐答案
offset_y
是裁剪图像的上区域和下区域之间的一部分空间。
offset_y
is a proportion of space between upper area and lower area of cropped image.
因此,实际像素偏移应该是这样的:
So, actual pixel offset should be like this:
y = (offset_y / 100) * (upperArea_of_cropImage.height + lowerArea_of_cropImage.height)
已编辑:
// where y is the actual pixels from the upper left corner of the real image to
// upper left corner of the cropped image
-- ================================ --
y { || || } a
--||..............................|| --
|| ||
|| ||
|| Cover ||
|| ||
||..............................|| --
|| || } b
|| || |
================================ --
offset_y that Facebook send to you actually was a/b not y
这篇关于计算Facebook封面偏移y的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!