web - using css pixel calculating screen size, where is wrong? -


in css w3(here),

1px = 0.75pt, 1pt = 2.54/72 cm,so 1 css pixel:1px = 0.26mm

for example, css pixel of iphone4 320px * 480px(not device pixel),
in width ,the length should be: 

320 *0.26 = 83.2mm

but iphone4 3.5"，so length in width 60mm,

it dont match result calculated above
wrong?
thanks

a css pixel not 0.26mm

from css w3:

the reference pixel visual angle of 1 pixel on device pixel density of 96dpi , distance reader of arm's length. nominal arm's length of 28 inches, visual angle therefore 0.0213 degrees. reading @ arm's length, 1px corresponds 0.26 mm (1/96 inch).

the iphone4 not 96dpi. device pixel ratio of 2, "css dpi" around 163. since 96dpi devices render 320px @ 83.2mm, mathematically, 163dpi devices should render 320px @ 49mm.


Comments

Post a Comment

Popular posts from this blog

Magento/PHP - Get phones on all members in a customer group -

i working on custom magento extension. working around adminhtml part , i've created custom form there. here form code: <?php class vivasindustries_smsnotification_block_adminhtml_sms_sendmass_edit_form extends mage_adminhtml_block_widget_form { public function _preparelayout() { $extensionpath = mage::getmoduledir('js', 'vivasindustries_smsnotification'); $head = $this->getlayout()->getblock('head'); $head->addjs('jquery.js'); $head->addjs('vivas.js'); return parent::_preparelayout(); } protected function _prepareform() { $form = new varien_data_form(array( 'id' => 'edit_form', 'action' => $this->geturl('*/*/save', array('id' => $this->getrequest()->get...
Read more

php - Bypass Geo Redirect for specific directories -

i'm trying bypass redirect specific url within site. wondering if might able help. the code below code use, original urls replaces example.com i'd able access http://example.com/admin without redirect occuring. is there way this, , there way using own ip? function country_geo_redirect() { $country = getenv('http_geoip_country_code'); if ($country == "us" ) { wp_redirect("http://usa.example.com/"); exit; } else if ($country == "gb" ) { wp_redirect("http://uk.example.com/"); exit; } } add_action('init', 'country_geo_redirect'); you can bypass redirection code if server found ip address. if ip address == <my ip address> ' nothing here else country_georedirect() end if
Read more

php - .htaccess mod_rewrite for dynamic url which has domain names -

i want convert url ex:( example.com/link.php?url=facebook.com ) ( example.com/facebook.com.php ) how can using .htaccess. or there other process make job easier ? i tried adding script .htaccess file options +followsymlinks rewriteengine on rewriterule url-(.*)\.htm$ link.php?url=$1 but converting url adding "url-" ( example.com/url-facebook.com.php ) i want remove "url-" , want make ( example.com/facebook.com.php ) rewriteengine on rewritecond %{the_request} ^get.*link\.php\?url\= [nc] rewritecond %{request_uri} !/system/.* [nc] rewriterule (.*?)link\.php\?url\=/*(.*) /$1$2 [r=301,ne,l] not sure how above work edit of used use remove index.php url
Read more