Emacs Font is wider

Emacs Font is wider than other applications. Most people don't notice the difference. If you can perceive it, you are not hallucinating. This can be attributed to the following:

Points per inch

#ifndef HAVE_ANDROID
/* Number of pt per inch (from the TeXbook).  */
#define PT_PER_INCH 72.27
#else
/* Android uses this value instead to compensate for different device
   dimensions.  */
#define PT_PER_INCH 160.00
#endif
  

Emacs definition is larger than the standard definition. The DTP point is defined as 1⁄72 of an inch. 

Round-off error

Emacs definition:

/* Return a pixel size (integer) corresponding to POINT size (double)
   on resolution DPI.  */
#define POINT_TO_PIXEL(POINT, DPI) ((POINT) * (DPI) / PT_PER_INCH + 0.5)

/* Return a point size corresponding to POINT size (integer)
   on resolution DPI.  Note that though point size is a double, we expect
   it to be rounded to an int, so we add 0.5 here.  If the desired value
   is tenths of points (as in xfld specs), then the pixel size should
   be multiplied BEFORE the conversion to avoid magnifying the error.  */
#define PIXEL_TO_POINT(PIXEL, DPI) ((PIXEL) * PT_PER_INCH / (DPI) + 0.5)
  

Rounding-off error is unavoidable. While looking for its source, look for how it's compensated in the application being compared.



Comments

Post a Comment

Popular posts from this blog

HTML Renderer (Emacs)

Image
  Emacs: A non-intrusive browser An Elisp implementation of HTML rendering using SVG. The browser functionality is an extension of eww . For Javascript, you can use either NodeJS or QuickJS as a JS interpreter . Developer Note: The entry point is shr-render.   Table Colspan example Rowspan example Sample Table <html>   <body>     <table border="1">       <tr bgcolor="#9acd32">         <th style="text-align:left">Title</th>         <th style="text-align:left">Artist</th>       </tr>       <tr>         <td>Empire Burlesque</td>         <td>Bob Dylan</td>       </tr>     </table>   </body> </html...
Read more

Mozilla Readability in GNU Emacs

Image
  Output using Readability (left) and original eww (right)   Mozilla Readability is a standalone version of the readability library used for Firefox Reader View . A simple hack to eww can bring the same feature in GNU Emacs. ( Note: eww already has a readable mode. This is just an alternative. Updated the post to reflect the same.)   - Install NodeJS   - Install npm modules. npm install @mozilla/readability jsdom   - Create a file readability.js with following content. Note the file location. var { Readability } = require('@mozilla/readability'); var { JSDOM } = require('jsdom'); var fs = require("fs"); var str = fs.readFileSync(process.stdin.fd).toString(); var doc = new JSDOM(str); var reader = new Readability(doc.window.document); var article = reader.parse(); console.log(article.content);     - Modify the following function to use the file location noted above . Evaluate the function. (defun mozilla-readability (start end)   (shell-command-o...
Read more

Data Visualization with GNU Emacs

Image
    GNU Emacs can be used for quick data visualization in combination with Gnuplot. When you have some data and you want to visualize what the correlation looks like, this command comes in handy. No need for any setup - no data file and no Gnuplot script. The command below uses some sensible defaults for trivial cases. If the first line contains string label, the same is used as a key label for the value and/or axes' names as appropriate. If there's a single column of data, it is used as Y value. If there's more than one column, first column is used as X value and other columns are plotted along Y-axis. Takes care of comma or whitespace separator. Note: The latest version of the code is available at the end of the post. Options available in latest version   - Install gnuplot executable and gnuplot Elisp package . - Evaluate the defun ( C-M-x ). - Select a data range using rectangle command copy-rectangle-as-kill (C-x r M-w). - Run M-x  gnuplot-rectangle. This open...
Read more