Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>The canvas is just 80x80 pixels. Your CSS is scaling it up to 640x480, meaning you just stretch the bitmap you're drawing to the canvas. (this explains your blurriness)</p> <p>The trick to achieving your scaling is here : </p> <pre><code>var scaleFactor = 10; for(i = 0; i &lt; 6400; i++) { d = random()*256|0; val = array[d]; viewbmd.fillStyle = "rgb(" + val + ", " + val + ", " + val + ")"; //fillrect draws your "pixels", viewbmd.fillRect(i%80*scaleFactor, (((i)/80)|0)*scaleFactor , scaleFactor, scaleFactor); } </code></pre> <p>In order to emulate drawing bix pixels, you multiply the x/y position of the rectangles you draw with the same number that determines their size (see scaleFactor).</p> <p>In the example, i'm drawing "pixels" that are actually 10x10 "points".</p> <p>This way, the initial picture is drawn correctly.</p> <p>We run into trouble though, the second we hit <code>flipSomePixels</code>, because it just takes actual pixels from the bitmap we drew earlier, and starts flipping those, so we will need a similar trick to draw the updated fake pixel there.</p> <p><strong>::update::</strong></p> <p>Thanks to Ken, i got an idea on how to achieve this in an "easier" way. We can draw the original 80x80 canvas off screen, and stretch that across a bigger canvas.</p> <p>We still need to do away with the css canvas resizing though, because resizing the canvas element will still cause the blurry scaling to happen. Instead, we make the canvas 640x640 and tell it to do crisp image rendering like this:</p> <p>-css:</p> <pre><code>canvas{ border:1px solid black; image-rendering: optimizeSpeed; image-rendering: -moz-crisp-edges; image-rendering: -webkit-optimize-contrast; image-rendering: -o-crisp-edges; image-rendering: optimize-contrast; -ms-interpolation-mode: nearest-neighbor; } </code></pre> <p>-html:</p> <pre><code>&lt;canvas width="640" height="640"&gt;&lt;/canvas&gt; </code></pre> <p>For a working example, see <a href="http://jsfiddle.net/QTvpe/10/" rel="nofollow">http://jsfiddle.net/QTvpe/10/</a></p>
    singulars
    1. This table or related slice is empty.
    1. PORe-write javascript animation to prevent scaling/blurring in browser
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USTimothy Groote
    1. USTimothy Groote
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PORe-write javascript animation to prevent scaling/blurring in browser
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COHi, Thank you for your reply. I appreciate your help. I thought that the canvas is 80X80, and scales to 640X640? I tried adding the new script (using scale = 8), but this did not solve the blurring. Sorry, not very skilled at this. Maybe, the problem is what you mentioned:"We run into trouble though, the second we hit flipSomePixels, because it just takes actual pixels from the bitmap we drew earlier, and starts flipping those, so we will need a similar trick to draw the updated fake pixel there." Not sure how to fix this. Still need help, please.
      singulars
      1. PO
      1. USuser1134527
    2. COSorry, perhaps i should have elaborated a bit more. The canvas is indeed tiny, and being scaled up (which looks hideous). The best way to fix this, is to make the canvas itself bigger, not to scale the canvas, and to just draw bigger squares rather than individual pixels.
      singulars
      1. PO
      1. USTimothy Groote
    3. COThe code example i gave gives a rough explanation of how to do that
      singulars
      1. PO
      1. USTimothy Groote
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload