On 23rd of April 2015, Mihai Șucan passed away due to metastatic
cancer caused by RDEB.
My name is Mihai and I work on the Firefox developer tools.
When it comes to web development, I like both server-side and
client-side work. I am mainly interested in web browsers, web
standards and related technologies.
26 June 2010, 20:08
Three days ago we received great news from Microsoft: the
third platform preview release of Internet Explorer 9 includes
support for the
Canvas 2D Context API. Canvas comes
into IE 9 together with numerous other platform improvements.
These days I have been working on my open source project, PaintWeb. I am quite
excited to see it running quite well in MSIE 9.
Go ahead and try the
PaintWeb demo page in Internet Explorer 9!
What works? Almost everything. Known issues:
globalCompositeOperation property is not yet
supported by MSIE 9. The Color mixer visualization looks a bit
weird because of this.
- If you change the
properties the Canvas element is cleared. This is wrong and breaks
the implementation of image load and zoom. Check a minimal test case.
integration into TinyMCE demo page fails to work. It seems that
TinyMCE 3.2.5 fails to work properly in MSIE 9. I shall upgrade it
to the latest version, and thus update the PaintWeb plugin as well.
You may also check the
PaintWeb change log, for more details.
12 March 2010, 16:57
In the latest article I
wrote about SVG and
Canvas I included a small HTML5 demo which renders a color histogram using
Canvas, analyzing any image element. Knowing that the Canvas
developers to also read video frames, I wanted to test how fast can
I changed the initial script so that now it works with HTML5
videos. Here is the
In this demo I include a small video and a big HD trailer - just
out of curiosity I wanted to see something that barely runs within
the browser. The demo works with Opera 10.5 and Firefox 3.6 -
tested on Linux and Windows. Currently, Chromium 5 on Linux crashes
when I try to load the page.
I did spend quite some time testing various improvements to the
performance of the script. I would note that changing the script to
not access the DOM elements and properties directly, does not bring
any important improvements in execution speed. However, the change
to use bitwise operations did make a difference. Further
improvements would come if I would inline functions and remove some
of the options. Still, any ideas on how to further improve the
performance of the demo would be welcome.
Working on this HTML5 demo I also explored a new API available in
Firefox 3.5: Web
Workers. As I expected, the
result of adding a web worker to this use-case is not something
I am happy with. In a web worker I cannot access the video, nor can
I access any of the canvas elements. I could move only a really
small part of the code into a worker, and the performance penalty
of sending the pixels in a message from the main thread to the
worker thread is too significant. In the end, it runs quite slower
than the script which does not use any web worker.
26th of June update:
Opera 10.6 beta 1 was released a few days ago. This release
brings support for Web Workers and it is really great to see that
Workers demo works in Opera as well.
Any feedback is appreciated.
23 June 2009, 19:51
HTML 5 Canvas
specification defines two important methods for text rendering:
strokeText(). You also
measureText() and the associated text-related
properties: font, textAlign and
The Canvas Text API is only implemented
in Webkit (Safari and Chrome) and in Gecko 1.9.1+ (Firefox 3.5+).
If you want to render text in your Canvas element in Gecko 1.9.0
(Firefox 3.0) you can use their proprietary
Canvas text rendering API which is now, obviously, deprecated
in favour of the standardized API. They provided the following
To style the text you only have the mozTextStyle
In PaintWeb I use
mozPathText() method when the standard API is not
Opera does not support the Canvas Text API. I learned that the
drawImage() 2D context method allows the drawing of
SVG document as well - this works only in Opera. I implemented the
text tool by adding a new minimal SVG document which contains a
<text> element. This was updated and drawn in
the Canvas element in sync with user interaction. However, after I
completed the implementation I found several bugs:
- SVG redraw issues. When you update the text styling properties,
or when you update the text itself, sometimes Opera fails to
entirely redraw the SVG document, irrespective of the SVG being
visible or not.
- memory leaks (test case). For some
unfortunate reason, each
drawImage(svgDocument) leaks some amount of
memory. Got a crasher with this, and a system freeze after filling
my physical memory (1 GB) and the swap (1 GB). ;)
- security violations (test case). Opera
considers the SVG document as being an external resource, thus it
marks the Canvas as being "dirty" once
drawImage(svgDocument) is invoked. You can
no longer read pixels using
getImageData(), nor can
you use the
toDataURL() method. This broke the
PaintWeb history mechanism, the selection tool, and the "image
The first two issues I said I can live with, but not with the
security violations. Thus, I have disabled the text tool in Opera.
I have reported the last two bugs to Opera with the associated
minimal test cases.
If you are interested to render text, you can even attempt
server-side "hacks". You could make a server-side script which
renders text, and you can then draw it in your Canvas with an image
element. This, however, defeats the purpose of PaintWeb - I want it
to be a "pure" client-side Web application.
Lastly, you can implement "vector drawing" of text using a
client-side font definition in some format, and then render it with
basic paths in Canvas. Again, this is beyond the purpose of
PaintWeb. Opera will implement Canvas Text some day. :)
For further details about attempts at rendering text when the
standard Canvas Text API is not available, please read the rendering
text blog post wrote by Christopher Clay at the end of 2006.
6 November 2008, 20:39
Today I finally managed to upload and release my latest project:
PaintWeb. Marius helped me with designing the GUI and with other suggestions.
PaintWeb is a
client-side Web application which allows users to draw online. It
makes use of some newer Web technologies, mainly
the HTML 5 Canvas 2D
context API. Currently,
it's in its infancy, but with lots of work planned ahead.
The major decision for me was to release this project as
open-source, under GPL v3. The project is
now hosted on the Google Code
Please contribute with feedback, bug reports and even code -
volunteers are welcome!
Lots of bugs in the Web application are already known, nonetheless
that shouldn't stop you from reporting them.
The Web application works in the latest versions of Opera, Firefox, Safari and Konqueror. Obviously, it also works with
any Gecko and WebKit based Web browsers.
Nightly builds of Firefox 3.1 and SVN trunk builds of WebKit have the best support for this Web
I'd like to mention that the greatest surprise to me was that the
new Konqueror 4 has its own Canvas implemention. They've done a
really great job!
I am looking forward to publish more information about the project
and to continue work on it.
Update 3 days later: Back in september we
presented PaintWeb at a local university-organised seminar. Today
we have updated the presentation and we translated it to English as
well. Go ahead and download the English or Romanian
5 November 2008, 19:44
Sunday I upgraded my Ubuntu
installation to the new version: Ubuntu 8.10. Almost three years
ago I switched to using Linux exclusively. I haven't reinstalled
Ubuntu since then. I always upgrade my system every 6 months, and
then I spend a few days fixing post-upgrade issues. It's a
I am working on a new painting Web application. The greatest
surprise to me was that the new Konqueror 4 implements
<canvas>, and it does this theoretically better
than Opera. I will make my Web
application public and you will see this. Amazing and very quick
work done by the Konqueror developers. Congratulations, guys!
Note: I initially thought that the Konqueror
implementation of Canvas is just a copy of the code from Webkit, but it's not. They wrote their own
code, which is great.
On a related note, I have published a new page with some of