Hi, I'd like to skew the graphics of a Form, is there an easy way to do this in v2 ?
What I want is to take the rectangle from a normal form, transform it into an arbitrarily-defined quadrilateral, and then paint on the screen. I saw that WarpBlt does something like this.. but it maps a quadrilateral section of a form onto a rectangle.
Hi,
is WarpBlt available in Squeak V2?
On Tue, Jul 22, 2008 at 7:53 PM, Iulian Wande Radu infinite.flow@gmail.com wrote:
Hi, I'd like to skew the graphics of a Form, is there an easy way to do this in v2 ?
What I want is to take the rectangle from a normal form, transform it into an arbitrarily-defined quadrilateral, and then paint on the screen. I saw that WarpBlt does something like this.. but it maps a quadrilateral section of a form onto a rectangle.
Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
what is Squeak V2?
On Tue, Jul 22, 2008 at 12:02 PM, Matthias Berth matthias.berth@googlemail.com wrote:
Hi,
is WarpBlt available in Squeak V2?
On Tue, Jul 22, 2008 at 7:53 PM, Iulian Wande Radu infinite.flow@gmail.com wrote:
Hi, I'd like to skew the graphics of a Form, is there an easy way to do this in v2 ?
What I want is to take the rectangle from a normal form, transform it into an arbitrarily-defined quadrilateral, and then paint on the screen. I saw that WarpBlt does something like this.. but it maps a quadrilateral section of a form onto a rectangle.
Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
Squeak V2 is the Squeak running on Version 2 source (the current Squeak version is around 3.9).
Back to the question... Yes WarpBlt is available in v2, but I can't seem to be able to use it for this purpose, because it maps a quad to a rectangle (not a rectangle to a quad). There must be a way to do this...
On Tue, Jul 22, 2008 at 3:27 PM, Brad Fuller bradallenfuller@gmail.com wrote:
what is Squeak V2?
On Tue, Jul 22, 2008 at 12:02 PM, Matthias Berth matthias.berth@googlemail.com wrote:
Hi,
is WarpBlt available in Squeak V2?
On Tue, Jul 22, 2008 at 7:53 PM, Iulian Wande Radu infinite.flow@gmail.com wrote:
Hi, I'd like to skew the graphics of a Form, is there an easy way to do
this
in v2 ?
What I want is to take the rectangle from a normal form, transform it
into
an arbitrarily-defined quadrilateral, and then paint on the screen. I
saw
that WarpBlt does something like this.. but it maps a quadrilateral
section
of a form onto a rectangle.
Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
-- Brad Fuller www.bradfuller.com _______________________________________________ Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
So it comes down to this:
given a projective transformation T from a rectangle (your form) to a quad Q (what you want to draw on screen), how can you express the same transformation in terms of mapping a quad to a rectangle (what WarpBlt needs)?
One possible plan is:
1) determine the transformation's parameters
2) take the bounding box of Q (a rectangle R) and transform it by the inverse of T, giving you a quad Q'
3) use WarpBlt to transform pixels in Q' (should be a superset of your form) to R
4) mask the result with your original quad Q, using pixel-by-pixel operations on Forms
I think all you need in terms of mathematics for this is in http://www.cs.cmu.edu/~ph/869/www/notes/proj/proj.pdf
Hope this helps, feel free to ask about the details,
Matthias
On Tue, Jul 22, 2008 at 9:31 PM, Iulian Wande Radu infinite.flow@gmail.com wrote:
Back to the question... Yes WarpBlt is available in v2, but I can't seem to be able to use it for this purpose, because it maps a quad to a rectangle (not a rectangle to a quad). There must be a way to do this...
On Tue, Jul 22, 2008 at 3:27 PM, Brad Fuller bradallenfuller@gmail.com wrote:
what is Squeak V2?
On Tue, Jul 22, 2008 at 12:02 PM, Matthias Berth matthias.berth@googlemail.com wrote:
Hi,
is WarpBlt available in Squeak V2?
On Tue, Jul 22, 2008 at 7:53 PM, Iulian Wande Radu infinite.flow@gmail.com wrote:
Hi, I'd like to skew the graphics of a Form, is there an easy way to do this in v2 ?
What I want is to take the rectangle from a normal form, transform it into an arbitrarily-defined quadrilateral, and then paint on the screen. I saw that WarpBlt does something like this.. but it maps a quadrilateral section of a form onto a rectangle.
Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
-- Brad Fuller www.bradfuller.com _______________________________________________ Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
At Tue, 22 Jul 2008 13:53:21 -0400, Iulian Wande Radu wrote:
Hi, I'd like to skew the graphics of a Form, is there an easy way to do this in v2 ?
What I want is to take the rectangle from a normal form, transform it into an arbitrarily-defined quadrilateral, and then paint on the screen. I saw that WarpBlt does something like this.. but it maps a quadrilateral section of a form onto a rectangle.
There was similar a discussion on this a while ago:
http://lists.squeakfoundation.org/pipermail/squeak-dev/2001-February/013402....
-- Yoshiki
Thank you for the guidelines for skewing forms.
I've followed Matthias' instructions (and the associated math doc) and skewing works well this way through WarpBlt. (The code linked by Yoshiki was too slow and didn't work fully).
I wrote the math conversions in a C DLL, and it would probably be useful for people. Is there any place where I could put the code so the community can use it ?
Cheers, Iulian
---------- Forwarded message ---------- From: Matthias Berth matthias.berth@googlemail.com Date: Tue, Jul 22, 2008 at 7:10 PM Subject: Re: [Newbies] Skewing Forms in Squeak V2 To: "A friendly place to get answers to even the most basic questions about Squeak." beginners@lists.squeakfoundation.org
So it comes down to this:
given a projective transformation T from a rectangle (your form) to a quad Q (what you want to draw on screen), how can you express the same transformation in terms of mapping a quad to a rectangle (what WarpBlt needs)?
One possible plan is:
1) determine the transformation's parameters
2) take the bounding box of Q (a rectangle R) and transform it by the inverse of T, giving you a quad Q'
3) use WarpBlt to transform pixels in Q' (should be a superset of your form) to R
4) mask the result with your original quad Q, using pixel-by-pixel operations on Forms
I think all you need in terms of mathematics for this is in http://www.cs.cmu.edu/~ph/869/www/notes/proj/proj.pdfhttp://www.cs.cmu.edu/%7Eph/869/www/notes/proj/proj.pdf
Hope this helps, feel free to ask about the details,
Matthias
On Thu, Jul 24, 2008 at 1:39 AM, Yoshiki Ohshima yoshiki@vpri.org wrote:
At Tue, 22 Jul 2008 13:53:21 -0400, Iulian Wande Radu wrote:
Hi, I'd like to skew the graphics of a Form, is there an easy way to do
this in v2 ?
What I want is to take the rectangle from a normal form, transform it
into an arbitrarily-defined quadrilateral, and
then paint on the screen. I saw that WarpBlt does something like this..
but it maps a quadrilateral section of a form
onto a rectangle.
There was similar a discussion on this a while ago:
http://lists.squeakfoundation.org/pipermail/squeak-dev/2001-February/013402....
-- Yoshiki _______________________________________________ Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
Hi Iulian,
I'm glad to hear that it worked for you. I wonder why you implemented it in a C DLL... As far as I can see, the manipulations with the parameters would be done only once for every quad you want to transform. The computation time for that should be negligible compared to the time it takes to actually transform all the pixels in the quad / rectangle. At least that's what I was thinking, maybe i am wrong?
Cheers
Matthias
On Tue, Sep 23, 2008 at 1:08 AM, Iulian Wande Radu infinite.flow@gmail.com wrote:
Thank you for the guidelines for skewing forms.
I've followed Matthias' instructions (and the associated math doc) and skewing works well this way through WarpBlt. (The code linked by Yoshiki was too slow and didn't work fully).
I wrote the math conversions in a C DLL, and it would probably be useful for people. Is there any place where I could put the code so the community can use it ?
Cheers, Iulian
---------- Forwarded message ---------- From: Matthias Berth matthias.berth@googlemail.com Date: Tue, Jul 22, 2008 at 7:10 PM Subject: Re: [Newbies] Skewing Forms in Squeak V2 To: "A friendly place to get answers to even the most basic questions about Squeak." beginners@lists.squeakfoundation.org
So it comes down to this:
given a projective transformation T from a rectangle (your form) to a quad Q (what you want to draw on screen), how can you express the same transformation in terms of mapping a quad to a rectangle (what WarpBlt needs)?
One possible plan is:
determine the transformation's parameters
take the bounding box of Q (a rectangle R) and transform it by the
inverse of T, giving you a quad Q'
- use WarpBlt to transform pixels in Q' (should be a superset of your
form) to R
- mask the result with your original quad Q, using pixel-by-pixel
operations on Forms
I think all you need in terms of mathematics for this is in http://www.cs.cmu.edu/~ph/869/www/notes/proj/proj.pdf
Hope this helps, feel free to ask about the details,
Matthias
On Thu, Jul 24, 2008 at 1:39 AM, Yoshiki Ohshima yoshiki@vpri.org wrote:
At Tue, 22 Jul 2008 13:53:21 -0400, Iulian Wande Radu wrote:
Hi, I'd like to skew the graphics of a Form, is there an easy way to do this in v2 ?
What I want is to take the rectangle from a normal form, transform it into an arbitrarily-defined quadrilateral, and then paint on the screen. I saw that WarpBlt does something like this.. but it maps a quadrilateral section of a form onto a rectangle.
There was similar a discussion on this a while ago:
http://lists.squeakfoundation.org/pipermail/squeak-dev/2001-February/013402....
-- Yoshiki _______________________________________________ Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
You're right about the timing. I'm fairly new to Smalltalk and had already hooked in a DLL for other things, so found it much easier to work matrix math in C :)
On Mon, Sep 22, 2008 at 7:58 PM, Matthias Berth < matthias.berth@googlemail.com> wrote:
Hi Iulian,
I'm glad to hear that it worked for you. I wonder why you implemented it in a C DLL... As far as I can see, the manipulations with the parameters would be done only once for every quad you want to transform. The computation time for that should be negligible compared to the time it takes to actually transform all the pixels in the quad / rectangle. At least that's what I was thinking, maybe i am wrong?
Cheers
Matthias
On Tue, Sep 23, 2008 at 1:08 AM, Iulian Wande Radu infinite.flow@gmail.com wrote:
Thank you for the guidelines for skewing forms.
I've followed Matthias' instructions (and the associated math doc) and skewing works well this way through WarpBlt. (The code linked by Yoshiki
was
too slow and didn't work fully).
I wrote the math conversions in a C DLL, and it would probably be useful
for
people. Is there any place where I could put the code so the community
can
use it ?
Cheers, Iulian
---------- Forwarded message ---------- From: Matthias Berth matthias.berth@googlemail.com Date: Tue, Jul 22, 2008 at 7:10 PM Subject: Re: [Newbies] Skewing Forms in Squeak V2 To: "A friendly place to get answers to even the most basic questions
about
Squeak." beginners@lists.squeakfoundation.org
So it comes down to this:
given a projective transformation T from a rectangle (your form) to a quad Q (what you want to draw on screen), how can you express the same transformation in terms of mapping a quad to a rectangle (what WarpBlt needs)?
One possible plan is:
determine the transformation's parameters
take the bounding box of Q (a rectangle R) and transform it by the
inverse of T, giving you a quad Q'
- use WarpBlt to transform pixels in Q' (should be a superset of your
form) to R
- mask the result with your original quad Q, using pixel-by-pixel
operations on Forms
I think all you need in terms of mathematics for this is in http://www.cs.cmu.edu/~ph/869/www/notes/proj/proj.pdf
Hope this helps, feel free to ask about the details,
Matthias
On Thu, Jul 24, 2008 at 1:39 AM, Yoshiki Ohshima yoshiki@vpri.org
wrote:
At Tue, 22 Jul 2008 13:53:21 -0400, Iulian Wande Radu wrote:
Hi, I'd like to skew the graphics of a Form, is there an easy way to
do
this in v2 ?
What I want is to take the rectangle from a normal form, transform it into an arbitrarily-defined quadrilateral, and then paint on the screen. I saw that WarpBlt does something like
this..
but it maps a quadrilateral section of a form onto a rectangle.
There was similar a discussion on this a while ago:
http://lists.squeakfoundation.org/pipermail/squeak-dev/2001-February/013402....
-- Yoshiki _______________________________________________ Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
beginners@lists.squeakfoundation.org
-
Brad Fuller -
Iulian Wande Radu -
Matthias Berth -
Yoshiki Ohshima