Thread View: borland.public.delphi.graphics
13 messages
13 total messages
Started by David HAROUCHE
Wed, 23 Jul 2008 15:55
transparent bitmap
Author: David HAROUCHE
Date: Wed, 23 Jul 2008 15:55
Date: Wed, 23 Jul 2008 15:55
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I'm trying to display successive rotated transparent bitmap on a TPaintBox, and that leaves traces... How not to...? DH
Re: transparent bitmap
Author: GrandmasterB
Date: Wed, 23 Jul 2008 18:16
Date: Wed, 23 Jul 2008 18:16
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"David HAROUCHE" <metanil@hotmail.com> wrote in message news:48875484$1@newsgroups.borland.com... > I'm trying to display successive rotated transparent bitmap on a > TPaintBox, and that leaves traces... It leaves traces? Do you mean like fingerprints and DNA evidence?
Re: transparent bitmap
Author: David HAROUCHE
Date: Wed, 23 Jul 2008 19:22
Date: Wed, 23 Jul 2008 19:22
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Yes, Scotland Yard just went out after my call and they say they just don't understand... Sherlock Holmes is now on the stage : refreshing the TPaintBox. after a canvas.Draw with a modified bitmap leaves some foot prints... Should I take a snapshot of what is under ...? DH
Re: transparent bitmap
Author: Pieter Zijlstra
Date: Wed, 23 Jul 2008 19:55
Date: Wed, 23 Jul 2008 19:55
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GrandmasterB wrote: > "David HAROUCHE" <metanil@hotmail.com> wrote in message > news:48878507@newsgroups.borland.com... > > Sherlock Holmes is now on the stage : refreshing the TPaintBox. > > after a canvas.Draw with a modified bitmap leaves some foot > > prints... > > > > Should I take a snapshot of what is under ...? > > It's elementary, my dear Watson... clear the canvas before you do the > paint. Then no evidence will be left behind. Dear Sherlock, you really don't get it, do you. He wants to be caught and therefor leave some traces behind. ;-) -- Pieter
Re: transparent bitmap
Author: GrandmasterB
Date: Wed, 23 Jul 2008 20:48
Date: Wed, 23 Jul 2008 20:48
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"David HAROUCHE" <metanil@hotmail.com> wrote in message news:48878507@newsgroups.borland.com... > Sherlock Holmes is now on the stage : refreshing the TPaintBox. after a > canvas.Draw with a modified bitmap leaves some foot prints... > > Should I take a snapshot of what is under ...? It's elementary, my dear Watson... clear the canvas before you do the paint. Then no evidence will be left behind.
Re: transparent bitmap
Author: Nils Haeck
Date: Wed, 23 Jul 2008 20:54
Date: Wed, 23 Jul 2008 20:54
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It looks like your algorithm to transform (rotate) the bitmap doesn't set all destination pixels correctly. You might look at that. Graphics32 has some good code. Nils "David HAROUCHE" <metanil@hotmail.com> schreef in bericht news:48875484$1@newsgroups.borland.com... > I'm trying to display successive rotated transparent bitmap on a > TPaintBox, and that leaves traces... > > How not to...? > > DH >
Re: transparent bitmap
Author: David HAROUCHE
Date: Wed, 23 Jul 2008 21:50
Date: Wed, 23 Jul 2008 21:50
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>> Clear the canvas before you do the paint. Clearing ? how ? >> Then no evidence will be left behind. Did you engaged Alfred Hitchcock ? DH
Re: transparent bitmap
Author: David HAROUCHE
Date: Wed, 23 Jul 2008 21:53
Date: Wed, 23 Jul 2008 21:53
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>> It looks like your algorithm to transform (rotate) the >>bitmap doesn't >> set all destination pixels correctly. No, it works fine, and leaves "transparent" pixels as it should... The problem is that if I draw the bitmap on the Canvas (bitmap;transparent is set to true) firs as it is, then rotated, the transparency dosent apply correctly on a transparent TForm : the form's background is a snapshot of what it was before under the form... DH
Re: transparent bitmap
Author: GrandmasterB
Date: Thu, 24 Jul 2008 18:48
Date: Thu, 24 Jul 2008 18:48
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"David HAROUCHE" <metanil@hotmail.com> wrote in message news:4887a7a0@newsgroups.borland.com... >>> Clear the canvas before you do the paint. > Clearing ? > how ? Its going to depend on what it is you are specifically doing. But in general, draw a rectangle over the canvas with the background color. Then draw your background image. Then draw your bitmap rotated at its new angle.
Re: transparent bitmap
Author: David HAROUCHE
Date: Fri, 25 Jul 2008 13:42
Date: Fri, 25 Jul 2008 13:42
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>> Its going to depend on what it is you are specifically doing. I just try to use bitmap.Transparent efficiently when I draw successives images on a TPaintBox located on a TForm that is Transparent...!!! >>But in general, draw a rectangle You surely mean canvas.FillRect ! >>Then draw your background image. Thats' where I think about a snapshot of the desktop of what is under the TPaintBox...! But what if a change occurs on the desktop ? >> Then draw your bitmap rotated at its new angle. That causes more flickers on screen... DH
Re: transparent bitmap
Author: GrandmasterB
Date: Fri, 25 Jul 2008 20:08
Date: Fri, 25 Jul 2008 20:08
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"David HAROUCHE" <metanil@hotmail.com> wrote in message news:4889d858@newsgroups.borland.com... >>>But in general, draw a rectangle > You surely mean canvas.FillRect ! No - I mean what I say, and say what I mean! And what I mean is draw a rectangle over the background, regardless of what graphics interface you are using. If you are using vcl drawing routines, then fillrect will do. I personally dont use the vcl routines much, so am more likely to use native gdi calls or gdi+ methods. >>> Then draw your bitmap rotated at its new angle. > That causes more flickers on screen... Then it sounds to me your real problem is flickering. I would focus on fixing that.
Re: transparent bitmap
Author: David HAROUCHE
Date: Fri, 25 Jul 2008 20:12
Date: Fri, 25 Jul 2008 20:12
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>> Then it sounds to me your real problem is flickering. I started another thread... ;) DH
Re: transparent bitmap
Author: Doug Eilertson
Date: Mon, 19 Oct 2009 16:43
Date: Mon, 19 Oct 2009 16:43
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Wrong name for a dumb ass. "GrandmasterB" <Fizzle@shizzle.com> wrote in message news:488767e5$1@newsgroups.borland.com... > "David HAROUCHE" <metanil@hotmail.com> wrote in message > news:48875484$1@newsgroups.borland.com... >> I'm trying to display successive rotated transparent bitmap on a >> TPaintBox, and that leaves traces... > > It leaves traces? Do you mean like fingerprints and DNA evidence? > > >
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