Mouse clicks based on sprite alpha
by Alexey Stashin · in Torque Game Builder · 12/05/2008 (1:30 pm) · 7 replies
Hello all,
How to get pixel alpha value of sprite to prevent clicks on transparent regions?
Or may be there is other way exist?
Thanks
How to get pixel alpha value of sprite to prevent clicks on transparent regions?
Or may be there is other way exist?
Thanks
About the author
#2
As I understand, direct pixel access impossible without source modification. Does source code has ways to make it possible?
12/06/2008 (1:24 am)
Thanks fo reply, but collision poly is not solution, I need to manage 100+ different images per scene and creating collision polys for each of them is nightmare.As I understand, direct pixel access impossible without source modification. Does source code has ways to make it possible?
#3
TGB will tell you what object has been picked (selected) and can provide you with the information for you to calculate what local-space coordinate of the object has been click. You can use this information to make local queries to the object.
In your case you want to interrogate alpha-texel info. It does sound like you need to try an alternative method, perhaps calculating these maps offline. You can then perform the look-up when you know where on the object you've clicked.
It is possible though, with the source, to expose a deeper query for image information. You'd have to first check what image-map the object uses as well as what frame. You can then go to the image-map and query the appropriate texel.
Don't forget though that you don't go to a sprite to ask it about the texels (image info) because it doesn't own it, the image-maps do.
Hope this helps,
Melv.
12/06/2008 (7:42 am)
Obviously almost anything is possible when you have the source code. I'll be honest though, the main point of TGB is to abstract you away from that. The feature you require depends on that.TGB will tell you what object has been picked (selected) and can provide you with the information for you to calculate what local-space coordinate of the object has been click. You can use this information to make local queries to the object.
In your case you want to interrogate alpha-texel info. It does sound like you need to try an alternative method, perhaps calculating these maps offline. You can then perform the look-up when you know where on the object you've clicked.
It is possible though, with the source, to expose a deeper query for image information. You'd have to first check what image-map the object uses as well as what frame. You can then go to the image-map and query the appropriate texel.
Don't forget though that you don't go to a sprite to ask it about the texels (image info) because it doesn't own it, the image-maps do.
Hope this helps,
Melv.
#4
12/06/2008 (11:58 am)
Great thanks, Melv. It is all I need to know before buying TGB Pro licence. 
#5
Thanks
12/21/2008 (5:44 am)
Hey Alexey Stashin did you manage to succeed on that quest? I'm having the same problem as you.Thanks
#6
If you will found solution, please write link here. Thanks
12/24/2008 (12:35 pm)
No, Gilberto, I don't have TGB Pro license and engine sources. I'm just choosing engine now for my casual projects and I didn't work with TGB closely yet.If you will found solution, please write link here. Thanks
#7
Check here -> http://www.garagegames.com/community/forums/viewthread/81610
02/03/2009 (6:28 am)
I've changed the source to manage this.Check here -> http://www.garagegames.com/community/forums/viewthread/81610
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