Welcome,
Guest
. Please
login
or
register
. Did you miss your
activation email?
French forum
Home
Help
Search
Login
Register
SFML community forums
»
Help
»
Graphics
»
Shaders and drawing vertex array
Print
Pages: [
1
]
Author
Topic: Shaders and drawing vertex array (Read 1590 times)
0 Members and 1 Guest are viewing this topic.
Avonclese
Newbie
Posts: 7
Shaders and drawing vertex array
«
on:
October 23, 2017, 02:19:30 pm »
Hello! Quick question regarding shaders and vertex arrays
Scenario...
Basic 2D game where I render 500 objects in a single draw call by having all their vertices combined in a single vertex array. Works perfectly.
I want to use a shader to apply some fancy shading to just ONE of those objects.
I supply my shader as an argument in the draw call, so it will therefore affects everything drawn.
So my question is: is it possible to have a shader only affect one object (set of vertices) through a single draw call or will I have to draw the object separately on its own?
Thank you!
Logged
eXpl0it3r
SFML Team
Hero Member
Posts: 11034
Re: Shaders and drawing vertex array
«
Reply #1 on:
October 23, 2017, 05:27:48 pm »
Afaik you need to draw it separately as a shader always applies to all vertices or fragments that were passed along.
Logged
Official FAQ:
https://www.sfml-dev.org/faq.php
Official Discord Server:
https://discord.gg/nr4X7Fh
——————————————————————
Dev Blog:
https://duerrenberger.dev/blog/
Laurent
Administrator
Hero Member
Posts: 32498
Re: Shaders and drawing vertex array
«
Reply #2 on:
October 23, 2017, 06:30:33 pm »
You could use an unused attribute (color alpha, texture coordinate, ...) as a flag to identify which vertices need to be processed by the shader. Then the shader can interpret this value and react accordingly.
Logged
Laurent Gomila - SFML developer
Print
Pages: [
1
]
SFML community forums
»
Help
»
Graphics
»
Shaders and drawing vertex array
anything