Java-Gaming.org    
Featured games (81)
games approved by the League of Dukes
Games in Showcase (489)
Games in Android Showcase (112)
games submitted by our members
Games in WIP (555)
games currently in development
News: Read the Java Gaming Resources, or peek at the official Java tutorials
 
    Home     Help   Search   Login   Register   
Pages: [1]
  ignore  |  Print  
  GLSL speed vs java speed  (Read 807 times)
0 Members and 1 Guest are viewing this topic.
Offline RobinB

JGO Ninja


Medals: 44
Projects: 1
Exp: 3 years


Spacegame in progress


« Posted 2014-02-07 19:07:32 »

Hello,

While working at same shader transformations im always wondering, what would be the fastest way to implement something, or is there no diffrence?
I would have benchmarked it if it wasnt just impossible to test, so does one of the glsl experts here have a answer for this?

Case:
I have the following calculation in the vertex shader, it simply converts the modelmatrix to an normal matrix:
1  
n = normalize(mat3(inverse(transpose(modelmatrix))) * normal);


If i would precalculate this matrix in java (every frame, every object, worst case) and send them to the shader for every object, would this be faster, slower or equal to the speed of calculating them every vertex.
I would say preloading then for every object, but this means no parallel calculations and sending a command to the shader for every frame.
Offline Danny02
« Reply #1 - Posted 2014-02-07 19:42:29 »

yes, it would be faster. Just calculate it on the CPU.
Also, you probably don't need the inverse transpose matrix. You only need to do this if you use non-uniform scaling(scale the axes differently).
Offline RobinB

JGO Ninja


Medals: 44
Projects: 1
Exp: 3 years


Spacegame in progress


« Reply #2 - Posted 2014-02-07 22:56:30 »

Thank you for your info, good to know about the invert / transpose, thats a lot easyer as i thought Smiley.
So filling a float buffer and sending it to gsl is still faster then a simple cast (for lets say 500 / 1000 triangles (without indexing, so 1500 / 3000 vertrices))?
1  
mat3(modelmatrix);
Games published by our own members! Check 'em out!
Legends of Yore - The Casual Retro Roguelike
Offline Danny02
« Reply #3 - Posted 2014-02-08 00:05:02 »

Doing this "cast" (it's actually a C constructor) is probably a NOP. You probably wouldn't notice a difference between the GPU/CPU versions in the case of big enough batches(i.e. more than a hand full triangles). I'm doing the CPU version in my "engine", because it is more generic (will work in any case).
Offline RobinB

JGO Ninja


Medals: 44
Projects: 1
Exp: 3 years


Spacegame in progress


« Reply #4 - Posted 2014-02-08 21:39:30 »

Thank you, ill forget it for now then Smiley
Pages: [1]
  ignore  |  Print  
 
 
You cannot reply to this message, because it is very, very old.

 

Add your game by posting it in the WIP section,
or publish it in Showcase.

The first screenshot will be displayed as a thumbnail.

Nickropheliac (12 views)
2014-08-31 22:59:12

TehJavaDev (23 views)
2014-08-28 18:26:30

CopyableCougar4 (27 views)
2014-08-22 19:31:30

atombrot (40 views)
2014-08-19 09:29:53

Tekkerue (38 views)
2014-08-16 06:45:27

Tekkerue (34 views)
2014-08-16 06:22:17

Tekkerue (24 views)
2014-08-16 06:20:21

Tekkerue (34 views)
2014-08-16 06:12:11

Rayexar (72 views)
2014-08-11 02:49:23

BurntPizza (47 views)
2014-08-09 21:09:32
List of Learning Resources
by Longor1996
2014-08-16 10:40:00

List of Learning Resources
by SilverTiger
2014-08-05 19:33:27

Resources for WIP games
by CogWheelz
2014-08-01 16:20:17

Resources for WIP games
by CogWheelz
2014-08-01 16:19:50

List of Learning Resources
by SilverTiger
2014-07-31 16:29:50

List of Learning Resources
by SilverTiger
2014-07-31 16:26:06

List of Learning Resources
by SilverTiger
2014-07-31 11:54:12

HotSpot Options
by dleskov
2014-07-08 01:59:08
java-gaming.org is not responsible for the content posted by its members, including references to external websites, and other references that may or may not have a relation with our primarily gaming and game production oriented community. inquiries and complaints can be sent via email to the info‑account of the company managing the website of java‑gaming.org
Powered by MySQL Powered by PHP Powered by SMF 1.1.18 | SMF © 2013, Simple Machines | Managed by Enhanced Four Valid XHTML 1.0! Valid CSS!