Sign in to follow this  

OpenGL GLSL problem with uniform

Recommended Posts

hello, i am using openGL with java and the GLSL i got an crazy problem and i dont know what to do. in java i send some data to the fragment shader: int ed = gl.glGetUniformLocationARB(program, "edges"); gl.glUniform4fARB(ed, 1.0f,1.0f,1.0f,1.0f); that works... (i also do this for textures etc) in the fragment shader: uniform vec4 edges; int off=0; int ec1; sampler2D tex[10]; //an array of sampler2d that is filled one time inside the fragment shader(that work perfect) ... void main(void) { ... ... ... //and here is the problem if (edges.r==0.0) ec1 = int (0); if (edges.r==1.0) ec1 = int (1); if (edges.r==2.0) ec1 = int (2); if (edges.r==3.0) ec1 = int (3); ... //that will crash and i dont know why?!?!?! texel_av = texture2D(tex[ec1] , texCoord)*pow1; //that work texel_av = texture2D(tex[0] , texCoord)*pow1; texel_av = texture2D(tex[1] , texCoord)*pow1; texel_av = texture2D(tex[2] , texCoord)*pow1; texel_av = texture2D(tex[3] , texCoord)*pow1; i dont know what to do..why is the fragment shader blocking all my basic like attempts to build some simple integer access to an array (and work with static vars inside the fragement)

Share this post

Link to post
Share on other sites
is it crashing or what??

If it is just saying that it cannot find the uniform it might be becouse your using 'texel_av =' rather then 'texel_av +=' which means the compiler might remove all but the last one. and then remove all unused varibles which might include the uniform.. would need more info on the error...

Share this post

Link to post
Share on other sites
Why are you declaring ec1 and off outside of main? If they're not uniform, varying or attribute variables, put them inside of your main function. Maybe that's the problem.

Share this post

Link to post
Share on other sites
the problem is that i am not able to work with uniform data(int)

its simple: i got an array of sampler2d..

that array works perfect when calling tex[ec1]
and ec is static (inside or outside the main of the fragment code)

but at this moment when i try to use any data from outside
the frament shader stops the work

uniform int data1;


sampler2d ( tex[data1] <- that stops the frag shader


if (data1==1) test1=1;
sampler2d ( tex[test1] <- that stops the fragment shader too


sampler2d ( tex[test1] <- that works

Share this post

Link to post
Share on other sites

int ed=gl.glGetUniformLocationARB(program, "edges");
gl.glUniform4fARB(ed, 0.0f,1.0f,0.0f,1.0f);

even this simple example fails:

//copy the working sampler2D t0 to tex0
if (edges.r==0.0) tex0=t0;

edges is filled with the correct data..but the fs
stops working when i use edges in any combination
with the sampler2d (direct and nodirect)

Share this post

Link to post
Share on other sites
//that will crash and i dont know why?!?!?!
texel_av = texture2D(tex[ec1] , texCoord)*pow1;

It shouldn't cause a crash. Update your drivers to get the latest.
If then you still have problems, it's possible to send a bug report to the company so that they correct their driver problem.

Share this post

Link to post
Share on other sites
I mean, how do you initialize this vector:

sampler2D tex[10];

How is this filled? I believed that you only could pass sampler2D as uniforms.

Share this post

Link to post
Share on other sites
i now understand what you asking about:

first i was trying to get the sampler2d tex[10]
as a uniform..that was not working so
i try an unprofessional way...

i get the uniform sampler2d t0,t1,t2,t3,t4,t5...

and then i copy them to tex (tex[0]=t0;tex[1]=t1...}

and that is all working perfect with no error

the problem in a short example:

static int var1= 1
uniform int var2; //var2 gets the int=1 from main code

sampler2d [tex[var1]... is working
sampler2d [tex[var2]... is not working (yes,var2 got data)


this is working!!!

"vec4 texel_av=0;\n" +

" if (edges.r==0.0) texel_av += texture2D(tex0 , texCoord)*pow1;\n" +
" if (edges.r==1.0) texel_av += texture2D(tex1 , texCoord)*pow1;\n" +
" if (edges.r==2.0) texel_av += texture2D(tex2 , texCoord)*pow1;\n" +
" if (edges.r==3.0) texel_av += texture2D(tex3 , texCoord)*pow1;\n" +

" if (edges.g==0.0) texel_av += texture2D(tex0 , texCoord)*pow4;\n" +
" if (edges.g==1.0) texel_av += texture2D(tex1 , texCoord)*pow4;\n" +
" if (edges.g==2.0) texel_av += texture2D(tex2 , texCoord)*pow4;\n" +
" if (edges.g==3.0) texel_av += texture2D(tex3 , texCoord)*pow4;\n" +

" if (edges.b==0.0) texel_av += texture2D(tex0 , texCoord)*pow2;\n" +
" if (edges.b==1.0) texel_av += texture2D(tex1 , texCoord)*pow2;\n" +
" if (edges.b==2.0) texel_av += texture2D(tex2 , texCoord)*pow2;\n" +
" if (edges.b==3.0) texel_av += texture2D(tex3 , texCoord)*pow2;\n" +

" if (edges.a==0.0) texel_av += texture2D(tex0 , texCoord)*pow3;\n" +
" if (edges.a==1.0) texel_av += texture2D(tex1 , texCoord)*pow3;\n" +
" if (edges.a==2.0) texel_av += texture2D(tex2 , texCoord)*pow3;\n" +
" if (edges.a==3.0) texel_av += texture2D(tex3 , texCoord)*pow3;\n" +

[Edited by - DerTherion on March 16, 2009 4:51:43 AM]

Share this post

Link to post
Share on other sites
static int var1= 1
uniform int var2; //var2 gets the int=1 from main code

sampler2d [tex[var1]... is working
sampler2d [tex[var2]... is not working (yes,var2 got data)

That's normal. It isn't supported. But still, it should cause your system to crash. Instead, it should give a error log.

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

  • Forum Statistics

    • Total Topics
    • Total Posts
  • Similar Content

    • By DelicateTreeFrog
      Hello! As an exercise for delving into modern OpenGL, I'm creating a simple .obj renderer. I want to support things like varying degrees of specularity, geometry opacity, things like that, on a per-material basis. Different materials can also have different textures. Basic .obj necessities. I've done this in old school OpenGL, but modern OpenGL has its own thing going on, and I'd like to conform as closely to the standards as possible so as to keep the program running correctly, and I'm hoping to avoid picking up bad habits this early on.
      Reading around on the OpenGL Wiki, one tip in particular really stands out to me on this page:
      For something like a renderer for .obj files, this sort of thing seems almost ideal, but according to the wiki, it's a bad idea. Interesting to note!
      So, here's what the plan is so far as far as loading goes:
      Set up a type for materials so that materials can be created and destroyed. They will contain things like diffuse color, diffuse texture, geometry opacity, and so on, for each material in the .mtl file. Since .obj files are conveniently split up by material, I can load different groups of vertices/normals/UVs and triangles into different blocks of data for different models. When it comes to the rendering, I get a bit lost. I can either:
      Between drawing triangle groups, call glUseProgram to use a different shader for that particular geometry (so a unique shader just for the material that is shared by this triangle group). or
      Between drawing triangle groups, call glUniform a few times to adjust different parameters within the "master shader", such as specularity, diffuse color, and geometry opacity. In both cases, I still have to call glBindTexture between drawing triangle groups in order to bind the diffuse texture used by the material, so there doesn't seem to be a way around having the CPU do *something* during the rendering process instead of letting the GPU do everything all at once.
      The second option here seems less cluttered, however. There are less shaders to keep up with while one "master shader" handles it all. I don't have to duplicate any code or compile multiple shaders. Arguably, I could always have the shader program for each material be embedded in the material itself, and be auto-generated upon loading the material from the .mtl file. But this still leads to constantly calling glUseProgram, much more than is probably necessary in order to properly render the .obj. There seem to be a number of differing opinions on if it's okay to use hundreds of shaders or if it's best to just use tens of shaders.
      So, ultimately, what is the "right" way to do this? Does using a "master shader" (or a few variants of one) bog down the system compared to using hundreds of shader programs each dedicated to their own corresponding materials? Keeping in mind that the "master shaders" would have to track these additional uniforms and potentially have numerous branches of ifs, it may be possible that the ifs will lead to additional and unnecessary processing. But would that more expensive than constantly calling glUseProgram to switch shaders, or storing the shaders to begin with?
      With all these angles to consider, it's difficult to come to a conclusion. Both possible methods work, and both seem rather convenient for their own reasons, but which is the most performant? Please help this beginner/dummy understand. Thank you!
    • By JJCDeveloper
      I want to make professional java 3d game with server program and database,packet handling for multiplayer and client-server communicating,maps rendering,models,and stuffs Which aspect of java can I learn and where can I learn java Lwjgl OpenGL rendering Like minecraft and world of tanks
    • By AyeRonTarpas
      A friend of mine and I are making a 2D game engine as a learning experience and to hopefully build upon the experience in the long run.

      -What I'm using:
          C++;. Since im learning this language while in college and its one of the popular language to make games with why not.     Visual Studios; Im using a windows so yea.     SDL or GLFW; was thinking about SDL since i do some research on it where it is catching my interest but i hear SDL is a huge package compared to GLFW, so i may do GLFW to start with as learning since i may get overwhelmed with SDL.  
      Knowing what we want in the engine what should our main focus be in terms of learning. File managements, with headers, functions ect. How can i properly manage files with out confusing myself and my friend when sharing code. Alternative to Visual studios: My friend has a mac and cant properly use Vis studios, is there another alternative to it?  
    • By ferreiradaselva
      Both functions are available since 3.0, and I'm currently using `glMapBuffer()`, which works fine.
      But, I was wondering if anyone has experienced advantage in using `glMapBufferRange()`, which allows to specify the range of the mapped buffer. Could this be only a safety measure or does it improve performance?
      Note: I'm not asking about glBufferSubData()/glBufferData. Those two are irrelevant in this case.
    • By xhcao
      Before using void glBindImageTexture(    GLuint unit, GLuint texture, GLint level, GLboolean layered, GLint layer, GLenum access, GLenum format), does need to make sure that texture is completeness. 
  • Popular Now