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Shader does not accept the Parameters.

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Vasilij

Feb 12, 2014; 4:07pm

Shader does not accept the Parameters.

Hello,

I have written vShader and fShader in GLSL ES 3.0.

I can compile them without errors and I link them to Shader-programm.
Now, when i initilaise them like this: positionIdx = gl.glGetAttribLocation(shaderProgram, "a_position");
the int-value of "positionIdx" is -1.What can be a problem?

jmaasing

Feb 12, 2014; 5:50pm

Re: Shader does not accept the Parameters.

Shader compilers are allowed to optimize away "in" parameters (and uniforms) that are not used in the shader program. So even if "a_position" is declared in the shader, if it is not used you can get -1 as result.

Vasilij

Feb 13, 2014; 8:14am

Re: Shader does not accept the Parameters.

In my opinion, i use that Parameters in Shaders.
Hier is a vShader:

in vec4 a_position;
void main()
{
gl_Position = a_position;
}

and a fShader:

in vec2 a_texCoord;
uniform sampler2D s_texture;
layout(location = 0) out vec4 data;
void main ()
{
data = texture(s_texture, a_texCoord);
}

I initialise them like this:
int positionIdx = gl.glGetAttribLocation(shaderProgram, "a_position");
int texCoordIdx = gl.glGetAttribLocation(shaderProgram, "a_texCoord");
int sampIdx = gl.glGetUniformLocation(shaderProgram, "s_texture");

Are my Shaders broken?

jmaasing

Feb 13, 2014; 9:33am

Re: Shader does not accept the Parameters.

The only thing I can think of is that they are missing a version tag. For example #version 410 core
So maybe your driver considers them an "old" version of GLSL and fails somehow but that should've resulted in them not compiling.

Vasilij

Feb 13, 2014; 10:11am

Re: Shader does not accept the Parameters.

Yes, i had this idea too.
I have added "#version 300 es" at the beginning of Shaders.
On PC there is an Error: "Incorrect GLSL version for token es: 300"

Not a Problem, because the RasPi can compile Shaders without Errors. But the int-Values are still -1.

jmaasing

Feb 13, 2014; 1:22pm

Re: Shader does not accept the Parameters.

I thought RasPi was GLES 2.0 only? If you give it GLES 3 shaders I guess they will fail to compile and maybe the compiler isn't nice enough to tell you they failed.

Sven Gothel

Feb 13, 2014; 1:58pm

Re: Shader does not accept the Parameters.

Administrator

On 02/13/2014 02:22 PM, jmaasing [via jogamp] wrote:
> I thought RasPi was GLES 2.0 only? If you give it GLES 3 shaders I guess they
> will fail to compile and maybe the compiler isn't nice enough to tell you they
> failed.

Note: If you look at our GearsES2 demo - or any other utilizing ShaderCode,
you will see that we add the GLSL version tag and other defines
at runtime depending on the used GLContext version.

Check call hierarchy on 'ShaderCode.addGLSLVersion(GL2ES2 gl)'.

Reason we do this is, b/c some GL implementation can by very picky
and refuse to run any shader code not matching the GLContext version.

~Sven

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jmaasing

Feb 13, 2014; 2:56pm

Re: Shader does not accept the Parameters.

Sven Gothel wrote

On 02/13/2014 02:22 PM, jmaasing [via jogamp] wrote:
> I thought RasPi was GLES 2.0 only? If you give it GLES 3 shaders I guess they
> will fail to compile and maybe the compiler isn't nice enough to tell you they
> failed.

Note: If you look at our GearsES2 demo - or any other utilizing ShaderCode,
you will see that we add the GLSL version tag and other defines
at runtime depending on the used GLContext version.

Check call hierarchy on 'ShaderCode.addGLSLVersion(GL2ES2 gl)'.

Reason we do this is, b/c some GL implementation can by very picky
and refuse to run any shader code not matching the GLContext version.

~Sven

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... [show rest of quote]

... [show rest of quote]

I did not know that, nice feature :-)

Vasilij

Feb 18, 2014; 11:40am

Re: Shader does not accept the Parameters.

Thank you for answers.
The error was in Shader, I have not see it because the Compiler on Raspi has compile it without errors.

Xerxes Rånby

Feb 18, 2014; 12:04pm

Re: Shader does not accept the Parameters.

Take a look at the JOGL wiki where we have collected knowledge on how to write cross GLProfile compatible shaders:
http://jogamp.org/wiki/index.php/How_to_write_cross_GLProfile_compatible_shader_using_JOGL

2014-02-18 12:40 GMT+01:00 Vasilij [via jogamp] <[hidden email]>:

Thank you for answers.
The error was in Shader, I have not see it because the Compiler on Raspi has compile it without errors.

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