CODEWITHSUNDEEP
androidopengl-es-2.0
Lee Netherton
Lee Netherton

Reputation: 22542

GLES20.glUniform4fv is giving GL_INVALID_OPERATION (1282)

I am having some problems uploading a small vector of vec4s to the GPU. I have boiled this problem down to the bare minimum code to throw an error.

Here is my Fragment shader:

precision mediump float;
uniform vec4 test[5];
void main() {
    gl_FragColor = test[0]+test[1]+test[2]+test[3]+test[4];
}

And the vertex shader is trivial:

attribute vec4 vPosition;        
void main(){
    gl_Position = vPosition;
}

Here is the code that tries to upload the vec4 vector:

    float[] testBuffer = new float[4*5];
    // Fill with 1/5s for now
    Arrays.fill(testBuffer, 0.2f);

    // Get the location
    int testLoc = GLES20.glGetUniformLocation(mProgram, "test");
    checkGlError("glGetUniformLocation test");

    // Upload the buffer
    GLES20.glUniform4fv(testLoc, 5, testBuffer, 0);
    checkGlError("glUniform4fv testBuffer");

The error is found on the second call to checkGlError(), and the error code is GL_INVALID_OPERATION.

I've read the documentation on glUniform and all of the sizes and types appear to be correct. testLoc is a valid location handle, and I have no errors when uploading the fragment and vertex shader code.

I just can't see what I'm doing wrong! Any ideas?

--UPDATED

Upvotes: 3

Views: 5668

Answers (1)

Christian Rau
Christian Rau

Reputation: 45948

See glUniform documentation:

GL_INVALID_OPERATION is generated if there is no current program object

Make sure your shader is currently bound/used when calling glUniform (glUseProgram has been called with the corresponding shader program handle). The uniform keeps its value when unbinding the shader (e.g. glUseProgram(0)), but the program has to be active when setting the uniform value.

Upvotes: 8

Related Questions