1
\$\begingroup\$

I'm trying to send an integer attribute to my GLSL shader. The shader receives the attribute as follows:

layout (location = 3) in int integer_value;

I'm creating the attribute as follows:

glBindBuffer(GL_ARRAY_BUFFER, this.integerValueVboId);
glBufferData(GL_ARRAY_BUFFER, integer_values_buffer, GL_STATIC_DRAW);
glVertexAttribPointer(3, 1, GL_INT, false, 0, 0);

this.integerValueVboId is a valid ID generated with all the other VBOs. integer_values_buffer is an IntBuffer confirmed to contain the correct integer values.

When I set one of the integer values to 1, the shader receives the integer value 1065353216, which I have found to be the value obtained when one interprets a float 1.0f as an integer value.

\$\endgroup\$
0
\$\begingroup\$

When specifying an integer attribute you need to use glVertexAttribIPointer:

For glVertexAttribPointer, if normalized is set to GL_TRUE, it indicates that values stored in an integer format are to be mapped to the range [-1,1] (for signed values) or [0,1] (for unsigned values) when they are accessed and converted to floating point. Otherwise, values will be converted to floats directly without normalization.

For glVertexAttribIPointer, only the integer types GL_BYTE, GL_UNSIGNED_BYTE, GL_SHORT, GL_UNSIGNED_SHORT, GL_INT, GL_UNSIGNED_INT are accepted. Values are always left as integer values.

(My emphasis)

| improve this answer | |
\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.