glVertexAttribPointer and double precision buffers
This post will hopefully help people avoid a mistake that cost me several hours of debugging. In one of my projects I have been working with OpenGL 4 double precision vertex buffers. As the buffer data was passed to the shader as a generic attribute, I have been using glVertexAttribPointer to specify the attribute location in the data stream. This worked fine with floating point data. When I needed to switch to double precision, I checked the glVertexAttribPointer specification: this function accepts GL_DOUBLE as an input type: therefore, I assumed that change was all I needed to pass double precision data to my shader. I noticed two other version of the attrib pointer function existed ( glVertexAttribIPointer and glVertexAttribLPointer ) but I thought they were just legacy functions or alternatives to using glVertexAttribPointer with GL_DOUBLE or GL_INT type specifiers. Things did not work as I expected. trying to pass double precision data to the shader caused a crash de