GLuint input_fbos[2]; // For rendering to the two layers of input_tex.
GLuint pbo; // For reading the data back.
void *pbo_contents; // Persistently mapped.
GLuint input_fbos[2]; // For rendering to the two layers of input_tex.
GLuint pbo; // For reading the data back.
void *pbo_contents; // Persistently mapped.