Use sizeof(GLfloat) instead of sizeof(GL_FLOAT)
GL_FLOAT is an enum, with the value 0x1406, while GLFloat is the actual type. Source: https://www.khronos.org/opengl/wiki/OpenGL_Type
GL_FLOAT is an enum, with the value 0x1406, while GLFloat is the actual type. Source: https://www.khronos.org/opengl/wiki/OpenGL_Type