useProgram(program) {
        if(this.state.currentProgramID === null || this.state.currentProgramID !== program.id) {
            this.gl.useProgram(program.program);
            this.state.currentProgramID = program.id;
        }
    }
Tell WebGL to use the specified program if it's not already in use

     params:
     @program (object): a program object
*