bindTexture(texture, slot, uniformName) {
    const gl = this.gl_;
    gl.activeTexture(gl.TEXTURE0 + slot);
    gl.bindTexture(gl.TEXTURE_2D, texture);
    gl.uniform1i(this.getUniformLocation(uniformName), slot);
  }
Prepare a program to use a texture.
@param {WebGLTexture} texture The texture.
@param {number} slot The texture slot.
@param {string} uniformName The corresponding uniform name.