content: /*
   * Copyright 2012 Hannes Janetzek
   *
   * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
   *
   * This program is free software: you can redistribute it and/or modify it under the
   * terms of the GNU Lesser General Public License as published by the Free Software
   * Foundation, either version 3 of the License, or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful, but WITHOUT ANY
   * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public License along with
   * this program. If not, see <http://www.gnu.org/licenses/>.
   */
  package org.oscim.renderer;
  
  public abstract class LayerRenderer {
  
      /**
       * flag to set when layer is ready for rendering
       */
      boolean isReady;
  
      /**
       * set by MapRenderer
       */
      boolean isInitialized;
  
      /**
       * Set 'ready for render' state when layer data is ready for rendering.
       *
       * @param ready true if render() should be called, false otherwise.
       */
      protected void setReady(boolean ready) {
          isReady = ready;
      }
  
      public boolean isReady() {
          return isReady;
      }
  
      /**
       * 0. Called on GL Thread before first update().
       */
      public boolean setup() {
          return true;
      }
  
      /**
       * 1. Called first by MapRenderer: Update the state here, compile
       * vertex-data and set setReady(true).
       *
       * @param position current MapPosition
       * @param changed  true when MapPosition has changed since last frame
       * @param matrices contains the current view- and projection-matrices
       *                 and 'mvp' matrix for temporary use.
       */
      public abstract void update(GLViewport viewport);
  
      /**
       * 2. Draw layer: called by MapRenderer when isReady == true.
       *
       * @param position current MapPosition
       * @param matrices contains the current view- and projection-matrices.
       *                 'matrices.mvp' is for temporary use to build the model-
       *                 view-projection to set as uniform.
       */
      public abstract void render(GLViewport viewport);
  
  }
  