content: /*
   * Copyright 2014 Toxic Bakery
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *       http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.geek.banner.transformer.simple;
  
  import android.graphics.Camera;
  import android.graphics.Matrix;
  import android.view.View;
  
  public class TabletTransformer extends ABaseTransformer {
  
  	private static final Matrix OFFSET_MATRIX = new Matrix();
  	private static final Camera OFFSET_CAMERA = new Camera();
  	private static final float[] OFFSET_TEMP_FLOAT = new float[2];
  
  	@Override
  	protected void onTransform(View view, float position) {
  		final float rotation = (position < 0 ? 30f : -30f) * Math.abs(position);
  
  		view.setTranslationX(getOffsetXForRotation(rotation, view.getWidth(), view.getHeight()));
  		view.setPivotX(view.getWidth() * 0.5f);
  		view.setPivotY(0);
  		view.setRotationY(rotation);
  	}
  
  	protected static final float getOffsetXForRotation(float degrees, int width, int height) {
  		OFFSET_MATRIX.reset();
  		OFFSET_CAMERA.save();
  		OFFSET_CAMERA.rotateY(Math.abs(degrees));
  		OFFSET_CAMERA.getMatrix(OFFSET_MATRIX);
  		OFFSET_CAMERA.restore();
  
  		OFFSET_MATRIX.preTranslate(-width * 0.5f, -height * 0.5f);
  		OFFSET_MATRIX.postTranslate(width * 0.5f, height * 0.5f);
  		OFFSET_TEMP_FLOAT[0] = width;
  		OFFSET_TEMP_FLOAT[1] = height;
  		OFFSET_MATRIX.mapPoints(OFFSET_TEMP_FLOAT);
  		return (width - OFFSET_TEMP_FLOAT[0]) * (degrees > 0.0f ? 1.0f : -1.0f);
  	}
  
  }
  