content: /*
   * Copyright (C) 2018 The Android Open Source Project
   *
   * 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 android.view.shadow;
  
  import com.android.ide.common.rendering.api.LayoutLog;
  import com.android.layoutlib.bridge.Bridge;
  
  import android.graphics.Bitmap;
  import android.view.math.Math3DHelper;
  
  /**
   * Generates ambient shadow bitmap
   */
  class AmbientShadowBitmapGenerator {
  
      private final AmbientShadowConfig mShadowConfig;
      private final TriangleBuffer mTriangleBuffer;
      private final AmbientShadowVertexCalculator mCalculator;
  
      private float mTranslateX;
      private float mTranslateY;
  
      private boolean mValid;
  
      public AmbientShadowBitmapGenerator(AmbientShadowConfig shadowConfig) {
          mShadowConfig = shadowConfig;
  
          mTriangleBuffer = new TriangleBuffer();
          mTriangleBuffer.setSize(mShadowConfig.getWidth(), mShadowConfig.getHeight(), 0);
  
          mCalculator = new AmbientShadowVertexCalculator(mShadowConfig);
      }
  
      /**
       * Populate vertices and fill the triangle buffers. To be called before {@link #getBitmap()}
       */
      public void populateShadow() {
          try {
              mValid = mCalculator.generateVertex(mShadowConfig.getPolygon());
              if (!mValid) {
                  Bridge.getLog().warning(LayoutLog.TAG_INFO,  "Arithmetic error while " +
                                  "drawing ambient shadow", null, null);
                  return;
              }
  
              float[] shadowBounds = Math3DHelper.flatBound(mCalculator.getVertex(), 2);
              if (shadowBounds[0] < 0) {
                  // translate to right by the offset amount.
                  mTranslateX = shadowBounds[0] * -1;
              } else if (shadowBounds[2] > mShadowConfig.getWidth()) {
                  // translate to left by the offset amount.
                  mTranslateX = shadowBounds[2] - mShadowConfig.getWidth();
              }
  
              if (shadowBounds[1] < 0) {
                  mTranslateY = shadowBounds[1] * -1;
              } else if (shadowBounds[3] > mShadowConfig.getHeight()) {
                  mTranslateY = shadowBounds[3] - mShadowConfig.getHeight();
              }
  
              Math3DHelper.translate(mCalculator.getVertex(), mTranslateX, mTranslateY, 2);
  
              mTriangleBuffer.drawTriangles(mCalculator.getIndex(), mCalculator.getVertex(),
                      mCalculator.getColor(), mShadowConfig.getShadowStrength());
          } catch (IndexOutOfBoundsException|ArithmeticException mathError) {
              Bridge.getLog().warning(LayoutLog.TAG_INFO,  "Arithmetic error while drawing " +
                              "ambient shadow",
                      mathError);
          } catch (Exception ex) {
              Bridge.getLog().warning(LayoutLog.TAG_INFO,  "Error while drawing shadow",
                      ex);
          }
      }
  
      public boolean isValid() {
          return mValid;
      }
  
      public Bitmap getBitmap() {
          return mTriangleBuffer.getImage();
      }
  
      public float getTranslateX() {
          return mTranslateX;
      }
  
      public float getTranslateY() {
          return mTranslateY;
      }
  }
  