content: /*
   * Copyright 2022 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 com.google.android.exoplayer2.effect;
  
  import android.content.Context;
  import android.opengl.Matrix;
  import android.util.Pair;
  import com.google.android.exoplayer2.util.FrameProcessingException;
  import com.google.common.collect.ImmutableList;
  
  /**
   * Specifies a 4x4 transformation {@link Matrix} to apply in the vertex shader for each frame.
   *
   * <p>The matrix is applied to points given in normalized device coordinates (-1 to 1 on x, y, and z
   * axes). Transformed pixels that are moved outside of the normal device coordinate range are
   * clipped.
   *
   * <p>Output frame pixels outside of the transformed input frame will be black, with alpha = 0 if
   * applicable.
   */
  public interface GlMatrixTransformation extends GlEffect {
    /**
     * Configures the input and output dimensions.
     *
     * <p>Must be called before {@link #getGlMatrixArray(long)}.
     *
     * @param inputWidth The input frame width, in pixels.
     * @param inputHeight The input frame height, in pixels.
     * @return The output frame width and height, in pixels.
     */
    default Pair<Integer, Integer> configure(int inputWidth, int inputHeight) {
      return Pair.create(inputWidth, inputHeight);
    }
  
    /**
     * Returns the 4x4 transformation {@link Matrix} to apply to the frame with the given timestamp.
     */
    float[] getGlMatrixArray(long presentationTimeUs);
  
    @Override
    default SingleFrameGlTextureProcessor toGlTextureProcessor(Context context, boolean useHdr)
        throws FrameProcessingException {
      return MatrixTextureProcessor.create(
          context,
          /* matrixTransformations= */ ImmutableList.of(this),
          /* rgbMatrices= */ ImmutableList.of(),
          useHdr);
    }
  }
  