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 com.google.android.exoplayer2.util.FrameProcessingException;
  import com.google.common.collect.ImmutableList;
  
  /**
   * Specifies a 4x4 RGB color transformation matrix to apply to each frame in the fragment shader.
   */
  public interface RgbMatrix extends GlEffect {
  
    /**
     * Returns the 4x4 RGB transformation {@linkplain android.opengl.Matrix matrix} to apply to the
     * color values of each pixel in the frame with the given timestamp.
     *
     * @param presentationTimeUs The timestamp of the frame to apply the matrix on.
     * @param useHdr If {@code true}, colors will be in linear RGB BT.2020. If {@code false}, colors
     *     will be in linear RGB BT.709. Must be consistent with {@code useHdr} in {@link
     *     #toGlTextureProcessor(Context, boolean)}.
     * @return The {@code RgbMatrix} to apply to the frame.
     */
    float[] getMatrix(long presentationTimeUs, boolean useHdr);
  
    @Override
    default SingleFrameGlTextureProcessor toGlTextureProcessor(Context context, boolean useHdr)
        throws FrameProcessingException {
      return MatrixTextureProcessor.create(
          context,
          /* matrixTransformations= */ ImmutableList.of(),
          /* rgbMatrices= */ ImmutableList.of(this),
          useHdr);
    }
  }
  