content: /*
   * Copyright (C) 2011 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.media.effect;
  
  
  /**
   * <p>Effects are high-performance transformations that can be applied to image frames. These are
   * passed in the form of OpenGL ES 2.0 texture names. Typical frames could be images loaded from
   * disk, or frames from the camera or other video streams.</p>
   *
   * <p>To create an Effect you must first create an EffectContext. You can obtain an instance of the
   * context's EffectFactory by calling
   * {@link android.media.effect.EffectContext#getFactory() getFactory()}. The EffectFactory allows
   * you to instantiate specific Effects.</p>
   *
   * <p>The application is responsible for creating an EGL context, and making it current before
   * applying an effect. An effect is bound to a single EffectContext, which in turn is bound to a
   * single EGL context. If your EGL context is destroyed, the EffectContext becomes invalid and any
   * effects bound to this context can no longer be used.</p>
   *
   */
  public abstract class Effect {
  
      /**
       * Get the effect name.
       *
       * Returns the unique name of the effect, which matches the name used for instantiating this
       * effect by the EffectFactory.
       *
       * @return The name of the effect.
       */
      public abstract String getName();
  
      /**
       * Apply an effect to GL textures.
       *
       * <p>Apply the Effect on the specified input GL texture, and write the result into the
       * output GL texture. The texture names passed must be valid in the current GL context.</p>
       *
       * <p>The input texture must be a valid texture name with the given width and height and must be
       * bound to a GL_TEXTURE_2D texture image (usually done by calling the glTexImage2D() function).
       * Multiple mipmap levels may be provided.</p>
       *
       * <p>If the output texture has not been bound to a texture image, it will be automatically
       * bound by the effect as a GL_TEXTURE_2D. It will contain one mipmap level (0), which will have
       * the same size as the input. No other mipmap levels are defined. If the output texture was
       * bound already, and its size does not match the input texture size, the result may be clipped
       * or only partially fill the texture.</p>
       *
       * <p>Note, that regardless of whether a texture image was originally provided or not, both the
       * input and output textures are owned by the caller. That is, the caller is responsible for
       * calling glDeleteTextures() to deallocate the input and output textures.</p>
       *
       * @param inputTexId The GL texture name of a valid and bound input texture.
       * @param width The width of the input texture in pixels.
       * @param height The height of the input texture in pixels.
       * @param outputTexId The GL texture name of the output texture.
       */
      public abstract void apply(int inputTexId, int width, int height, int outputTexId);
  
      /**
       * Set a filter parameter.
       *
       * Consult the effect documentation for a list of supported parameter keys for each effect.
       *
       * @param parameterKey The name of the parameter to adjust.
       * @param value The new value to set the parameter to.
       * @throws InvalidArgumentException if parameterName is not a recognized name, or the value is
       *         not a valid value for this parameter.
       */
      public abstract void setParameter(String parameterKey, Object value);
  
      /**
       * Set an effect listener.
       *
       * Some effects may report state changes back to the host, if a listener is set. Consult the
       * individual effect documentation for more details.
       *
       * @param listener The listener to receive update callbacks on.
       */
      public void setUpdateListener(EffectUpdateListener listener) {
      }
  
      /**
       * Release an effect.
       *
       * <p>Releases the effect and any resources associated with it. You may call this if you need to
       * make sure acquired resources are no longer held by the effect. Releasing an effect makes it
       * invalid for reuse.</p>
       *
       * <p>Note that this method must be called with the EffectContext and EGL context current, as
       * the effect may release internal GL resources.</p>
       */
      public abstract void release();
  }
  
  