content: /*
   * Copyright (C) 2010 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.android.gallery3d.glrenderer;
  
  import android.graphics.Bitmap;
  import android.graphics.Rect;
  import android.graphics.RectF;
  
  //
  // GLCanvas gives a convenient interface to draw using OpenGL.
  //
  // When a rectangle is specified in this interface, it means the region
  // [x, x+width) * [y, y+height)
  //
  public interface GLCanvas {
  
      public GLId getGLId();
  
      // Tells GLCanvas the size of the underlying GL surface. This should be
      // called before first drawing and when the size of GL surface is changed.
      // This is called by GLRoot and should not be called by the clients
      // who only want to draw on the GLCanvas. Both width and height must be
      // nonnegative.
      public abstract void setSize(int width, int height);
  
      // Clear the drawing buffers. This should only be used by GLRoot.
      public abstract void clearBuffer();
  
      public abstract void clearBuffer(float[] argb);
  
      // Sets and gets the current alpha, alpha must be in [0, 1].
      public abstract void setAlpha(float alpha);
  
      public abstract float getAlpha();
  
      // (current alpha) = (current alpha) * alpha
      public abstract void multiplyAlpha(float alpha);
  
      // Change the current transform matrix.
      public abstract void translate(float x, float y, float z);
  
      public abstract void translate(float x, float y);
  
      public abstract void scale(float sx, float sy, float sz);
  
      public abstract void rotate(float angle, float x, float y, float z);
  
      public abstract void multiplyMatrix(float[] mMatrix, int offset);
  
      // Pushes the configuration state (matrix, and alpha) onto
      // a private stack.
      public abstract void save();
  
      // Same as save(), but only save those specified in saveFlags.
      public abstract void save(int saveFlags);
  
      public static final int SAVE_FLAG_ALL = 0xFFFFFFFF;
      public static final int SAVE_FLAG_ALPHA = 0x01;
      public static final int SAVE_FLAG_MATRIX = 0x02;
  
      // Pops from the top of the stack as current configuration state (matrix,
      // alpha, and clip). This call balances a previous call to save(), and is
      // used to remove all modifications to the configuration state since the
      // last save call.
      public abstract void restore();
  
      // Draws a line using the specified paint from (x1, y1) to (x2, y2).
      // (Both end points are included).
      public abstract void drawLine(float x1, float y1, float x2, float y2, GLPaint paint);
  
      // Draws a rectangle using the specified paint from (x1, y1) to (x2, y2).
      // (Both end points are included).
      public abstract void drawRect(float x1, float y1, float x2, float y2, GLPaint paint);
  
      // Fills the specified rectangle with the specified color.
      public abstract void fillRect(float x, float y, float width, float height, int color);
  
      // Draws a texture to the specified rectangle.
      public abstract void drawTexture(
              BasicTexture texture, int x, int y, int width, int height);
  
      public abstract void drawMesh(BasicTexture tex, int x, int y, int xyBuffer,
              int uvBuffer, int indexBuffer, int indexCount);
  
      // Draws the source rectangle part of the texture to the target rectangle.
      public abstract void drawTexture(BasicTexture texture, RectF source, RectF target);
  
      // Draw a texture with a specified texture transform.
      public abstract void drawTexture(BasicTexture texture, float[] mTextureTransform,
                  int x, int y, int w, int h);
  
      // Draw two textures to the specified rectangle. The actual texture used is
      // from * (1 - ratio) + to * ratio
      // The two textures must have the same size.
      public abstract void drawMixed(BasicTexture from, int toColor,
              float ratio, int x, int y, int w, int h);
  
      // Draw a region of a texture and a specified color to the specified
      // rectangle. The actual color used is from * (1 - ratio) + to * ratio.
      // The region of the texture is defined by parameter "src". The target
      // rectangle is specified by parameter "target".
      public abstract void drawMixed(BasicTexture from, int toColor,
              float ratio, RectF src, RectF target);
  
      // Unloads the specified texture from the canvas. The resource allocated
      // to draw the texture will be released. The specified texture will return
      // to the unloaded state. This function should be called only from
      // BasicTexture or its descendant
      public abstract boolean unloadTexture(BasicTexture texture);
  
      // Delete the specified buffer object, similar to unloadTexture.
      public abstract void deleteBuffer(int bufferId);
  
      // Delete the textures and buffers in GL side. This function should only be
      // called in the GL thread.
      public abstract void deleteRecycledResources();
  
      // Dump statistics information and clear the counters. For debug only.
      public abstract void dumpStatisticsAndClear();
  
      public abstract void beginRenderTarget(RawTexture texture);
  
      public abstract void endRenderTarget();
  
      /**
       * Sets texture parameters to use GL_CLAMP_TO_EDGE for both
       * GL_TEXTURE_WRAP_S and GL_TEXTURE_WRAP_T. Sets texture parameters to be
       * GL_LINEAR for GL_TEXTURE_MIN_FILTER and GL_TEXTURE_MAG_FILTER.
       * bindTexture() must be called prior to this.
       *
       * @param texture The texture to set parameters on.
       */
      public abstract void setTextureParameters(BasicTexture texture);
  
      /**
       * Initializes the texture to a size by calling texImage2D on it.
       *
       * @param texture The texture to initialize the size.
       * @param format The texture format (e.g. GL_RGBA)
       * @param type The texture type (e.g. GL_UNSIGNED_BYTE)
       */
      public abstract void initializeTextureSize(BasicTexture texture, int format, int type);
  
      /**
       * Initializes the texture to a size by calling texImage2D on it.
       *
       * @param texture The texture to initialize the size.
       * @param bitmap The bitmap to initialize the bitmap with.
       */
      public abstract void initializeTexture(BasicTexture texture, Bitmap bitmap);
  
      /**
       * Calls glTexSubImage2D to upload a bitmap to the texture.
       *
       * @param texture The target texture to write to.
       * @param xOffset Specifies a texel offset in the x direction within the
       *            texture array.
       * @param yOffset Specifies a texel offset in the y direction within the
       *            texture array.
       * @param format The texture format (e.g. GL_RGBA)
       * @param type The texture type (e.g. GL_UNSIGNED_BYTE)
       */
      public abstract void texSubImage2D(BasicTexture texture, int xOffset, int yOffset,
              Bitmap bitmap,
              int format, int type);
  
      /**
       * Generates buffers and uploads the buffer data.
       *
       * @param buffer The buffer to upload
       * @return The buffer ID that was generated.
       */
      public abstract int uploadBuffer(java.nio.FloatBuffer buffer);
  
      /**
       * Generates buffers and uploads the element array buffer data.
       *
       * @param buffer The buffer to upload
       * @return The buffer ID that was generated.
       */
      public abstract int uploadBuffer(java.nio.ByteBuffer buffer);
  
      /**
       * After LightCycle makes GL calls, this method is called to restore the GL
       * configuration to the one expected by GLCanvas.
       */
      public abstract void recoverFromLightCycle();
  
      /**
       * Gets the bounds given by x, y, width, and height as well as the internal
       * matrix state. There is no special handling for non-90-degree rotations.
       * It only considers the lower-left and upper-right corners as the bounds.
       *
       * @param bounds The output bounds to write to.
       * @param x The left side of the input rectangle.
       * @param y The bottom of the input rectangle.
       * @param width The width of the input rectangle.
       * @param height The height of the input rectangle.
       */
      public abstract void getBounds(Rect bounds, int x, int y, int width, int height);
  }
  