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      1 /*
      2  * Copyright (C) 2012 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.gallery3d.ui;
     18 
     19 import javax.microedition.khronos.opengles.GL11;
     20 import javax.microedition.khronos.opengles.GL11Ext;
     21 
     22 // ExtTexture is a texture whose content comes from a external texture.
     23 // Before drawing, setSize() should be called.
     24 public class ExtTexture extends BasicTexture {
     25 
     26     private static int[] sTextureId = new int[1];
     27     private static float[] sCropRect = new float[4];
     28     private int mTarget;
     29 
     30     public ExtTexture(int target) {
     31         GLId.glGenTextures(1, sTextureId, 0);
     32         mId = sTextureId[0];
     33         mTarget = target;
     34     }
     35 
     36     private void uploadToCanvas(GLCanvas canvas) {
     37         GL11 gl = canvas.getGLInstance();
     38 
     39         int width = getWidth();
     40         int height = getHeight();
     41         // Define a vertically flipped crop rectangle for OES_draw_texture.
     42         // The four values in sCropRect are: left, bottom, width, and
     43         // height. Negative value of width or height means flip.
     44         sCropRect[0] = 0;
     45         sCropRect[1] = height;
     46         sCropRect[2] = width;
     47         sCropRect[3] = -height;
     48 
     49         // Set texture parameters.
     50         gl.glBindTexture(mTarget, mId);
     51         gl.glTexParameterfv(mTarget,
     52                 GL11Ext.GL_TEXTURE_CROP_RECT_OES, sCropRect, 0);
     53         gl.glTexParameteri(mTarget,
     54                 GL11.GL_TEXTURE_WRAP_S, GL11.GL_CLAMP_TO_EDGE);
     55         gl.glTexParameteri(mTarget,
     56                 GL11.GL_TEXTURE_WRAP_T, GL11.GL_CLAMP_TO_EDGE);
     57         gl.glTexParameterf(mTarget,
     58                 GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_LINEAR);
     59         gl.glTexParameterf(mTarget,
     60                 GL11.GL_TEXTURE_MAG_FILTER, GL11.GL_LINEAR);
     61 
     62         setAssociatedCanvas(canvas);
     63         mState = STATE_LOADED;
     64     }
     65 
     66     @Override
     67     protected boolean onBind(GLCanvas canvas) {
     68         if (!isLoaded()) {
     69             uploadToCanvas(canvas);
     70         }
     71 
     72         return true;
     73     }
     74 
     75     @Override
     76     public int getTarget() {
     77         return mTarget;
     78     }
     79 
     80     @Override
     81     public boolean isOpaque() {
     82         return true;
     83     }
     84 
     85     @Override
     86     public void yield() {
     87         // we cannot free the texture because we have no backup.
     88     }
     89 }
     90