samples/sdk-hellovr/src/main/java/com/google/vr/sdk/samples/hellovr/Texture.java

/*
 * Copyright 2018 Google Inc. All Rights Reserved.
 *
 * 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.vr.sdk.samples.hellovr;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.opengl.GLES20;
import android.opengl.GLUtils;
import java.io.IOException;

/** A texture, meant for use with TexturedMesh. */
/* package */ class Texture {
  private final int[] textureId = new int[1];

  /**
   * Initializes the texture.
   *
   * @param context Context for loading the texture file.
   * @param texturePath Path to the image to use for the texture.
   */
  public Texture(Context context, String texturePath) throws IOException {
    GLES20.glGenTextures(1, textureId, 0);
    bind();
    GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE);
    GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE);
    GLES20.glTexParameteri(
        GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR_MIPMAP_NEAREST);
    GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
    Bitmap textureBitmap = BitmapFactory.decodeStream(context.getAssets().open(texturePath));
    GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, textureBitmap, 0);
    textureBitmap.recycle();
    GLES20.glGenerateMipmap(GLES20.GL_TEXTURE_2D);
  }

  /** Binds the texture to GL_TEXTURE0. */
  public void bind() {
    GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
    GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureId[0]);
  }
}