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我正在尝试在 Cardboard 上的 VR 中显示 PDF。为此，我创建了一个带有 pdfRenderer.page 的位图，并将其作为纹理应用。

但目前，我有一个黑屏（初始纹理的颜色）。我得出结论，位图的创建不起作用，但我不知道如何修复它。

这就是我创建位图的方式： 

public Bitmap render(){
        if (renderer.getPageCount() <= nbPage) {
            return null;
        }
        // Make sure to close the current page before opening another one.
        if (null != mCurrentPage) {
            mCurrentPage.close();
        }

        if (null != bitmap){
            bitmap.recycle();
        }

        // Use `openPage` to open a specific page in PDF.
        mCurrentPage = renderer.openPage(currentPage);

        int REQ_WIDTH = mCurrentPage.getWidth();
        int REQ_HEIGHT = mCurrentPage.getHeight();

        bitmap = Bitmap.createBitmap(REQ_WIDTH, REQ_HEIGHT, Bitmap.Config.ARGB_8888);

        mCurrentPage.render(bitmap, null, null, PdfRenderer.Page.RENDER_MODE_FOR_DISPLAY);

        return bitmap;
    }

这就是我将它作为纹理应用的方式：

public static int loadTexture(final Context context, Bitmap bitmap) {
        final int[] textureHandle = new int[1];

        GLES20.glGenTextures(1, textureHandle, 0);

        if (textureHandle[0] != 0)
        {

            // Bind to the texture in OpenGL
            GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandle[0]);

            // Set filtering
            GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST);
            GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_NEAREST);

            // Load the bitmap into the bound texture.
            GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);

            // Recycle the bitmap, since its data has been loaded into OpenGL.
            bitmap.recycle();
        }

        if (textureHandle[0] == 0)
        {
            throw new RuntimeException("Error loading texture.");
        }

        return textureHandle[0];
    }

如果有帮助，此代码适用于资源中的图像：

public static int loadTexture(final Context context, final int resourceId) {
        final int[] textureHandle = new int[1];

        GLES20.glGenTextures(1, textureHandle, 0);

        if (textureHandle[0] != 0)
        {
            final BitmapFactory.Options options = new BitmapFactory.Options();
            options.inScaled = false;   // No pre-scaling

            // Read in the resource
            final Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), resourceId, options);

            // Bind to the texture in OpenGL
            GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandle[0]);

            // Set filtering
            GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST);
            GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_NEAREST);

            // Load the bitmap into the bound texture.
            GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);

            // Recycle the bitmap, since its data has been loaded into OpenGL.
            bitmap.recycle();
        }

        if (textureHandle[0] == 0)
        {
            throw new RuntimeException("Error loading texture.");
        }

        return textureHandle[0];
    }

唯一的区别是 inScaled 选项，但我不知道这是否很重要？

谢谢您的帮助 ！

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