iPhone 6s / RoboVM（？）GLTexImage2D渲染问题

我们最终在App Store上发布了我们的独立游戏，只是发现我们在iPhone 6s上存在重大渲染问题。

该游戏是使用LibGDX和RoboVM（v.1.12）开发的

我们正在使用iOS本机图形库将unicode文本呈现为纹理，以将其传递给LibGDX以显示为图像。为此，我们首先创建要打印的字符串，然后调用其draw（）方法：

    final String tmp = text.substring(0, text.length() >= MAX_NAME_LEN ? MAX_NAME_LEN : text.length());

    final NSMutableString string = new NSMutableString(tmp.length());
    //Allocate space for the bitmap to draw on
    int w = (int) width;
    int h = (int) height;
    final int bufferLen = w * h;
    final CGBitmapContext context = new CGBitmapContext(
        w, h, 8, 0, CGColorSpace.deviceRGB(), CGImageAlphaInfo.PremultipliedLast
    );

    final CGColor bgColor = UIColor.clear().getCGColor();

    final CGRect rect = new CGRect(0, 0, width, height);

    string.setString(tmp);

    final UIColor textColor = new UIColor(color.r, color.g, color.b, color.a);
    final UIFont font = UIFont.getBoldSystemFont(size);

    final NSString tester = new NSString("a");
    final CGSize textSize = tester.getSize(font);
    int strLen = string.toString().length();

    /**
     * Computes the optimal length of the string and removes characters beyound the
     * screen bounduaries.
     * If the string has been reduced, appends an ellipsis at the end
     */
    final NSRange range = new NSRange();
    boolean removed = false;
    while (strLen > 0 && textSize.getWidth() * strLen > width - textSize.getWidth() * 2) {
        range.setLocation(strLen - 1);
        range.setLength(1);
        string.deleteCharacters(range);

        strLen = string.toString().length();
        removed = true;
    }
    //append ellipsis at the end if we removed a char
    if (removed) {
        string.append("\u2026");
    }

    context.setFillColor(bgColor);
    context.fillRect(rect);
    //set up drawing attributes
    final NSAttributedStringAttributes attributes = new NSAttributedStringAttributes();
    attributes.set(NSAttributedStringAttribute.Font, font);
    attributes.set(NSAttributedStringAttribute.ForegroundColor, textColor);
    final NSMutableParagraphStyle paragraphStyle = new NSMutableParagraphStyle();
    paragraphStyle.setParagraphStyle(NSParagraphStyle.getDefaultParagraphStyle());
    paragraphStyle.setLineBreakMode(NSLineBreakMode.TruncatingTail);
    attributes.set(NSAttributedStringAttribute.ParagraphStyle, paragraphStyle);

    final NSAttributedString finalStr = new NSAttributedString(string.toString(), attributes);

    UIGraphics.pushContext(context);
    context.setTextMatrix(CGAffineTransform.Identity());
    context.translateCTM(0f, h);
    context.scaleCTM(1, -1);
    finalStr.draw(new CGPoint(rect.getX(), (rect.getY() + textSize.getHeight()) / 2));
    UIGraphics.popContext();


    return new BufferTextureData((int)context.getWidth(), (int)context.getHeight(), 0, GL20.GL_RGBA, GL20.GL_RGBA, GL20.GL_UNSIGNED_BYTE, context.getData().asIntBuffer(bufferLen));

然后，TextureBufferData通过以下方式将Buffer绑定到纹理：

private Buffer data;

public BufferTextureData(int width, int height, int mipMapLevel, int internalFormat, int format, int type, Buffer data) {
    this.width = width;
    this.height = height;
    this.mipLevel = mipMapLevel;
    this.internalFormat = internalFormat;
    this.format = format;
    this.type = type;
    this.data = data;
}

[...]

@Override
public void consumeCustomData(final int target) {
    Gdx.app.debug("BufferTextureData", "consuming data for target: " + target);
    Gdx.gl20.glTexImage2D(target, mipLevel, internalFormat, width, height, 0, format, type, data);
    data = null;
}

我们在以下设备上测试了此代码，没有任何问题：-iPhone 6-iPad Air 2-iPhone 5s以及iPhone 6s模拟器。

问题是，在iPhone 6s的实际设备上，我们得到以下信息：

如您所见，文本完全失真。似乎在绘图调用期间写入了保存绘图数据的缓冲区，但是我们确保在绘图线程上调用该方法以避免GL上下文切换。

我们真的不知道在哪里寻找。该代码可在iPhone6s模拟器（x64 CPU）和所有其他设备上无缝运行的事实使我认为问题可能是硬件相关的还是由RoboVM处理内存的方式引起的，但这只是一个猜测。

是否有人遇到过同样的问题，或者是否有可能导致这种现象的想法？

提前致谢