如何在OpenTK中翻转QuickFont

Question

I have an orthogonal view (which is flipped 180 degree) containing some text written using QuickFont in OpenTK. I wanted to flip the text so I thought of setting QFontBuilderConfiguration.TransformToCurrentOrthogProjection and TransformViewport for QFontRenderOptions but its not working. Following is my code-

const float LeftX = 0.0f;
const float RightX = 16.0f;
const float BottomY = 12.0f;
const float TopY = 0.0f;
const float FarZ = 1.0f;
const float NearZ = -1.0f;

protected override void OnLoad(EventArgs e)
{
    base.OnLoad(e);
    QFontBuilderConfiguration fontBuilderConfiguration = new QFontBuilderConfiguration();
    fontBuilderConfiguration.TransformToCurrentOrthogProjection = true; // Adding this throwing error
    font = new QFont("Fonts/HappySans.ttf", 30, fontBuilderConfiguration);
    QFontRenderOptions fontRenderOptions = new QFontRenderOptions();
    fontRenderOptions.TransformToViewport = new TransformViewport(0, 0, RightX, BottomY);
    font.PushOptions(fontRenderOptions);
    GL.ClearColor(Color.AliceBlue);
    GL.Disable(EnableCap.DepthTest);
}

protected override void OnResize(EventArgs e)
{
    base.OnResize(e);
    GL.Viewport(0, 0, Width, Height);
    GL.MatrixMode(MatrixMode.Projection);
    GL.LoadIdentity();
    GL.Ortho(RightX, LeftX, TopY, BottomY, FarZ, NearZ);
}

Finally the output should be flipped text.

Answer 1

我想当您打开“ TransformToCurrentOrthogProjection”选项时，如果需要旋转 ，QuickFont会简单地将字体缩放到当前投影，因此请尝试：

GL.Rotate(180, 0, 0, 1);