/// <summary>
/// 用一个纹理绘制指定范围内的可见字符
/// </summary>
/// <param name="fontFilename">字体文件名</param>
/// <param name="fontHeight">此值越大，绘制文字的清晰度越高，但占用的纹理资源就越多。</param>
/// <param name="firstChar">要显示的第一个字符</param>
/// <param name="lastChar">要显示的最后一个字符</param>
public FontElement(string fontFilename, int fontHeight, char firstChar, char lastChar)
{
if (firstChar > lastChar)
{
throw new ArgumentException("first char should <= last char");
}
int[] maxTextureWidth = new int[1];
// Get the maximum texture size supported by GL.
GL.GetInteger(GetTarget.MaxTextureSize, maxTextureWidth);
this.ttfTexture = FontTextureHelper.GetTTFTexture(fontFilename, fontHeight, maxTextureWidth[0], firstChar, lastChar);
}
/// <summary>
/// 用一个纹理绘制指定范围内的可见字符
/// </summary>
/// <param name="fontFilename">字体文件名</param>
/// <param name="fontHeight">此值越大，绘制文字的清晰度越高，但占用的纹理资源就越多。</param>
/// <param name="firstChar">要显示的第一个字符</param>
/// <param name="lastChar">要显示的最后一个字符</param>
public WholeFontTextureElement(string textureFilename, string xmlFilename)
{
this.ttfTexture = FontTextureHelper.GetTTFTexture(textureFilename, xmlFilename);
}