private static int[] GetRealFontHeight(Bitmap bmp)
{
int width, height;
int frequency = 2;// higher frequency gets lower performance.
int[] ret = new int[2];
Color c;
bool goOut = false;
for (height = 1; height < bmp.Height - 1; height += frequency)
{
for (width = 1; width < bmp.Width - 1; width += frequency)
{
c = bmp.GetPixel(width, height);
if (c.Name.Length>0 && c.Name != "0")//got it!
{
ret[0] = height;
goOut = true;
break;
}
else
{
goOut = false;
}
}
if (goOut)
break;
}
goOut = false;
for (height = bmp.Height - 1; height > 1; height -= frequency)
{
for (width = bmp.Width - 1; width > 1; width -= frequency)
{
c = bmp.GetPixel(width, height);
if (c.Name.Length > 0 && c.Name != "0")
{
ret[1] = height;
goOut = true;
break;
}
else
{
goOut = false;
}
}
if (goOut)
break;
}
return ret;
}
在画图之前,用这个方法确定精确的字体高度,这样的染色的时候才不至于走样.大家可以通过http://www.ladysolution.cn/logo.aspx 生成图片看一下效果.如果用GDI+自带的计算高度的方法,比如GetHeight()和Height属性,在blend的时候换个字体必定有误差.
二. 画倒影, RotateFlip依然是主力
倒影倒是很简单,把BLEND设好,定位好,画出来就行:
Create mirror#region Create mirror
…….
Graphics gBack_mirror = Graphics.FromImage(backImage_mirror);
pStart = new Point(1, -pre[0]);
pEnd = new Point(1, pre[1] - pre[0]);
LinearGradientBrush backColor_mirror = new LinearGradientBrush(pStart, pEnd, Color.White, endColor);
……
gBack_mirror.DrawString(logoText, logoFont, backColor_mirror, new PointF(.0f, -pre[0]));
……
gBack.DrawImage(backImage_mirror, new Point(0, pre[1]+3));
#endregion
三. 计算好你的下笔点,通过第一点中的方法,可以拿到某字体在某size时的实际高度有多少,这样我们在画笔或写字之前通过调用此方法就可以得出你的着笔点的坐标:
private static int[] prerendText(int LogoWidth, int LogoHeight, string logoText, Font logoFont)
{
Bitmap bp = new Bitmap(LogoWidth, LogoHeight);
Graphics g = Graphics.FromImage(bp);
g.DrawString(logoText, logoFont, SystemBrushes.Info, new PointF(.0f, .0f));
int[] ret = new int[2];
ret = GetRealFontHeight(bp);
g.Dispose();
bp.Dispose();
return ret;
}
此方法返回某字体在某size下的最上方坐标和最下方坐标,有了坐标就好办事了:
int[] pre = prerendText(LogoWidth, LogoHeight, logoText, logoFont);
……
Point pStart = new Point(1, pre[0]-2);
Point pEnd = new Point(1, pre[1]+2);
LinearGradientBrush backColor = new LinearGradientBrush(pStart, pEnd, startColor, endColor);
return filename;
使用这种方法,画出来的图会比只用GDI+画出来更漂亮些,颜色更准确些.
来源:http://www.cnblogs.com/dingsea
