/// <summary>
/// 撕纸效果
/// </summary>
public class TearHelper
{
private static SolidBrush out_sb = new SolidBrush(Color.FromArgb(80, 110, 105, 109));
private static Pen out_pen = new Pen(Color.FromArgb(220, 128, 128, 128));
/// <summary>
/// 撕纸
/// </summary>
/// <param name="img">要处理的图片</param>
/// <param name="tearOrientation">撕裂方位</param>
/// <param name="shadowOrientation">撕裂阴影方位</param>
/// <param name="avulsion">撕纸效果厚度(默认值8)</param>
/// <param name="shadow">撕纸效果阴影厚度(默认值4)</param>
/// <param name="interval">撕纸效果间距(默认值4)</param>
/// <returns></returns>
public static Bitmap TearIamge(Image img, TearOrientation tearOrientation = TearOrientation.Bottom|TearOrientation.Right, ShadowOrientation shadowOrientation = ShadowOrientation.Bottom|ShadowOrientation.Right, int avulsion = 8, int shadow = 4, int interval = 4)
{
Bitmap bmp = new Bitmap(img.Width, img.Height);
Graphics bmp_g = Graphics.FromImage(bmp);
Region r = bmp_g.Clip;
int x = 0;
#region 内图大小
Rectangle bmp_in_rect = new Rectangle(0, 0, img.Width, img.Height);
if (tearOrientation.HasFlag(TearOrientation.Bottom))
{
bmp_in_rect.Height -= avulsion;
if (shadowOrientation.HasFlag(ShadowOrientation.Bottom))
{
bmp_in_rect.Height -= shadow;
}
}
if (tearOrientation.HasFlag(TearOrientation.Right))
{
bmp_in_rect.Width -= avulsion;
if (shadowOrientation.HasFlag(ShadowOrientation.Right))
{
bmp_in_rect.Width -= shadow;
}
}
if (tearOrientation.HasFlag(TearOrientation.Left))
{
bmp_in_rect.Width -= avulsion;
bmp_in_rect.X += avulsion;
if (shadowOrientation.HasFlag(ShadowOrientation.Left))
{
bmp_in_rect.Width -= shadow;
bmp_in_rect.X += shadow;
}
}
if (tearOrientation.HasFlag(TearOrientation.Top))
{
bmp_in_rect.Height -= avulsion;
bmp_in_rect.Y += avulsion;
if (shadowOrientation.HasFlag(ShadowOrientation.Top))
{
bmp_in_rect.Height -= shadow;
bmp_in_rect.Y += shadow;
}
}
#endregion
#region 计算撕纸路径
#region
int bottom_in_len = 0;
Point[] bottom_in_point;
int bottom_out_len = 0;
Point[] bottom_out_point;
if (tearOrientation.HasFlag(TearOrientation.Bottom))
{
bottom_in_len = (int)Math.Round((double)bmp_in_rect.Width / interval, 0);
bottom_in_point = new Point[bottom_in_len];
for (int i = 0; i < bottom_in_len; i++)
{
x++;
bottom_in_point[i] = new Point(bmp_in_rect.X + i * interval, bmp_in_rect.Bottom + (int)(RandomNumber(x * interval) * avulsion));
}
if (bottom_in_point[bottom_in_len - 1].X > bmp_in_rect.Right)
{
bottom_in_point[bottom_in_len - 1].X = bmp_in_rect.Right;
}
if (shadowOrientation.HasFlag(ShadowOrientation.Bottom))
{
bottom_out_len = bottom_in_len;
bottom_out_point = new Point[bottom_out_len];
for (int i = 0; i < bottom_out_len; i++)
{
bottom_out_point[i] = new Point(bottom_in_point[i].X, bottom_in_point[i].Y + shadow);
}
}
else
{
bottom_out_len = 2;
bottom_out_point = new Point[bottom_out_len];
bottom_out_point[0] = new Point(bmp_in_rect.Left, bmp_in_rect.Bottom);
bottom_out_point[1] = new Point(bmp_in_rect.Right, bmp_in_rect.Bottom);
}
}
else
{
bottom_in_len = 2;
bottom_in_point = new Point[bottom_in_len];
bottom_in_point[0] = new Point(bmp_in_rect.Left, bmp_in_rect.Bottom);
bottom_in_point[1] = new Point(bmp_in_rect.Right, bmp_in_rect.Bottom);
bottom_out_len = 2;
bottom_out_point = new Point[bottom_out_len];
bottom_out_point[0] = new Point(bmp_in_rect.Left, bmp_in_rect.Bottom);
bottom_out_point[1] = new Point(bmp_in_rect.Right, bmp_in_rect.Bottom);
}
#endregion
#region
int right_in_len = 0;
Point[] right_in_point;
int right_out_len = 0;
Point[] right_out_point;
if (tearOrientation.HasFlag(TearOrientation.Right))
{
right_in_len = (int)Math.Round((double)bmp_in_rect.Height / interval, 0);
right_in_point = new Point[right_in_len];
for (int i = 0; i < right_in_len; i++)
{
x++;
right_in_point[i] = new Point(bmp_in_rect.Right + (int)(RandomNumber(x * interval) * avulsion), bmp_in_rect.Bottom - i * interval);
}
if (right_in_point[right_in_len - 1].Y < bmp_in_rect.Top)
{
right_in_point[right_in_len - 1].Y = bmp_in_rect.Top;
}
if (shadowOrientation.HasFlag(ShadowOrientation.Right))
{
right_out_len = right_in_len;
right_out_point = new Point[right_out_len];
for (int i = 0; i < right_out_len; i++)
{
right_out_point[i] = new Point(right_in_point[i].X + shadow, right_in_point[i].Y);
}
}
else
{
right_out_len = 2;
right_out_point = new Point[right_out_len];
right_out_point[0] = new Point(bmp_in_rect.Right, bmp_in_rect.Bottom);
right_out_point[1] = new Point(bmp_in_rect.Right, bmp_in_rect.Top);
}
}
else
{
right_in_len = 2;
right_in_point = new Point[right_in_len];
right_in_point[0] = new Point(bmp_in_rect.Right, bmp_in_rect.Bottom);
right_in_point[1] = new Point(bmp_in_rect.Right, bmp_in_rect.Top);
right_out_len = 2;
right_out_point = new Point[right_out_len];
right_out_point[0] = new Point(bmp_in_rect.Right, bmp_in_rect.Bottom);
right_out_point[1] = new Point(bmp_in_rect.Right, bmp_in_rect.Top);
}
#endregion
#region
int top_in_len = 0;
Point[] top_in_point;
int top_out_len = 0;
Point[] top_out_point;
if (tearOrientation.HasFlag(TearOrientation.Top))
{
top_in_len = (int)Math.Round((double)bmp_in_rect.Width / interval, 0);
top_in_point = new Point[top_in_len];
for (int i = 0; i < top_in_len; i++)
{
x++;
top_in_point[i] = new Point(bmp_in_rect.Right - i * interval, bmp_in_rect.Y - (int)(RandomNumber(x * interval) * avulsion));
}
if (top_in_point[top_in_len - 1].X < bmp_in_rect.Left)
{
top_in_point[top_in_len - 1].X = bmp_in_rect.Left;
}
if (shadowOrientation.HasFlag(ShadowOrientation.Top))
{
top_out_len = top_in_len;
top_out_point = new Point[top_out_len];
for (int i = 0; i < top_out_len; i++)
{
top_out_point[i] = new Point(top_in_point[i].X, top_in_point[i].Y - shadow);
}
}
else
{
top_out_len = 2;
top_out_point = new Point[top_out_len];
top_out_point[0] = new Point(bmp_in_rect.Right, bmp_in_rect.Top);
top_out_point[1] = new Point(bmp_in_rect.Left, bmp_in_rect.Top);
}
}
else
{
top_in_len = 2;
top_in_point = new Point[top_in_len];
top_in_point[0] = new Point(bmp_in_rect.Right, bmp_in_rect.Top);
top_in_point[1] = new Point(bmp_in_rect.Left, bmp_in_rect.Top);
top_out_len = 2;
top_out_point = new Point[top_out_len];
top_out_point[0] = new Point(bmp_in_rect.Right, bmp_in_rect.Top);
top_out_point[1] = new Point(bmp_in_rect.Left, bmp_in_rect.Top);
}
#endregion
#region
int left_in_len = 0;
Point[] left_in_point;
int left_out_len = 0;
Point[] left_out_point;
if (tearOrientation.HasFlag(TearOrientation.Left))
{
left_in_len = (int)Math.Round((double)bmp_in_rect.Height / interval, 0);
left_in_point = new Point[left_in_len];
for (int i = 0; i < left_in_len; i++)
{
x++;
left_in_point[i] = new Point(bmp_in_rect.X - (int)(RandomNumber(x * interval) * avulsion), bmp_in_rect.Y + i * interval);
}
if (left_in_point[left_in_len - 1].Y > bmp_in_rect.Bottom)
{
left_in_point[left_in_len - 1].Y = bmp_in_rect.Bottom;
}
if (shadowOrientation.HasFlag(ShadowOrientation.Left))
{
left_out_len = left_in_len;
left_out_point = new Point[left_out_len];
for (int i = 0; i < left_out_len; i++)
{
left_out_point[i] = new Point(left_in_point[i].X - shadow, left_in_point[i].Y);
}
}
else
{
left_out_len = 2;
left_out_point = new Point[left_out_len];
left_out_point[0] = new Point(bmp_in_rect.Left, bmp_in_rect.Top);
left_out_point[1] = new Point(bmp_in_rect.Left, bmp_in_rect.Bottom);
}
}
else
{
left_in_len = 2;
left_in_point = new Point[left_in_len];
left_in_point[0] = new Point(bmp_in_rect.Left, bmp_in_rect.Top);
left_in_point[1] = new Point(bmp_in_rect.Left, bmp_in_rect.Bottom);
left_out_len = 2;
left_out_point = new Point[left_out_len];
left_out_point[0] = new Point(bmp_in_rect.Left, bmp_in_rect.Top);
left_out_point[1] = new Point(bmp_in_rect.Left, bmp_in_rect.Bottom);
}
#endregion
#endregion
#region 撕纸效果阴影
if (shadowOrientation != ShadowOrientation.None)
{
GraphicsPath out_gp = new GraphicsPath();
out_gp.AddLines(bottom_out_point);
out_gp.AddLines(right_out_point);
out_gp.AddLines(top_out_point);
out_gp.AddLines(left_out_point);
Region out_r = new System.Drawing.Region(out_gp);
bmp_g.Clip = out_r;
bmp_g.FillRegion(out_sb, out_r);
out_r.Dispose();
out_gp.Dispose();
}
#endregion
#region 撕纸效果
GraphicsPath in_gp = new GraphicsPath();
in_gp.AddLines(bottom_in_point);
in_gp.AddLines(right_in_point);
in_gp.AddLines(top_in_point);
in_gp.AddLines(left_in_point);
Region in_r = new System.Drawing.Region(in_gp);
bmp_g.Clip = in_r;
int in_x = bmp_in_rect.X - (tearOrientation.HasFlag(TearOrientation.Left) ? (shadowOrientation.HasFlag(ShadowOrientation.Left) ? avulsion + shadow : avulsion) : 0);
int in_y = bmp_in_rect.Y - (tearOrientation.HasFlag(TearOrientation.Top) ? (shadowOrientation.HasFlag(ShadowOrientation.Top) ? avulsion + shadow : avulsion) : 0);
bmp_g.DrawImage(img, in_x, in_y);
bmp_g.Clip = r;
bmp_g.DrawPath(out_pen, in_gp);
in_gp.Dispose();
#endregion
in_r.Dispose();
bmp_g.Dispose();
return bmp;
}
/// <summary>
///返回0.0-1.0的随机数
/// </summary>
/// <param name="x"></param>
/// <returns></returns>
private static double RandomNumber(int x)
{
x = (x << 13) ^ x;
return Math.Abs((1.0 - ((x * (x * x * 15731 + 789221) + 1376312589) & 0x7fffffff) / 1073741824.0));
}
/// <summary>
/// 撕裂方位
/// </summary>
[Flags]
[Description("撕裂方位")]
public enum TearOrientation
{
None = 0,
/// <summary>
/// 上边
/// </summary>
Top = 2,
/// <summary>
/// 下边
/// </summary>
Bottom = 4,
/// <summary>
/// 左边
/// </summary>
Left = 8,
/// <summary>
/// 右边
/// </summary>
Right = 16
}
/// <summary>
/// 撕裂阴影方位
/// </summary>
[Flags]
[Description("撕裂阴影方位")]
public enum ShadowOrientation
{
None = 0,
/// <summary>
/// 上边
/// </summary>
Top = 2,
/// <summary>
/// 下边
/// </summary>
Bottom = 4,
/// <summary>
/// 左边
/// </summary>
Left = 8,
/// <summary>
/// 右边
/// </summary>
Right = 16
}
}源码下载：撕纸效果.zip