C# Signature:
[DllImport("gdi32.dll")]
static extern uint GetGlyphOutline(IntPtr hdc, uint uChar, uint uFormat,
out GLYPHMETRICS lpgm, uint cbBuffer, IntPtr lpvBuffer, ref MAT2 lpmat2);
VB Signature
Public Declare Function GetGlyphOutline Lib "gdi32.dll"( _
hdc As IntPtr, uChar As UInteger, uFormat As UInteger, _
ByRef lpgm As GLYPHMETRICS, cbBuffer As UInteger, lpvBuffer As IntPtr, ByRef lpmat2 As MAT2) As Integer
User-Defined Types:
[StructLayout(LayoutKind.Sequential)]
public struct TTPOLYGONHEADER
{
public int cb;
public int dwType;
[MarshalAs(UnmanagedType.Struct)] public POINTFX pfxStart;
}
[StructLayout(LayoutKind.Sequential)]
public struct TTPOLYCURVEHEADER
{
public short wType;
public short cpfx;
}
[StructLayout(LayoutKind.Sequential)]
public struct FIXED
{
public short fract;
public short value;
}
[StructLayout(LayoutKind.Sequential)]
public struct MAT2
{
[MarshalAs(UnmanagedType.Struct)] public FIXED eM11;
[MarshalAs(UnmanagedType.Struct)] public FIXED eM12;
[MarshalAs(UnmanagedType.Struct)] public FIXED eM21;
[MarshalAs(UnmanagedType.Struct)] public FIXED eM22;
}
[StructLayout(LayoutKind.Sequential)]
public struct POINT
{
public int x;
public int y;
}
[StructLayout(LayoutKind.Sequential)]
public struct POINTFX
{
[MarshalAs(UnmanagedType.Struct)] public FIXED x;
[MarshalAs(UnmanagedType.Struct)] public FIXED y;
}
[StructLayout(LayoutKind.Sequential)]
public struct GLYPHMETRICS
{
public int gmBlackBoxX;
public int gmBlackBoxY;
[MarshalAs(UnmanagedType.Struct)] public POINT gmptGlyphOrigin;
public short gmCellIncX;
public short gmCellIncY;
}
Notes:
None.
Tips & Tricks:
Please add some!
Sample Code:
// Parse a glyph outline in native format
public static void GetGlyphShape(Font font, Char c)
{
GLYPHMETRICS metrics = new GLYPHMETRICS();
MAT2 matrix = new MAT2();
matrix.eM11.value = 1;
matrix.eM12.value = 0;
matrix.eM21.value = 0;
matrix.eM22.value = 1;
using(Bitmap b = new Bitmap(1,1))
{
using(Graphics g = Graphics.FromImage(b))
{
IntPtr hdc = g.GetHdc();
IntPtr prev = SelectObject(hdc, font.ToHfont());
int bufferSize = (int)GetGlyphOutline(hdc, (uint)c, (uint)2, out metrics, 0, IntPtr.Zero, ref matrix);
IntPtr buffer = Marshal.AllocHGlobal(bufferSize);
try
{
uint ret;
if((ret = GetGlyphOutline(hdc, (uint)c, (uint)2, out metrics, (uint)bufferSize, buffer, ref matrix)) > 0)
{
int polygonHeaderSize = Marshal.SizeOf(typeof(TTPOLYGONHEADER));
int curveHeaderSize = Marshal.SizeOf(typeof(TTPOLYCURVEHEADER));
int pointFxSize = Marshal.SizeOf(typeof(POINTFX));
int index = 0;
while(index < bufferSize)
{
TTPOLYGONHEADER header = (TTPOLYGONHEADER)Marshal.PtrToStructure(new IntPtr(buffer.ToInt32()+index), typeof(TTPOLYGONHEADER));
int startX = header.pfxStart.x.value;
int startY = -header.pfxStart.y.value;
// ...do something with start coords...
int endCurvesIndex = index+header.cb;
index+=polygonHeaderSize;
while(index < endCurvesIndex)
{
TTPOLYCURVEHEADER curveHeader = (TTPOLYCURVEHEADER)Marshal.PtrToStructure(new IntPtr(buffer.ToInt32()+index), typeof(TTPOLYCURVEHEADER));
index+=curveHeaderSize;
POINTFX[] curvePoints = new POINTFX[curveHeader.cpfx];
for(int i = 0; i < curveHeader.cpfx; i++)
{
curvePoints[i] = (POINTFX)Marshal.PtrToStructure(new IntPtr(buffer.ToInt32()+index), typeof(POINTFX));
index+=pointFxSize;
}
if(curveHeader.wType == (int)1)
{
// POLYLINE
for(int i=0; i < curveHeader.cpfx; i++)
{
short x = curvePoints[i].x.value;
short y = (short)-curvePoints[i].y.value;
// ...do something with line points...
}
}
else
{
// CURVE
for(int i=0; i < curveHeader.cpfx - 1; i++)
{
POINTFX pfxB = curvePoints[i];
POINTFX pfxC = curvePoints[i+1];
short cx = pfxB.x.value;
short cy = (short)-pfxB.y.value;
short ax;
short ay;
if(i < curveHeader.cpfx - 2)
{
ax = (short)((pfxB.x.value+pfxC.x.value) / 2);
ay = (short)-((pfxB.y.value+pfxC.y.value) / 2);
}
else
{
ax = pfxC.x.value;
ay = (short)-pfxC.y.value;
} // ...do something with curve points...
}
}
}
}
}
else
{
throw new Exception("Could not retrieve glyph (GDI Error: 0x"+ret.ToString("X")+")");
}
g.ReleaseHdc(hdc);
}
finally
{
Marshal.FreeHGlobal(buffer);
}
}
}
return shape;
}
Alternative Managed API:
Do you know one? Please contribute it!
