class fontTools.pens.ttGlyphPen.TTGlyphPen(glyphSet, handleOverflowingTransforms=True)[source]

Pen used for drawing to a TrueType glyph.

If handleOverflowingTransforms is True, the components’ transform values are checked that they don’t overflow the limits of a F2Dot14 number: -2.0 <= v < +2.0. If any transform value exceeds these, the composite glyph is decomposed. An exception to this rule is done for values that are very close to +2.0 (both for consistency with the -2.0 case, and for the relative frequency these occur in real fonts). When almost +2.0 values occur (and all other values are within the range -2.0 <= x <= +2.0), they are clamped to the maximum positive value that can still be encoded as an F2Dot14: i.e. 1.99993896484375. If False, no check is done and all components are translated unmodified into the glyf table, followed by an inevitable struct.error once an attempt is made to compile them.

addComponent(glyphName, transformation)[source]

Add a sub glyph. The ‘transformation’ argument must be a 6-tuple containing an affine transformation, or a Transform object from the fontTools.misc.transform module. More precisely: it should be a sequence containing 6 numbers.


Close the current sub path. You must call either pen.closePath() or pen.endPath() after each sub path.


Draw a cubic bezier with an arbitrary number of control points.

The last point specified is on-curve, all others are off-curve (control) points. If the number of control points is > 2, the segment is split into multiple bezier segments. This works like this:

Let n be the number of control points (which is the number of arguments to this call minus 1). If n==2, a plain vanilla cubic bezier is drawn. If n==1, we fall back to a quadratic segment and if n==0 we draw a straight line. It gets interesting when n>2: n-1 PostScript-style cubic segments will be drawn as if it were one curve. See decomposeSuperBezierSegment().

The conversion algorithm used for n>2 is inspired by NURB splines, and is conceptually equivalent to the TrueType “implied points” principle. See also decomposeQuadraticSegment().


End the current sub path, but don’t close it. You must call either pen.closePath() or pen.endPath() after each sub path.


Draw a straight line from the current point to ‘pt’.

property log

Begin a new sub path, set the current point to ‘pt’. You must end each sub path with a call to pen.closePath() or pen.endPath().


Draw a whole string of quadratic curve segments.

The last point specified is on-curve, all others are off-curve points.

This method implements TrueType-style curves, breaking up curves using ‘implied points’: between each two consequtive off-curve points, there is one implied point exactly in the middle between them. See also decomposeQuadraticSegment().

The last argument (normally the on-curve point) may be None. This is to support contours that have NO on-curve points (a rarely seen feature of TrueType outlines).