Inside Macintosh: QuickDraw GX Graphics /

Chapter 3 - Geometric Styles / Geometric Styles Reference

Functions / Getting and Setting Curve Error

GXSetShapeCurveError

You can use the GXSetShapeCurveError function to change the curve error of the style object associated with a particular shape.

void GXSetShapeCurveError(gxShape target, Fixed error);

target

A reference to the shape whose curve error you want to change.

error

The new curve error.

DESCRIPTION

The GXSetShapeCurveError function replaces the curve error of the style object associated with the shape specified by the source parameter with the value in the error parameter. You may specify any nonnegative value for this parameter.

If the target shape shares its style object with other shapes, this function makes a copy of the style object, sets the target shape to reference the copy, and changes the curve error of the copy. (However, if the effect of this function would leave the curve error unchanged, this function does not create a copy of the style object; instead, it posts a notice.)

When the curve error is 0, QuickDraw GX does not approximate a path shape with a polygon shape when converting from a path to a polygon. Instead, QuickDraw GX simply removes off-curve control points, as shown in "Using Curve Error When Converting Paths to Polygons" on page 3-45.

ERRORS, WARNINGS, AND NOTICES

Errors
out_of_memory
shape_is_nil
parameter_out_of_range	(debugging version)
Notices (debugging version)
curve_error_already_set

SEE ALSO

For a discussion of curve error, see "Curve Error" on page 3-14.

For examples of curve error, see "Using Curve Error When Converting Paths to Polygons" on page 3-45 and "Using Curve Error When Reducing Shapes" on page 3-49.

To determine the curve error of a style object, use the GXGetStyleCurveError function, which is described on page 3-115. To change the curve error of a style object, use the GXSetStyleCurveError function, which is described on page 3-116.

To determine the curve error of a style object associated with a particular shape, use the GXGetShapeCurveError function, which is described on page 3-117.

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