Inside Macintosh: QuickDraw GX Graphics /

Chapter 6 - Picture Shapes / Applying Functions Described Elsewhere to Picture Shapes

Functions That Post Errors or Warnings When Applied to Pictures

Some QuickDraw GX functions that operate on other types of shapes do nothing but post an error or a warning if you try to apply them to a picture shape.

For example, there are a number of shape-related functions and geometric operations that you cannot apply to picture shapes. Table 6-2 lists these functions, which are described in full in Chapter 2, "Geometric Shapes," and Chapter 4, "Geometric Operations."

Geometric operations that post errors or warnings when applied to pictures

Function name	Error or warning posted
GXBreakShape	graphic_type_does_not_contain_points
GXContainsShape	shape_operator_may_not_be_a_picture
GXCountShapePoints	graphic_type_does_not_contain_points
GXDifferenceShape	shape_operator_may_not_be_a_picture
GXExcludeShape	shape_operator_may_not_be_a_picture
GXGetShapeCenter	illegal_type_for_shape
GXGetShapeDirection	graphic_type_does_not_have_multiple_contours
GXGetShapeLength	shape_does_not_have_length
GXGetShapePoints	graphic_type_does_not_contain_points
GXInsetShape	graphic_type_cannot_be_inset
GXIntersectShape	shape_operator_may_not_be_a_picture
GXInvertShape	shape_cannot_be_inverted
GXReverseDifferenceShape	shape_operator_may_not_be_a_picture
GXReverseShape	contour_out_of_range
GXShapeLengthToPoint	shape_does_not_have_length
GXSetShapePoints	graphic_type_does_not_contain_points
GXTouchesShape	shape_operator_may_not_be_a_picture
GXUnionShape	shape_operator_may_not_be_a_picture

Most of these geometric operations do not apply to picture shapes because a picture's geometry is substantially different from the geometry of a geometric shape.

You can apply a few of the geometric operations to pictures, however. These functions are discussed in "Geometric Operations Applicable to Pictures" beginning on page 6-55.

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