java - 使用 itext 或 pdfbox 的 PdfAnnotation 标记的 QuadBounds Order

Question

  0  1                      2  3
 *  (x1,y1) ***************  (x2,y2)
 *          *             *
 *          *             *             
 *   4  5   *             *    6 7       
 *  (x3,y3) ***************  (x4,y4)

PdfAnnotation 或 PDFAnnotation 的 float 组顺序是否正确？我尝试创建一个 pdf 注释，但注释是凹的而不是凸的，就像通常使用 adobe reader 或 acrobat 创建的注释一样

Answer 1

Pdf 规范在四边形坐标上规定:

The coordinates for each quadrilateral are given in the order

x1 y1 x2 y2 x3 y3 x4 y4

specifying the four vertices of the quadrilateral in counterclockwise order. For orientation purposes, such as when applying an underline border style, the bottom of a quadrilateral is the line formed by (x1, y1) and (x2, y2).

(multiple subsections of section 12.5.6 in ISO 32000-1)

因此:

*   6  7                      4  5       
*  (x4,y4) ***************  (x3,y3)
*          *             *
*          *             *             
*   0  1   *             *    2  3
*  (x1,y1) ***************  (x2,y2)