Coordinate conversion (revision)
View saves (Offsetx, Offset "indicates the starting coordinates of the document relative to the view.
Documents require this starting coordinate when drawing, indicating that the entire document should be drawn from here.
The above figure:
Viewwidth-docwidth <= offsetx <= 0ViewHeight-Docheight <= Offsety <= 0
If the view is larger than the document:
Offsetx = (ViewWidth - DocWidth) / 2Offsety = (ViewHeight - ViewHeight) / 2
View 4 important values about the document: DOCWIDTH, DOCHEIGHT, OFFSETX, OFFSETY
Convert the coordinates of the view to document coordinates:
INT TRANSTODOC (INT X) {??? Return X OffsetX;}
Int transportoc (int y) {??? Return Y offsety;}
Drawing operation start coordinates of documents are determined by Offsetx, Offsety:
Void View :: UpdateView (graphics g) {??? g.moveto (offsetx, offsety); ??? Document.draw (g);}
