Graphics Coordinates

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The graphics coordinate system starts with the x,y coordinates (0,0) at the top left corner of the window. The coordinates are specified in dialog units (unless overridden by the THOUS, MM, or POINTS attributes when used on graphics placed in a REPORT). A dialog unit is defined as one-quarter the average character width and one-eighth the average character height of the font specified in the window's FONT attribute (or the system font, if no FONT attribute is specified on the window).

Graphics drawn outside the currently visible portion of the window will appear if the window is scrolled. The size of the virtual screen over which the window may scroll automatically expands to include all graphics drawn to the window. Drawing graphics outside the visible portion of the window automatically causes the scroll bars to appear (if the window has the HSCROLL, VSCROLL, or HVSCROLL attribute).