MakeDraw

The MakeDraw library has been updated to version 2.58 and is available from !Store and PackMan.

New in version 2.58 is the ability to extend an existing draw file. Routines have been added to draw a quarter of a circle between two defined points. This makes drawing a precise rectangle with rounded corners of a specified radius quite easy. Circles are drawn as an approximation but this is the best that can be achieved by a Bezier curve (an error of about one part in 4000 or 5000) and so is similar to the method used by the !Draw application.

The MakeDraw library has been updated to version 2.64 and is available from !Store and PackMan.

New in version 2.64 is the ability to draw a sector of a circle defined either as a stand alone line, specifying start and end points as well as the locus of the centre of the full circle. Alternatively it will draw a line segment which is sector of a circle to a specified point, from the last drawn point taking its start point and direction from that.

It’d be nice to get the terminology right. A sector isn’t a line, it’s an area bounded by two radii and an arc of a circle. I think you’re actually talking about an arc.

Yes, you are right, many thanks. A sector is, indeed, the area enclosed by an arc and two radii. I meant an arc.

The MakeDraw library has been updated to version 2.66 and is available from !Store and PackMan and from my web site.

New in version 2.66 is the ability to draw a circular arc defined either as a stand alone line, specifying start and end points as well as the locus of the centre of the full circle. Alternatively it will draw a line segment which is an arc of a circle to a specified point, from the last drawn point taking its start point and direction from that. This line segment is not a segment, which would be the area bounded by the line segment and its chord.

This diagram shows clockwise arcs with the arc length (and radius) increasing until it goes green (when the angle subtended is approaching 180°) and then anticlockwise arcs (with the arc length increasing more rapidly) showing that when the subtended angle is above 180°, a straight line is drawn instead. Once the arc is greater than a quadrant, accuracy reduces as a Bezier curve over more than a quadrant approximates much more poorly to a circular arc. The arc is produced by the routine:

PROCmdStartPath(x0,y0)
PROCmdLineTo(x1,y1)
PROCmdArcTo(x2,y2)
PROCmdEndPath

A big smile and a big thumbs up to you, Chris! What a lovely reaction; I’m always wary of making comments like that because so many people react badly. Kudos to you!

MakeDraw is now at version 2.76 – the latest addition is a routine that measures the filled area of an arbitrary shape.

MakeDraw is now at version 2.82 – the latest bug fix is not to assume a sprite file loaded from disc has no extension words. Prompted by an article by nemo in the latest Archive and a strange bug that took me a while to track down.

A full list of the changes from versions 2.76 is given below (and all changes are listed with the app):

New in version 2.76
-------------------
(25) PROCmdPlotArea(ptr%,keep%,RETURN area) added which allows
     a path object that has been created in memory to be examined
     to calculate the filled area. The pointer ptr% points to the
     path object in memory (for example by using PROCmdDiagramInfo
     just before the path object is created). The flag keep% is
     used to decide whether to keep or discard the sprite object
     used to work out the filled area, the result of which is
     returned in the third parameter, in square user units. 
     See lines 61500 to 61626.

New in version 2.80
-------------------
(14) PROCmdInclude(f$,x,y) now includes a test to check whether
     a font table is present in the file being included (if not,
     then suppress spurious error) and in the present file (if
     not then fail all fonts in file being included) - see 
     lines 60891 to 61117.

New in version 2.81
-------------------
(14) PROCmdInclude(f$,x,y) bug fixes - see lines 60911 and 61040.

New in version 2.82
-------------------
(7)  Draw object type 5 (Sprite object) bug fixes
     now allows for extension words in a sprite file loaded
     from disc - see lines 60670 to 60677. (Still assumes you
     want the first sprite in the file.)