Allow object literals for 2D-Shape functions in additional to positional parameters

• functions with more than a few parameters are hard to remember how to use
• object literals to the rescue!
• allow object literal parameter in p5.js Shape functions for readability
• leveraging api patterns from SmallTalk, Objective-C, Swift, and modern JavaScript frameworks (eg. react)
• arc function example

// arc(x, y, w, h, start, stop, [mode], [detail])
  arc(50, 50, 80, 80, 0, PI + HALF_PI);
-- ++ allow object literal option
  arc( {x: 50, y:50, w:80, h:80, start:0, stop:PI + HALF_PI } );

• change is totally opt-in, existing syntax is still allowed
• document change could be limited to one extra line in syntax summary for each Shape function

function arc() Syntax

arc(x, y, w, h, start, stop, [mode], [detail])
arc({ x, y, w, h, start, stop, mode, detail })

• Other Shapes updates for object literal parameter:

ellipse({ x, y, w, h})

circle({ x, y, d })

rect({ x, y, w, h, tl, tr, br, bl })

triangle({ x1, y1, x2, y2, x3, y3 })

triangle([{ x, y }, { x, y }, { x, y }])

line({ x1, y1, x2, y2 })
line([{ x, y }, { x, y }])
line({ x1, y1, z1, x2, y2, z2 })
line([{ x, y, z }, { x, y, z }])

• Details:

This proposal would affect the following Shape functions:
arc()
circle()
ellipse()
line()
point()
quad()
rect()
square()
triangle()

Start by reviewing the p5.js Shape functions listed in the issue, beginning with arc() and its positional and object-literal syntax examples. Check how ellipse(), circle(), rect(), triangle(), line(), point(), quad(), and square() are documented and handled. Done means the proposed object-literal forms work while existing positional syntax remains supported, with the syntax summaries updated.