Can I define new graphics directives?

Question

Is it possible to define new graphics directives?

For example, suppose I want to be able to use the following code:

Graphics[{ BigPointSize[0.07], SmallPointSize[0.04],
           Red, BigPoint[{1,1}], BigPoint[{1,3}], SmallPoint[{3,1}],
           Blue, SmallPoint[{2,2}], SmallPoint[{3,2}], BigPoint[{0,0}]
        }]

Is there any way to define BigPointSize, SmallPointSize, BigPoint, and SmallPoint so that this code will work as intended? Ideally BigPointSize and SmallPointSize should have all of the functionality of other graphics directives, e.g. scoping inside of lists, and the ability to call the command multiple times within the same list.

(Obviously it's possible to draw these points in other ways, but I'm curious whether it's possible to get this syntax to work.)

Edit: Just to clarify, I would like BigPointSize and SmallPointSize to work the same way as PointSize and other graphics directives. For example, the code

Graphics[{ BigPointSize[0.1],
           { BigPointSize[0.05], BigPoint[{0,0}] },
           BigPoint[{1,0}]
        }]

should produce one point of size 0.05 and one point of size 0.1.

Answer 1

Protect[BigPointSize, BigPoint, SmallPointSize, SmallPoint];

UserGraphics[gr_, opt : OptionsPattern[Graphics]] := Module[
  {
    BigPointSizeStack, BigPointSizeExec, BigPointExec,
    SmallPointSizeStack, SmallPointSizeExec, SmallPointExec,
    TempList, TempListExec,
  },

  BigPointSizeStack = {0.1};  (* default value *)
  BigPointSizeExec[s_] := (BigPointSizeStack[[-1]] = s; {});
  BigPointExec[p_] := {PointSize[BigPointSizeStack[[-1]]], Point[p]};

  SmallPointSizeStack = {0.1};(* default value *)
  SmallPointSizeExec[s_] := (SmallPointSizeStack[[-1]] = s; {});
  SmallPointExec[p_] := {PointSize[SmallPointSizeStack[[-1]]], Point[p]};

  TempListExec[x___] := Module[{retval},
    AppendTo[BigPointSizeStack, BigPointSizeStack[[-1]]];
    AppendTo[SmallPointSizeStack, SmallPointSizeStack[[-1]]];

    retval = {x} /. {
                      BigPointSize -> BigPointSizeExec,
                      SmallPointSize -> SmallPointSizeExec,
                      BigPoint -> BigPointExec,
                      SmallPoint -> SmallPointExec
                    };

   BigPointSizeStack = Delete[BigPointSizeStack, -1];
   BigPointSizeStack = Delete[SmallPointSizeStack, -1];
   retval
   ];

  Graphics[(gr //. x_List :> TempList @@ x) /. TempList :> TempListExec, opt]
]




gr = {Line[{{0, -1}, {6, 0}}], BigPoint[{1, 0}], BigPointSize[0.02], 
      BigPoint[{2, 0}], {BigPointSize[0.03], BigPoint[{3, 0}], Red, 
      BigPointSize[0.04], BigPoint[{4, 0}]}, BigPoint[{5, 0}]};



UserGraphics[gr, Frame -> True, PlotRange -> {{0, 6}, {-1, 1}}]

I don't belive, but I wrote it, and it works !!!

I tried to use obvious tricks and commands, which easily can be found in the documentation. The function UserGraphics supports all options and properties of Graphics. It also supports BigPointSize, SmallPointSize directives, and BigPoint, SmallPoint primitives.

It is the first version, so all found bugs/questions/comments/remarks are welcome !

Answer 2

It is possible to use Style options as "graphics directives", and CurrentValue can be used to query the values of these options. For example, suppose we use AutoIndent as the graphics directive:

Graphics[
    {
    AutoIndent -> .1, {PointSize[Dynamic@CurrentValue@AutoIndent], Point[{0,0}]}, 
    {AutoIndent -> .2, {PointSize[Dynamic@CurrentValue@AutoIndent], Point[{1,1}]}},
    {PointSize[Dynamic@CurrentValue@AutoIndent], Point[{1,0}]}
    },
    ImageSize->200,
    PlotRange->{{-1,2},{-1,2}},
    Axes->True
]

Notice how the point at {1, 0} uses the initial AutoIndent value. It is also possible to use Typeset`MakeBoxes so that BigPointSize and BigPoint only evaluate when the Graphics expression is converted to boxes, as pointed out by Simon Woods in his answer to How to create custom [Graphics](http://reference.wolfram.com/language/ref/Graphics) primitive?. I will use a couple AutoStyleOptions settings as my "graphics directives":

Typeset`MakeBoxes[BigPointSize[rhs_], StandardForm, Graphics] := Typeset`Hold[
    "AutoStyleOptionsHighlightGlobalToLocalScopeConflicts"->rhs
]
Typeset`MakeBoxes[SmallPointSize[rhs_], StandardForm, Graphics] := Typeset`Hold[
    "AutoStyleOptionsHighlightMissingArgumentsWithTemplate"->rhs
]
Typeset`MakeBoxes[BigPoint[a_], StandardForm, Graphics] := {
    PointSize -> Dynamic @ Replace[
        CurrentValue["AutoStyleOptionsHighlightGlobalToLocalScopeConflicts"],
        Except[_?NumberQ]->.1
    ],
    PointBox[a]
}
Typeset`MakeBoxes[SmallPoint[a_], StandardForm, Graphics] := {
    PointSize -> Dynamic @ Replace[
        CurrentValue["AutoStyleOptionsHighlightMissingArgumentsWithTemplate"],
        Except[_?NumberQ]->.03
    ],
    PointBox[a]
}

And here's an example:

Graphics[
    {
    Line[{{0,-1},{6,0}}],
    BigPoint[{1,0}], Red, SmallPoint[{1,.5}],
    BigPointSize[0.02], SmallPointSize[.01],
    BigPoint[{2,0}], Blue, SmallPoint[{2, .5}],
    {
        BigPointSize[0.03], SmallPointSize[.04], BigPoint[{3,0}],
        Green, BigPointSize[0.04], BigPoint[{4,0}], SmallPoint[{4, .5}]
    },
    BigPoint[{5,0}], SmallPoint[{5, .5}]
    },
    Frame->True,
    PlotRange->{{0,6},{-1,1}}
]

Answer 3

BigPointSizeValue = 1;

BigPointSize[s_] := (BigPointSizeValue = s;)

BigPoint[p_] := {PointSize[BigPointSizeValue], Point[p]}

SmallPointSizeValue = 1;

SmallPointSize[s_]:=(SmallPointSizeValue = s;)

SmallPoint[p_] := {PointSize[SmallPointSizeValue], Point[p]}