Drawing

You can draw all kinds of things in buttons.

you make a list of drawing primitives, whose values you can change

In the interests of quick display, drawing is organized to reflect the low-level drawing primitives.

color

A color specification is a scalar, or an array of one to four scalars.

f or {f}: sets all three colors to f on a scale of 0 to 1.

{f, alpha}: sets all three colors to f with opaqueness alpha

{r, g, b}: sets colors to red, green, and blue

{r, g, b, alpha}: sets colors to red, green, and blue, with opaqueness alpha

drawElem

Every call to draw returns a drawElem, which can be used as an argument to setDrawElement. For the curious, it contains

drawElem.type is the command from the draw() call that did it.

drawElem.vector is the array of floats used by low-level rendering

drawElem.uie is the UIE (a button) in which the drawing is done

drawElem.flags encodes characteristics of this drawElem

setDrawElement(drawElem, command[, args...])

• setDrawElement (drawElem, “origin”, x, y) : adjust x and y coordinates of drawElem

• setDrawElement (drawElem, “size”, width, height) : adjust size of rects and ovals

• setDrawElement (drawElem, “color”, color) : change color of drawElem

draw(b, command[, args...])

plot(b, command [, args...]) *deprecated*

Add to graphics list in button b. Return a drawElem.

• draw (b, “clear”) : clear all drawing in b and return NULL

• draw (b, “move”, x, y) : set drawing point to x, y

• draw (b, “line”, x, y) : draw line from drawing point to x, y

• draw (b, “relativeMove”, x, y) : move drawing point in direction x, y

  more remarks

  and yet more

• draw (b, “relativeLine”, x, y) : draw line from drawing point in direction x, y

• draw (b, “closePath”) : see drawing complicated stuff

• draw (b, “stroke”) : see drawing complicated stuff

• draw (b, “fill”) : see drawing complicated stuff

• draw (b, “lineWidth”, w) : set stroke line width to w

• draw (b, “color”, colorArray) : set stroke color to color colorArray.

• draw (b, “oval”, x, y, width, height) : draw oval of width and height centered on x, y

• draw (b, “rect”, x, y, width, height) : draw rect of width and height centered on x, y

• draw (b, “curve”, x, y, cx1, cy1, cx2, cy2) : draw a Bezier curve from drawing point to x, y with control points cx1, cy1 and cx2, cy2

• draw (b, “relativeCurve”, x, y, cx1, cy1, cx2, cy2) : draw a Bezier curve from drawing point in the direction x, y with control points cx1, cy1 and cx2, cy2

• draw (b, “moveP”, x, y) : same as “move” but in pixels

• draw (b, “lineP”, x, y) : same as “line” but in pixels

• draw (b, “relativeMoveP”, x, y) : same as “relativeMove” but in pixels

• draw (b, “relativeLineP”, x, y) : same as “relativeLine” but in pixels

• draw (b, “ovalP”, x, y, width, height) : same as “oval” but in pixels

• draw (b, “rectP”, x, y, width, height) : same as “rect” but in pixels

• draw (b, “curveP”, x, y, cx1, cy1, cx2, cy2) : same as “curve” but in pixels

• draw (b, “relativeCurveP”, x, y, cx1, cy1, cx2, cy2) : same as “relativeCurve” but in pixels

Draw a marker of size size at drawing point. Drawing point is unchanged

• draw (b, “marker”, x, y, size, m) : x and y between 0 and 1, m is one of:

  o: Circle +: Plus sign *: Asterisk .: Point x: Cross s: Square d: Diamond ^: Upward-pointing triangle v: Downward-pointing triangle >: Right-pointing triangle <: Left-pointing triangle p: Five-pointed star (pentagram) h: Six-pointed star (hexagram)