/* CFDG Lesson */

startshape TOC
	// each grammar file must
	// have a "startshape"
	// statement to say which
	// shape to begin with

shape TOC
{
	// a "rule" statement says how
	// to compose a shape out of
	// other shapes

    CHAPTER1 [ x 0 y 0 ]
    CHAPTER2 [ x 10 y 0 ]
    CHAPTER3 [ x 0 y -10 ]
    CHAPTER4 [ x 10 y -10 ]
	// each entry in the rule
	// names a shape to draw and
	// some "adjustments" in curly
	// braces

    TITLES [ ]
}

shape CHAPTER1
{
    ## BASIC SHAPES ##
    SQUARE [ x 2 y 5 size 3 ]
    CIRCLE [ x 6 y 5 size 3 ]
    TRIANGLE [ x 4 y 2 size 3 ]
	// these shapes are special:
	// they draw a shape into the
	// image, centered at the
	// current location
    SHAPES [ y 1 size 3 ]
	// This tells you the relative
	// sizes and positions of each
	// basic shape.
}

shape SHAPES
{
	SQUARE []
	CIRCLE [b 0.3]
	TRIANGLE [b 0.5]
	TRIANGLE [r 60 b 0.7]
}

shape CHAPTER2
{
    ## BASIC ADJUSTMENTS ##
    SQUARE [ ]
	// empty adjustments
	// this is the lone square in
	// chapter 2's area

    SQUARE [ x 3 y 7 ]
	// adjust location

	// even though adjustments
	// are written after the shape
	// they are applied before!

    SQUARE [ x 5 y 7 rotate 30 ]
	// adjust rotation
    SQUARE [ x 3 y 5 size 0.75 ]
	// adjust size

	// notice that rotation and size
	// are adjusted after location

    SQUARE [ x 5 y 5
        brightness 0.5 ]
	// adjust brightness

    SQUARE [ x 7 y 6
	// shorthands:
        r 45 // for rotate
        s 0.7 // for size
        b 0.7 // for brightness
    ]

    FOURSQUARE [ x 5 y 1
        size 0.2 rotate 10 ]
	// adjustments are cumulative
}
shape FOURSQUARE
{
    SQUARE [ x 0 y 0 size 5  3]
    SQUARE [ x 0 y 5 size 2 4 ]
    SQUARE [ x 5 y 5 size 3 ]
    SQUARE [ x 5 y 0 size 2 ]
	// even though these are
	// at locations and sizes
	// that seem big, they have
	// all been relocated, scaled
	// and rotated when the rule
	// for CHAPTER2 used
	// FOURSQUARE
	// Two SQUAREs have been
	// have been turned into
	// rectangles
}

shape CHAPTER3
{
    ## RECURSION ##
    SPIRAL [ x 0 y 3 ]
}
shape SPIRAL
{
    CIRCLE [ size 0.5 ]
    SPIRAL [ y 0.2
         rotate -3
         size 0.995 ]
	// a shape can use itself so
	// long as it keeps getting
	// smaller

	// the system will stop the
	// recursion when the shapes
	// get too small to see
}

shape CHAPTER4
{
    ## RANDOMNESS ##
    TREE [ x 1 y 0 ]
    TREE [ x 6 y 0 ]
    TREE [ x 1 y 4 ]
    TREE [ x 6 y 4 ]
	// even though these are the
	// same shape used four
	// times, each looks different
}
shape TREE
rule 20 {
	// first rule for TREE
    CIRCLE [ size 0.25 ]
    TREE [ y 0.1 size 0.97 ]
}
rule 1.5 {
	// second rule for TREE
    BRANCH [  ]
}
// When expanding a TREE, a
// rule is picked randomly.
// The first rule has been given a
// weight of 20, the second of 1.5,
// so the first will be picked
// proportionally more often

shape BRANCH
{
    BRANCH_LEFT [ ]
    BRANCH_RIGHT [ ]
}
shape BRANCH_LEFT
rule {
    TREE [ rotate 20 ]
}
rule {
    TREE [ rotate 30 ]
}
rule {
    TREE [ rotate 40 ]
}
rule {
	// empty rules are okay
}
// If no weight is given for a rule
// the weight is 1.  Hence, the
// above four rules are picked
// equally randomly

shape BRANCH_RIGHT
rule {
    TREE [ rotate -20 ]
}
rule {
    TREE [ rotate -30 ]
}
rule {
    TREE [ rotate -40 ]
}
rule {
	// empty rules are okay
}



## Utilities ##
import i_pix.cfdg
// The "include" statement reads
// in all the rules from another file.
// Any "startshape" in the included
// file is ignored.

shape TITLES
{
	TITLE1 [ x 0 y 8.5 ]
	TITLE2 [ x 10 y 8.5 ]
	TITLE3 [ x 0 y -1.5 ]
	TITLE4 [ x 10 y -1.5 ]
}
shape TITLE1
{
	O_5by5 [ x 0 ]
	N_5by5 [ x 1.2 ]
	E_5by5 [ x 2.4 ]
}
shape TITLE2
{
	T_5by5 [ x 0 ]
	W_5by5 [ x 1.2 ]
	O_5by5 [ x 2.4 ]
}
shape TITLE3
{
	T_5by5 [ x 0 ]
	H_5by5 [ x 1.2 ]
	R_5by5 [ x 2.4 ]
	E_5by5 [ x 3.6 ]
	E_5by5 [ x 4.8 ]
}
shape TITLE4
{
	F_5by5 [ x 0 ]
	O_5by5 [ x 1.2 ]
	U_5by5 [ x 2.4 ]
	R_5by5 [ x 3.6 ]
}