[script] Add examples

Add some simple examples to demonstrate CairoScript, courtesy of M Joonas
Philaja.

configure.ac

@@ -554,6 +554,7 @@ test/pdiff/Makefile
 perf/Makefile
 util/Makefile
 util/cairo-script/Makefile
+util/cairo-script/examples/Makefile
 util/cairo-trace/Makefile
 util/cairo-trace/cairo-trace
 doc/Makefile

util/cairo-script/Makefile.am

@@ -1,3 +1,5 @@
+SUBDIRS = examples
+
 lib_LTLIBRARIES = libcairo-script-interpreter.la
 noinst_PROGRAMS = csi-replay csi-exec
 

util/cairo-script/examples/Makefile.am

@@ -0,0 +1,10 @@
+EXTRA_DIST = \
+	dragon.cs \
+	hilbert.cs \
+	infinichess.cs \
+	interference.cs \
+	pythagoras-tree.cs \
+	sierpinski.cs \
+	wedgeAnnulus_crop_ybRings.cs \
+	world-map.cs \
+	zrusin.cs

util/cairo-script/examples/dragon.cs

@@ -0,0 +1,48 @@
+%!CairoScript
+/pot { % n -- n
+  1 sub
+  dup  -1 bitshift or
+  dup  -2 bitshift or
+  dup  -4 bitshift or
+  dup  -8 bitshift or
+  dup -16 bitshift or
+  1 add
+} bind def
+
+/direction { % i -- bool
+  dup 2 lt { pop true } {
+      dup 1 add dup pot dup 3 -1 roll eq { pop pop true } {
+	  2 div 1 sub 2 mul exch sub direction not
+      } ifelse
+  } ifelse
+} bind def
+
+/path { % cr dx dy -- cr
+  0 1 2048 {
+    4 1 roll 3 copy L pop 4 -1 roll direction {
+      exch neg
+    } {
+      neg exch
+    } ifelse
+  } for
+  pop pop
+} bind def
+
+dict
+  /width  512 set
+  /height 512 set
+  surface context
+
+1 g set-source paint
+
+//LINE_CAP_ROUND set-line-cap
+//LINE_JOIN_ROUND set-line-join
+4 set-line-width
+
+256 256 m  12 0 path 0 0 0 rgb set-source stroke
+256 256 m -12 0 path 1 0 0 rgb set-source stroke
+256 256 m 0  12 path 0 1 0 rgb set-source stroke
+256 256 m 0 -12 path 0 0 1 rgb set-source stroke
+
+/target get (out.png) write-to-png pop
+pop

util/cairo-script/examples/hilbert.cs

@@ -0,0 +1,51 @@
+%!CairoScript
+
+/hA { % cr dist lvl *hA* cr dist
+  dup not { pop } {
+      1 sub
+      3 copy hB 0 exch L pop
+      3 copy hA 0 L pop
+      3 copy hA neg 0 exch L pop
+      hC
+  } ifelse
+} bind def
+
+/hB { % cr dist lvl *hB* cr dist
+  dup not { pop } {
+      1 sub
+      3 copy hA 0 L pop
+      3 copy hB 0 exch L pop
+      3 copy hB neg 0 L pop
+      hD
+  } ifelse
+} bind def
+
+/hC { % cr dist lvl *hC* cr dist
+  dup not { pop } {
+      1 sub
+      3 copy hD neg 0 L pop
+      3 copy hC neg 0 exch L pop
+      3 copy hC 0 L pop
+      hA
+  } ifelse
+} bind def
+
+/hD { % cr dist lvl *hD* cr dist
+  dup not { pop } {
+      1 sub
+      3 copy hC neg 0 exch L pop
+      3 copy hD neg 0 L pop
+      3 copy hD 0 exch L pop
+      hB
+  } ifelse
+} bind def
+
+dict
+  /width  1024 set
+  /height 1024 set
+  surface context
+
+2 2 m 4 10 hA pop 1 g set-source stroke
+
+/target get (out.png) write-to-png pop
+pop

util/cairo-script/examples/infinichess.cs

@@ -0,0 +1,29 @@
+/xdef { exch def } def
+/-rot { 3 1 roll } def
+/rot { 3 -1 roll } def
+/2dup { 2 copy } def
+
+/SIZE 600. def
+<< /width SIZE /height SIZE >> surface context
+1 1 1 set-source-rgb paint
+0 0 0 set-source-rgb
+EVEN_ODD set-fill-rule
+SIZE SIZE scale
+
+0.5 0 translate
+
+save
+1 1 scale
+/n 90 def
+n neg 1 n {
+	/x xdef
+	0 0 m
+	x 1 l
+	x 0.5 add 1 l
+	0 0 l
+} for
+restore
+fill
+
+/target get (out.png) write-to-png pop
+pop

util/cairo-script/examples/interference.cs

@@ -0,0 +1,46 @@
+/rot { 3 -1 roll } def
+/2dup { 2 copy } def
+
+/circle { % context radius -- context
+	2dup 0 m pop
+	0 0 rot 0 math.2pi arc h
+} def
+
+/circles { % context #circles -- context
+	1 1 rot { circle } for
+} def
+
+/SIDE 600. def
+/SIZE 600. def
+<< /width SIZE /height SIZE >> surface context
+1 1 1 set-source-rgb paint
+0 0 0 set-source-rgb
+//EVEN_ODD set-fill-rule
+
+/r 4 def
+/n SIDE 1.5 mul r div integer def
+
+SIZE SIDE div dup scale
+
+save
+  302 200 translate
+  r dup scale
+  n circles
+restore
+
+save
+  100 300 translate
+  r dup scale
+  n circles
+restore
+
+save
+  500 400 translate
+  r dup scale
+  n circles
+restore
+
+fill
+
+/target get (out.png) write-to-png pop
+pop

util/cairo-script/examples/pythagoras-tree.cs

@@ -0,0 +1,53 @@
+%!CairoScript
+
+/pi4 0.785398163 def
+/sqrt2 1.414213562 def
+
+/R { % cr size *R* cr
+  dup 1 lt { pop } {
+      exch /current-point get % size cr x y
+      4 2 roll % x y size cr
+
+      % draw a rectangle in relative co-ordinates
+      1 index 2 div neg dup exch M
+      1 index 0 L
+      0 2 index L
+      1 index neg 0 L
+      h
+
+      save
+      1 index dup 2 div neg exch translate
+      4 2 roll 3 copy % size cr x y cr x y
+      m
+      //pi4 rotate
+      pop 4 2 roll % x y size cr
+      1 index //sqrt2 div
+      R
+      restore
+
+      save
+      1 index dup 2 div exch translate
+      4 2 roll 3 copy % size cr x y cr x y
+      m
+      //pi4 neg rotate
+      pop 4 2 roll % x y size cr
+      1 index //sqrt2 div
+      R
+      restore
+
+      4 1 roll pop pop pop
+  } ifelse
+} bind def
+
+dict
+  /width  1024 set
+  /height 512 set
+  surface context
+
+1 1 1 set-source-rgb paint
+
+0 512 translate 1 -1 scale
+512 64 m 128. R 0 0 0 set-source-rgb fill
+
+/target get (out.png) write-to-png pop
+pop

util/cairo-script/examples/sierpinski.cs

@@ -0,0 +1,37 @@
+%!CairoScript
+
+/1sqrt3 0.577359269 def
+
+/T { % cr size -- cr
+  exch % size cr
+  0 0 m 1 index 0 l 1 index dup 2 div exch //1sqrt3 mul l h
+
+  exch 2 div
+  dup 4 ge {
+    exch % size/2 cr
+
+    1 index T
+    save 1 index 0 translate 1 index T restore
+    save 1 index dup 2 div exch //1sqrt3 mul translate 1 index T restore
+
+    exch
+  } if
+  pop
+} bind def
+
+dict
+  /width  512 set
+  /height 300 set
+  surface context
+
+1 1 1 set-source-rgb paint
+
+.5 set-line-width
+
+0 300 translate
+1 -1 scale
+
+512 T 0 0 0 set-source-rgb stroke
+
+/target get (out.png) write-to-png pop
+pop

util/cairo-script/examples/wedgeAnnulus_crop_ybRings.cs

@@ -0,0 +1,30 @@
+/SIDE 600 def
+
+<< /width SIDE /height SIDE >> surface context
+
+1 1 1 rgb set-source
+paint
+
+SIDE dup scale
+0.5 0.5 translate
+0.5 -0.5 scale
+
+/theta math.pi 10 div def
+
+10 {
+  N
+  0 0 1.0 0 //theta arc
+  0 0 0.2 //theta 0 arc-
+  h
+  //theta rotate
+  //theta rotate
+} repeat
+
+0 0 0.2 0 0 1 radial
+  0.0 1 1 0 1 add-color-stop
+  1.0 0 0 1 1 add-color-stop
+set-source
+fill
+
+/target get (out.png) write-to-png pop
+pop