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Peano curve (view source)

Revision as of 21:55, 12 November 2021

34,118 bytes added ,  2 years ago
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→‎{{header|Phix}}: added syntax colouring, made p2js compatible
m (→‎{{header|Phix}}: added syntax colouring, made p2js compatible)
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=={{header|Phix}}==
{{libheader|Phix/pGUI}}
{{libheader|Phix/online}}
You can run this online [http://phix.x10.mx/p2js/peano.htm here].
Space key toggles between switchback and meander curves.
<!--<lang Phix>(phixonline)-- demo\rosetta\peano_curve.exw>
<span style="color: #000080;font-style:italic;">--
include pGUI.e
-- demo\rosetta\peano_curve.exw
 
-- ============================
Ihandle dlg, canvas
--
cdCanvas cddbuffer, cdcanvas
-- Draws a peano curve. Space key toggles between switchback and meander curves.
 
--</span>
bool meander = false -- space toggles (false==draw switchback curve)
<span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
constant width = 81
<span style="color: #008080;">include</span> <span style="color: #000000;">pGUI</span><span style="color: #0000FF;">.</span><span style="color: #000000;">e</span>
 
sequence points = {}
<span style="color: #004080;">Ihandle</span> <span style="color: #000000;">dlg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">canvas</span>
 
<span style="color: #004080;">cdCanvas</span> <span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">cdcanvas</span>
-- switchback peano:
--
<span style="color: #004080;">bool</span> <span style="color: #000000;">meander</span> <span style="color: #0000FF;">=</span> <span style="color: #004600;">false</span> <span style="color: #000080;font-style:italic;">-- space toggles (false==draw switchback curve)</span>
-- There are (as per wp) four shapes to draw:
<span style="color: #008080;">constant</span> <span style="color: #000000;">width</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">81</span>
--
-- 1: +-v ^ 2: ^ v-+ 3: v ^-+ 2: +-^ v
<span style="color: #004080;">sequence</span> <span style="color: #000000;">points</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{}</span>
-- | | | | | | | | | | | |
-- ^ v-+ +-v ^ +-^ v v ^-+
<span style="color: #000080;font-style:italic;">-- switchback peano:
--
--
-- 1 starts bottom left, ends top right
-- There are (as per wp) four shapes to draw:
-- 2 starts bottom right, ends top left
--
-- 3 starts top left, ends bottom right
-- 1: +-v ^ 2: ^ v-+ 3: v ^-+ 2: +-^ v
-- 4 starts top right, ends bottom left
-- | | | | | | | | | | | |
--
-- ^ v-+ +-v ^ +-^ v v ^-+
-- given the centre point (think {1,1}), and using {0,0} as the bottom left:
--
-- 1 starts bottom left, ends top right
constant shapes = {{{-1,-1},{-1,0},{-1,+1},{0,+1},{0,0},{0,-1},{+1,-1},{+1,0},{+1,+1}},
-- 2 starts bottom right, ends top left
{{+1,-1},{+1,0},{+1,+1},{0,+1},{0,0},{0,-1},{-1,-1},{-1,0},{-1,+1}}, -- (== sq_mul(shapes[1],{-1,0}))
-- 3 starts top left, ends bottom right
{{-1,+1},{-1,0},{-1,-1},{0,-1},{0,0},{0,+1},{+1,+1},{+1,0},{+1,-1}}, -- (== reverse(shapes[2]))
-- 4 starts top right, ends bottom left
{{+1,+1},{+1,0},{+1,-1},{0,-1},{0,0},{0,+1},{-1,+1},{-1,0},{-1,-1}}} -- (== reverse(shapes[1]))
--
 
-- given the centre point (think {1,1}), and using {0,0} as the bottom left:
constant subshapes = {{1,2,1,3,4,3,1,2,1},
--</span>
{2,1,2,4,3,4,2,1,2}, -- == sq_sub({3,3,3,7,7,7,3,3,3},subshapes[1])
<span style="color: #008080;">constant</span> <span style="color: #000000;">shapes</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{{{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">},{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">},{+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">}},</span>
{3,4,3,1,2,1,3,4,3}, -- == sq_sub(5,subshapes[2])
<span style="color: #0000FF;">{{+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">},{+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">},{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">}},</span> <span style="color: #000080;font-style:italic;">-- (== sq_mul(shapes[1],{-1,0}))</span>
{4,3,4,2,1,2,4,3,4}} -- == sq_sub(5,subshapes[1])
<span style="color: #0000FF;">{{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">},{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">},{+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">}},</span> <span style="color: #000080;font-style:italic;">-- (== reverse(shapes[2]))</span>
 
<span style="color: #0000FF;">{{+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">},{+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">},{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">}}}</span> <span style="color: #000080;font-style:italic;">-- (== reverse(shapes[1]))</span>
-- As noted, it should theoretically be possible to simplify/shorten/remove/inline those tables
 
<span style="color: #008080;">constant</span> <span style="color: #000000;">subshapes</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},</span>
procedure switchback_peano(integer x, y, level, shape)
<span style="color: #0000FF;">{</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">},</span> <span style="color: #000080;font-style:italic;">-- == sq_sub({3,3,3,7,7,7,3,3,3},subshapes[1])</span>
-- (written from scratch, with a nod to the meander algorithm [below])
<span style="color: #0000FF;">{</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">},</span> <span style="color: #000080;font-style:italic;">-- == sq_sub(5,subshapes[2])</span>
if level<=1 then
<span style="color: #0000FF;">{</span><span style="color: #000000;">4</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">}}</span> <span style="color: #000080;font-style:italic;">-- == sq_sub(5,subshapes[1])
points = append(points, {x*10, y*10})
return
-- As noted, it should theoretically be possible to simplify/shorten/remove/inline those tables</span>
end if
level /= 3
<span style="color: #008080;">procedure</span> <span style="color: #000000;">switchback_peano</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">x</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">level</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">shape</span><span style="color: #0000FF;">)</span>
for i=1 to 9 do
<span style="color: #000080;font-style:italic;">-- (written from scratch, with a nod to the meander algorithm [below])</span>
integer {dx,dy} = shapes[shape][i]
<span style="color: #008080;">if</span> <span style="color: #000000;">level</span><span style="color: #0000FF;"><=</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span>
switchback_peano(x+dx*level,y+dy*level,level,subshapes[shape][i])
<span style="color: #000000;">points</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">points</span><span style="color: #0000FF;">,</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">x</span><span style="color: #0000FF;">*</span><span style="color: #000000;">10</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">*</span><span style="color: #000000;">10</span><span style="color: #0000FF;">})</span>
end for
<span style="color: #008080;">return</span>
end procedure
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
 
<span style="color: #000000;">level</span> <span style="color: #0000FF;">/=</span> <span style="color: #000000;">3</span>
procedure meander_peano(integer x, y, lg, i1, i2)
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">9</span> <span style="color: #008080;">do</span>
-- (translated from Go)
<span style="color: #004080;">integer</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">dx</span><span style="color: #0000FF;">,</span><span style="color: #000000;">dy</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">shapes</span><span style="color: #0000FF;">[</span><span style="color: #000000;">shape</span><span style="color: #0000FF;">][</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span>
if lg=1 then
<span style="color: #000000;">switchback_peano</span><span style="color: #0000FF;">(</span><span style="color: #000000;">x</span><span style="color: #0000FF;">+</span><span style="color: #000000;">dx</span><span style="color: #0000FF;">*</span><span style="color: #000000;">level</span><span style="color: #0000FF;">,</span><span style="color: #000000;">y</span><span style="color: #0000FF;">+</span><span style="color: #000000;">dy</span><span style="color: #0000FF;">*</span><span style="color: #000000;">level</span><span style="color: #0000FF;">,</span><span style="color: #000000;">level</span><span style="color: #0000FF;">,</span><span style="color: #000000;">subshapes</span><span style="color: #0000FF;">[</span><span style="color: #000000;">shape</span><span style="color: #0000FF;">][</span><span style="color: #000000;">i</span><span style="color: #0000FF;">])</span>
integer px := (width-x) * 10,
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
py := (width-y) * 10
<span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
points = append(points, {px, py})
return
<span style="color: #008080;">procedure</span> <span style="color: #000000;">meander_peano</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">x</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">i1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">i2</span><span style="color: #0000FF;">)</span>
end if
<span style="color: #000080;font-style:italic;">-- (translated from Go)</span>
lg /= 3
<span style="color: #008080;">if</span> <span style="color: #000000;">lg</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span>
meander_peano(x+2*i1*lg, y+2*i1*lg, lg, i1, i2)
<span style="color: #004080;">integer</span> <span style="color: #000000;">px</span> <span style="color: #0000FF;">:=</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">width</span><span style="color: #0000FF;">-</span><span style="color: #000000;">x</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;">*</span> <span style="color: #000000;">10</span><span style="color: #0000FF;">,</span>
meander_peano(x+(i1-i2+1)*lg, y+(i1+i2)*lg, lg, i1, 1-i2)
<span style="color: #000000;">py</span> <span style="color: #0000FF;">:=</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">width</span><span style="color: #0000FF;">-</span><span style="color: #000000;">y</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;">*</span> <span style="color: #000000;">10</span>
meander_peano(x+lg, y+lg, lg, i1, 1-i2)
<span style="color: #000000;">points</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">points</span><span style="color: #0000FF;">,</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">px</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">py</span><span style="color: #0000FF;">})</span>
meander_peano(x+(i1+i2)*lg, y+(i1-i2+1)*lg, lg, 1-i1, 1-i2)
<span style="color: #008080;">return</span>
meander_peano(x+2*i2*lg, y+2*(1-i2)*lg, lg, i1, i2)
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
meander_peano(x+(1+i2-i1)*lg, y+(2-i1-i2)*lg, lg, i1, i2)
<span style="color: #000000;">lg</span> <span style="color: #0000FF;">/=</span> <span style="color: #000000;">3</span>
meander_peano(x+2*(1-i1)*lg, y+2*(1-i1)*lg, lg, i1, i2)
<span style="color: #000000;">meander_peano</span><span style="color: #0000FF;">(</span><span style="color: #000000;">x</span><span style="color: #0000FF;">+</span><span style="color: #000000;">2</span><span style="color: #0000FF;">*</span><span style="color: #000000;">i1</span><span style="color: #0000FF;">*</span><span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">+</span><span style="color: #000000;">2</span><span style="color: #0000FF;">*</span><span style="color: #000000;">i1</span><span style="color: #0000FF;">*</span><span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">i1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">i2</span><span style="color: #0000FF;">)</span>
meander_peano(x+(2-i1-i2)*lg, y+(1+i2-i1)*lg, lg, 1-i1, i2)
<span style="color: #000000;">meander_peano</span><span style="color: #0000FF;">(</span><span style="color: #000000;">x</span><span style="color: #0000FF;">+(</span><span style="color: #000000;">i1</span><span style="color: #0000FF;">-</span><span style="color: #000000;">i2</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">+(</span><span style="color: #000000;">i1</span><span style="color: #0000FF;">+</span><span style="color: #000000;">i2</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">i1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">1</span><span style="color: #0000FF;">-</span><span style="color: #000000;">i2</span><span style="color: #0000FF;">)</span>
meander_peano(x+2*(1-i2)*lg, y+2*i2*lg, lg, 1-i1, i2)
<span style="color: #000000;">meander_peano</span><span style="color: #0000FF;">(</span><span style="color: #000000;">x</span><span style="color: #0000FF;">+</span><span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">+</span><span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">i1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">1</span><span style="color: #0000FF;">-</span><span style="color: #000000;">i2</span><span style="color: #0000FF;">)</span>
end procedure
<span style="color: #000000;">meander_peano</span><span style="color: #0000FF;">(</span><span style="color: #000000;">x</span><span style="color: #0000FF;">+(</span><span style="color: #000000;">i1</span><span style="color: #0000FF;">+</span><span style="color: #000000;">i2</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">+(</span><span style="color: #000000;">i1</span><span style="color: #0000FF;">-</span><span style="color: #000000;">i2</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">1</span><span style="color: #0000FF;">-</span><span style="color: #000000;">i1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">1</span><span style="color: #0000FF;">-</span><span style="color: #000000;">i2</span><span style="color: #0000FF;">)</span>
 
<span style="color: #000000;">meander_peano</span><span style="color: #0000FF;">(</span><span style="color: #000000;">x</span><span style="color: #0000FF;">+</span><span style="color: #000000;">2</span><span style="color: #0000FF;">*</span><span style="color: #000000;">i2</span><span style="color: #0000FF;">*</span><span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">+</span><span style="color: #000000;">2</span><span style="color: #0000FF;">*(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">-</span><span style="color: #000000;">i2</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">i1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">i2</span><span style="color: #0000FF;">)</span>
function redraw_cb(Ihandle /*ih*/, integer /*posx*/, integer /*posy*/)
<span style="color: #000000;">meander_peano</span><span style="color: #0000FF;">(</span><span style="color: #000000;">x</span><span style="color: #0000FF;">+(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">+</span><span style="color: #000000;">i2</span><span style="color: #0000FF;">-</span><span style="color: #000000;">i1</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">+(</span><span style="color: #000000;">2</span><span style="color: #0000FF;">-</span><span style="color: #000000;">i1</span><span style="color: #0000FF;">-</span><span style="color: #000000;">i2</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">i1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">i2</span><span style="color: #0000FF;">)</span>
if length(points)=0 then
<span style="color: #000000;">meander_peano</span><span style="color: #0000FF;">(</span><span style="color: #000000;">x</span><span style="color: #0000FF;">+</span><span style="color: #000000;">2</span><span style="color: #0000FF;">*(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">-</span><span style="color: #000000;">i1</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">+</span><span style="color: #000000;">2</span><span style="color: #0000FF;">*(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">-</span><span style="color: #000000;">i1</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">i1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">i2</span><span style="color: #0000FF;">)</span>
if meander then
<span style="color: #000000;">meander_peano</span><span style="color: #0000FF;">(</span><span style="color: #000000;">x</span><span style="color: #0000FF;">+(</span><span style="color: #000000;">2</span><span style="color: #0000FF;">-</span><span style="color: #000000;">i1</span><span style="color: #0000FF;">-</span><span style="color: #000000;">i2</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">+(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">+</span><span style="color: #000000;">i2</span><span style="color: #0000FF;">-</span><span style="color: #000000;">i1</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">1</span><span style="color: #0000FF;">-</span><span style="color: #000000;">i1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">i2</span><span style="color: #0000FF;">)</span>
meander_peano(0, 0, width, 0, 0)
<span style="color: #000000;">meander_peano</span><span style="color: #0000FF;">(</span><span style="color: #000000;">x</span><span style="color: #0000FF;">+</span><span style="color: #000000;">2</span><span style="color: #0000FF;">*(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">-</span><span style="color: #000000;">i2</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">+</span><span style="color: #000000;">2</span><span style="color: #0000FF;">*</span><span style="color: #000000;">i2</span><span style="color: #0000FF;">*</span><span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lg</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">1</span><span style="color: #0000FF;">-</span><span style="color: #000000;">i1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">i2</span><span style="color: #0000FF;">)</span>
else
<span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
switchback_peano(41, 41, width, 1)
end if
<span style="color: #008080;">function</span> <span style="color: #000000;">redraw_cb</span><span style="color: #0000FF;">(</span><span style="color: #004080;">Ihandle</span> <span style="color: #000080;font-style:italic;">/*ih*/</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">integer</span> <span style="color: #000080;font-style:italic;">/*posx*/</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">/*posy*/</span><span style="color: #0000FF;">)</span>
end if
<span style="color: #008080;">if</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">points</span><span style="color: #0000FF;">)=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
cdCanvasActivate(cddbuffer)
<span style="color: #008080;">if</span> <span style="color: #000000;">meander</span> <span style="color: #008080;">then</span>
cdCanvasBegin(cddbuffer, CD_OPEN_LINES)
<span style="color: #000000;">meander_peano</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">width</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0</span><span style="color: #0000FF;">)</span>
for i=1 to length(points) do
integer {x,y}<span style="color: points[i]#008080;">else</span>
<span style="color: #000000;">switchback_peano</span><span style="color: #0000FF;">(</span><span style="color: #000000;">41</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">41</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">width</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
cdCanvasVertex(cddbuffer, x, y)
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
end for
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
cdCanvasEnd(cddbuffer)
<span style="color: #7060A8;">cdCanvasActivate</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">)</span>
cdCanvasFlush(cddbuffer)
<span style="color: #7060A8;">cdCanvasBegin</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #004600;">CD_OPEN_LINES</span><span style="color: #0000FF;">)</span>
return IUP_DEFAULT
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">points</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
end function
<span style="color: #004080;">integer</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">x</span><span style="color: #0000FF;">,</span><span style="color: #000000;">y</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">points</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span>
 
<span style="color: #7060A8;">cdCanvasVertex</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">x</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">)</span>
function map_cb(Ihandle ih)
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
cdcanvas = cdCreateCanvas(CD_IUP, ih)
<span style="color: #7060A8;">cdCanvasEnd</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">)</span>
cddbuffer = cdCreateCanvas(CD_DBUFFER, cdcanvas)
<span style="color: #7060A8;">cdCanvasFlush</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">)</span>
cdCanvasSetBackground(cddbuffer, CD_WHITE)
<span style="color: #008080;">return</span> <span style="color: #004600;">IUP_DEFAULT</span>
cdCanvasSetForeground(cddbuffer, CD_MAGENTA)
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
return IUP_DEFAULT
end function
<span style="color: #008080;">function</span> <span style="color: #000000;">map_cb</span><span style="color: #0000FF;">(</span><span style="color: #004080;">Ihandle</span> <span style="color: #000000;">ih</span><span style="color: #0000FF;">)</span>
 
<span style="color: #000000;">cdcanvas</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">cdCreateCanvas</span><span style="color: #0000FF;">(</span><span style="color: #004600;">CD_IUP</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ih</span><span style="color: #0000FF;">)</span>
function esc_close(Ihandle /*ih*/, atom c)
<span style="color: #000000;">cddbuffer</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">cdCreateCanvas</span><span style="color: #0000FF;">(</span><span style="color: #004600;">CD_DBUFFER</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">cdcanvas</span><span style="color: #0000FF;">)</span>
if c=K_ESC then return IUP_CLOSE end if
<span style="color: #7060A8;">cdCanvasSetBackground</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #004600;">CD_WHITE</span><span style="color: #0000FF;">)</span>
if c=' ' then
<span style="color: #7060A8;">cdCanvasSetForeground</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #004600;">CD_MAGENTA</span><span style="color: #0000FF;">)</span>
meander = not meander
<span style="color: #008080;">return</span> <span style="color: #004600;">IUP_DEFAULT</span>
points = {}
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
cdCanvasClear(cddbuffer)
IupUpdate(canvas)
<span style="color: #008080;">function</span> <span style="color: #000000;">key_cb</span><span style="color: #0000FF;">(</span><span style="color: #004080;">Ihandle</span> <span style="color: #000080;font-style:italic;">/*ih*/</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">)</span>
end if
<span style="color: #008080;">if</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">=</span><span style="color: #004600;">K_ESC</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #004600;">IUP_CLOSE</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
return IUP_CONTINUE
<span style="color: #008080;">if</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">=</span><span style="color: #008000;">' '</span> <span style="color: #008080;">then</span>
end function
<span style="color: #000000;">meander</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">not</span> <span style="color: #000000;">meander</span>
 
<span style="color: #000000;">points</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{}</span>
procedure main()
<span style="color: #7060A8;">cdCanvasClear</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">)</span>
IupOpen()
<span style="color: #7060A8;">IupUpdate</span><span style="color: #0000FF;">(</span><span style="color: #000000;">canvas</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
canvas = IupCanvas(NULL)
<span style="color: #008080;">return</span> <span style="color: #004600;">IUP_CONTINUE</span>
IupSetAttribute(canvas, "RASTERSIZE", "822x822") -- initial size
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
IupSetCallback(canvas, "MAP_CB", Icallback("map_cb"))
 
<span style="color: #008080;">procedure</span> <span style="color: #000000;">main</span><span style="color: #0000FF;">()</span>
dlg = IupDialog(canvas)
<span style="color: #7060A8;">IupOpen</span><span style="color: #0000FF;">()</span>
IupSetAttribute(dlg, "TITLE", "Peano Curve")
<span style="color: #000000;">canvas</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupCanvas</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"RASTERSIZE=822x822"</span><span style="color: #0000FF;">)</span>
IupSetAttribute(dlg, "DIALOGFRAME", "YES") -- no resize here
<span style="color: #7060A8;">IupSetCallbacks</span><span style="color: #0000FF;">(</span><span style="color: #000000;">canvas</span><span style="color: #0000FF;">,</span> <span style="color: #0000FF;">{</span><span style="color: #008000;">"MAP_CB"</span><span style="color: #0000FF;">,</span> <span style="color: #7060A8;">Icallback</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"map_cb"</span><span style="color: #0000FF;">),</span>
IupSetCallback(dlg, "K_ANY", Icallback("esc_close"))
<span style="color: #008000;">"ACTION"</span><span style="color: #0000FF;">,</span> <span style="color: #7060A8;">Icallback</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"redraw_cb"</span><span style="color: #0000FF;">)})</span>
IupSetCallback(canvas, "ACTION", Icallback("redraw_cb"))
<span style="color: #000000;">dlg</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupDialog</span><span style="color: #0000FF;">(</span><span style="color: #000000;">canvas</span><span style="color: #0000FF;">,</span><span style="color: #008000;">`TITLE="Peano Curve"`</span><span style="color: #0000FF;">)</span>
 
<span style="color: #7060A8;">IupSetAttribute</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dlg</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"DIALOGFRAME"</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"YES"</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- no resize here</span>
IupMap(dlg)
<span style="color: #7060A8;">IupSetCallback</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dlg</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"KEY_CB"</span><span style="color: #0000FF;">,</span> <span style="color: #7060A8;">Icallback</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"key_cb"</span><span style="color: #0000FF;">))</span>
IupShowXY(dlg,IUP_CENTER,IUP_CENTER)
<span style="color: #7060A8;">IupShow</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dlg</span><span style="color: #0000FF;">)</span>
IupMainLoop()
<span style="color: #008080;">if</span> <span style="color: #7060A8;">platform</span><span style="color: #0000FF;">()!=</span><span style="color: #004600;">JS</span> <span style="color: #008080;">then</span>
IupClose()
<span style="color: #7060A8;">IupMainLoop</span><span style="color: #0000FF;">()</span>
end procedure
<span style="color: #7060A8;">IupClose</span><span style="color: #0000FF;">()</span>
main()</lang>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
<span style="color: #000000;">main</span><span style="color: #0000FF;">()</span>
<!--</lang>-->
 
=={{header|Prolog}}==
Petelomax
7,806

edits

Retrieved from "https://rosettacode.org/wiki/Special:MobileDiff/283117"