From 9bdbb88d2d4a79da872d62b2091fbf7e824d6d60 Mon Sep 17 00:00:00 2001
From: Erich Eckner <git@eckner.net>
Date: Mon, 10 Jul 2023 21:48:00 +0200
Subject: nun gebogen

---
 spectre.lps     | 99 +++++++++++++++++++++++++++++++++------------------------
 spectreunit.pas | 47 ++++++++++++++++++++-------
 unit1.pas       |  2 +-
 3 files changed, 94 insertions(+), 54 deletions(-)

diff --git a/spectre.lps b/spectre.lps
index 975dbf5..9168810 100644
--- a/spectre.lps
+++ b/spectre.lps
@@ -20,9 +20,8 @@
         <HasResources Value="True"/>
         <ResourceBaseClass Value="Form"/>
         <UnitName Value="Unit1"/>
-        <IsVisibleTab Value="True"/>
-        <TopLine Value="32"/>
-        <CursorPos X="40" Y="62"/>
+        <TopLine Value="33"/>
+        <CursorPos Y="47"/>
         <UsageCount Value="20"/>
         <Loaded Value="True"/>
         <LoadedDesigner Value="True"/>
@@ -30,9 +29,10 @@
       <Unit>
         <Filename Value="spectreunit.pas"/>
         <IsPartOfProject Value="True"/>
+        <IsVisibleTab Value="True"/>
         <EditorIndex Value="1"/>
-        <TopLine Value="19"/>
-        <CursorPos Y="49"/>
+        <TopLine Value="42"/>
+        <CursorPos X="41" Y="70"/>
         <UsageCount Value="20"/>
         <Loaded Value="True"/>
       </Unit>
@@ -47,14 +47,15 @@
       <Unit>
         <Filename Value="/usr/lib/lazarus/lcl/graphics.pp"/>
         <UnitName Value="Graphics"/>
-        <EditorIndex Value="-1"/>
-        <TopLine Value="952"/>
-        <CursorPos X="3" Y="969"/>
+        <EditorIndex Value="2"/>
+        <TopLine Value="183"/>
+        <CursorPos X="3" Y="201"/>
         <UsageCount Value="10"/>
+        <Loaded Value="True"/>
       </Unit>
       <Unit>
         <Filename Value="../units/lowlevelunit.pas"/>
-        <EditorIndex Value="3"/>
+        <EditorIndex Value="5"/>
         <TopLine Value="1036"/>
         <CursorPos Y="1063"/>
         <UsageCount Value="10"/>
@@ -77,45 +78,23 @@
       </Unit>
       <Unit>
         <Filename Value="../units/matheunit.pas"/>
-        <EditorIndex Value="2"/>
+        <EditorIndex Value="4"/>
         <TopLine Value="1235"/>
         <CursorPos X="5" Y="1268"/>
         <UsageCount Value="10"/>
         <Loaded Value="True"/>
       </Unit>
+      <Unit>
+        <Filename Value="/usr/lib/lazarus/components/lazutils/graphtype.pp"/>
+        <UnitName Value="GraphType"/>
+        <EditorIndex Value="3"/>
+        <TopLine Value="26"/>
+        <CursorPos X="3" Y="43"/>
+        <UsageCount Value="10"/>
+        <Loaded Value="True"/>
+      </Unit>
     </Units>
-    <JumpHistory HistoryIndex="28">
-      <Position>
-        <Filename Value="../units/lowlevelunit.pas"/>
-      </Position>
-      <Position>
-        <Filename Value="../units/lowlevelunit.pas"/>
-        <Caret Line="29" Column="12"/>
-      </Position>
-      <Position>
-        <Filename Value="../units/lowlevelunit.pas"/>
-        <Caret Line="35" Column="19" TopLine="7"/>
-      </Position>
-      <Position>
-        <Filename Value="../units/lowlevelunit.pas"/>
-        <Caret Line="37" Column="47" TopLine="9"/>
-      </Position>
-      <Position>
-        <Filename Value="../units/lowlevelunit.pas"/>
-        <Caret Line="69" Column="29" TopLine="41"/>
-      </Position>
-      <Position>
-        <Filename Value="../units/lowlevelunit.pas"/>
-        <Caret Line="74" Column="41" TopLine="46"/>
-      </Position>
-      <Position>
-        <Filename Value="../units/lowlevelunit.pas"/>
-        <Caret Line="78" Column="41" TopLine="50"/>
-      </Position>
-      <Position>
-        <Filename Value="../units/lowlevelunit.pas"/>
-        <Caret Line="82" Column="52" TopLine="54"/>
-      </Position>
+    <JumpHistory HistoryIndex="29">
       <Position>
         <Filename Value="../units/lowlevelunit.pas"/>
         <Caret Line="84" Column="50" TopLine="56"/>
@@ -200,6 +179,42 @@
         <Filename Value="../units/matheunit.pas"/>
         <Caret Line="1268" Column="5" TopLine="1235"/>
       </Position>
+      <Position>
+        <Filename Value="spectreunit.pas"/>
+        <Caret Line="63" Column="24" TopLine="33"/>
+      </Position>
+      <Position>
+        <Filename Value="/usr/lib/lazarus/lcl/graphics.pp"/>
+        <Caret Line="1093" Column="15" TopLine="1078"/>
+      </Position>
+      <Position>
+        <Filename Value="/usr/lib/lazarus/lcl/graphics.pp"/>
+        <Caret Line="201" Column="3" TopLine="183"/>
+      </Position>
+      <Position>
+        <Filename Value="spectreunit.pas"/>
+        <Caret Line="63" Column="75" TopLine="34"/>
+      </Position>
+      <Position>
+        <Filename Value="spectreunit.pas"/>
+        <Caret Line="65" Column="40" TopLine="33"/>
+      </Position>
+      <Position>
+        <Filename Value="spectreunit.pas"/>
+        <Caret Line="64" Column="16" TopLine="36"/>
+      </Position>
+      <Position>
+        <Filename Value="spectreunit.pas"/>
+        <Caret Line="59" Column="12" TopLine="36"/>
+      </Position>
+      <Position>
+        <Filename Value="spectreunit.pas"/>
+        <Caret Line="64" Column="81" TopLine="34"/>
+      </Position>
+      <Position>
+        <Filename Value="spectreunit.pas"/>
+        <Caret Line="70" Column="62" TopLine="44"/>
+      </Position>
     </JumpHistory>
     <RunParams>
       <FormatVersion Value="2"/>
diff --git a/spectreunit.pas b/spectreunit.pas
index f84fb98..7b258e3 100644
--- a/spectreunit.pas
+++ b/spectreunit.pas
@@ -12,6 +12,9 @@ type
   private
     _o:           tExtPoint;
     _alpha,_size: extended;
+    _ecken:       array of tExtPoint;
+    _winkel:      array of extended;
+    procedure berechneEckenUndWinkel;
   public
     constructor create(x,y,alpha,size: extended);
     procedure draw(c: tCanvas);
@@ -19,8 +22,10 @@ type
 
 implementation
 
+// https://www.chiark.greenend.org.uk/~sgtatham/quasiblog/aperiodic-spectre/
+
 uses
-  matheunit;
+  matheunit, graphType;
 
 constructor tSpectre.create(x,y,alpha,size: extended);
 begin
@@ -28,23 +33,43 @@ begin
   _o:=extPoint(x,y);
   _alpha:=alpha;
   _size:=size;
+  berechneEckenUndWinkel;
 end;
 
-procedure tSpectre.draw(c: tCanvas);
+procedure tSpectre.berechneEckenUndWinkel;
 var
-  r: tExtPoint;
-  a: extended;
   i: longint;
 const
   winkel: array of extended = (90,-60,90,-60,90,60,-90,60,90,60,-90,60,0,60);
 begin
-  r:=_o;
-  a:=_alpha;
-  c.moveTo(point(round(r)));
-  for i:=0 to length(winkel)-1 do begin
-    r:=r + _size * einheitsVektor(a);
-    c.lineTo(point(round(r)));
-    a:=a - winkel[i]/180*pi;
+  setLength(_winkel,length(winkel));
+  setLength(_ecken,length(winkel)+1);
+  _winkel[0]:=_alpha;
+  _ecken[0]:=_o;
+  for i:=0 to length(winkel)-2 do begin
+    _ecken[i+1]:=_ecken[i] + _size * einheitsVektor(_winkel[i]);
+    _winkel[i+1]:=_winkel[i] - winkel[i]/180*pi;
+  end;
+  _ecken[length(_ecken)-1]:=_ecken[0];
+end;
+
+procedure tSpectre.draw(c: tCanvas);
+var
+  i:     longint;
+  p:     tInt64Point;
+  s:     string;
+  a,b,m: tExtPoint;
+begin
+  s:='lorem ipsum';
+  p:=round(0.5*(_ecken[0]+_ecken[6]-extPoint(c.textWidth(s),c.textHeight(s))));
+  c.TextOut(p['x'],p['y'],s);
+  for i:=0 to length(_ecken)-2 do begin
+    a:=_ecken[i+byte(odd(i))];
+    b:=_ecken[i+1-byte(odd(i))];
+    m:=a + rotationsMatrix(pi/3)*(b-a);
+    c.Arc(
+      round(m['x']-_size),round(m['y']-_size)+1,round(m['x']+_size),round(m['y']+_size)+1,
+      round(b['x']),round(b['y']),round(a['x']),round(a['y']));
   end;
 end;
 
diff --git a/unit1.pas b/unit1.pas
index ed06ce3..f6b029c 100644
--- a/unit1.pas
+++ b/unit1.pas
@@ -59,7 +59,7 @@ end;
 procedure TForm1.FormCreate(Sender: TObject);
 begin
   setLength(spectres,1);
-  spectres[0]:=tSpectre.create(100,100,pi/4,30);
+  spectres[0]:=tSpectre.create(100,150,pi/4,30);
 end;
 
 end.
-- 
cgit v1.2.3-54-g00ecf