Add fixed point move routine and sample

src/inc/turtle.plh

@@ -6,6 +6,7 @@ import turtle
     predef turn(angle)#0
     predef moveTo(x, y)#0
     predef move(dist)#0
+    predef movep4(dist)#0
     predef penUp#0
     predef penDown#0
 end

src/libsrc/turtle.pla

@@ -137,6 +137,18 @@ export def move(dist)#0
     fin
 end
 
+export def movep4(distp4)#0
+    var oldX, oldY
+
+    oldX      = turtleXp4 >> 4
+    oldY      = turtleYp4 >> 4
+    turtleXp4 = turtleXp4 + mulcos(distp4, turtleAngle)
+    turtleYp4 = turtleYp4 + mulsin(distp4, turtleAngle)
+    if pen
+        clipLine(turtleXp4 >> 4, turtleYp4 >> 4, oldX, oldY)
+    fin
+end
+
 export def penUp#0
     pen = 0
 end

src/scripts/hrturtle.4th

@@ -51,4 +51,36 @@ SRC" TURTLE.4TH"
 
 : RESET PENUP 140 80 MOVETO 0 TURNTO PENDOWN ;
 
+1 VARIABLE MAXDEPTH
+
+1 VARIABLE DEPTH
+
+: POW3
+    1 SWAP 1- ?DUP 0= IF EXIT THEN
+    0 DO
+        3 *
+    LOOP
+;
+
+: TRIEDGE
+    DEPTH @ MAXDEPTH @ = IF
+        8960 DEPTH @ POW3 / 1 + 1 RSHIFT MOVEP4
+    ELSE
+        1 DEPTH +!
+        RECURSE -60 TURN
+        RECURSE 120 TURN
+        RECURSE -60 TURN
+        RECURSE
+        -1 DEPTH +!
+    THEN
+;
+
+: SNOWFLAKE MAXDEPTH ! PENUP 0 159 MOVETO 0 TURNTO PENDOWN 1 DEPTH ! TRIEDGE ;
+
 SHOW SPIN RESET SPIRAL RESET ZOOM
+0 CLEARTO 3 HGRCOLOR
+1 SNOWFLAKE
+2 SNOWFLAKE
+3 SNOWFLAKE
+4 SNOWFLAKE
+5 SNOWFLAKE

src/scripts/turtle.4th

@@ -9,5 +9,6 @@ LOOKUP TURNTO        PLASMA TURNTO
 LOOKUP TURN          PLASMA TURN
 LOOKUP MOVETO        PLASMA MOVETO
 LOOKUP MOVE          PLASMA MOVE
+LOOKUP MOVEP4        PLASMA MOVEP4
 LOOKUP PENUP         PLASMA PENUP
 LOOKUP PENDOWN       PLASMA PENDOWN