Initial commit of source code.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

klippy/lookahead.py

@@ -0,0 +1,50 @@
+# Move queue look-ahead
+#
+# Copyright (C) 2016  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+
+class MoveQueue:
+    def __init__(self, dummy_move):
+        self.dummy_move = dummy_move
+        self.queue = []
+        self.prev_junction_max = 0.
+        self.junction_flush = 0.
+    def prev_move(self):
+        if self.queue:
+            return self.queue[-1]
+        return self.dummy_move
+    def flush(self, lazy=False):
+        next_junction_max = 0.
+        can_flush = not lazy
+        flush_count = len(self.queue)
+        junction_end = [None] * flush_count
+        for i in range(len(self.queue)-1, -1, -1):
+            move = self.queue[i]
+            junction_end[i] = next_junction_max
+            if not can_flush:
+                flush_count -= 1
+            next_junction_max = next_junction_max + move.junction_delta
+            if next_junction_max >= move.junction_start_max:
+                next_junction_max = move.junction_start_max
+                can_flush = True
+        prev_junction_max = self.prev_junction_max
+        for i in range(flush_count):
+            move = self.queue[i]
+            next_junction_max = min(prev_junction_max + move.junction_delta
+                                    , junction_end[i])
+            move.process(prev_junction_max, next_junction_max)
+            prev_junction_max = next_junction_max
+        del self.queue[:flush_count]
+        self.prev_junction_max = prev_junction_max
+        self.junction_flush = 0.
+        if self.queue:
+            self.junction_flush = self.queue[-1].junction_max
+    def add_move(self, move):
+        self.queue.append(move)
+        if len(self.queue) == 1:
+            self.junction_flush = move.junction_max
+            return
+        self.junction_flush -= move.junction_delta
+        if self.junction_flush <= 0.:
+            self.flush(lazy=True)