simplify all generated toolpath to avoid multiple points on a straight line

(this avoids a severe slow-down of the machine in case of too many small steps)


git-svn-id: https://pycam.svn.sourceforge.net/svnroot/pycam/trunk@526 bbaffbd6-741e-11dd-a85d-61de82d9cad9

src/pycam/PathProcessors/ContourCutter.py

@@ -21,6 +21,7 @@ along with PyCAM.  If not, see <http://www.gnu.org/licenses/>.
 """
 
 from pycam.Geometry.PolygonExtractor import PolygonExtractor
+from pycam.Toolpath import simplify_toolpath
 
 class ContourCutter:
     def __init__(self):
@@ -62,6 +63,7 @@ class ContourCutter:
         if paths:
             for p in paths:
                 p.append(p.points[0])
+                simplify_toolpath(p)
         if paths:
             self.paths.extend(paths)
         self.pe = None

src/pycam/PathProcessors/PathAccumulator.py

@@ -21,15 +21,9 @@ You should have received a copy of the GNU General Public License
 along with PyCAM.  If not, see <http://www.gnu.org/licenses/>.
 """
 
+from pycam.Toolpath import simplify_toolpath
 from pycam.Geometry.Path import Path
 
-def _check_colinearity(p1, p2, p3):
-    v1 = p2.sub(p1)
-    v2 = p3.sub(p2)
-    v1.normalize()
-    v2.normalize()
-    # compare if the normalized distances between p1-p2 and p2-p3 are equal
-    return v1 == v2
 
 class PathAccumulator:
     def __init__(self, zigzag=False):
@@ -41,12 +35,6 @@ class PathAccumulator:
     def append(self, p):
         if self.curr_path == None:
             self.curr_path = Path()
-        if (len(self.curr_path.points) >= 2) and \
-                (_check_colinearity(self.curr_path.points[-2],
-                self.curr_path.points[-1], p)):
-            # remove the previous point since it is in line with its
-            # predecessor and the new point
-            self.curr_path.points.pop()
         self.curr_path.append(p)
 
     def new_direction(self, direction):
@@ -63,10 +51,12 @@ class PathAccumulator:
 
     def end_scanline(self):
         if self.curr_path:
-            if self.zigzag and (self.scanline%2 == 0):
+            if self.zigzag and (self.scanline % 2 == 0):
                 self.curr_path.reverse()
+            simplify_toolpath(self.curr_path)
             self.paths.append(self.curr_path)
             self.curr_path = None
 
     def finish(self):
         pass
+

src/pycam/PathProcessors/PolygonCutter.py

@@ -23,6 +23,7 @@ along with PyCAM.  If not, see <http://www.gnu.org/licenses/>.
 
 from pycam.Geometry.Path import Path
 from pycam.Geometry.PolygonExtractor import PolygonExtractor
+from pycam.Toolpath import simplify_toolpath
 
 
 class PolygonCutter:
@@ -67,5 +68,7 @@ class PolygonCutter:
                     p.append(points[i])
                 paths.append(p)
         if paths:
+            for p in paths:
+                simplify_toolpath(p)
             self.paths.extend(paths)
 

src/pycam/PathProcessors/SimpleCutter.py

@@ -21,6 +21,7 @@ along with PyCAM.  If not, see <http://www.gnu.org/licenses/>.
 """
 
 from pycam.Geometry.Path import Path
+from pycam.Toolpath import simplify_toolpath
 
 class SimpleCutter:
     def __init__(self):
@@ -37,6 +38,7 @@ class SimpleCutter:
             self.curr_path = None
         curr_path.append(p)
         if self.curr_path == None:
+            simplify_toolpath(curr_path)
             self.paths.append(curr_path)
 
     def new_direction(self, direction):

src/pycam/PathProcessors/ZigZagCutter.py

@@ -21,6 +21,7 @@ along with PyCAM.  If not, see <http://www.gnu.org/licenses/>.
 """
 
 from pycam.Geometry.Path import Path
+from pycam.Toolpath import simplify_toolpath
 
 class ZigZagCutter:
     def __init__(self):
@@ -58,7 +59,9 @@ class ZigZagCutter:
         self.curr_scanline = []
 
     def end_scanline(self):
-        self.paths += self.curr_scanline
+        for path in self.curr_scanline:
+            simplify_toolpath(path)
+            self.paths.append(path)
         self.curr_scanline = None
 
     def finish(self):

src/pycam/Toolpath/__init__.py

@@ -20,7 +20,7 @@ You should have received a copy of the GNU General Public License
 along with PyCAM.  If not, see <http://www.gnu.org/licenses/>.
 """
 
-__all__ = ["ToolPathList", "ToolPath", "Generator"]
+__all__ = ["simplify_toolpath", "ToolPathList", "ToolPath", "Generator"]
 
 from pycam.Geometry.Point import Point
 import pycam.Utils.log
@@ -29,6 +29,36 @@ import os
 
 log = pycam.Utils.log.get_logger()
 
+
+def _check_colinearity(p1, p2, p3):
+    v1 = p2.sub(p1)
+    v2 = p3.sub(p2)
+    v1.normalize()
+    v2.normalize()
+    # compare if the normalized distances between p1-p2 and p2-p3 are equal
+    return v1 == v2
+
+
+def simplify_toolpath(path):
+    """ remove multiple points in a line from a toolpath
+
+    If A, B, C and D are on a straight line, then B and C will be removed.
+    This reduces memory consumption and avoids a severe slow-down of the machine
+    when moving along very small steps.
+    The toolpath is simplified _in_place_.
+    @value path: a single separate segment of a toolpath
+    @type path: pycam.Geometry.Path.Path
+    """
+    index = 1
+    points = path.points
+    while index < len(points) - 1:
+        if _check_colinearity(points[index-1], points[index], points[index+1]):
+            points.pop(index)
+            # don't increase the counter - otherwise we skip one point
+        else:
+            index += 1
+
+
 class ToolPathList(list):
 
     def add_toolpath(self, toolpath, name, toolpath_settings):