EngraveCutter now uses a separated PathProcessor for the last (drop) layer

git-svn-id: https://pycam.svn.sourceforge.net/svnroot/pycam/trunk@380 bbaffbd6-741e-11dd-a85d-61de82d9cad9

pycam/PathGenerators/EngraveCutter.py

@@ -21,10 +21,12 @@ You should have received a copy of the GNU General Public License
 along with PyCAM.  If not, see <http://www.gnu.org/licenses/>.
 """
 
+import pycam.PathProcessors.PathAccumulator
 from pycam.Geometry import Point
 from pycam.Geometry.utils import INFINITE
 from pycam.PathGenerators import get_max_height_triangles, get_max_height_ode, get_free_horizontal_paths_ode, get_free_horizontal_paths_triangles, ProgressCounter
 import math
+import sys
 
 class EngraveCutter:
 
@@ -33,11 +35,16 @@ class EngraveCutter:
         self.cutter = cutter
         self.model = model
         self.contour_model = contour_model
-        self.pa = path_processor
+        self.pa_push = path_processor
+        # We use a separated path processor for the last "drop" layer.
+        # This path processor does not need to be configurable.
+        self.pa_drop = pycam.PathProcessors.PathAccumulator()
         self.physics = physics
         self.safety_height = safety_height
+        self._boundary_warning_already_shown = False
 
     def GenerateToolPath(self, minz, maxz, horiz_step, dz, draw_callback=None):
+        quit_requested = False
         # calculate the number of steps
         num_of_layers = 1 + int(math.ceil(abs(maxz - minz) / dz))
         if num_of_layers > 1:
@@ -51,10 +58,12 @@ class EngraveCutter:
 
         paths = []
         current_layer = 0
-        lines = self.contour_model.get_lines()
-        progress_counter = ProgressCounter(len(z_steps) * len(lines),
+        num_of_lines = len(self.contour_model.get_lines())
+        progress_counter = ProgressCounter(len(z_steps) * num_of_lines,
                 draw_callback)
 
+        line_groups = self.contour_model.get_line_groups()
+
         # push slices for all layers above ground
         for z in z_steps[:-1]:
             # update the progress bar and check, if we should cancel the process
@@ -63,37 +72,61 @@ class EngraveCutter:
                 # cancel immediately
                 break
 
-            for line in lines:
-                self.GenerateToolPathLinePush(line, z)
-                progress_counter.increment()
-            self.pa.finish()
+            for line_group in line_groups:
+                for line in line_group:
+                    self.GenerateToolPathLinePush(self.pa_push, line, z)
+                    if progress_counter.increment():
+                        # cancel requested
+                        quit_requested = True
+                        break
+            self.pa_push.finish()
 
             # the path accumulator will be reset for each slice - we need to store the result
-            if self.pa.paths:
-                paths += self.pa.paths
+            if self.pa_push.paths:
+                paths += self.pa_push.paths
+
+            # break the outer loop if requested
+            if quit_requested:
+                break
 
             current_layer += 1
 
+        if quit_requested:
+            return paths
+
         if draw_callback:
             draw_callback(text="Engrave: processing layer %d/%d" \
                     % (current_layer, num_of_layers))
 
         # process the final layer with a drop cutter
-        for line in lines:
-            self.GenerateToolPathLineDrop(line, minz, maxz, horiz_step,
+        for line_group in self.contour_model.get_line_groups():
+            self.pa_drop.new_direction(0)
+            self.pa_drop.new_scanline()
+            for line in line_group:
+                self.GenerateToolPathLineDrop(self.pa_drop, line, minz, maxz, horiz_step,
                         draw_callback=draw_callback)
-            progress_counter.increment()
-        self.pa.finish()
+                if progress_counter.increment():
+                    # quit requested
+                    quit_requested = True
+                    break
+            self.pa_drop.end_scanline()
+            self.pa_drop.end_direction()
+            # break the outer loop if requested
+            if quit_requested:
+                break
+        self.pa_drop.finish()
         # the path accumulator will be reset for each slice - we need to store the result
-        if self.pa.paths:
-            paths += self.pa.paths
+        if self.pa_drop.paths:
+            paths += self.pa_drop.paths
         
         return paths
 
-    def GenerateToolPathLinePush(self, line, z, draw_callback=None):
+    def GenerateToolPathLinePush(self, pa, line, z, draw_callback=None):
         p1 = Point(line.p1.x, line.p1.y, z)
         p2 = Point(line.p2.x, line.p2.y, z)
-        if not self.model:
+        # no model -> no possible obstacles
+        # model is completely below z (e.g. support bridges) -> no obstacles
+        if not self.model or (self.model.maxz < z):
             points = [p1, p2]
         elif self.physics:
             points = get_free_horizontal_paths_ode(self.physics, p1.x, p2.x,
@@ -103,18 +136,21 @@ class EngraveCutter:
                     self.cutter, p1.x, p2.x, p1.y, p2.y, z)
         if points:
             for p in points:
-                self.pa.append(p)
+                pa.append(p)
             self.cutter.moveto(p)
             if draw_callback:
-                draw_callback(tool_position=p)
+                draw_callback(tool_position=tool_position)
 
 
-    def GenerateToolPathLineDrop(self, line, minz, maxz, horiz_step,
+    def GenerateToolPathLineDrop(self, pa, line, minz, maxz, horiz_step,
             draw_callback=None):
+        pa.new_direction(0)
+        pa.new_scanline()
         p1 = Point(line.p1.x, line.p1.y, minz)
         p2 = Point(line.p2.x, line.p2.y, minz)
         distance = line.len()
-        num_of_steps = 1 + int(math.ceil(distance / horiz_step))
+        # we want to have at least five steps each
+        num_of_steps = max(5, 1 + int(math.ceil(distance / horiz_step)))
         # steps may be negative
         x_step = (p2.x - p1.x) / (num_of_steps - 1)
         y_step = (p2.y - p1.y) / (num_of_steps - 1)
@@ -126,7 +162,8 @@ class EngraveCutter:
 
         for x, y in step_coords:
             if not self.model:
-                points = [p1, p2]
+                # no obstacle -> minimum height
+                points = [Point(x, y, minz)]
             elif self.physics:
                 points = get_max_height_ode(self.physics, x, y, minz, maxz)
             else:
@@ -135,10 +172,10 @@ class EngraveCutter:
 
             if points:
                 for p in points:
-                    self.pa.append(p)
+                    pa.append(p)
             else:
                 p = Point(x, y, self.safety_height)
-                self.pa.append(p)
+                pa.append(p)
                 if not self._boundary_warning_already_shown:
                     print >>sys.stderr, "WARNING: DropCutter exceed the height" \
                             + " of the boundary box: using a safe height " \
@@ -147,7 +184,7 @@ class EngraveCutter:
             self.cutter.moveto(p)
             # "draw_callback" returns true, if the user requested quitting via the GUI
             if draw_callback and draw_callback(tool_position=p):
-                #print "Quit requested?"
                 break
-
+        pa.end_scanline()
+        pa.end_direction()