added matplotlib post-processor for static drawings.

diff --git a/src/Dyna/Backend/Python/post/draw.py b/src/Dyna/Backend/Python/post/draw.py
new file mode 100644 (file)
index 0000000..cd212b7
--- /dev/null
+++ b/src/Dyna/Backend/Python/post/draw.py
@@ -0,0 +1,79 @@
+import pylab as pl
+from matplotlib.animation import FuncAnimation
+from collections import defaultdict
+
+class draw(object):
+    """
+    Postprocessor for animated visualization of basic elements such as lines and
+    text.
+
+    We look for the following patterns in the dynabase
+
+             visual element
+                   v
+        frame(T, &text(String, tuple(X, Y))).
+              ^
+           time index
+
+    Frames should have value true. The example above places a text element reading
+    `String` at position `(X,Y)` in a frame at time `T`. This element can be
+    specified by dyna rule.
+    """
+
+    def __init__(self, interp):
+        self.interp = interp
+
+    def main(self):
+
+        frame = defaultdict(list)
+        for _, [t, item], val in self.interp.chart['frame/2'][:,:,:]:
+            if val:
+                frame[t].append(item)
+
+        if not frame:
+            print 'no frames found.'
+            return
+
+        nframes = max(frame)
+
+        assert nframes == 0, 'many frames found. Did you mean to use an animtation?'
+
+        def draw_frame(t):
+            ax.cla()
+            ax.grid(False)
+            if t not in frame:
+                print 'frame', t, 'missing.'
+            for item in frame[t]:
+                fn = item. fn
+
+                if fn == 'title/1':
+                    [title] = item.args
+                    ax.set_title(title)
+
+                elif fn == 'xlim/2':
+                    [a,b] = item.args
+                    ax.set_xlim(a,b)
+
+                elif fn == 'ylim/2':
+                    [a,b] = item.args
+                    ax.set_ylim(a,b)
+
+                elif fn == 'line/2':
+                    [(a,b), (c,d)] = item.args
+                    ax.plot([a,c], [b,d], color='b', alpha=0.5)
+
+                elif fn == 'text/2':
+                    (s,(x,y)) = item.args
+                    ax.text(x,y,s)
+
+                else:
+                    print 'dont know how to render', item
+
+        fig = pl.figure(figsize=(10,10))
+        ax = pl.axes()
+
+        draw_frame(0)
+        
+        #pl.ion(); pl.show()
+        #from arsenal.debug import ip; ip()
+        pl.show()