First draft of heuristic-based block rotation

src/mceditlib/blocktypes/rotation.py

@@ -0,0 +1,143 @@
+"""
+    rotation
+"""
+from __future__ import absolute_import, division, print_function, unicode_literals
+import logging
+
+import numpy
+
+log = logging.getLogger(__name__)
+
+
+def parseBlockstate(state):
+    assert state[0] == '[' and state[-1] == ']'
+    state = state[1:-1]
+    return dict(pair.split('=') for pair in state.split(','))
+
+
+def joinBlockstate(stateDict):
+    return '[' + ','.join(k + '=' + v for k, v in stateDict.items()) + ']'
+
+
+def yAxisTable(blocktypes):
+    mapping = {
+        'north': 'east',
+        'east': 'south',
+        'south': 'west',
+        'west': 'north',
+    }
+
+    rail_shapes = {
+        'ascending_north': 'ascending_east',
+        'ascending_east': 'ascending_south',
+        'ascending_south': 'ascending_west',
+        'ascending_west': 'ascending_north',
+        'east_west': 'north_south',
+        'north_east': 'south_east',
+        'south_east': 'south_west',
+        'south_west': 'north_west',
+        'north_west': 'north_east',
+
+    }
+    table = numpy.indices((32768, 16))
+
+    # Roll array so table[x, y] returns [x, y]
+    table = numpy.rollaxis(numpy.rollaxis(table, 1), 2, 1)
+
+    for block in blocktypes:
+        stateString = block.blockState
+        if not len(stateString):
+            continue
+
+        try:
+            state = parseBlockstate(stateString)
+        except:
+            log.exception("Error parsing blockstate: %s", stateString)
+            continue
+
+        # First pass: facing=north and similar
+        newState = {}
+        for k, v in state.items():
+            n = mapping.get(v)
+            if n:
+                newState[k] = n
+            else:
+                newState[k] = v
+
+        state = newState
+        newState = dict(state)
+
+        # Second pass: north=true and similar
+        for k, v in mapping.items():
+            if k in state:
+                if state[k] == 'true':
+                    newState[k] = 'false'
+                    newState[v] = 'true'
+
+        # For signs and banners: rotation=10 and similar
+        # y-axis only
+
+        state = newState
+
+        if 'rotation' in state:
+            rotation = (int(state['rotation']) + 4) % 16
+            state['rotation'] = unicode(rotation)
+
+        # For logs and such: axis=x and similar
+
+        if 'axis' in state:
+            axis = state['axis']
+
+            # y-axis only
+            if axis == 'x':
+                axis = 'z'
+            if axis == 'z':
+                axis = 'x'
+
+            state['axis'] = axis
+
+        # For rails, powered rails, etc: shape=north_east
+        # y-axis only
+
+        if 'shape' in state:
+            shape = state['shape']
+
+            newShape = rail_shapes.get(shape)
+            if newShape:
+                state['shape'] = newShape
+
+        newStateString = joinBlockstate(state)
+
+        print("Changed %s \nto %s" % (stateString, newStateString))
+
+        try:
+            newBlock = blocktypes[block.internalName, newStateString]
+        except KeyError:
+            print("no mapping for %s%s" % (block.internalName, newStateString))
+
+        table[block.ID, block.meta] = [newBlock.ID, newBlock.meta]
+
+    return table
+
+def test_yAxisTable():
+    from . import PCBlockTypeSet
+    blocktypes = PCBlockTypeSet()
+    table = yAxisTable(blocktypes)
+
+    changed = False
+    changedNames = set()
+    for i in range(32768):
+        for j in range(16):
+            e = table[i,j]
+            if e[0] != i and e[1] != j:
+                changed = True
+                name = blocktypes[i, j].internalName
+                if name not in changedNames:
+                    print("%s is changed" % name)
+                    changedNames.add(name)
+
+    assert changed, "Table is unchanged"
+
+
+
+