Adding the FastOPC python client

tools/fastopc.py

+"""Simple high-performance Open Pixel Control client."""
+#
+# Copyright (c) 2013 Micah Elizabeth Scott
+# 
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+# 
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+# 
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+   
+import json
+import numpy
+import os
+import socket
+import struct
+import time
+
+
+class FastOPC(object):
+    """High-performance Open Pixel Control client, using Numeric Python.
+       By default, assumes the OPC server is running on localhost. This may be overridden
+       with the OPC_SERVER environment variable, or the 'server' keyword argument.
+       """
+
+    def __init__(self, server=None):
+        self.server = server or os.getenv('OPC_SERVER') or '127.0.0.1:7890'
+        self.host, port = self.server.split(':')
+        self.port = int(port)
+        self.socket = None
+
+
+    def send(self, packet):
+        """Send a low-level packet to the OPC server, connecting if necessary
+           and handling disconnects. Returns True on success.
+           """
+
+        if self.socket is None:
+            try:
+                self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+                self.socket.connect((self.host, self.port))
+                self.socket.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, True)
+            except socket.error:
+                self.socket = None
+
+        if self.socket is not None:        
+            try:
+                self.socket.send(packet)
+                return True
+            except socket.error:
+                self.socket = None
+
+        # Limit CPU usage when polling for a server
+        time.sleep(0.1)
+
+        return False
+
+    def putPixels(self, channel, *sources):
+        """Send a list of 8-bit colors to the indicated channel. (OPC command 0x00).
+           This command accepts a list of pixel sources, which are concatenated and sent.
+           Pixel sources may be:
+
+            - Strings or buffer objects containing pre-formatted 8-bit RGB pixel data
+            - NumPy arrays or sequences containing 8-bit RGB pixel data.
+              If values are out of range, the array is modified.
+           """
+
+        parts = []
+        bytes = 0
+
+        for source in sources:
+            if isinstance(source, buffer):
+                source = str(source)
+            elif not isinstance(source, str):
+                if not isinstance(source, numpy.ndarray):
+                    source = numpy.array(source)
+                numpy.clip(source, 0, 255, source)
+                source = source.astype('B').tostring()
+
+            bytes += len(source)
+            parts.append(source)
+
+        parts.insert(0, struct.pack('>BBH', channel, 0, bytes))
+        self.send(''.join(parts))
+
+    def sysEx(self, systemId, commandId, msg):
+        self.send(struct.pack(">BBHHH", 0, 0xFF, len(msg) + 4, systemId, commandId) + msg)
+
+    def setGlobalColorCorrection(self, gamma, r, g, b):
+        self.sysEx(1, 1, json.dumps({'gamma': gamma, 'whitepoint':[r,g,b]}))