beremiz

use pregenerated CRC32 lookup tables for retain on Win32 and GNU/Linux

2019-01-06, Andrey Skvortsov
68f4f2d4516b
use pregenerated CRC32 lookup tables for retain on Win32 and GNU/Linux

This code could be possible reused on low-end targets with limited RAM.

code to generate lookup table:
[---------------------------------------------------------------------]

/* CRC lookup table and initial state. */
uint32_t crc32_table[256];

/* Generate CRC32 lookup table. */
void GenerateCRC32Table(void)
{
unsigned int i, j;
/* Use CRC-32-IEEE 802.3 polynomial 0x04C11DB7 (bit reflected). */
uint32_t poly = 0xEDB88320;

for (i = 0; i <= 0xFF; i++)
{
uint32_t c = i;
for (j = 0 ; j < 8 ; j++)
c = (c & 1) ? (c >> 1 ) ^ poly : (c >> 1);
crc32_table[i] = c;
}
}

void main(void)
{
GenerateCRC32Table();
int j=0;
for(int i=0; i<256; i++) {
printf("0x%08X, ", crc32_table[i]);
if (++j >= 8) {
j = 0;
printf("\n");
}
}
}
[---------------------------------------------------------------------]
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# This file is part of Beremiz, a Integrated Development Environment for
# programming IEC 61131-3 automates supporting plcopen standard and CanFestival.
#
# Copyright (C) 2012: Edouard TISSERANT and Laurent BESSARD
#
# See COPYING file for copyrights details.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
from __future__ import absolute_import
import wx
from util.BitmapLibrary import GetBitmap
# -------------------------------------------------------------------------------
# Custom button for Graphic Viewer Class
# -------------------------------------------------------------------------------
class GraphButton(object):
"""
Class that implements a custom button for graphic Viewer
"""
def __init__(self, x, y, bitmap, callback):
"""
Constructor
@param x: X coordinate of Button in Graphic Viewer
@param y: Y coordinate of Button in Graphic Viewer
@param bitmap: Name of bitmap to use for button
@param callback: Reference to function to call when button is pressed
"""
# Save button position
self.SetPosition(x, y)
# Set button bitmap
self.SetBitmap(bitmap)
# By default button is hide and enabled
self.Shown = False
self.Enabled = True
# Save reference to callback function
self.Callback = callback
def __del__(self):
"""
Destructor
"""
# Remove reference to callback function
self.callback = None
def SetBitmap(self, bitmap):
"""
Set bitmap to use for button
@param bitmap: Name of bitmap to use for button
"""
# Get wx.Bitmap object corresponding to bitmap
self.Bitmap = GetBitmap(bitmap)
def GetSize(self):
"""
Return size of button
@return: wx.Size object containing button size
"""
# Button size is size of bitmap
return self.Bitmap.GetSize()
def SetPosition(self, x, y):
"""
Set button position
@param x: X coordinate of Button in Graphic Viewer
@param y: Y coordinate of Button in Graphic Viewer
"""
self.Position = wx.Point(x, y)
def Show(self, show=True):
"""
Mark if button to be displayed in Graphic Viewer
@param show: True if button to be displayed in Graphic Viewer
(default True)
"""
self.Shown = show
def Hide(self):
"""
Hide button from Graphic Viewer
"""
self.Show(False)
def IsShown(self):
"""
Return if button is displayed in Graphic Viewer
@return: True if button is displayed in Graphic Viewer
"""
return self.Shown
def Enable(self, enable=True):
"""
Mark if button is active in Graphic Viewer
@param enable: True if button is active in Graphic Viewer
(default True)
"""
self.Enabled = enable
def Disable(self):
"""
Deactivate button in Graphic Viewer
"""
self.Enabled = False
def IsEnabled(self):
"""
Return if button is active in Graphic Viewer
@return: True if button is active in Graphic Viewer
"""
return self.Enabled
def HitTest(self, x, y):
"""
Test if point is inside button
@param x: X coordinate of point
@param y: Y coordinate of point
@return: True if button is active and displayed and point is inside
button
"""
# Return immediately if button is hidden or inactive
if not (self.IsShown() and self.IsEnabled()):
return False
# Test if point is inside button
w, h = self.Bitmap.GetSize()
rect = wx.Rect(self.Position.x, self.Position.y, w, h)
return rect.InsideXY(x, y)
def ProcessCallback(self):
"""
Call callback function if defined
"""
if self.Callback is not None:
self.Callback()
def Draw(self, dc):
"""
Draw button in Graphic Viewer
@param dc: wx.DC object corresponding to Graphic Viewer device context
"""
# Only draw button if button is active and displayed
if self.Shown and self.Enabled:
dc.DrawBitmap(self.Bitmap, self.Position.x, self.Position.y, True)