MorseDecoder.cpp

00001 /* 
00002     Copyright (c) 2014 Romain Berrada
00003     
00004     Permission is hereby granted, free of charge, to any person obtaining a copy of this software 
00005     and associated documentation files (the "Software"), to deal in the Software without restriction, 
00006     including without limitation the rights to use, copy, modify, merge, publish, distribute, 
00007     sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is 
00008     furnished to do so, subject to the following conditions:
00009 
00010     The above copyright notice and this permission notice shall be included in all copies or 
00011     substantial portions of the Software.
00012 
00013     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING 
00014     BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
00015     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
00016     DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
00017     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00018 */
00019 
00020 #include "Morse.h"
00021 #include "mbed.h"
00022 
00023 struct _morse_tree {
00024     char value;
00025     const struct _morse_tree* dot;
00026     const struct _morse_tree* dash;
00027 };
00028 
00029 // Depth 5 of the tree
00030 static const struct _morse_tree _morse_tree_1 = {'1', 0, 0};
00031 static const struct _morse_tree _morse_tree_2 = {'2', 0, 0};
00032 static const struct _morse_tree _morse_tree_3 = {'3', 0, 0};
00033 static const struct _morse_tree _morse_tree_4 = {'4', 0, 0};
00034 static const struct _morse_tree _morse_tree_5 = {'5', 0, 0};
00035 static const struct _morse_tree _morse_tree_6 = {'6', 0, 0};
00036 static const struct _morse_tree _morse_tree_7 = {'7', 0, 0};
00037 static const struct _morse_tree _morse_tree_8 = {'8', 0, 0};
00038 static const struct _morse_tree _morse_tree_9 = {'9', 0, 0};
00039 static const struct _morse_tree _morse_tree_0 = {'0', 0, 0};
00040 static const struct _morse_tree _morse_tree_AR= {'@', 0, 0};                           // @ added as DOT,DOT,DOT,DASH,DOT
00041 static const struct _morse_tree _morse_tree_IN= {'?', 0, 0};                           // ? added as DOT,DOT,DASH,DOT,DOT
00042 
00043 // Depth 4 of the tree
00044 static const struct _morse_tree _morse_tree_H = {'H', &_morse_tree_5, &_morse_tree_4};
00045 static const struct _morse_tree _morse_tree_V = {'V',&_morse_tree_AR ,&_morse_tree_3};
00046 static const struct _morse_tree _morse_tree_F = {'F',&_morse_tree_IN, 0};
00047 static const struct _morse_tree _morse_tree_MN= {'-', 0,              &_morse_tree_2}; // - added as DOT,DOT,DASH,DASH
00048 static const struct _morse_tree _morse_tree_L = {'L', 0,              0};
00049 static const struct _morse_tree _morse_tree_SL= {'/', 0,              0};              // / added as DOT,DASH,DOT,DASH
00050 static const struct _morse_tree _morse_tree_P = {'P', 0,              0};
00051 static const struct _morse_tree _morse_tree_J = {'J', 0,              &_morse_tree_1};
00052 static const struct _morse_tree _morse_tree_B = {'B', &_morse_tree_6, 0};
00053 static const struct _morse_tree _morse_tree_X = {'X', 0, 0};
00054 static const struct _morse_tree _morse_tree_C = {'C', 0, 0};
00055 static const struct _morse_tree _morse_tree_Y = {'Y', 0, 0};
00056 static const struct _morse_tree _morse_tree_Z = {'Z', &_morse_tree_7, 0};
00057 static const struct _morse_tree _morse_tree_Q = {'Q', 0, 0};
00058 static const struct _morse_tree _morse_tree_UN= {'_', &_morse_tree_8, 0};              // _ added as DASH,DASH,DASH,DOT
00059 static const struct _morse_tree _morse_tree_DO= {'.', &_morse_tree_9, &_morse_tree_0}; // . added as DASH,DASH,DASH,DASH
00060 
00061 // Depth 3 of the tree
00062 static const struct _morse_tree _morse_tree_S = {'S', &_morse_tree_H, &_morse_tree_V};
00063 static const struct _morse_tree _morse_tree_U = {'U', &_morse_tree_F, &_morse_tree_MN};
00064 static const struct _morse_tree _morse_tree_R = {'R', &_morse_tree_L, &_morse_tree_SL};
00065 static const struct _morse_tree _morse_tree_W = {'W', &_morse_tree_P, &_morse_tree_J};
00066 static const struct _morse_tree _morse_tree_D = {'D', &_morse_tree_B, &_morse_tree_X};
00067 static const struct _morse_tree _morse_tree_K = {'K', &_morse_tree_C, &_morse_tree_Y};
00068 static const struct _morse_tree _morse_tree_G = {'G', &_morse_tree_Z, &_morse_tree_Q};
00069 static const struct _morse_tree _morse_tree_O = {'O', &_morse_tree_UN,&_morse_tree_DO};
00070 
00071 // Depth 2 of the tree
00072 static const struct _morse_tree _morse_tree_I = {'I', &_morse_tree_S, &_morse_tree_U};
00073 static const struct _morse_tree _morse_tree_A = {'A', &_morse_tree_R, &_morse_tree_W};
00074 static const struct _morse_tree _morse_tree_N = {'N', &_morse_tree_D, &_morse_tree_K};
00075 static const struct _morse_tree _morse_tree_M = {'M', &_morse_tree_G, &_morse_tree_O};
00076 
00077 // Depth 1 of the tree
00078 static const struct _morse_tree _morse_tree_E = {'E', &_morse_tree_I, &_morse_tree_A};
00079 static const struct _morse_tree _morse_tree_T = {'T', &_morse_tree_N, &_morse_tree_M};
00080 
00081 static const struct _morse_tree _morse_tree_root = {'#', &_morse_tree_E, &_morse_tree_T};
00082 
00083 unsigned int morse_getWordSize(Morse_data* data) {
00084     unsigned int i;
00085     unsigned int blank_counter=0;
00086     unsigned int size=0;
00087     
00088     for (i=0; i<data->length; i++) {
00089         if (data->data[i]==false) blank_counter++;
00090         else { // else true
00091             // checks all the blanks so far, and then reset the counter
00092             if (blank_counter==3) size++; // if blanks to separate two chars
00093             else if (blank_counter==7) size+=2; // if blanks for a space : acknowledge the space and the char before the space
00094             blank_counter=0;
00095         }
00096     }
00097     size++; // acknowledge the last char
00098     if (blank_counter>=7) size++;
00099     return size;
00100 }
00101 
00102 void morse_decode(Morse_data* data, char* word) {
00103     unsigned int i;
00104     unsigned int char_i=0;
00105     unsigned int false_counter=0;
00106     unsigned int true_counter=0;
00107     const struct _morse_tree* tree = &_morse_tree_root; // CHANGE TO THE BINRARY TREE IMPLEMENTATION AND PUT THE ROOT INSTEAD
00108 
00109     for (i=0; i<data->length; i++) {
00110         if (data->data[i]==false) {
00111             // if false, increase the false_counter, manage the number of true and false before, and reset the true_counter
00112             false_counter++;
00113             
00114             if (true_counter==1) tree = tree->dot;
00115             else if (true_counter==3) tree = tree->dash;
00116             
00117             if (false_counter==3) {
00118                 word[char_i++] = tree->value;
00119                 tree = &_morse_tree_root;
00120             }
00121             else if (false_counter==7) word[char_i++] = ' ';
00122 
00123             true_counter=0;
00124         }
00125         else { // else true
00126             true_counter++;
00127             false_counter=0;
00128         }   
00129     }
00130     
00131     if (true_counter==1) word[char_i++] = tree->dot->value;
00132     else if (true_counter==3) word[char_i++] = tree->dash->value;
00133 
00134     word[char_i] = '\0'; // finally, end the char array
00135 }