triwave.cpp

00001 /** triwave class
00002  * Copyright (c) 2014, 2015 Motoo Tanaka @ Design Methodology Lab
00003  *
00004  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00005  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00006  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00007  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00008  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00009  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00010  * THE SOFTWARE.
00011  */
00012 #include "triwave.h"
00013 
00014 triwave::triwave(float v, int f, int d, int p) : sqrwave(v, f, d, p) 
00015 {
00016     _name = "tri" ; 
00017 }
00018 
00019 triwave::~triwave(void) { }
00020 
00021 int triwave::value(void)
00022 {
00023     int result = 0 ;
00024     if (_cycle == 0) {
00025         if (_duty == 100) {
00026             result = _amp ;
00027         } else {
00028             result = 0 ;
00029         }
00030     } else if (_duty == 100) { // saw wave
00031         result = _amp * _pos / _cycle ;
00032     } else if (_duty == 0) { // reversed saw wave
00033         result = _amp * (_cycle - _pos) / _cycle ;
00034     } else { // tri wave
00035         if (_pos < (int)((_duty * _cycle)/100)) {
00036             result = _amp * _pos / ((_duty * _cycle) / 100) ;
00037         } else {
00038             result = _amp - _amp * (_pos - (_duty * _cycle)/100) / ((_cycle * (100 - _duty))/100) ;
00039         }
00040     }
00041     return( result ) ;
00042 }