mirror of https://github.com/ArduPilot/ardupilot
105 lines
2.3 KiB
C++
105 lines
2.3 KiB
C++
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#include <AP_Curve.h>
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// Constructor
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template <class T, uint8_t SIZE>
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AP_Curve<T,SIZE>::AP_Curve() :
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_num_points(0)
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{
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// clear the curve
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clear();
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};
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// clear the curve
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template <class T, uint8_t SIZE>
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void AP_Curve<T,SIZE>::clear() {
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// clear the curve
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for( uint8_t i=0; i<SIZE; i++ ) {
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_x[i] = 0;
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_y[i] = 0;
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_slope[i] = 0.0;
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}
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_num_points = 0;
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}
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// add_point - adds a point to the curve
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template <class T, uint8_t SIZE>
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bool AP_Curve<T,SIZE>::add_point( T x, T y )
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{
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if( _num_points < SIZE ) {
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_x[_num_points] = x;
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_y[_num_points] = y;
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// increment the number of points
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_num_points++;
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// if we have at least two points calculate the slope
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if( _num_points > 1 ) {
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_slope[_num_points-2] = (float)(_y[_num_points-1] - _y[_num_points-2]) / (float)(_x[_num_points-1] - _x[_num_points-2]);
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_slope[_num_points-1] = _slope[_num_points-2]; // the final slope is for interpolation beyond the end of the curve
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}
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return true;
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}else{
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// we do not have room for the new point
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return false;
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}
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}
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// get_y - returns the y value on the curve for a given x value
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template <class T, uint8_t SIZE>
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T AP_Curve<T,SIZE>::get_y( T x )
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{
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uint8_t i;
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T result;
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// deal with case where ther is no curve
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if( _num_points == 0 ) {
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return x;
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}
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// when x value is lower than the first point's x value, return minimum y value
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if( x <= _x[0] ) {
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return _y[0];
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}
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// when x value is higher than the last point's x value, return maximum y value
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if( x >= _x[_num_points-1] ) {
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return _y[_num_points-1];
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}
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// deal with the normal case
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for( i=0; i<_num_points-1; i++ ) {
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if( x >= _x[i] && x <= _x[i+1] ) {
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result = _y[i] + (x - _x[i]) * _slope[i];
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return result;
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}
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}
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// we should never get here
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return x;
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}
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// displays the contents of the curve (for debugging)
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template <class T, uint8_t SIZE>
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void AP_Curve<T,SIZE>::dump_curve(AP_HAL::BetterStream* s)
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{
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s->println_P(PSTR("Curve:"));
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for( uint8_t i = 0; i<_num_points; i++ ){
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s->print_P(PSTR("x:"));
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s->print(_x[i]);
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s->print_P(PSTR("\ty:"));
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s->print(_y[i]);
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s->print_P(PSTR("\tslope:"));
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s->print(_slope[i],4);
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s->println();
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}
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}
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template class AP_Curve<int16_t,3>;
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template class AP_Curve<int16_t,4>;
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template class AP_Curve<int16_t,5>;
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template class AP_Curve<uint16_t,3>;
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template class AP_Curve<uint16_t,4>;
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template class AP_Curve<uint16_t,5>;
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