Christopher Doel / Mbed 2 deprecated el17cd

Cube Dodger A 3D 'endless runner' game

Dependencies:   mbed

Gamepad/Gamepad.cpp@46:824ec81ff578, 2019-05-08 (annotated)

Committer:
el17cd
Date:
Wed May 08 18:17:59 2019 +0000
Revision:
46:824ec81ff578
Parent:
0:efb5eec6b8ea 
Potentiometer now changes screen contrast for use on other devices.; Final Submission.; I have read and agreed with the Statement of Academic Integrity.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
el17cd 0:efb5eec6b8ea 1 #include "Gamepad.h"
el17cd 0:efb5eec6b8ea 2
el17cd 0:efb5eec6b8ea 3 #include "mbed.h"
el17cd 0:efb5eec6b8ea 4
el17cd 0:efb5eec6b8ea 5 //////////// constructor/destructor ////////////
el17cd 0:efb5eec6b8ea 6 Gamepad::Gamepad()
el17cd 0:efb5eec6b8ea 7 :
el17cd 0:efb5eec6b8ea 8 _led1(new PwmOut(PTA1)),
el17cd 0:efb5eec6b8ea 9 _led2(new PwmOut(PTA2)),
el17cd 0:efb5eec6b8ea 10 _led3(new PwmOut(PTC2)),
el17cd 0:efb5eec6b8ea 11 _led4(new PwmOut(PTC3)),
el17cd 0:efb5eec6b8ea 12 _led5(new PwmOut(PTC4)),
el17cd 0:efb5eec6b8ea 13 _led6(new PwmOut(PTD3)),
el17cd 0:efb5eec6b8ea 14
el17cd 0:efb5eec6b8ea 15 _button_A(new InterruptIn(PTB9)),
el17cd 0:efb5eec6b8ea 16 _button_B(new InterruptIn(PTD0)),
el17cd 0:efb5eec6b8ea 17 _button_X(new InterruptIn(PTC17)),
el17cd 0:efb5eec6b8ea 18 _button_Y(new InterruptIn(PTC12)),
el17cd 0:efb5eec6b8ea 19 _button_L(new InterruptIn(PTB18)),
el17cd 0:efb5eec6b8ea 20 _button_R(new InterruptIn(PTB3)),
el17cd 0:efb5eec6b8ea 21 _button_back(new InterruptIn(PTB19)),
el17cd 0:efb5eec6b8ea 22 _button_start(new InterruptIn(PTC5)),
el17cd 0:efb5eec6b8ea 23 _button_joystick(new InterruptIn(PTC16)),
el17cd 0:efb5eec6b8ea 24
el17cd 0:efb5eec6b8ea 25 _vert(new AnalogIn(PTB10)),
el17cd 0:efb5eec6b8ea 26 _horiz(new AnalogIn(PTB11)),
el17cd 0:efb5eec6b8ea 27
el17cd 0:efb5eec6b8ea 28 _buzzer(new PwmOut(PTC10)),
el17cd 0:efb5eec6b8ea 29 _pot(new AnalogIn(PTB2)),
el17cd 0:efb5eec6b8ea 30
el17cd 0:efb5eec6b8ea 31 _timeout(new Timeout()),
el17cd 0:efb5eec6b8ea 32
el17cd 0:efb5eec6b8ea 33 _event_state(0),
el17cd 0:efb5eec6b8ea 34
el17cd 0:efb5eec6b8ea 35 _x0(0),
el17cd 0:efb5eec6b8ea 36 _y0(0)
el17cd 0:efb5eec6b8ea 37 {}
el17cd 0:efb5eec6b8ea 38
el17cd 0:efb5eec6b8ea 39 Gamepad::~Gamepad()
el17cd 0:efb5eec6b8ea 40 {
el17cd 0:efb5eec6b8ea 41 delete _led1,_led2,_led3,_led4,_led5,_led6;
el17cd 0:efb5eec6b8ea 42 delete _button_A,_button_B,_button_joystick,_vert,_horiz;
el17cd 0:efb5eec6b8ea 43 delete _button_X,_button_Y,_button_back,_button_start;
el17cd 0:efb5eec6b8ea 44 delete _button_L,_button_R, _buzzer, _pot, _timeout;
el17cd 0:efb5eec6b8ea 45 }
el17cd 0:efb5eec6b8ea 46
el17cd 0:efb5eec6b8ea 47 ///////////////// public methods /////////////////
el17cd 0:efb5eec6b8ea 48
el17cd 0:efb5eec6b8ea 49 void Gamepad::init()
el17cd 0:efb5eec6b8ea 50 {
el17cd 0:efb5eec6b8ea 51 leds_off();
el17cd 0:efb5eec6b8ea 52 init_buttons();
el17cd 0:efb5eec6b8ea 53
el17cd 0:efb5eec6b8ea 54 // read centred values of joystick
el17cd 0:efb5eec6b8ea 55 _x0 = _horiz->read();
el17cd 0:efb5eec6b8ea 56 _y0 = _vert->read();
el17cd 0:efb5eec6b8ea 57
el17cd 0:efb5eec6b8ea 58 // clear all flags
el17cd 0:efb5eec6b8ea 59 _event_state = 0;
el17cd 0:efb5eec6b8ea 60 }
el17cd 0:efb5eec6b8ea 61
el17cd 0:efb5eec6b8ea 62 void Gamepad::leds_off()
el17cd 0:efb5eec6b8ea 63 {
el17cd 0:efb5eec6b8ea 64 leds(0.0);
el17cd 0:efb5eec6b8ea 65 }
el17cd 0:efb5eec6b8ea 66
el17cd 0:efb5eec6b8ea 67 void Gamepad::leds_on()
el17cd 0:efb5eec6b8ea 68 {
el17cd 0:efb5eec6b8ea 69 leds(1.0);
el17cd 0:efb5eec6b8ea 70 }
el17cd 0:efb5eec6b8ea 71
el17cd 0:efb5eec6b8ea 72 void Gamepad::leds(float val) const
el17cd 0:efb5eec6b8ea 73 {
el17cd 0:efb5eec6b8ea 74 if (val < 0.0f) {
el17cd 0:efb5eec6b8ea 75 val = 0.0f;
el17cd 0:efb5eec6b8ea 76 }
el17cd 0:efb5eec6b8ea 77 if (val > 1.0f) {
el17cd 0:efb5eec6b8ea 78 val = 1.0f;
el17cd 0:efb5eec6b8ea 79 }
el17cd 0:efb5eec6b8ea 80
el17cd 0:efb5eec6b8ea 81 // leds are active-low, so subtract from 1.0
el17cd 0:efb5eec6b8ea 82 // 0.0 corresponds to fully-off, 1.0 to fully-on
el17cd 0:efb5eec6b8ea 83 val = 1.0f - val;
el17cd 0:efb5eec6b8ea 84
el17cd 0:efb5eec6b8ea 85 _led1->write(val);
el17cd 0:efb5eec6b8ea 86 _led2->write(val);
el17cd 0:efb5eec6b8ea 87 _led3->write(val);
el17cd 0:efb5eec6b8ea 88 _led4->write(val);
el17cd 0:efb5eec6b8ea 89 _led5->write(val);
el17cd 0:efb5eec6b8ea 90 _led6->write(val);
el17cd 0:efb5eec6b8ea 91 }
el17cd 0:efb5eec6b8ea 92
el17cd 0:efb5eec6b8ea 93 void Gamepad::led(int n,float val) const
el17cd 0:efb5eec6b8ea 94 {
el17cd 0:efb5eec6b8ea 95 // ensure they are within vlaid range
el17cd 0:efb5eec6b8ea 96 if (val < 0.0f) {
el17cd 0:efb5eec6b8ea 97 val = 0.0f;
el17cd 0:efb5eec6b8ea 98 }
el17cd 0:efb5eec6b8ea 99 if (val > 1.0f) {
el17cd 0:efb5eec6b8ea 100 val = 1.0f;
el17cd 0:efb5eec6b8ea 101 }
el17cd 0:efb5eec6b8ea 102
el17cd 0:efb5eec6b8ea 103 switch (n) {
el17cd 0:efb5eec6b8ea 104
el17cd 0:efb5eec6b8ea 105 // check for valid LED number and set value
el17cd 0:efb5eec6b8ea 106
el17cd 0:efb5eec6b8ea 107 case 1:
el17cd 0:efb5eec6b8ea 108 _led1->write(1.0f-val); // active-low so subtract from 1
el17cd 0:efb5eec6b8ea 109 break;
el17cd 0:efb5eec6b8ea 110 case 2:
el17cd 0:efb5eec6b8ea 111 _led2->write(1.0f-val); // active-low so subtract from 1
el17cd 0:efb5eec6b8ea 112 break;
el17cd 0:efb5eec6b8ea 113 case 3:
el17cd 0:efb5eec6b8ea 114 _led3->write(1.0f-val); // active-low so subtract from 1
el17cd 0:efb5eec6b8ea 115 break;
el17cd 0:efb5eec6b8ea 116 case 4:
el17cd 0:efb5eec6b8ea 117 _led4->write(1.0f-val); // active-low so subtract from 1
el17cd 0:efb5eec6b8ea 118 break;
el17cd 0:efb5eec6b8ea 119 case 5:
el17cd 0:efb5eec6b8ea 120 _led5->write(1.0f-val); // active-low so subtract from 1
el17cd 0:efb5eec6b8ea 121 break;
el17cd 0:efb5eec6b8ea 122 case 6:
el17cd 0:efb5eec6b8ea 123 _led6->write(1.0f-val); // active-low so subtract from 1
el17cd 0:efb5eec6b8ea 124 break;
el17cd 0:efb5eec6b8ea 125
el17cd 0:efb5eec6b8ea 126 }
el17cd 0:efb5eec6b8ea 127 }
el17cd 0:efb5eec6b8ea 128
el17cd 0:efb5eec6b8ea 129 float Gamepad::read_pot() const
el17cd 0:efb5eec6b8ea 130 {
el17cd 0:efb5eec6b8ea 131 return _pot->read();
el17cd 0:efb5eec6b8ea 132 }
el17cd 0:efb5eec6b8ea 133
el17cd 0:efb5eec6b8ea 134 void Gamepad::tone(float frequency, float duration)
el17cd 0:efb5eec6b8ea 135 {
el17cd 0:efb5eec6b8ea 136 _buzzer->period(1.0f/frequency);
el17cd 0:efb5eec6b8ea 137 _buzzer->write(0.5); // 50% duty cycle - square wave
el17cd 0:efb5eec6b8ea 138 _timeout->attach(callback(this, &Gamepad::tone_off), duration );
el17cd 0:efb5eec6b8ea 139 }
el17cd 0:efb5eec6b8ea 140
el17cd 0:efb5eec6b8ea 141 bool Gamepad::check_event(GamepadEvent const id)
el17cd 0:efb5eec6b8ea 142 {
el17cd 0:efb5eec6b8ea 143 // Check whether event flag is set
el17cd 0:efb5eec6b8ea 144 if (_event_state[id]) {
el17cd 0:efb5eec6b8ea 145 _event_state.reset(id); // clear flag
el17cd 0:efb5eec6b8ea 146 return true;
el17cd 0:efb5eec6b8ea 147 } else {
el17cd 0:efb5eec6b8ea 148 return false;
el17cd 0:efb5eec6b8ea 149 }
el17cd 0:efb5eec6b8ea 150 }
el17cd 0:efb5eec6b8ea 151
el17cd 0:efb5eec6b8ea 152 // this method gets the magnitude of the joystick movement
el17cd 0:efb5eec6b8ea 153 float Gamepad::get_mag()
el17cd 0:efb5eec6b8ea 154 {
el17cd 0:efb5eec6b8ea 155 Polar p = get_polar();
el17cd 0:efb5eec6b8ea 156 return p.mag;
el17cd 0:efb5eec6b8ea 157 }
el17cd 0:efb5eec6b8ea 158
el17cd 0:efb5eec6b8ea 159 // this method gets the angle of joystick movement (0 to 360, 0 North)
el17cd 0:efb5eec6b8ea 160 float Gamepad::get_angle()
el17cd 0:efb5eec6b8ea 161 {
el17cd 0:efb5eec6b8ea 162 Polar p = get_polar();
el17cd 0:efb5eec6b8ea 163 return p.angle;
el17cd 0:efb5eec6b8ea 164 }
el17cd 0:efb5eec6b8ea 165
el17cd 0:efb5eec6b8ea 166 Direction Gamepad::get_direction()
el17cd 0:efb5eec6b8ea 167 {
el17cd 0:efb5eec6b8ea 168 float angle = get_angle(); // 0 to 360, -1 for centred
el17cd 0:efb5eec6b8ea 169
el17cd 0:efb5eec6b8ea 170 Direction d;
el17cd 0:efb5eec6b8ea 171 // partition 360 into segments and check which segment the angle is in
el17cd 0:efb5eec6b8ea 172 if (angle < 0.0f) {
el17cd 0:efb5eec6b8ea 173 d = CENTRE; // check for -1.0 angle
el17cd 0:efb5eec6b8ea 174 } else if (angle < 22.5f) { // then keep going in 45 degree increments
el17cd 0:efb5eec6b8ea 175 d = N;
el17cd 0:efb5eec6b8ea 176 } else if (angle < 67.5f) {
el17cd 0:efb5eec6b8ea 177 d = NE;
el17cd 0:efb5eec6b8ea 178 } else if (angle < 112.5f) {
el17cd 0:efb5eec6b8ea 179 d = E;
el17cd 0:efb5eec6b8ea 180 } else if (angle < 157.5f) {
el17cd 0:efb5eec6b8ea 181 d = SE;
el17cd 0:efb5eec6b8ea 182 } else if (angle < 202.5f) {
el17cd 0:efb5eec6b8ea 183 d = S;
el17cd 0:efb5eec6b8ea 184 } else if (angle < 247.5f) {
el17cd 0:efb5eec6b8ea 185 d = SW;
el17cd 0:efb5eec6b8ea 186 } else if (angle < 292.5f) {
el17cd 0:efb5eec6b8ea 187 d = W;
el17cd 0:efb5eec6b8ea 188 } else if (angle < 337.5f) {
el17cd 0:efb5eec6b8ea 189 d = NW;
el17cd 0:efb5eec6b8ea 190 } else {
el17cd 0:efb5eec6b8ea 191 d = N;
el17cd 0:efb5eec6b8ea 192 }
el17cd 0:efb5eec6b8ea 193
el17cd 0:efb5eec6b8ea 194 return d;
el17cd 0:efb5eec6b8ea 195 }
el17cd 0:efb5eec6b8ea 196
el17cd 0:efb5eec6b8ea 197 ///////////////////// private methods ////////////////////////
el17cd 0:efb5eec6b8ea 198
el17cd 0:efb5eec6b8ea 199 void Gamepad::tone_off()
el17cd 0:efb5eec6b8ea 200 {
el17cd 0:efb5eec6b8ea 201 // called after timeout
el17cd 0:efb5eec6b8ea 202 _buzzer->write(0.0);
el17cd 0:efb5eec6b8ea 203 }
el17cd 0:efb5eec6b8ea 204
el17cd 0:efb5eec6b8ea 205 void Gamepad::init_buttons()
el17cd 0:efb5eec6b8ea 206 {
el17cd 0:efb5eec6b8ea 207 // turn on pull-downs as other side of button is connected to 3V3
el17cd 0:efb5eec6b8ea 208 // button is 0 when not pressed and 1 when pressed
el17cd 0:efb5eec6b8ea 209 _button_A->mode(PullDown);
el17cd 0:efb5eec6b8ea 210 _button_B->mode(PullDown);
el17cd 0:efb5eec6b8ea 211 _button_X->mode(PullDown);
el17cd 0:efb5eec6b8ea 212 _button_Y->mode(PullDown);
el17cd 0:efb5eec6b8ea 213 _button_back->mode(PullDown);
el17cd 0:efb5eec6b8ea 214 _button_start->mode(PullDown);
el17cd 0:efb5eec6b8ea 215 _button_L->mode(PullDown);
el17cd 0:efb5eec6b8ea 216 _button_R->mode(PullDown);
el17cd 0:efb5eec6b8ea 217 _button_joystick->mode(PullDown);
el17cd 0:efb5eec6b8ea 218 // therefore setup rising edge interrupts
el17cd 0:efb5eec6b8ea 219 _button_A->rise(callback(this,&Gamepad::a_isr));
el17cd 0:efb5eec6b8ea 220 _button_B->rise(callback(this,&Gamepad::b_isr));
el17cd 0:efb5eec6b8ea 221 _button_X->rise(callback(this,&Gamepad::x_isr));
el17cd 0:efb5eec6b8ea 222 _button_Y->rise(callback(this,&Gamepad::y_isr));
el17cd 0:efb5eec6b8ea 223 _button_L->rise(callback(this,&Gamepad::l_isr));
el17cd 0:efb5eec6b8ea 224 _button_R->rise(callback(this,&Gamepad::r_isr));
el17cd 0:efb5eec6b8ea 225 _button_start->rise(callback(this,&Gamepad::start_isr));
el17cd 0:efb5eec6b8ea 226 _button_back->rise(callback(this,&Gamepad::back_isr));
el17cd 0:efb5eec6b8ea 227 _button_joystick->rise(callback(this,&Gamepad::joy_isr));
el17cd 0:efb5eec6b8ea 228 }
el17cd 0:efb5eec6b8ea 229
el17cd 0:efb5eec6b8ea 230 // button interrupts ISRs
el17cd 0:efb5eec6b8ea 231 // Each of these simply sets the appropriate event bit in the _event_state
el17cd 0:efb5eec6b8ea 232 // variable
el17cd 0:efb5eec6b8ea 233 void Gamepad::a_isr()
el17cd 0:efb5eec6b8ea 234 {
el17cd 0:efb5eec6b8ea 235 _event_state.set(A_PRESSED);
el17cd 0:efb5eec6b8ea 236 }
el17cd 0:efb5eec6b8ea 237 void Gamepad::b_isr()
el17cd 0:efb5eec6b8ea 238 {
el17cd 0:efb5eec6b8ea 239 _event_state.set(B_PRESSED);
el17cd 0:efb5eec6b8ea 240 }
el17cd 0:efb5eec6b8ea 241 void Gamepad::x_isr()
el17cd 0:efb5eec6b8ea 242 {
el17cd 0:efb5eec6b8ea 243 _event_state.set(X_PRESSED);
el17cd 0:efb5eec6b8ea 244 }
el17cd 0:efb5eec6b8ea 245 void Gamepad::y_isr()
el17cd 0:efb5eec6b8ea 246 {
el17cd 0:efb5eec6b8ea 247 _event_state.set(Y_PRESSED);
el17cd 0:efb5eec6b8ea 248 }
el17cd 0:efb5eec6b8ea 249 void Gamepad::l_isr()
el17cd 0:efb5eec6b8ea 250 {
el17cd 0:efb5eec6b8ea 251 _event_state.set(L_PRESSED);
el17cd 0:efb5eec6b8ea 252 }
el17cd 0:efb5eec6b8ea 253 void Gamepad::r_isr()
el17cd 0:efb5eec6b8ea 254 {
el17cd 0:efb5eec6b8ea 255 _event_state.set(R_PRESSED);
el17cd 0:efb5eec6b8ea 256 }
el17cd 0:efb5eec6b8ea 257 void Gamepad::back_isr()
el17cd 0:efb5eec6b8ea 258 {
el17cd 0:efb5eec6b8ea 259 _event_state.set(BACK_PRESSED);
el17cd 0:efb5eec6b8ea 260 }
el17cd 0:efb5eec6b8ea 261 void Gamepad::start_isr()
el17cd 0:efb5eec6b8ea 262 {
el17cd 0:efb5eec6b8ea 263 _event_state.set(START_PRESSED);
el17cd 0:efb5eec6b8ea 264 }
el17cd 0:efb5eec6b8ea 265 void Gamepad::joy_isr()
el17cd 0:efb5eec6b8ea 266 {
el17cd 0:efb5eec6b8ea 267 _event_state.set(JOY_PRESSED);
el17cd 0:efb5eec6b8ea 268 }
el17cd 0:efb5eec6b8ea 269
el17cd 0:efb5eec6b8ea 270 // get raw joystick coordinate in range -1 to 1
el17cd 0:efb5eec6b8ea 271 // Direction (x,y)
el17cd 0:efb5eec6b8ea 272 // North (0,1)
el17cd 0:efb5eec6b8ea 273 // East (1,0)
el17cd 0:efb5eec6b8ea 274 // South (0,-1)
el17cd 0:efb5eec6b8ea 275 // West (-1,0)
el17cd 0:efb5eec6b8ea 276 Vector2D Gamepad::get_coord()
el17cd 0:efb5eec6b8ea 277 {
el17cd 0:efb5eec6b8ea 278 // read() returns value in range 0.0 to 1.0 so is scaled and centre value
el17cd 0:efb5eec6b8ea 279 // substracted to get values in the range -1.0 to 1.0
el17cd 0:efb5eec6b8ea 280 float x = 2.0f*( _horiz->read() - _x0 );
el17cd 0:efb5eec6b8ea 281 float y = 2.0f*( _vert->read() - _y0 );
el17cd 0:efb5eec6b8ea 282
el17cd 0:efb5eec6b8ea 283 // Note: the x value here is inverted to ensure the positive x is to the
el17cd 0:efb5eec6b8ea 284 // right. This is simply due to how the potentiometer on the joystick
el17cd 0:efb5eec6b8ea 285 // I was using was connected up. It could have been corrected in hardware
el17cd 0:efb5eec6b8ea 286 // by swapping the power supply pins. Instead it is done in software so may
el17cd 0:efb5eec6b8ea 287 // need to be changed depending on your wiring setup
el17cd 0:efb5eec6b8ea 288
el17cd 0:efb5eec6b8ea 289 Vector2D coord = {-x,y};
el17cd 0:efb5eec6b8ea 290 return coord;
el17cd 0:efb5eec6b8ea 291 }
el17cd 0:efb5eec6b8ea 292
el17cd 0:efb5eec6b8ea 293 // This maps the raw x,y coord onto a circular grid.
el17cd 0:efb5eec6b8ea 294 // See: http://mathproofs.blogspot.co.uk/2005/07/mapping-square-to-circle.html
el17cd 0:efb5eec6b8ea 295 Vector2D Gamepad::get_mapped_coord()
el17cd 0:efb5eec6b8ea 296 {
el17cd 0:efb5eec6b8ea 297 Vector2D coord = get_coord();
el17cd 0:efb5eec6b8ea 298
el17cd 0:efb5eec6b8ea 299 // do the transformation
el17cd 0:efb5eec6b8ea 300 float x = coord.x*sqrt(1.0f-pow(coord.y,2.0f)/2.0f);
el17cd 0:efb5eec6b8ea 301 float y = coord.y*sqrt(1.0f-pow(coord.x,2.0f)/2.0f);
el17cd 0:efb5eec6b8ea 302
el17cd 0:efb5eec6b8ea 303 Vector2D mapped_coord = {x,y};
el17cd 0:efb5eec6b8ea 304 return mapped_coord;
el17cd 0:efb5eec6b8ea 305 }
el17cd 0:efb5eec6b8ea 306
el17cd 0:efb5eec6b8ea 307 // this function converts the mapped coordinates into polar form
el17cd 0:efb5eec6b8ea 308 Polar Gamepad::get_polar()
el17cd 0:efb5eec6b8ea 309 {
el17cd 0:efb5eec6b8ea 310 // get the mapped coordinate
el17cd 0:efb5eec6b8ea 311 Vector2D coord = get_mapped_coord();
el17cd 0:efb5eec6b8ea 312
el17cd 0:efb5eec6b8ea 313 // at this point, 0 degrees (i.e. x-axis) will be defined to the East.
el17cd 0:efb5eec6b8ea 314 // We want 0 degrees to correspond to North and increase clockwise to 359
el17cd 0:efb5eec6b8ea 315 // like a compass heading, so we need to swap the axis and invert y
el17cd 0:efb5eec6b8ea 316 float x = coord.y;
el17cd 0:efb5eec6b8ea 317 float y = coord.x;
el17cd 0:efb5eec6b8ea 318
el17cd 0:efb5eec6b8ea 319 float mag = sqrt(x*x+y*y); // pythagoras
el17cd 0:efb5eec6b8ea 320 float angle = RAD2DEG*atan2(y,x);
el17cd 0:efb5eec6b8ea 321 // angle will be in range -180 to 180, so add 360 to negative angles to
el17cd 0:efb5eec6b8ea 322 // move to 0 to 360 range
el17cd 0:efb5eec6b8ea 323 if (angle < 0.0f) {
el17cd 0:efb5eec6b8ea 324 angle+=360.0f;
el17cd 0:efb5eec6b8ea 325 }
el17cd 0:efb5eec6b8ea 326
el17cd 0:efb5eec6b8ea 327 // the noise on the ADC causes the values of x and y to fluctuate slightly
el17cd 0:efb5eec6b8ea 328 // around the centred values. This causes the random angle values to get
el17cd 0:efb5eec6b8ea 329 // calculated when the joystick is centred and untouched. This is also when
el17cd 0:efb5eec6b8ea 330 // the magnitude is very small, so we can check for a small magnitude and then
el17cd 0:efb5eec6b8ea 331 // set the angle to -1. This will inform us when the angle is invalid and the
el17cd 0:efb5eec6b8ea 332 // joystick is centred
el17cd 0:efb5eec6b8ea 333
el17cd 0:efb5eec6b8ea 334 if (mag < TOL) {
el17cd 0:efb5eec6b8ea 335 mag = 0.0f;
el17cd 0:efb5eec6b8ea 336 angle = -1.0f;
el17cd 0:efb5eec6b8ea 337 }
el17cd 0:efb5eec6b8ea 338
el17cd 0:efb5eec6b8ea 339 Polar p = {mag,angle};
el17cd 0:efb5eec6b8ea 340 return p;
el17cd 0:efb5eec6b8ea 341 }