harry rance / Mbed 2 deprecated Revised_Space_Invaders

Harry Rance 200925395 Embedded Systems Project

Dependencies:   mbed

Gamepad.cpp@2:50feb42b982c, 2017-04-26 (annotated)

Committer:
harryrance
Date:
Wed Apr 26 17:40:17 2017 +0000
Revision:
2:50feb42b982c
Parent:
0:c9bf674fe0c7 
Game engine complete. Boss fight implemented (very hard!) and end game screen characteristics change depending on whether you defeated the boss or the boss defeated you.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
harryrance 0:c9bf674fe0c7 1 #include "Gamepad.h"
harryrance 0:c9bf674fe0c7 2
harryrance 0:c9bf674fe0c7 3 #include "mbed.h"
harryrance 0:c9bf674fe0c7 4
harryrance 0:c9bf674fe0c7 5 //////////// constructor/destructor ////////////
harryrance 0:c9bf674fe0c7 6 Gamepad::Gamepad()
harryrance 0:c9bf674fe0c7 7 :
harryrance 0:c9bf674fe0c7 8 _led1(new PwmOut(PTA1)),
harryrance 0:c9bf674fe0c7 9 _led2(new PwmOut(PTA2)),
harryrance 0:c9bf674fe0c7 10 _led3(new PwmOut(PTC2)),
harryrance 0:c9bf674fe0c7 11 _led4(new PwmOut(PTC3)),
harryrance 0:c9bf674fe0c7 12 _led5(new PwmOut(PTC4)),
harryrance 0:c9bf674fe0c7 13 _led6(new PwmOut(PTD3)),
harryrance 0:c9bf674fe0c7 14
harryrance 0:c9bf674fe0c7 15 _button_A(new InterruptIn(PTB9)),
harryrance 0:c9bf674fe0c7 16 _button_B(new InterruptIn(PTD0)),
harryrance 0:c9bf674fe0c7 17 _button_X(new InterruptIn(PTC17)),
harryrance 0:c9bf674fe0c7 18 _button_Y(new InterruptIn(PTC12)),
harryrance 0:c9bf674fe0c7 19 _button_L(new InterruptIn(PTB18)),
harryrance 0:c9bf674fe0c7 20 _button_R(new InterruptIn(PTB3)),
harryrance 0:c9bf674fe0c7 21 _button_back(new InterruptIn(PTB19)),
harryrance 0:c9bf674fe0c7 22 _button_start(new InterruptIn(PTC5)),
harryrance 0:c9bf674fe0c7 23 _button_joystick(new InterruptIn(PTC16)),
harryrance 0:c9bf674fe0c7 24
harryrance 0:c9bf674fe0c7 25 _vert(new AnalogIn(PTB10)),
harryrance 0:c9bf674fe0c7 26 _horiz(new AnalogIn(PTB11)),
harryrance 0:c9bf674fe0c7 27
harryrance 0:c9bf674fe0c7 28 _buzzer(new PwmOut(PTC10)),
harryrance 0:c9bf674fe0c7 29 _pot(new AnalogIn(PTB2)),
harryrance 0:c9bf674fe0c7 30
harryrance 0:c9bf674fe0c7 31 _timeout(new Timeout()),
harryrance 0:c9bf674fe0c7 32
harryrance 0:c9bf674fe0c7 33 _event_state(0),
harryrance 0:c9bf674fe0c7 34
harryrance 0:c9bf674fe0c7 35 _x0(0),
harryrance 0:c9bf674fe0c7 36 _y0(0)
harryrance 0:c9bf674fe0c7 37 {}
harryrance 0:c9bf674fe0c7 38
harryrance 0:c9bf674fe0c7 39 Gamepad::~Gamepad()
harryrance 0:c9bf674fe0c7 40 {
harryrance 0:c9bf674fe0c7 41 delete _led1,_led2,_led3,_led4,_led5,_led6;
harryrance 0:c9bf674fe0c7 42 delete _button_A,_button_B,_button_joystick,_vert,_horiz;
harryrance 0:c9bf674fe0c7 43 delete _button_X,_button_Y,_button_back,_button_start;
harryrance 0:c9bf674fe0c7 44 delete _button_L,_button_R, _buzzer, _pot, _timeout;
harryrance 0:c9bf674fe0c7 45 }
harryrance 0:c9bf674fe0c7 46
harryrance 0:c9bf674fe0c7 47 ///////////////// public methods /////////////////
harryrance 0:c9bf674fe0c7 48
harryrance 0:c9bf674fe0c7 49 void Gamepad::init()
harryrance 0:c9bf674fe0c7 50 {
harryrance 0:c9bf674fe0c7 51 leds_off();
harryrance 0:c9bf674fe0c7 52 init_buttons();
harryrance 0:c9bf674fe0c7 53
harryrance 0:c9bf674fe0c7 54 // read centred values of joystick
harryrance 0:c9bf674fe0c7 55 _x0 = _horiz->read();
harryrance 0:c9bf674fe0c7 56 _y0 = _vert->read();
harryrance 0:c9bf674fe0c7 57
harryrance 0:c9bf674fe0c7 58 // clear all flags
harryrance 0:c9bf674fe0c7 59 _event_state = 0;
harryrance 0:c9bf674fe0c7 60 }
harryrance 0:c9bf674fe0c7 61
harryrance 0:c9bf674fe0c7 62 void Gamepad::leds_off()
harryrance 0:c9bf674fe0c7 63 {
harryrance 0:c9bf674fe0c7 64 leds(0.0);
harryrance 0:c9bf674fe0c7 65 }
harryrance 0:c9bf674fe0c7 66
harryrance 0:c9bf674fe0c7 67 void Gamepad::leds_on()
harryrance 0:c9bf674fe0c7 68 {
harryrance 0:c9bf674fe0c7 69 leds(1.0);
harryrance 0:c9bf674fe0c7 70 }
harryrance 0:c9bf674fe0c7 71
harryrance 0:c9bf674fe0c7 72 void Gamepad::leds(float val) const
harryrance 0:c9bf674fe0c7 73 {
harryrance 0:c9bf674fe0c7 74 if (val < 0.0f) {
harryrance 0:c9bf674fe0c7 75 val = 0.0f;
harryrance 0:c9bf674fe0c7 76 }
harryrance 0:c9bf674fe0c7 77 if (val > 1.0f) {
harryrance 0:c9bf674fe0c7 78 val = 1.0f;
harryrance 0:c9bf674fe0c7 79 }
harryrance 0:c9bf674fe0c7 80
harryrance 0:c9bf674fe0c7 81 // leds are active-low, so subtract from 1.0
harryrance 0:c9bf674fe0c7 82 // 0.0 corresponds to fully-off, 1.0 to fully-on
harryrance 0:c9bf674fe0c7 83 val = 1.0f - val;
harryrance 0:c9bf674fe0c7 84
harryrance 0:c9bf674fe0c7 85 _led1->write(val);
harryrance 0:c9bf674fe0c7 86 _led2->write(val);
harryrance 0:c9bf674fe0c7 87 _led3->write(val);
harryrance 0:c9bf674fe0c7 88 _led4->write(val);
harryrance 0:c9bf674fe0c7 89 _led5->write(val);
harryrance 0:c9bf674fe0c7 90 _led6->write(val);
harryrance 0:c9bf674fe0c7 91 }
harryrance 0:c9bf674fe0c7 92
harryrance 0:c9bf674fe0c7 93 void Gamepad::led(int n,float val) const
harryrance 0:c9bf674fe0c7 94 {
harryrance 0:c9bf674fe0c7 95 // ensure they are within vlaid range
harryrance 0:c9bf674fe0c7 96 if (val < 0.0f) {
harryrance 0:c9bf674fe0c7 97 val = 0.0f;
harryrance 0:c9bf674fe0c7 98 }
harryrance 0:c9bf674fe0c7 99 if (val > 1.0f) {
harryrance 0:c9bf674fe0c7 100 val = 1.0f;
harryrance 0:c9bf674fe0c7 101 }
harryrance 2:50feb42b982c 102
harryrance 0:c9bf674fe0c7 103 switch (n) {
harryrance 2:50feb42b982c 104
harryrance 0:c9bf674fe0c7 105 // check for valid LED number and set value
harryrance 0:c9bf674fe0c7 106
harryrance 0:c9bf674fe0c7 107 case 1:
harryrance 0:c9bf674fe0c7 108 _led1->write(1.0f-val); // active-low so subtract from 1
harryrance 0:c9bf674fe0c7 109 break;
harryrance 0:c9bf674fe0c7 110 case 2:
harryrance 0:c9bf674fe0c7 111 _led2->write(1.0f-val); // active-low so subtract from 1
harryrance 0:c9bf674fe0c7 112 break;
harryrance 0:c9bf674fe0c7 113 case 3:
harryrance 0:c9bf674fe0c7 114 _led3->write(1.0f-val); // active-low so subtract from 1
harryrance 0:c9bf674fe0c7 115 break;
harryrance 0:c9bf674fe0c7 116 case 4:
harryrance 0:c9bf674fe0c7 117 _led4->write(1.0f-val); // active-low so subtract from 1
harryrance 0:c9bf674fe0c7 118 break;
harryrance 0:c9bf674fe0c7 119 case 5:
harryrance 0:c9bf674fe0c7 120 _led5->write(1.0f-val); // active-low so subtract from 1
harryrance 0:c9bf674fe0c7 121 break;
harryrance 0:c9bf674fe0c7 122 case 6:
harryrance 0:c9bf674fe0c7 123 _led6->write(1.0f-val); // active-low so subtract from 1
harryrance 0:c9bf674fe0c7 124 break;
harryrance 0:c9bf674fe0c7 125
harryrance 0:c9bf674fe0c7 126 }
harryrance 0:c9bf674fe0c7 127 }
harryrance 0:c9bf674fe0c7 128
harryrance 0:c9bf674fe0c7 129 float Gamepad::read_pot() const
harryrance 0:c9bf674fe0c7 130 {
harryrance 0:c9bf674fe0c7 131 return _pot->read();
harryrance 0:c9bf674fe0c7 132 }
harryrance 0:c9bf674fe0c7 133
harryrance 0:c9bf674fe0c7 134 void Gamepad::tone(float frequency, float duration)
harryrance 0:c9bf674fe0c7 135 {
harryrance 0:c9bf674fe0c7 136 _buzzer->period(1.0f/frequency);
harryrance 0:c9bf674fe0c7 137 _buzzer->write(0.5); // 50% duty cycle - square wave
harryrance 0:c9bf674fe0c7 138 _timeout->attach(callback(this, &Gamepad::tone_off), duration );
harryrance 0:c9bf674fe0c7 139 }
harryrance 0:c9bf674fe0c7 140
harryrance 0:c9bf674fe0c7 141 bool Gamepad::check_event(GamepadEvent const id)
harryrance 0:c9bf674fe0c7 142 {
harryrance 0:c9bf674fe0c7 143 // Check whether event flag is set
harryrance 0:c9bf674fe0c7 144 if (_event_state[id]) {
harryrance 0:c9bf674fe0c7 145 _event_state.reset(id); // clear flag
harryrance 0:c9bf674fe0c7 146 return true;
harryrance 0:c9bf674fe0c7 147 } else {
harryrance 0:c9bf674fe0c7 148 return false;
harryrance 0:c9bf674fe0c7 149 }
harryrance 0:c9bf674fe0c7 150 }
harryrance 0:c9bf674fe0c7 151
harryrance 0:c9bf674fe0c7 152 // this method gets the magnitude of the joystick movement
harryrance 0:c9bf674fe0c7 153 float Gamepad::get_mag()
harryrance 0:c9bf674fe0c7 154 {
harryrance 0:c9bf674fe0c7 155 Polar p = get_polar();
harryrance 0:c9bf674fe0c7 156 return p.mag;
harryrance 0:c9bf674fe0c7 157 }
harryrance 0:c9bf674fe0c7 158
harryrance 0:c9bf674fe0c7 159 // this method gets the angle of joystick movement (0 to 360, 0 North)
harryrance 0:c9bf674fe0c7 160 float Gamepad::get_angle()
harryrance 0:c9bf674fe0c7 161 {
harryrance 0:c9bf674fe0c7 162 Polar p = get_polar();
harryrance 0:c9bf674fe0c7 163 return p.angle;
harryrance 0:c9bf674fe0c7 164 }
harryrance 0:c9bf674fe0c7 165
harryrance 0:c9bf674fe0c7 166 Direction Gamepad::get_direction()
harryrance 0:c9bf674fe0c7 167 {
harryrance 0:c9bf674fe0c7 168 float angle = get_angle(); // 0 to 360, -1 for centred
harryrance 0:c9bf674fe0c7 169
harryrance 0:c9bf674fe0c7 170 Direction d;
harryrance 0:c9bf674fe0c7 171 // partition 360 into segments and check which segment the angle is in
harryrance 0:c9bf674fe0c7 172 if (angle < 0.0f) {
harryrance 0:c9bf674fe0c7 173 d = CENTRE; // check for -1.0 angle
harryrance 0:c9bf674fe0c7 174 } else if (angle < 22.5f) { // then keep going in 45 degree increments
harryrance 0:c9bf674fe0c7 175 d = N;
harryrance 0:c9bf674fe0c7 176 } else if (angle < 67.5f) {
harryrance 0:c9bf674fe0c7 177 d = NE;
harryrance 0:c9bf674fe0c7 178 } else if (angle < 112.5f) {
harryrance 0:c9bf674fe0c7 179 d = E;
harryrance 0:c9bf674fe0c7 180 } else if (angle < 157.5f) {
harryrance 0:c9bf674fe0c7 181 d = SE;
harryrance 0:c9bf674fe0c7 182 } else if (angle < 202.5f) {
harryrance 0:c9bf674fe0c7 183 d = S;
harryrance 0:c9bf674fe0c7 184 } else if (angle < 247.5f) {
harryrance 0:c9bf674fe0c7 185 d = SW;
harryrance 0:c9bf674fe0c7 186 } else if (angle < 292.5f) {
harryrance 0:c9bf674fe0c7 187 d = W;
harryrance 0:c9bf674fe0c7 188 } else if (angle < 337.5f) {
harryrance 0:c9bf674fe0c7 189 d = NW;
harryrance 0:c9bf674fe0c7 190 } else {
harryrance 0:c9bf674fe0c7 191 d = N;
harryrance 0:c9bf674fe0c7 192 }
harryrance 0:c9bf674fe0c7 193
harryrance 0:c9bf674fe0c7 194 return d;
harryrance 0:c9bf674fe0c7 195 }
harryrance 0:c9bf674fe0c7 196
harryrance 0:c9bf674fe0c7 197 ///////////////////// private methods ////////////////////////
harryrance 0:c9bf674fe0c7 198
harryrance 0:c9bf674fe0c7 199 void Gamepad::tone_off()
harryrance 0:c9bf674fe0c7 200 {
harryrance 0:c9bf674fe0c7 201 // called after timeout
harryrance 0:c9bf674fe0c7 202 _buzzer->write(0.0);
harryrance 0:c9bf674fe0c7 203 }
harryrance 0:c9bf674fe0c7 204
harryrance 0:c9bf674fe0c7 205 void Gamepad::init_buttons()
harryrance 0:c9bf674fe0c7 206 {
harryrance 0:c9bf674fe0c7 207 // turn on pull-downs as other side of button is connected to 3V3
harryrance 0:c9bf674fe0c7 208 // button is 0 when not pressed and 1 when pressed
harryrance 0:c9bf674fe0c7 209 _button_A->mode(PullDown);
harryrance 0:c9bf674fe0c7 210 _button_B->mode(PullDown);
harryrance 0:c9bf674fe0c7 211 _button_X->mode(PullDown);
harryrance 0:c9bf674fe0c7 212 _button_Y->mode(PullDown);
harryrance 0:c9bf674fe0c7 213 _button_back->mode(PullDown);
harryrance 0:c9bf674fe0c7 214 _button_start->mode(PullDown);
harryrance 0:c9bf674fe0c7 215 _button_L->mode(PullDown);
harryrance 0:c9bf674fe0c7 216 _button_R->mode(PullDown);
harryrance 0:c9bf674fe0c7 217 _button_joystick->mode(PullDown);
harryrance 0:c9bf674fe0c7 218 // therefore setup rising edge interrupts
harryrance 0:c9bf674fe0c7 219 _button_A->rise(callback(this,&Gamepad::a_isr));
harryrance 0:c9bf674fe0c7 220 _button_B->rise(callback(this,&Gamepad::b_isr));
harryrance 0:c9bf674fe0c7 221 _button_X->rise(callback(this,&Gamepad::x_isr));
harryrance 0:c9bf674fe0c7 222 _button_Y->rise(callback(this,&Gamepad::y_isr));
harryrance 0:c9bf674fe0c7 223 _button_L->rise(callback(this,&Gamepad::l_isr));
harryrance 0:c9bf674fe0c7 224 _button_R->rise(callback(this,&Gamepad::r_isr));
harryrance 0:c9bf674fe0c7 225 _button_start->rise(callback(this,&Gamepad::start_isr));
harryrance 0:c9bf674fe0c7 226 _button_back->rise(callback(this,&Gamepad::back_isr));
harryrance 0:c9bf674fe0c7 227 _button_joystick->rise(callback(this,&Gamepad::joy_isr));
harryrance 0:c9bf674fe0c7 228 }
harryrance 0:c9bf674fe0c7 229
harryrance 0:c9bf674fe0c7 230 // button interrupts ISRs
harryrance 0:c9bf674fe0c7 231 // Each of these simply sets the appropriate event bit in the _event_state
harryrance 0:c9bf674fe0c7 232 // variable
harryrance 0:c9bf674fe0c7 233 void Gamepad::a_isr()
harryrance 0:c9bf674fe0c7 234 {
harryrance 0:c9bf674fe0c7 235 _event_state.set(A_PRESSED);
harryrance 0:c9bf674fe0c7 236 }
harryrance 0:c9bf674fe0c7 237 void Gamepad::b_isr()
harryrance 0:c9bf674fe0c7 238 {
harryrance 0:c9bf674fe0c7 239 _event_state.set(B_PRESSED);
harryrance 0:c9bf674fe0c7 240 }
harryrance 0:c9bf674fe0c7 241 void Gamepad::x_isr()
harryrance 0:c9bf674fe0c7 242 {
harryrance 0:c9bf674fe0c7 243 _event_state.set(X_PRESSED);
harryrance 0:c9bf674fe0c7 244 }
harryrance 0:c9bf674fe0c7 245 void Gamepad::y_isr()
harryrance 0:c9bf674fe0c7 246 {
harryrance 0:c9bf674fe0c7 247 _event_state.set(Y_PRESSED);
harryrance 0:c9bf674fe0c7 248 }
harryrance 0:c9bf674fe0c7 249 void Gamepad::l_isr()
harryrance 0:c9bf674fe0c7 250 {
harryrance 0:c9bf674fe0c7 251 _event_state.set(L_PRESSED);
harryrance 0:c9bf674fe0c7 252 }
harryrance 0:c9bf674fe0c7 253 void Gamepad::r_isr()
harryrance 0:c9bf674fe0c7 254 {
harryrance 0:c9bf674fe0c7 255 _event_state.set(R_PRESSED);
harryrance 0:c9bf674fe0c7 256 }
harryrance 0:c9bf674fe0c7 257 void Gamepad::back_isr()
harryrance 0:c9bf674fe0c7 258 {
harryrance 0:c9bf674fe0c7 259 _event_state.set(BACK_PRESSED);
harryrance 0:c9bf674fe0c7 260 }
harryrance 0:c9bf674fe0c7 261 void Gamepad::start_isr()
harryrance 0:c9bf674fe0c7 262 {
harryrance 0:c9bf674fe0c7 263 _event_state.set(START_PRESSED);
harryrance 0:c9bf674fe0c7 264 }
harryrance 0:c9bf674fe0c7 265 void Gamepad::joy_isr()
harryrance 0:c9bf674fe0c7 266 {
harryrance 0:c9bf674fe0c7 267 _event_state.set(JOY_PRESSED);
harryrance 0:c9bf674fe0c7 268 }
harryrance 0:c9bf674fe0c7 269
harryrance 0:c9bf674fe0c7 270 // get raw joystick coordinate in range -1 to 1
harryrance 0:c9bf674fe0c7 271 // Direction (x,y)
harryrance 0:c9bf674fe0c7 272 // North (0,1)
harryrance 0:c9bf674fe0c7 273 // East (1,0)
harryrance 0:c9bf674fe0c7 274 // South (0,-1)
harryrance 0:c9bf674fe0c7 275 // West (-1,0)
harryrance 0:c9bf674fe0c7 276 Vector2D Gamepad::get_coord()
harryrance 0:c9bf674fe0c7 277 {
harryrance 0:c9bf674fe0c7 278 // read() returns value in range 0.0 to 1.0 so is scaled and centre value
harryrance 0:c9bf674fe0c7 279 // substracted to get values in the range -1.0 to 1.0
harryrance 0:c9bf674fe0c7 280 float x = 2.0f*( _horiz->read() - _x0 );
harryrance 0:c9bf674fe0c7 281 float y = 2.0f*( _vert->read() - _y0 );
harryrance 0:c9bf674fe0c7 282
harryrance 0:c9bf674fe0c7 283 // Note: the x value here is inverted to ensure the positive x is to the
harryrance 0:c9bf674fe0c7 284 // right. This is simply due to how the potentiometer on the joystick
harryrance 0:c9bf674fe0c7 285 // I was using was connected up. It could have been corrected in hardware
harryrance 0:c9bf674fe0c7 286 // by swapping the power supply pins. Instead it is done in software so may
harryrance 0:c9bf674fe0c7 287 // need to be changed depending on your wiring setup
harryrance 0:c9bf674fe0c7 288
harryrance 0:c9bf674fe0c7 289 Vector2D coord = {-x,y};
harryrance 0:c9bf674fe0c7 290 return coord;
harryrance 0:c9bf674fe0c7 291 }
harryrance 0:c9bf674fe0c7 292
harryrance 0:c9bf674fe0c7 293 // This maps the raw x,y coord onto a circular grid.
harryrance 0:c9bf674fe0c7 294 // See: http://mathproofs.blogspot.co.uk/2005/07/mapping-square-to-circle.html
harryrance 0:c9bf674fe0c7 295 Vector2D Gamepad::get_mapped_coord()
harryrance 0:c9bf674fe0c7 296 {
harryrance 0:c9bf674fe0c7 297 Vector2D coord = get_coord();
harryrance 0:c9bf674fe0c7 298
harryrance 0:c9bf674fe0c7 299 // do the transformation
harryrance 0:c9bf674fe0c7 300 float x = coord.x*sqrt(1.0f-pow(coord.y,2.0f)/2.0f);
harryrance 0:c9bf674fe0c7 301 float y = coord.y*sqrt(1.0f-pow(coord.x,2.0f)/2.0f);
harryrance 0:c9bf674fe0c7 302
harryrance 0:c9bf674fe0c7 303 Vector2D mapped_coord = {x,y};
harryrance 0:c9bf674fe0c7 304 return mapped_coord;
harryrance 0:c9bf674fe0c7 305 }
harryrance 0:c9bf674fe0c7 306
harryrance 0:c9bf674fe0c7 307 // this function converts the mapped coordinates into polar form
harryrance 0:c9bf674fe0c7 308 Polar Gamepad::get_polar()
harryrance 0:c9bf674fe0c7 309 {
harryrance 0:c9bf674fe0c7 310 // get the mapped coordinate
harryrance 0:c9bf674fe0c7 311 Vector2D coord = get_mapped_coord();
harryrance 0:c9bf674fe0c7 312
harryrance 0:c9bf674fe0c7 313 // at this point, 0 degrees (i.e. x-axis) will be defined to the East.
harryrance 0:c9bf674fe0c7 314 // We want 0 degrees to correspond to North and increase clockwise to 359
harryrance 0:c9bf674fe0c7 315 // like a compass heading, so we need to swap the axis and invert y
harryrance 0:c9bf674fe0c7 316 float x = coord.y;
harryrance 0:c9bf674fe0c7 317 float y = coord.x;
harryrance 0:c9bf674fe0c7 318
harryrance 0:c9bf674fe0c7 319 float mag = sqrt(x*x+y*y); // pythagoras
harryrance 0:c9bf674fe0c7 320 float angle = RAD2DEG*atan2(y,x);
harryrance 0:c9bf674fe0c7 321 // angle will be in range -180 to 180, so add 360 to negative angles to
harryrance 0:c9bf674fe0c7 322 // move to 0 to 360 range
harryrance 0:c9bf674fe0c7 323 if (angle < 0.0f) {
harryrance 0:c9bf674fe0c7 324 angle+=360.0f;
harryrance 0:c9bf674fe0c7 325 }
harryrance 0:c9bf674fe0c7 326
harryrance 0:c9bf674fe0c7 327 // the noise on the ADC causes the values of x and y to fluctuate slightly
harryrance 0:c9bf674fe0c7 328 // around the centred values. This causes the random angle values to get
harryrance 0:c9bf674fe0c7 329 // calculated when the joystick is centred and untouched. This is also when
harryrance 0:c9bf674fe0c7 330 // the magnitude is very small, so we can check for a small magnitude and then
harryrance 0:c9bf674fe0c7 331 // set the angle to -1. This will inform us when the angle is invalid and the
harryrance 0:c9bf674fe0c7 332 // joystick is centred
harryrance 0:c9bf674fe0c7 333
harryrance 0:c9bf674fe0c7 334 if (mag < TOL) {
harryrance 0:c9bf674fe0c7 335 mag = 0.0f;
harryrance 0:c9bf674fe0c7 336 angle = -1.0f;
harryrance 0:c9bf674fe0c7 337 }
harryrance 0:c9bf674fe0c7 338
harryrance 0:c9bf674fe0c7 339 Polar p = {mag,angle};
harryrance 0:c9bf674fe0c7 340 return p;
harryrance 0:c9bf674fe0c7 341 }
harryrance 2:50feb42b982c 342