JSActionAnalog.m

   1 //
   2 //  JSActionAnalog.m
   3 //  Enjoy
   4 //
   5 //  Created by Sam McCall on 5/05/09.
   6 //
   7
   8 // TODO: Dead zone should be configurable per-device.
   9 #define DEAD_ZONE 0.3
  10
  11 #import "JSActionAnalog.h"
  12
  13 static float normalize(int p, int min, int max) {
  14     return 2 * (p - min) / (float)(max - min) - 1;
  15 }
  16
  17 @implementation JSActionAnalog {
  18     float magnitude;
  19     int rawMin;
  20     int rawMax;
  21 }
  22
  23 - (id)initWithIndex:(int)index rawMin:(int)rawMin_ rawMax:(int)rawMax_ {
  24     if ((self = [super init])) {
  25         self.name = [[NSString alloc] initWithFormat: @"Axis %d", index];
  26         self.children = @[[[JSAction alloc] initWithName:@"Low" base:self],
  27                           [[JSAction alloc] initWithName:@"High" base:self]];
  28         rawMax = rawMax_;
  29         rawMin = rawMin_;
  30     }
  31     return self;
  32 }
  33
  34 - (id)findSubActionForValue:(IOHIDValueRef)value {
  35     float mag = normalize(IOHIDValueGetIntegerValue(value), rawMin, rawMax);
  36     if (mag < -DEAD_ZONE)
  37         return self.children[0];
  38     else if (mag > DEAD_ZONE)
  39         return self.children[1];
  40     else
  41         return nil;
  42 }
  43
  44 - (void)notifyEvent:(IOHIDValueRef)value {
  45     magnitude = normalize(IOHIDValueGetIntegerValue(value), rawMin, rawMax);
  46     [self.children[0] setActive:magnitude < -DEAD_ZONE];
  47     [self.children[1] setActive:magnitude > DEAD_ZONE];
  48 }
  49
  50 - (float)magnitude {
  51     return magnitude;
  52 }
  53
  54 @end