iokit/Families/IOHIDSystem/IOHIDDescriptorParser/HIDPostProcessRIValue.c

   1 /*
   2  * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23         File:           HIDPostProcessRIValue.c
  24
  25         Contains:       xxx put contents here xxx
  26
  27         Version:        xxx put version here xxx
  28
  29         Copyright:      © 1999 by Apple Computer, Inc., all rights reserved.
  30
  31         File Ownership:
  32
  33                 DRI:                            xxx put dri here xxx
  34
  35                 Other Contact:          xxx put other contact here xxx
  36
  37                 Technology:                     xxx put technology here xxx
  38
  39         Writers:
  40
  41                 (BWS)   Brent Schorsch
  42
  43         Change History (most recent first):
  44
  45           <USB1>          4/7/99        BWS             first checked in
  46 */
  47
  48 #include "HIDLib.h"
  49
  50 /*
  51  *------------------------------------------------------------------------------
  52  *
  53  * HIDPostProcessRIValue -      performs any post-processing necessary for data
  54  *                                                      retrieved _from_ a report for the specified report
  55  *                                                      item. Currently, the only post-processing done
  56  *                                                      is reversing when appropriate
  57  *
  58  *       Input:
  59  *                        reportItem                    - The report item
  60  *                        value                                 - the value, from HIDGetData
  61  *       Output:
  62  *                        value                                 - The processed value
  63  *       Returns:
  64  *                        kHIDSuccess                   - Success
  65  *
  66  *------------------------------------------------------------------------------
  67 */
  68
  69 OSStatus HIDPostProcessRIValue (HIDReportItem *         reportItem,
  70                                                                 SInt32 *                        value)
  71 {
  72
  73         // if isReversed, returnValue = ((min - returnValue) + max)
  74         if (reportItem->flags & kHIDReportItemFlag_Reversed)
  75                 *value = ((reportItem->globals.logicalMinimum - (*value)) +
  76                                                         reportItem->globals.logicalMaximum);
  77
  78         return kHIDSuccess;
  79 }
  80
  81 /*
  82  *------------------------------------------------------------------------------
  83  *
  84  * HIDPreProcessRIValue -       performs any pre-processing necessary for data
  85  *                                                      ouput _to_ a report for the specified report
  86  *                                                      item. Currently, the only pre-processing done
  87  *                                                      is reversing when appropriate
  88  *
  89  *       Input:
  90  *                        reportItem                    - The report item
  91  *                        value                                 - the value, destined for HIDPutData
  92  *       Output:
  93  *                        value                                 - The processed value
  94  *       Returns:
  95  *                        kHIDSuccess                   - Success
  96  *
  97  *------------------------------------------------------------------------------
  98 */
  99
 100 OSStatus HIDPreProcessRIValue  (HIDReportItem *         reportItem,
 101                                                                 SInt32 *                        value)
 102 {
 103
 104         // if isReversed, returnValue = ((min - returnValue) + max)
 105         if (reportItem->flags & kHIDReportItemFlag_Reversed)
 106                 *value = ((reportItem->globals.logicalMinimum - (*value)) +
 107                                                         reportItem->globals.logicalMaximum);
 108
 109         return kHIDSuccess;
 110 }
 111
 112