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comparison src/joystick/iphoneos/SDLUIAccelerationDelegate.m @ 2439:78bddf0c0fa2 gsoc2008_iphone

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Cleaned up code, added comments.
author Holmes Futrell <hfutrell@umail.ucsb.edu>
date Fri, 15 Aug 2008 19:16:01 +0000
parents 32b9909db651
children
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2438:fe9d15725d96 2439:78bddf0c0fa2
1 // 1 /*
2 // SDLUIAccelerationDelegate.m 2 SDL - Simple DirectMedia Layer
3 // iPodSDL 3 Copyright (C) 1997-2006 Sam Lantinga
4 // 4
5 // Created by Holmes Futrell on 6/21/08. 5 This library is free software; you can redistribute it and/or
6 // Copyright 2008 __MyCompanyName__. All rights reserved. 6 modify it under the terms of the GNU Lesser General Public
7 // 7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 This library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with this library; if not, write to the Free Software
17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18
19 Sam Lantinga
20 slouken@libsdl.org
21 */
8 22
9 #import "SDLUIAccelerationDelegate.h" 23 #import "SDLUIAccelerationDelegate.h"
24 /* needed for SDL_IPHONE_MAX_GFORCE macro */
10 #import "../../../include/SDL_config_iphoneos.h" 25 #import "../../../include/SDL_config_iphoneos.h"
11 26
12 static SDLUIAccelerationDelegate *sharedDelegate=nil; 27 static SDLUIAccelerationDelegate *sharedDelegate=nil;
13 28
14 @implementation SDLUIAccelerationDelegate 29 @implementation SDLUIAccelerationDelegate
15 30
31 /*
32 Returns a shared instance of the SDLUIAccelerationDelegate, creating the shared delegate if it doesn't exist yet.
33 */
16 +(SDLUIAccelerationDelegate *)sharedDelegate { 34 +(SDLUIAccelerationDelegate *)sharedDelegate {
17 if (sharedDelegate == nil) { 35 if (sharedDelegate == nil) {
18 sharedDelegate = [[SDLUIAccelerationDelegate alloc] init]; 36 sharedDelegate = [[SDLUIAccelerationDelegate alloc] init];
19 } 37 }
20 return sharedDelegate; 38 return sharedDelegate;
21 } 39 }
22 40 /*
41 UIAccelerometerDelegate delegate method. Invoked by the UIAccelerometer instance when it has new data for us.
42 We just take the data and mark that we have new data available so that the joystick system will pump it to the
43 events system when SDL_SYS_JoystickUpdate is called.
44 */
23 -(void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration { 45 -(void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration {
24 46
25 x = acceleration.x; 47 x = acceleration.x;
26 y = acceleration.y; 48 y = acceleration.y;
27 z = acceleration.z; 49 z = acceleration.z;
28 50
29 hasNewData = YES; 51 hasNewData = YES;
30 //timestamp = acceleration.timestamp;
31
32 } 52 }
33 53 /*
54 getLastOrientation -- put last obtained accelerometer data into Sint16 array
55
56 Called from the joystick system when it needs the accelerometer data.
57 Function grabs the last data sent to the accelerometer and converts it
58 from floating point to Sint16, which is what the joystick system expects.
59
60 To do the conversion, the data is first clamped onto the interval
61 [-SDL_IPHONE_MAX_G_FORCE, SDL_IPHONE_MAX_G_FORCE], then the data is multiplied
62 by MAX_SINT16 so that it is mapped to the full range of an Sint16.
63
64 You can customize the clamped range of this function by modifying the
65 SDL_IPHONE_MAX_GFORCE macro in SDL_config_iphoneos.h.
66
67 Once converted to Sint16, the accelerometer data no longer has coherent units.
68 You can convert the data back to units of g-force by multiplying it
69 in your application's code by SDL_IPHONE_MAX_GFORCE / 0x7FFF.
70 */
34 -(void)getLastOrientation:(Sint16 *)data { 71 -(void)getLastOrientation:(Sint16 *)data {
35 72
36 #define MAX_SINT16 0x7FFF 73 #define MAX_SINT16 0x7FFF
37 74
75 /* clamp the data */
38 if (x > SDL_IPHONE_MAX_GFORCE) x = SDL_IPHONE_MAX_GFORCE; 76 if (x > SDL_IPHONE_MAX_GFORCE) x = SDL_IPHONE_MAX_GFORCE;
39 else if (x < -SDL_IPHONE_MAX_GFORCE) x = -SDL_IPHONE_MAX_GFORCE; 77 else if (x < -SDL_IPHONE_MAX_GFORCE) x = -SDL_IPHONE_MAX_GFORCE;
40
41 if (y > SDL_IPHONE_MAX_GFORCE) y = SDL_IPHONE_MAX_GFORCE; 78 if (y > SDL_IPHONE_MAX_GFORCE) y = SDL_IPHONE_MAX_GFORCE;
42 else if (y < -SDL_IPHONE_MAX_GFORCE) y = -SDL_IPHONE_MAX_GFORCE; 79 else if (y < -SDL_IPHONE_MAX_GFORCE) y = -SDL_IPHONE_MAX_GFORCE;
43
44 if (z > SDL_IPHONE_MAX_GFORCE) z = SDL_IPHONE_MAX_GFORCE; 80 if (z > SDL_IPHONE_MAX_GFORCE) z = SDL_IPHONE_MAX_GFORCE;
45 else if (z < -SDL_IPHONE_MAX_GFORCE) z = -SDL_IPHONE_MAX_GFORCE; 81 else if (z < -SDL_IPHONE_MAX_GFORCE) z = -SDL_IPHONE_MAX_GFORCE;
46 82
83 /* pass in data mapped to range of SInt16 */
47 data[0] = (x / SDL_IPHONE_MAX_GFORCE) * MAX_SINT16; 84 data[0] = (x / SDL_IPHONE_MAX_GFORCE) * MAX_SINT16;
48 data[1] = (y / SDL_IPHONE_MAX_GFORCE) * MAX_SINT16; 85 data[1] = (y / SDL_IPHONE_MAX_GFORCE) * MAX_SINT16;
49 data[2] = (z / SDL_IPHONE_MAX_GFORCE) * MAX_SINT16; 86 data[2] = (z / SDL_IPHONE_MAX_GFORCE) * MAX_SINT16;
50 87
51 } 88 }
52 89
90 /*
91 Initialize SDLUIAccelerationDelegate. Since we don't have any data yet,
92 just set our last received data to zero, and indicate we don't have any;
93 */
53 -(id)init { 94 -(id)init {
54
55 self = [super init]; 95 self = [super init];
56 x = y = z = 0.0; 96 x = y = z = 0.0;
97 hasNewData = NO;
57 return self; 98 return self;
58
59 } 99 }
60 100
61 -(void)dealloc { 101 -(void)dealloc {
62 sharedDelegate = nil; 102 sharedDelegate = nil;
103 [self shutdown];
63 [super dealloc]; 104 [super dealloc];
64 } 105 }
65 106
107 /*
108 Lets our delegate start receiving accelerometer updates.
109 */
66 -(void)startup { 110 -(void)startup {
67 [UIAccelerometer sharedAccelerometer].delegate = self; 111 [UIAccelerometer sharedAccelerometer].delegate = self;
68 isRunning = YES; 112 isRunning = YES;
69 } 113 }
70 114 /*
115 Stops our delegate from receiving accelerometer updates.
116 */
71 -(void)shutdown { 117 -(void)shutdown {
72 [UIAccelerometer sharedAccelerometer].delegate = nil; 118 if ([UIAccelerometer sharedAccelerometer].delegate == self) {
119 [UIAccelerometer sharedAccelerometer].delegate = nil;
120 }
73 isRunning = NO; 121 isRunning = NO;
74 } 122 }
75 123 /*
124 Our we currently receiving accelerometer updates?
125 */
76 -(BOOL)isRunning { 126 -(BOOL)isRunning {
77 return isRunning; 127 return isRunning;
78 } 128 }
79 129 /*
130 Do we have any data that hasn't been pumped into SDL's event system?
131 */
80 -(BOOL)hasNewData { 132 -(BOOL)hasNewData {
81 return hasNewData; 133 return hasNewData;
82 } 134 }
83 135 /*
136 When the joystick system grabs the new data, it sets this to NO.
137 */
84 -(void)setHasNewData:(BOOL)value { 138 -(void)setHasNewData:(BOOL)value {
85 hasNewData = value; 139 hasNewData = value;
86 } 140 }
87 141
88 @end 142 @end