1 ////////////////////////////////////////////////////////////////////////////////////////
2 //
3 // Nestopia - NES/Famicom emulator written in C++
4 //
5 // Copyright (C) 2003-2008 Martin Freij
6 //
7 // This file is part of Nestopia.
8 //
9 // Nestopia is free software; you can redistribute it and/or modify
10 // it under the terms of the GNU General Public License as published by
11 // the Free Software Foundation; either version 2 of the License, or
12 // (at your option) any later version.
13 //
14 // Nestopia is distributed in the hope that it will be useful,
15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17 // GNU General Public License for more details.
18 //
19 // You should have received a copy of the GNU General Public License
20 // along with Nestopia; if not, write to the Free Software
21 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
22 //
23 ////////////////////////////////////////////////////////////////////////////////////////
24 
25 #include "NstInpDevice.hpp"
26 #include "NstInpTopRider.hpp"
27 
28 namespace Nes
29 {
30 	namespace Core
31 	{
32 		namespace Input
33 		{
34 			#ifdef NST_MSVC_OPTIMIZE
35 			#pragma optimize("s", on)
36 			#endif
37 
TopRider(const Cpu & c)38 			TopRider::TopRider(const Cpu& c)
39 			: Device(c,Api::Input::TOPRIDER)
40 			{
41 				TopRider::Reset();
42 			}
43 
Reset()44 			void TopRider::Reset()
45 			{
46 				state[0] = 0;
47 				state[1] = 0;
48 				stream[0] = 0;
49 				stream[1] = 0;
50 				strobe = 0;
51 				buttons = 0;
52 				brake = 0;
53 				accel = 0;
54 				pos = 0;
55 			}
56 
SaveState(State::Saver & saver,const byte id) const57 			void TopRider::SaveState(State::Saver& saver,const byte id) const
58 			{
59 				saver.Begin( AsciiId<'T','R'>::R(0,0,id) ).End();
60 			}
61 
62 			#ifdef NST_MSVC_OPTIMIZE
63 			#pragma optimize("", on)
64 			#endif
65 
BeginFrame(Controllers * const controllers)66 			void TopRider::BeginFrame(Controllers* const controllers)
67 			{
68 				if (controllers)
69 				{
70 					Controllers::TopRider::callback( controllers->topRider );
71 
72 					uint data = controllers->topRider.buttons;
73 
74 					if ((data & STEERING) == STEERING)
75 						data &= STEERING ^ 0xFFU;
76 
77                          if ( !(data & STEERING) ) pos += (pos > 0 ? -1 : pos < 0 ? +1 : 0);
78 					else if ( data & STEER_LEFT  ) pos -= (pos > -MAX_STEER);
79 					else if ( data & STEER_RIGHT ) pos += (pos < +MAX_STEER);
80 
81 					if (data & BRAKE) brake += (brake < MAX_BRAKE);
82 					else              brake -= (brake > 0);
83 
84 					if (data & ACCEL) accel += (accel < MAX_ACCEL);
85 					else              accel -= (accel > 0);
86 
87 					buttons &= (0x80U|0x40U);
88 
89 					if (data & SHIFT_GEAR)
90 					{
91 						if (!(buttons & 0x40))
92 						{
93 							buttons ^= 0x80;
94 							buttons |= 0x40;
95 						}
96 					}
97 					else
98 					{
99 						buttons &= 0x40U ^ 0xFFU;
100 					}
101 
102 					buttons |=
103 					(
104 						(( data & REAR   ) >> 5) |
105 						(( data & SELECT ) << 3) |
106 						(( data & START  ) << 1)
107 					);
108 
109 					data = 0;
110 
111 					if (pos > 0)
112 					{
113                              if (pos > DEADZONE_MAX) data = (0x20U | 0x080U);
114 						else if (pos > DEADZONE_MID) data = (0x20U | 0x000U);
115 						else if (pos > DEADZONE_MIN) data = (0x00U | 0x080U);
116 					}
117 					else
118 					{
119                              if (pos < -DEADZONE_MAX) data = (0x40U | 0x100U);
120 						else if (pos < -DEADZONE_MID) data = (0x40U | 0x000U);
121 						else if (pos < -DEADZONE_MIN) data = (0x00U | 0x100U);
122 					}
123 
124 					state[0] = data | ((buttons & 0x01) << (4+7))  | ((buttons & 0x80) << (4-1));
125 
126 					data = 0;
127 
128 					if (accel > 8 || brake < 8)
129 					{
130                              if (accel > DEADZONE_MAX) data = 0x008;
131 						else if (accel > DEADZONE_MID) data = 0x080;
132 						else if (accel > DEADZONE_MIN) data = 0x100;
133 					}
134 					else
135 					{
136 						state[0] |= 0x200;
137 
138                              if (brake > DEADZONE_MAX) data = 0x10;
139 						else if (brake > DEADZONE_MID) data = 0x20;
140 						else if (brake > DEADZONE_MIN) data = 0x40;
141 					}
142 
143 					state[1] = data | ((buttons & 0x30) << (3+2));
144 				}
145 				else
146 				{
147 					buttons = 0;
148 					brake = 0;
149 					accel = 0;
150 					pos = 0;
151 					state[0] = 0;
152 					state[1] = 0;
153 				}
154 			}
155 
Poke(uint data)156 			void TopRider::Poke(uint data)
157 			{
158 				const uint prev = strobe;
159 				strobe = data & 0x1;
160 
161 				if (prev > strobe)
162 				{
163 					stream[0] = state[0];
164 					stream[1] = state[1];
165 				}
166 			}
167 
Peek(uint port)168 			uint TopRider::Peek(uint port)
169 			{
170 				if (port)
171 				{
172 					port = (stream[0] & 0x10) | (stream[1] & 0x08);
173 					stream[0] >>= 1, stream[1] >>= 1;
174 				}
175 
176 				return port;
177 			}
178 		}
179 	}
180 }
181