1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
// Emacs style mode select -*- C++ -*-
//-----------------------------------------------------------------------------
//
// Copyright(C) 2009 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
// 02111-1307, USA.
//
// DESCRIPTION:
// OPL SDL interface.
//
//-----------------------------------------------------------------------------
#include "config.h"
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include "SDL.h"
#include "SDL_mixer.h"
#include "fmopl.h"
#include "opl.h"
#include "opl_internal.h"
// TODO:
#define opl_sample_rate 22050
static FM_OPL *opl_emulator = NULL;
static int sdl_was_initialised = 0;
static int mixing_freq, mixing_channels;
static Uint16 mixing_format;
static int SDLIsInitialised(void)
{
int freq, channels;
Uint16 format;
return Mix_QuerySpec(&freq, &format, &channels);
}
// Callback function to fill a new sound buffer:
static void OPL_Mix_Callback(void *udata, Uint8 *stream, int len)
{
}
static void OPL_SDL_Shutdown(void)
{
if (sdl_was_initialised)
{
Mix_CloseAudio();
SDL_QuitSubSystem(SDL_INIT_AUDIO);
sdl_was_initialised = 0;
}
if (opl_emulator != NULL)
{
OPLDestroy(opl_emulator);
opl_emulator = NULL;
}
}
static int OPL_SDL_Init(unsigned int port_base)
{
// Check if SDL_mixer has been opened already
// If not, we must initialise it now
if (!SDLIsInitialised())
{
if (SDL_Init(SDL_INIT_AUDIO) < 0)
{
fprintf(stderr, "Unable to set up sound.\n");
return 0;
}
if (Mix_OpenAudio(opl_sample_rate, AUDIO_S16SYS, 2, 1024) < 0)
{
fprintf(stderr, "Error initialising SDL_mixer: %s\n", Mix_GetError());
SDL_QuitSubSystem(SDL_INIT_AUDIO);
return 0;
}
SDL_PauseAudio(0);
// When this module shuts down, it has the responsibility to
// shut down SDL.
sdl_was_initialised = 1;
}
else
{
sdl_was_initialised = 0;
}
// Get the mixer frequency, format and number of channels.
Mix_QuerySpec(&mixing_freq, &mixing_format, &mixing_channels);
// Only supports AUDIO_S16SYS
if (mixing_format != AUDIO_S16SYS || mixing_channels != 2)
{
fprintf(stderr,
"OPL_SDL only supports native signed 16-bit LSB, "
"stereo format!\n");
OPL_SDL_Shutdown();
return 0;
}
// Create the emulator structure:
opl_emulator = makeAdlibOPL(mixing_freq);
if (opl_emulator == NULL)
{
fprintf(stderr, "Failed to initialise software OPL emulator!\n");
OPL_SDL_Shutdown();
return 0;
}
// TODO: This should be music callback? or-?
Mix_SetPostMix(OPL_Mix_Callback, NULL);
return 1;
}
static unsigned int OPL_SDL_PortRead(opl_port_t port)
{
if (opl_emulator != NULL)
{
return OPLRead(opl_emulator, port);
}
else
{
return 0;
}
}
static void OPL_SDL_PortWrite(opl_port_t port, unsigned int value)
{
if (opl_emulator != NULL)
{
OPLWrite(opl_emulator, port, value);
}
}
opl_driver_t opl_sdl_driver =
{
"SDL",
OPL_SDL_Init,
OPL_SDL_Shutdown,
OPL_SDL_PortRead,
OPL_SDL_PortWrite
};
|
