(svn r2000) Split the sound system into backend (mixer.[ch]) and frontend (sound.[ch])

8 files changed, 201 insertions, 168 deletions

diff --git a/Makefile b/Makefile
index 1401c69d0..c8a38190a 100644
--- a/Makefile
+++ b/Makefile
@@ -600,6 +600,7 @@ C_SOURCES += minilzo.c
 C_SOURCES += misc.c
 C_SOURCES += misc_cmd.c
 C_SOURCES += misc_gui.c
+C_SOURCES += mixer.c
 C_SOURCES += music_gui.c
 C_SOURCES += namegen.c
 C_SOURCES += network.c
diff --git a/mixer.c b/mixer.c
new file mode 100644
index 000000000..1a113dbed
--- /dev/null
+++ b/mixer.c
@@ -0,0 +1,154 @@
+#include "stdafx.h"
+#include "ttd.h"
+#include "mixer.h"
+
+struct MixerChannel {
+	// Mixer
+	Mixer *mx;
+	bool active;
+
+	// pointer to allocated buffer memory
+	int8 *memory;
+
+	// current position in memory
+	uint32 pos;
+	uint32 frac_pos;
+	uint32 frac_speed;
+	uint32 samples_left;
+
+	// Mixing volume
+	uint volume_left;
+	uint volume_right;
+
+	uint flags;
+};
+
+struct Mixer {
+	uint32 play_rate;
+	MixerChannel channels[8];
+};
+
+
+static void mix_int8_to_int16(MixerChannel *sc, int16 *buffer, uint samples)
+{
+	int8 *b;
+	uint32 frac_pos;
+	uint32 frac_speed;
+	uint volume_left;
+	uint volume_right;
+
+	if (samples > sc->samples_left) samples = sc->samples_left;
+	sc->samples_left -= samples;
+	assert(samples > 0);
+
+	b = sc->memory + sc->pos;
+	frac_pos = sc->frac_pos;
+	frac_speed = sc->frac_speed;
+	volume_left = sc->volume_left;
+	volume_right = sc->volume_right;
+
+	if (frac_speed == 0x10000) {
+		// Special case when frac_speed is 0x10000
+		do {
+			buffer[0] += *b * volume_left >> 8;
+			buffer[1] += *b * volume_right >> 8;
+			b++;
+			buffer += 2;
+		} while (--samples > 0);
+	} else {
+		do {
+			buffer[0] += *b * volume_left >> 8;
+			buffer[1] += *b * volume_right >> 8;
+			buffer += 2;
+			frac_pos += frac_speed;
+			b += frac_pos >> 16;
+			frac_pos &= 0xffff;
+		} while (--samples > 0);
+	}
+
+	sc->frac_pos = frac_pos;
+	sc->pos = b - sc->memory;
+}
+
+static void MxCloseChannel(MixerChannel *mc)
+{
+	if (mc->flags & MX_AUTOFREE) free(mc->memory);
+	mc->memory = NULL;
+	mc->active = false;
+}
+
+void MxMixSamples(Mixer *mx, void *buffer, uint samples)
+{
+	MixerChannel *mc;
+
+	// Clear the buffer
+	memset(buffer, 0, sizeof(int16) * 2 * samples);
+
+	// Mix each channel
+	for (mc = mx->channels; mc != endof(mx->channels); mc++) {
+		if (mc->active) {
+			mix_int8_to_int16(mc, buffer, samples);
+			if (mc->samples_left == 0) MxCloseChannel(mc);
+		}
+	}
+
+	#if 0
+	{
+		static FILE *out = NULL;
+		if (out == NULL)
+			out = fopen("d:\\dump.raw", "wb");
+		fwrite(buffer, samples * 4, 1, out);
+	}
+	#endif
+}
+
+MixerChannel *MxAllocateChannel(Mixer *mx)
+{
+	MixerChannel *mc;
+	for (mc = mx->channels; mc != endof(mx->channels); mc++)
+		if (mc->memory == NULL) {
+			mc->active = false;
+			mc->mx = mx;
+			return mc;
+		}
+	return NULL;
+}
+
+void MxSetChannelRawSrc(MixerChannel *mc, int8 *mem, uint size, uint rate, uint flags)
+{
+	mc->memory = mem;
+	mc->flags = flags;
+	mc->frac_pos = 0;
+	mc->pos = 0;
+
+	mc->frac_speed = (rate << 16) / mc->mx->play_rate;
+
+	// adjust the magnitude to prevent overflow
+	while (size & 0xFFFF0000) {
+		size >>= 1;
+		rate = (rate >> 1) + 1;
+	}
+
+	mc->samples_left = size * mc->mx->play_rate / rate;
+}
+
+void MxSetChannelVolume(MixerChannel *mc, uint left, uint right)
+{
+	mc->volume_left = left;
+	mc->volume_right = right;
+}
+
+
+void MxActivate(MixerChannel* mc)
+{
+	mc->active = true;
+}
+
+
+bool MxInitialize(uint rate)
+{
+	static Mixer mx;
+	_mixer = &mx;
+	mx.play_rate = rate;
+	return true;
+}
diff --git a/mixer.h b/mixer.h
new file mode 100644
index 000000000..86ace050d
--- /dev/null
+++ b/mixer.h
@@ -0,0 +1,24 @@
+#ifndef MIXER_H
+#define MIXER_H
+
+typedef struct Mixer Mixer;
+typedef struct MixerChannel MixerChannel;
+
+enum {
+	MX_AUTOFREE = 1,
+//	MX_8BIT = 2,
+//	MX_STEREO = 4,
+//	MX_UNSIGNED = 8,
+};
+
+VARDEF Mixer *_mixer;
+
+bool MxInitialize(uint rate);
+void MxMixSamples(Mixer *mx, void *buffer, uint samples);
+
+MixerChannel *MxAllocateChannel(Mixer *mx);
+void MxSetChannelRawSrc(MixerChannel *mc, int8 *mem, uint size, uint rate, uint flags);
+void MxSetChannelVolume(MixerChannel *mc, uint left, uint right);
+void MxActivate(MixerChannel*);
+
+#endif
diff --git a/sdl.c b/sdl.c
index 9433faa73..c2f432c9d 100644
--- a/sdl.c
+++ b/sdl.c
@@ -4,7 +4,7 @@
 #include "ttd.h"
 #include "debug.h"
 #include "gfx.h"
-#include "sound.h"
+#include "mixer.h"
 #include "window.h"
 #include <SDL.h>
 #include "player.h"
diff --git a/sound.c b/sound.c
index 28055dee4..d0600445a 100644
--- a/sound.c
+++ b/sound.c
@@ -1,33 +1,13 @@
 #include "stdafx.h"
 #include "ttd.h"
 #include "map.h"
+#include "mixer.h"
 #include "sound.h"
 #include "vehicle.h"
 #include "window.h"
 #include "viewport.h"
 #include "fileio.h"
 
-typedef struct MixerChannel {
-	// Mixer
-	Mixer *mx;
-	bool active;
-
-	// pointer to allocated buffer memory
-	int8 *memory;
-
-	// current position in memory
-	uint32 pos;
-	uint32 frac_pos;
-	uint32 frac_speed;
-	uint32 samples_left;
-
-	// Mixing volume
-	uint volume_left;
-	uint volume_right;
-
-	uint flags;
-} MixerChannel;
-
 typedef struct FileEntry {
 	uint32 file_offset;
 	uint32 file_size;
@@ -36,150 +16,29 @@ typedef struct FileEntry {
 	uint8 channels;
 } FileEntry;
 
-struct Mixer {
-	uint32 play_rate;
-	FileEntry *files;
-	uint32 file_count;
-	MixerChannel channels[8];
-};
-
-enum {
-	MX_AUTOFREE = 1,
-//	MX_8BIT = 2,
-//	MX_STEREO = 4,
-	MX_UNSIGNED = 8,
-};
+static uint _file_count;
+static FileEntry* _files;
 
 #define SOUND_SLOT 31
 
 
-static void mix_int8_to_int16(MixerChannel *sc, int16 *buffer, uint samples)
-{
-	int8 *b;
-	uint32 frac_pos;
-	uint32 frac_speed;
-	uint volume_left;
-	uint volume_right;
-
-	if (samples > sc->samples_left) samples = sc->samples_left;
-	sc->samples_left -= samples;
-	assert(samples > 0);
-
-	b = sc->memory + sc->pos;
-	frac_pos = sc->frac_pos;
-	frac_speed = sc->frac_speed;
-	volume_left = sc->volume_left;
-	volume_right = sc->volume_right;
-
-	if (frac_speed == 0x10000) {
-		// Special case when frac_speed is 0x10000
-		do {
-			buffer[0] += *b * volume_left >> 8;
-			buffer[1] += *b * volume_right >> 8;
-			b++;
-			buffer += 2;
-		} while (--samples > 0);
-	} else {
-		do {
-			buffer[0] += *b * volume_left >> 8;
-			buffer[1] += *b * volume_right >> 8;
-			buffer += 2;
-			frac_pos += frac_speed;
-			b += frac_pos >> 16;
-			frac_pos &= 0xffff;
-		} while (--samples > 0);
-	}
-
-	sc->frac_pos = frac_pos;
-	sc->pos = b - sc->memory;
-}
-
-static void MxCloseChannel(MixerChannel *mc)
-{
-	if (mc->flags & MX_AUTOFREE) free(mc->memory);
-	mc->memory = NULL;
-	mc->active = false;
-}
-
-void MxMixSamples(Mixer *mx, void *buffer, uint samples)
-{
-	MixerChannel *mc;
-
-	// Clear the buffer
-	memset(buffer, 0, sizeof(int16) * 2 * samples);
-
-	// Mix each channel
-	for (mc = mx->channels; mc != endof(mx->channels); mc++) {
-		if (mc->active) {
-			mix_int8_to_int16(mc, buffer, samples);
-			if (mc->samples_left == 0) MxCloseChannel(mc);
-		}
-	}
-
-	#if 0
-	{
-		static FILE *out = NULL;
-		if (out == NULL)
-			out = fopen("d:\\dump.raw", "wb");
-		fwrite(buffer, samples * 4, 1, out);
-	}
-	#endif
-}
-
-static MixerChannel *MxAllocateChannel(Mixer *mx)
-{
-	MixerChannel *mc;
-	for (mc = mx->channels; mc != endof(mx->channels); mc++)
-		if (mc->memory == NULL) {
-			mc->active = false;
-			mc->mx = mx;
-			return mc;
-		}
-	return NULL;
-}
-
-static void MxSetChannelRawSrc(MixerChannel *mc, int8 *mem, uint size, uint rate, uint flags)
-{
-	mc->memory = mem;
-	mc->flags = flags;
-	mc->frac_pos = 0;
-	mc->pos = 0;
-
-	mc->frac_speed = (rate << 16) / mc->mx->play_rate;
-
-	// adjust the magnitude to prevent overflow
-	while (size & 0xFFFF0000) {
-		size >>= 1;
-		rate = (rate >> 1) + 1;
-	}
-
-	mc->samples_left = size * mc->mx->play_rate / rate;
-}
-
-static void MxSetChannelVolume(MixerChannel *mc, uint left, uint right)
-{
-	mc->volume_left = left;
-	mc->volume_right = right;
-}
-
-static void MxOpenBankFile(Mixer *mx, const char *filename)
+static void OpenBankFile(const char *filename)
 {
 	uint count, i;
 	uint32 size, tag;
 	FileEntry *fe;
 
 	FioOpenFile(SOUND_SLOT, filename);
-	mx->file_count = count = FioReadDword() >> 3;
-	fe = mx->files = calloc(sizeof(FileEntry), count);
+	_file_count = count = FioReadDword() >> 3;
+	fe = _files = calloc(sizeof(FileEntry), count);
 
 	FioSeekTo(0, SEEK_SET);
 
-	for (i = 0; i != count; i++, fe++) {
-		fe->file_offset = FioReadDword();
-		fe->file_size = FioReadDword();
+	for (i = 0; i != count; i++) {
+		fe[i].file_offset = FioReadDword();
+		fe[i].file_size = FioReadDword();
 	}
 
-	fe = mx->files;
 	for (i = 0; i != count; i++, fe++) {
 		char name[255];
 
@@ -227,9 +86,9 @@ static void MxOpenBankFile(Mixer *mx, const char *filename)
 	}
 }
 
-static bool MxSetBankSource(MixerChannel *mc, uint bank)
+static bool SetBankSource(MixerChannel *mc, uint bank)
 {
-	FileEntry *fe = &mc->mx->files[bank];
+	FileEntry *fe = &_files[bank];
 	int8 *mem;
 	uint i;
 
@@ -245,17 +104,14 @@ static bool MxSetBankSource(MixerChannel *mc, uint bank)
 
 	assert(fe->bits_per_sample == 8 && fe->channels == 1 && fe->file_size != 0 && fe->rate != 0);
 
-	MxSetChannelRawSrc(mc, mem, fe->file_size, fe->rate, MX_AUTOFREE | MX_UNSIGNED);
+	MxSetChannelRawSrc(mc, mem, fe->file_size, fe->rate, MX_AUTOFREE);
 
 	return true;
 }
 
-bool MxInitialize(uint rate, const char *filename)
+bool SoundInitialize(const char *filename)
 {
-	static Mixer mx;
-	_mixer = &mx;
-	mx.play_rate = rate;
-	MxOpenBankFile(&mx, filename);
+	OpenBankFile(filename);
 	return true;
 }
 
@@ -266,9 +122,9 @@ static void StartSound(uint sound, uint panning, uint volume)
 		MixerChannel *mc = MxAllocateChannel(_mixer);
 		if (mc == NULL)
 			return;
-		if (MxSetBankSource(mc, sound)) {
+		if (SetBankSource(mc, sound)) {
 			MxSetChannelVolume(mc, volume << 8, volume << 8);
-			mc->active = true;
+			MxActivate(mc);
 		}
 	}
 }
diff --git a/sound.h b/sound.h
index 10859e63f..8b3522d65 100644
--- a/sound.h
+++ b/sound.h
@@ -1,8 +1,6 @@
 #ifndef SOUND_H
 #define SOUND_H
 
-typedef struct Mixer Mixer;
-
 typedef struct MusicFileSettings {
 	byte playlist;
 	byte music_vol;
@@ -17,10 +15,8 @@ VARDEF byte _music_wnd_cursong;
 VARDEF bool _song_is_active;
 VARDEF byte _cur_playlist[33];
 VARDEF MusicFileSettings msf;
-VARDEF Mixer *_mixer;
 
-bool MxInitialize(uint rate, const char *filename);
-void MxMixSamples(Mixer *mx, void *buffer, uint samples);
+bool SoundInitialize(const char *filename);
 
 typedef enum SoundFx {
 	SND_02_SPLAT,                          //  0 == 0x00 !
diff --git a/ttd.c b/ttd.c
index c1a4f8956..a230a5ab2 100644
--- a/ttd.c
+++ b/ttd.c
@@ -8,6 +8,7 @@
 
 #define VARDEF
 #include "ttd.h"
+#include "mixer.h"
 #include "spritecache.h"
 #include "gfx.h"
 #include "gui.h"
@@ -626,7 +627,8 @@ int ttd_main(int argc, char* argv[])
 	// Sample catalogue
 	DEBUG(misc, 1) ("Loading sound effects...");
 	_os_version = GetOSVersion();
-	MxInitialize(11025, "sample.cat");
+	MxInitialize(11025);
+	SoundInitialize("sample.cat");
 
 	// This must be done early, since functions use the InvalidateWindow* calls
 	InitWindowSystem();
diff --git a/win32.c b/win32.c
index 9bd3a9cab..8f1e124d3 100644
--- a/win32.c
+++ b/win32.c
@@ -4,7 +4,7 @@
 #include "string.h"
 #include "table/strings.h"
 #include "gfx.h"
-#include "sound.h"
+#include "mixer.h"
 #include "window.h"
 #include "gui.h"
 #include <windows.h>