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authorpeter1138 <peter1138@openttd.org>2010-03-06 11:08:31 +0000
committerpeter1138 <peter1138@openttd.org>2010-03-06 11:08:31 +0000
commit77fe7e0a74c597794d90e7776aa100a82fe2a60a (patch)
tree049718321cb28fbaee6c85be2d98ebe54a44b330
parent1eb52326cf810d9ea4380cd97ac84daaf4f358d8 (diff)
downloadopenttd-77fe7e0a74c597794d90e7776aa100a82fe2a60a.tar.xz
(svn r19332) -Codechange: Simplify sound panning by using float data, and switch to sinusoidal algorithm to maintain output level.
-rw-r--r--src/mixer.cpp15
-rw-r--r--src/mixer.h2
-rw-r--r--src/sound.cpp16
3 files changed, 18 insertions, 15 deletions
diff --git a/src/mixer.cpp b/src/mixer.cpp
index 1b054f4e3..36c982bec 100644
--- a/src/mixer.cpp
+++ b/src/mixer.cpp
@@ -10,6 +10,7 @@
/** @file mixer.cpp Mixing of sound samples. */
#include "stdafx.h"
+#include <math.h>
#include "core/math_func.hpp"
struct MixerChannel {
@@ -185,10 +186,18 @@ void MxSetChannelRawSrc(MixerChannel *mc, int8 *mem, size_t size, uint rate, boo
mc->is16bit = is16bit;
}
-void MxSetChannelVolume(MixerChannel *mc, uint left, uint right)
+/**
+ * Set volume and pan parameters for a sound.
+ * @param mc MixerChannel to set
+ * @param volume Volume level for sound, range is 0..16384
+ * @param pan Pan position for sound, range is 0..1
+ */
+void MxSetChannelVolume(MixerChannel *mc, uint volume, float pan)
{
- mc->volume_left = left;
- mc->volume_right = right;
+ /* Use sinusoidal pan to maintain overall sound power level regardless
+ * of position. */
+ mc->volume_left = volume * sin((1.0 - pan) * M_PI / 2.0);
+ mc->volume_right = volume * sin(pan * M_PI / 2.0);
}
diff --git a/src/mixer.h b/src/mixer.h
index a471fb6e7..0ccee6109 100644
--- a/src/mixer.h
+++ b/src/mixer.h
@@ -19,7 +19,7 @@ void MxMixSamples(void *buffer, uint samples);
MixerChannel *MxAllocateChannel();
void MxSetChannelRawSrc(MixerChannel *mc, int8 *mem, size_t size, uint rate, bool is16bit);
-void MxSetChannelVolume(MixerChannel *mc, uint left, uint right);
+void MxSetChannelVolume(MixerChannel *mc, uint volume, float pan);
void MxActivateChannel(MixerChannel*);
#endif /* MIXER_H */
diff --git a/src/sound.cpp b/src/sound.cpp
index e337b5ebc..4edfccdc2 100644
--- a/src/sound.cpp
+++ b/src/sound.cpp
@@ -24,9 +24,6 @@
static SoundEntry _original_sounds[ORIGINAL_SAMPLE_COUNT];
MusicFileSettings msf;
-/* Number of levels of panning per side */
-#define PANNING_LEVELS 16
-
static void OpenBankFile(const char *filename)
{
memset(_original_sounds, 0, sizeof(_original_sounds));
@@ -158,7 +155,7 @@ void InitializeSound()
}
/* Low level sound player */
-static void StartSound(SoundID sound_id, int panning, uint volume)
+static void StartSound(SoundID sound_id, float pan, uint volume)
{
if (volume == 0) return;
@@ -174,12 +171,9 @@ static void StartSound(SoundID sound_id, int panning, uint volume)
if (!SetBankSource(mc, sound)) return;
/* Apply the sound effect's own volume. */
- volume = (sound->volume * volume) / 128;
+ volume = sound->volume * volume;
- panning = Clamp(panning, -PANNING_LEVELS, PANNING_LEVELS);
- uint left_vol = (volume * PANNING_LEVELS) - (volume * panning);
- uint right_vol = (volume * PANNING_LEVELS) + (volume * panning);
- MxSetChannelVolume(mc, left_vol * 128 / PANNING_LEVELS, right_vol * 128 / PANNING_LEVELS);
+ MxSetChannelVolume(mc, volume, pan);
MxActivateChannel(mc);
}
@@ -244,7 +238,7 @@ static void SndPlayScreenCoordFx(SoundID sound, int left, int right, int top, in
top < vp->virtual_top + vp->virtual_height && bottom > vp->virtual_top) {
int screen_x = (left + right) / 2 - vp->virtual_left;
int width = (vp->virtual_width == 0 ? 1 : vp->virtual_width);
- int panning = (screen_x * PANNING_LEVELS * 2) / width - PANNING_LEVELS;
+ float panning = (float)screen_x / width;
StartSound(
sound,
@@ -278,7 +272,7 @@ void SndPlayVehicleFx(SoundID sound, const Vehicle *v)
void SndPlayFx(SoundID sound)
{
- StartSound(sound, 0, msf.effect_vol);
+ StartSound(sound, 0.5, msf.effect_vol);
}
INSTANTIATE_BASE_MEDIA_METHODS(BaseMedia<SoundsSet>, SoundsSet)