cpp/openttd-patchpack/source Changeset - r14734:58c3f99dc69c

Changeset - r14734:58c3f99dc69c

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peter1138 - 14 years ago 2010-03-06 11:08:31
peter1138@openttd.org

(svn r19332) -Codechange: Simplify sound panning by using float data, and switch to sinusoidal algorithm to maintain output level.

3 files changed with 18 insertions and 15 deletions:

src/mixer.cpp

src/mixer.h

src/sound.cpp

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src/mixer.cpp

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@@ @@ -7,12 +7,13 @@ @@
  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
  */
 /** @file mixer.cpp Mixing of sound samples. */
 #include "stdafx.h"
 #include <math.h>
 #include "core/math_func.hpp"
 struct MixerChannel {
 	bool active;
 	/* pointer to allocated buffer memory */
@@ @@ -182,16 +183,24 @@ void MxSetChannelRawSrc(MixerChannel *mc @@
+	}
 	mc->samples_left = (uint)size * _play_rate / rate;
 	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);
+}
 void MxActivateChannel(MixerChannel *mc)
+{
 	mc->active = true;

src/mixer.h

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@@ @@ -16,10 +16,10 @@ struct MixerChannel; @@
 bool MxInitialize(uint rate);
 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 */

src/sound.cpp

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@@ @@ -21,15 +21,12 @@ @@
 #define SET_TYPE "sounds"
 #include "base_media_func.h"
 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));
 	/* If there is no sound file (nosound set), don't load anything */
 	if (filename == NULL) return;
@@ @@ -155,13 +152,13 @@ void InitializeSound() @@
+{
 	DEBUG(misc, 1, "Loading sound effects...");
 	OpenBankFile(BaseSounds::GetUsedSet()->files->filename);
+}
 /* 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;
 	const SoundEntry *sound = GetSound(sound_id);
 	if (sound == NULL) return;
@@ @@ -171,18 +168,15 @@ static void StartSound(SoundID sound_id, @@
 	MixerChannel *mc = MxAllocateChannel();
 	if (mc == NULL) return;
 	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);
+}
 static const byte _vol_factor_by_zoom[] = {255, 190, 134, 87};
 assert_compile(lengthof(_vol_factor_by_zoom) == ZOOM_LVL_COUNT);
@@ @@ -241,13 +235,13 @@ static void SndPlayScreenCoordFx(SoundID @@
 		if (vp != NULL &&
 				left < vp->virtual_left + vp->virtual_width && right > vp->virtual_left &&
 				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,
 				panning,
 				(msf.effect_vol * _vol_factor_by_zoom[vp->zoom - ZOOM_LVL_BEGIN]) / 256
 			);
@@ @@ -275,13 +269,13 @@ void SndPlayVehicleFx(SoundID sound, con @@
 		v->coord.top, v->coord.bottom
 	);
+}
 void SndPlayFx(SoundID sound)
+{
 	StartSound(sound, 0, msf.effect_vol);
+	StartSound(sound, 0.5, msf.effect_vol);
+}
 INSTANTIATE_BASE_MEDIA_METHODS(BaseMedia<SoundsSet>, SoundsSet)
 /** Names corresponding to the sound set's files */
 static const char * const _sound_file_names[] = { "samples" };

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