cpp/openttd-patchpack/source Changeset - r28190:29617a715136

Changeset - r28190:29617a715136

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Peter Nelson - 5 months ago 2023-11-28 00:05:30
peter1138@openttd.org

Codechange: Template input buffer type in audio mixer. (#11505)

This reduces code duplication.

1 file changed with 12 insertions and 44 deletions:

src/mixer.cpp

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src/mixer.cpp

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@@ @@ -63,13 +63,17 @@ static int RateConversion(T *b, int frac @@
 	return ((b[0] * ((1 << 16) - frac_pos)) + (b[1] * frac_pos)) >> 16;
+}
 template <typename T>
 static void mix_int16(MixerChannel *sc, int16_t *buffer, uint samples, uint8_t effect_vol)
+{
 	/* Shift required to get sample value into range for the data type. */
 	const uint SHIFT = sizeof(T) * CHAR_BIT;
 	if (samples > sc->samples_left) samples = sc->samples_left;
 	sc->samples_left -= samples;
 	assert(samples > 0);
-	const int16_t *b = (const int16_t *)sc->memory + sc->pos;
+	const T *b = (const T *)sc->memory + sc->pos;
 	uint32_t frac_pos = sc->frac_pos;
 	uint32_t frac_speed = sc->frac_speed;
 	int volume_left = sc->volume_left * effect_vol / 255;
@@ @@ -78,16 +82,16 @@ static void mix_int16(MixerChannel *sc, @@
 	if (frac_speed == 0x10000) {
 		/* Special case when frac_speed is 0x10000 */
 		do {
 			buffer[0] = Clamp(buffer[0] + (*b * volume_left  >> 16), -MAX_VOLUME, MAX_VOLUME);
 			buffer[1] = Clamp(buffer[1] + (*b * volume_right >> 16), -MAX_VOLUME, MAX_VOLUME);
 			buffer[0] = Clamp(buffer[0] + (*b * volume_left  >> SHIFT), -MAX_VOLUME, MAX_VOLUME);
 			buffer[1] = Clamp(buffer[1] + (*b * volume_right >> SHIFT), -MAX_VOLUME, MAX_VOLUME);
 			b++;
 			buffer += 2;
 		} while (--samples > 0);
 	} else {
 		do {
 			int data = RateConversion(b, frac_pos);
 			buffer[0] = Clamp(buffer[0] + (data * volume_left  >> 16), -MAX_VOLUME, MAX_VOLUME);
 			buffer[1] = Clamp(buffer[1] + (data * volume_right >> 16), -MAX_VOLUME, MAX_VOLUME);
 			buffer[0] = Clamp(buffer[0] + (data * volume_left  >> SHIFT), -MAX_VOLUME, MAX_VOLUME);
 			buffer[1] = Clamp(buffer[1] + (data * volume_right >> SHIFT), -MAX_VOLUME, MAX_VOLUME);
 			buffer += 2;
 			frac_pos += frac_speed;
 			b += frac_pos >> 16;
@@ @@ -96,43 +100,7 @@ static void mix_int16(MixerChannel *sc, @@
+	}
 	sc->frac_pos = frac_pos;
 	sc->pos = b - (const int16_t *)sc->memory;
+}
 static void mix_int8_to_int16(MixerChannel *sc, int16_t *buffer, uint samples, uint8_t effect_vol)
+{
 	if (samples > sc->samples_left) samples = sc->samples_left;
 	sc->samples_left -= samples;
 	assert(samples > 0);
 	const int8_t *b = sc->memory + sc->pos;
 	uint32_t frac_pos = sc->frac_pos;
 	uint32_t frac_speed = sc->frac_speed;
 	int volume_left = sc->volume_left * effect_vol / 255;
 	int volume_right = sc->volume_right * effect_vol / 255;
 	if (frac_speed == 0x10000) {
 		/* Special case when frac_speed is 0x10000 */
 		do {
 			buffer[0] = Clamp(buffer[0] + (*b * volume_left  >> 8), -MAX_VOLUME, MAX_VOLUME);
 			buffer[1] = Clamp(buffer[1] + (*b * volume_right >> 8), -MAX_VOLUME, MAX_VOLUME);
 			b++;
 			buffer += 2;
 		} while (--samples > 0);
 	} else {
 		do {
 			int data = RateConversion(b, frac_pos);
 			buffer[0] = Clamp(buffer[0] + (data * volume_left  >> 8), -MAX_VOLUME, MAX_VOLUME);
 			buffer[1] = Clamp(buffer[1] + (data * volume_right >> 8), -MAX_VOLUME, MAX_VOLUME);
 			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;
 	sc->pos = b - (const T *)sc->memory;
+}
 static void MxCloseChannel(uint8_t channel_index)
@@ @@ -172,9 +140,9 @@ void MxMixSamples(void *buffer, uint sam @@
 	for (uint8_t idx : SetBitIterator(active)) {
 		MixerChannel *mc = &_channels[idx];
 		if (mc->is16bit) {
 			mix_int16(mc, (int16_t*)buffer, samples, effect_vol);
+			mix_int16<int16_t>(mc, (int16_t*)buffer, samples, effect_vol);
 		} else {
-			mix_int8_to_int16(mc, (int16_t*)buffer, samples, effect_vol);
+			mix_int16<int8_t>(mc, (int16_t*)buffer, samples, effect_vol);
+		}
 		if (mc->samples_left == 0) MxCloseChannel(idx);
+	}

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