mirror
/
OpenTTD
mirror of https://github.com/OpenTTD/OpenTTD
1
0
Fork 0
Code Issues

Codechange: Use a type alias for mixer channel masking.

pull/13152/head
Peter Nelson 2024-10-13 12:50:22 +01:00 committed by Peter Nelson
parent cba329d9e2
commit bccf5343f4
1 changed files with 11 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
src/mixer.cpp
View File

@ -34,8 +34,10 @@ struct MixerChannel {
bool is16bit; bool is16bit;
}; };
static std::atomic<uint8_t> _active_channels; using MixerChannelMask = uint8_t; ///< Type representing a bitmask of mixer channels.
static std::atomic<uint8_t> _stop_channels;
static std::atomic<MixerChannelMask> _active_channels;
static std::atomic<MixerChannelMask> _stop_channels;
static MixerChannel _channels[8]; static MixerChannel _channels[8];
static uint32_t _play_rate = 11025; static uint32_t _play_rate = 11025;
static uint32_t _max_size = UINT_MAX; static uint32_t _max_size = UINT_MAX;
@ -106,7 +108,7 @@ static void mix_int16(MixerChannel *sc, int16_t *buffer, uint samples, uint8_t e
static void MxCloseChannel(uint8_t channel_index) static void MxCloseChannel(uint8_t channel_index)
{ {
_active_channels.fetch_and(~(1 << channel_index), std::memory_order_release); _active_channels.fetch_and(~(1U << channel_index), std::memory_order_release);
} }
/** /**
@ -138,7 +140,7 @@ void MxMixSamples(void *buffer, uint samples)
} }
/* Check if any channels should be stopped. */ /* Check if any channels should be stopped. */
uint8_t stop = _stop_channels.load(std::memory_order_acquire); MixerChannelMask stop = _stop_channels.load(std::memory_order_acquire);
for (uint8_t idx : SetBitIterator(stop)) { for (uint8_t idx : SetBitIterator(stop)) {
MxCloseChannel(idx); MxCloseChannel(idx);
} }
@ -153,7 +155,7 @@ void MxMixSamples(void *buffer, uint samples)
effect_vol_setting) / (127 * 127); effect_vol_setting) / (127 * 127);
/* Mix each channel */ /* Mix each channel */
uint8_t active = _active_channels.load(std::memory_order_acquire); MixerChannelMask active = _active_channels.load(std::memory_order_acquire);
for (uint8_t idx : SetBitIterator(active)) { for (uint8_t idx : SetBitIterator(active)) {
MixerChannel *mc = &_channels[idx]; MixerChannel *mc = &_channels[idx];
if (mc->is16bit) { if (mc->is16bit) {
@ -167,8 +169,8 @@ void MxMixSamples(void *buffer, uint samples)
MixerChannel *MxAllocateChannel() MixerChannel *MxAllocateChannel()
{ {
uint8_t currently_active = _active_channels.load(std::memory_order_acquire); MixerChannelMask currently_active = _active_channels.load(std::memory_order_acquire);
uint8_t available = ~currently_active; MixerChannelMask available = ~currently_active;
if (available == 0) return nullptr; if (available == 0) return nullptr;
uint8_t channel_index = FindFirstBit(available); uint8_t channel_index = FindFirstBit(available);
@ -217,8 +219,8 @@ void MxSetChannelVolume(MixerChannel *mc, uint volume, float pan)
void MxActivateChannel(MixerChannel *mc) void MxActivateChannel(MixerChannel *mc)
{ {
uint8_t channel_index = mc - _channels; uint8_t channel_index = mc - _channels;
_stop_channels.fetch_and(~(1 << channel_index), std::memory_order_release); _stop_channels.fetch_and(~(1U << channel_index), std::memory_order_release);
_active_channels.fetch_or((1 << channel_index), std::memory_order_release); _active_channels.fetch_or((1U << channel_index), std::memory_order_release);
} }
/** /**