engine: Inline conversion functions for better optimizations

Author: dimhotepus

engine/audio/private/snd_dma.cpp

@@ -1838,32 +1838,6 @@ ConVar snd_showstart( "snd_showstart", "0", FCVAR_CHEAT );	// showstart always s
 
 #define SND_GAIN_PLAYER_WEAPON_DB 2.0F	// increase player weapon gain by N dB
 
-// dB = 20 log (amplitude/32768)		0 to -90.3dB
-// amplitude = 32768 * 10 ^ (dB/20)		0 to +/- 32768
-// gain = amplitude/32768				0 to 1.0
-
-float Gain_To_dB ( float gain )
-{
-	float dB = 20 * logf ( gain );
-	return dB;
-}
-
-float dB_To_Gain ( float dB )
-{
-	float gain = powf (10, dB / 20.0F);
-	return gain;
-}
-
-float Gain_To_Amplitude ( float gain )
-{
-	return gain * 32768;
-}
-
-float Amplitude_To_Gain ( float amplitude )
-{
-	return amplitude / 32768;
-}
-
 soundlevel_t SND_GetSndlvl ( channel_t *pchannel )
 {
 	return DIST_MULT_TO_SNDLVL( pchannel->dist_mult );

engine/audio/private/snd_dsp.cpp

@@ -47,11 +47,6 @@ extern ConVar das_debug;
 void DSP_ReleaseMemory( void );
 bool DSP_LoadPresetFile( void );
 
-extern float Gain_To_dB ( float gain );
-extern float dB_To_Gain ( float dB );
-extern float Gain_To_Amplitude ( float gain );
-extern float Amplitude_To_Gain ( float amplitude );
-
 extern bool g_bdas_room_init;
 extern bool g_bdas_init_nodes;
 

engine/audio/private/snd_mix_buf.h

@@ -120,4 +120,26 @@ constexpr inline short CLIP(T x) noexcept {
   return x > 32767 ? 32767 : (x < -32767 ? -32767 : static_cast<short>(x));
 }
 
+// dB = 20 log (amplitude/32768)		0 to -90.3dB
+// amplitude = 32768 * 10 ^ (dB/20)		0 to +/- 32768
+// gain = amplitude/32768				0 to 1.0
+[[nodiscard]] inline float Gain_To_dB(float gain) {
+	float dB = 20.0f * logf ( gain );
+	return dB;
+}
+
+[[nodiscard]] inline float dB_To_Gain(float dB) {
+	float gain = powf (10.0f, dB / 20.0f);
+	return gain;
+}
+
+[[nodiscard]] constexpr inline float Gain_To_Amplitude(float gain) {
+	return gain * 32768.0f;
+}
+
+[[nodiscard]] constexpr inline float Amplitude_To_Gain(float amplitude) {
+	return amplitude / 32768.0f;
+}
+
+
 #endif // SND_MIX_BUF_H