diff options
Diffstat (limited to 'Alc/hrtf.c')
| -rw-r--r-- | Alc/hrtf.c | 23 |
1 files changed, 5 insertions, 18 deletions
@@ -312,14 +312,14 @@ ALuint GetMovingHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat a } -/* Calculates HRTF coefficients for B-Format channels. */ +/* Calculates HRTF coefficients for B-Format channels (only up to first-order). */ void GetBFormatHrtfCoeffs(const struct Hrtf *Hrtf, const ALuint num_chans, ALfloat (**coeffs_list)[2], ALuint **delay_list) { ALuint elev_idx, azi_idx; ALfloat scale; ALuint i, c; - assert(num_chans <= MAX_AMBI_COEFFS); + assert(num_chans <= 4); for(c = 0;c < num_chans;c++) { @@ -352,10 +352,9 @@ void GetBFormatHrtfCoeffs(const struct Hrtf *Hrtf, const ALuint num_chans, ALflo for(azi_idx = 0;azi_idx < azcount;azi_idx++) { ALuint lidx, ridx; - ALfloat az; - ALfloat ambi_coeffs[MAX_AMBI_COEFFS]; + ALfloat ambi_coeffs[4]; + ALfloat az, gain; ALfloat x, y, z; - ALfloat gain; lidx = evoffset + azi_idx; ridx = evoffset + ((azcount-azi_idx) % azcount); @@ -367,22 +366,10 @@ void GetBFormatHrtfCoeffs(const struct Hrtf *Hrtf, const ALuint num_chans, ALflo y = sinf(-az) * cosf(elev); z = sinf(elev); - ambi_coeffs[0] = 0.7071f; /* sqrt(1.0 / 2.0) */ + ambi_coeffs[0] = 1.4142f; ambi_coeffs[1] = x; /* X */ ambi_coeffs[2] = y; /* Y */ ambi_coeffs[3] = z; /* Z */ - ambi_coeffs[4] = 0.5f * (3.0f*z*z - 1.0f); /* 0.5 * (3*Z*Z - 1) */ - ambi_coeffs[5] = 2.0f * z * x; /* 2*Z*X */ - ambi_coeffs[6] = 2.0f * y * z; /* 2*Y*Z */ - ambi_coeffs[7] = x*x - y*y; /* X*X - Y*Y */ - ambi_coeffs[8] = 2.0f * x * y; /* 2*X*Y */ - ambi_coeffs[9] = 0.5f * z * (5.0f*z*z - 3.0f); /* 0.5 * Z * (5*Z*Z - 3) */ - ambi_coeffs[10] = 0.7262f * x * (5.0f*z*z - 1.0f); /* sqrt(135.0 / 256.0) * X * (5*Z*Z - 1) */ - ambi_coeffs[11] = 0.7262f * y * (5.0f*z*z - 1.0f); /* sqrt(135.0 / 256.0) * Y * (5*Z*Z - 1) */ - ambi_coeffs[12] = 2.5981f * z * (x*x - y*y); /* sqrt(27.0 / 4.0) * Z * (X*X - Y*Y) */ - ambi_coeffs[13] = 5.1962f * x * y * z; /* sqrt(27) * X * Y * Z */ - ambi_coeffs[14] = x * (x*x - 3.0f*y*y); /* X * (X*X - 3*Y*Y) */ - ambi_coeffs[15] = y * (3.0f*x*x - y*y); /* Y * (3*X*X - Y*Y) */ for(c = 0;c < num_chans;c++) { |