diff options
Diffstat (limited to 'examples')
| -rw-r--r-- | examples/almultireverb.c | 379 |
1 files changed, 236 insertions, 143 deletions
diff --git a/examples/almultireverb.c b/examples/almultireverb.c index 47bc86e2..44398db3 100644 --- a/examples/almultireverb.c +++ b/examples/almultireverb.c @@ -231,12 +231,227 @@ static ALfloat dot_product(const ALfloat vec0[3], const ALfloat vec1[3]) return vec0[0]*vec1[0] + vec0[1]*vec1[1] + vec0[2]*vec1[2]; } +/* Helper to normalize a given vector. */ +static void normalize(ALfloat vec[3]) +{ + ALfloat mag = sqrtf(dot_product(vec, vec)); + if(mag > 0.00001f) + { + vec[0] /= mag; + vec[1] /= mag; + vec[2] /= mag; + } + else + { + vec[0] = 0.0f; + vec[1] = 0.0f; + vec[2] = 0.0f; + } +} + + +/* The main update function to update the listener and environment effects. */ +static void UpdateListenerAndEffects(float timediff, const ALuint slots[2], const ALuint effects[2], const EFXEAXREVERBPROPERTIES reverbs[2]) +{ + static const ALfloat listener_move_scale = 10.0f; + /* Individual reverb zones are connected via "portals". Each portal has a + * position (center point of the connecting area), a normal (facing + * direction), and a radius (approximate size of the connecting area). + */ + const ALfloat portal_pos[3] = { 0.0f, 0.0f, 0.0f }; + const ALfloat portal_norm[3] = { sqrtf(0.5f), 0.0f, -sqrtf(0.5f) }; + const ALfloat portal_radius = 2.5f; + ALfloat other_dir[3], this_dir[3]; + ALfloat listener_pos[3]; + ALfloat local_norm[3]; + ALfloat local_dir[3]; + ALfloat near_edge[3]; + ALfloat far_edge[3]; + ALfloat dist, edist; + + /* Update the listener position for the amount of time passed. This uses a + * simple triangular LFO to offset the position (moves along the X axis + * between -listener_move_scale and +listener_move_scale for each + * transition). + */ + listener_pos[0] = (fabsf(2.0f - timediff/2.0f) - 1.0f) * listener_move_scale; + listener_pos[1] = 0.0f; + listener_pos[2] = 0.0f; + alListenerfv(AL_POSITION, listener_pos); + + /* Calculate local_dir, which represents the listener-relative point to the + * adjacent zone (should also include orientation). Because EAX Reverb uses + * right-handed coordinates instead of left-handed like the rest of OpenAL, + * negate Z for the local values. + */ + local_dir[0] = portal_pos[0] - listener_pos[0]; + local_dir[1] = portal_pos[1] - listener_pos[1]; + local_dir[2] = -(portal_pos[2] - listener_pos[2]); + /* A normal application would also rotate the portal's normal given the + * listener orientation, to get the listener-relative normal. + */ + local_norm[0] = portal_norm[0]; + local_norm[1] = portal_norm[1]; + local_norm[2] = -portal_norm[2]; + + /* Calculate the distance from the listener to the portal, and ensure it's + * far enough away to not suffer severe floating-point precision issues. + */ + dist = sqrtf(dot_product(local_dir, local_dir)); + if(dist > 0.00001f) + { + const EFXEAXREVERBPROPERTIES *other_reverb, *this_reverb; + ALuint other_effect, this_effect; + ALfloat magnitude, dir_dot_norm; + + /* Normalize the direction to the portal. */ + local_dir[0] /= dist; + local_dir[1] /= dist; + local_dir[2] /= dist; + + /* Calculate the dot product of the portal's local direction and local + * normal, which is used for angular and side checks later on. + */ + dir_dot_norm = dot_product(local_dir, local_norm); + + /* Figure out which zone we're in. */ + if(dir_dot_norm <= 0.0f) + { + /* We're in front of the portal, so we're in Zone 0. */ + this_effect = effects[0]; + other_effect = effects[1]; + this_reverb = &reverbs[0]; + other_reverb = &reverbs[1]; + } + else + { + /* We're behind the portal, so we're in Zone 1. */ + this_effect = effects[1]; + other_effect = effects[0]; + this_reverb = &reverbs[1]; + other_reverb = &reverbs[0]; + } + + /* Calculate the listener-relative extents of the portal. */ + /* First, project the listener-to-portal vector onto the portal's plane + * to get the portal-relative direction along the plane that goes away + * from the listener (toward the farthest edge of the portal). + */ + far_edge[0] = local_dir[0] - local_norm[0]*dir_dot_norm; + far_edge[1] = local_dir[1] - local_norm[1]*dir_dot_norm; + far_edge[2] = local_dir[2] - local_norm[2]*dir_dot_norm; + + edist = sqrtf(dot_product(far_edge, far_edge)); + if(edist > 0.0001f) + { + /* Rescale the portal-relative vector to be at the radius edge. */ + ALfloat mag = portal_radius / edist; + far_edge[0] *= mag; + far_edge[1] *= mag; + far_edge[2] *= mag; + + /* Calculate the closest edge of the portal by negating the + * farthest, and add an offset to make them both relative to the + * listener. + */ + near_edge[0] = local_dir[0]*dist - far_edge[0]; + near_edge[1] = local_dir[1]*dist - far_edge[1]; + near_edge[2] = local_dir[2]*dist - far_edge[2]; + far_edge[0] += local_dir[0]*dist; + far_edge[1] += local_dir[1]*dist; + far_edge[2] += local_dir[2]*dist; + + /* Normalize the listener-relative extents of the portal, then + * calculate the panning magnitude for the other zone given the + * apparent size of the opening. The panning magnitude affects the + * envelopment of the environment, with 1 being a point, 0.5 being + * half coverage around the listener, and 0 being full coverage. + */ + normalize(far_edge); + normalize(near_edge); + magnitude = 1.0f - acosf(dot_product(far_edge, near_edge))/(float)(M_PI*2.0); + + /* Recalculate the panning direction, to be directly between the + * direction of the two extents. + */ + local_dir[0] = far_edge[0] + near_edge[0]; + local_dir[1] = far_edge[1] + near_edge[1]; + local_dir[2] = far_edge[2] + near_edge[2]; + normalize(local_dir); + } + else + { + /* If we get here, the listener is directly in front of or behind + * the center of the portal, making all aperture edges effectively + * equidistant. Calculating the panning magnitude is simplified, + * using the arctangent of the radius and distance. + */ + magnitude = 1.0f - (atan2f(portal_radius, dist) / (float)M_PI); + } + + /* Scale the other zone's panning vector. */ + other_dir[0] = local_dir[0] * magnitude; + other_dir[1] = local_dir[1] * magnitude; + other_dir[2] = local_dir[2] * magnitude; + /* Pan the current zone to the opposite direction of the portal, and + * take the remaining percentage of the portal's magnitude. + */ + this_dir[0] = local_dir[0] * (magnitude-1.0f); + this_dir[1] = local_dir[1] * (magnitude-1.0f); + this_dir[2] = local_dir[2] * (magnitude-1.0f); + + /* Now set the effects' panning vectors and gain. Energy is shared + * between environments, so attenuate according to each zone's + * contribution (note: gain^2 = energy). + */ + alEffectf(this_effect, AL_EAXREVERB_REFLECTIONS_GAIN, this_reverb->flReflectionsGain * sqrtf(magnitude)); + alEffectf(this_effect, AL_EAXREVERB_LATE_REVERB_GAIN, this_reverb->flLateReverbGain * sqrtf(magnitude)); + alEffectfv(this_effect, AL_EAXREVERB_REFLECTIONS_PAN, this_dir); + alEffectfv(this_effect, AL_EAXREVERB_LATE_REVERB_PAN, this_dir); + + alEffectf(other_effect, AL_EAXREVERB_REFLECTIONS_GAIN, other_reverb->flReflectionsGain * sqrtf(1.0f-magnitude)); + alEffectf(other_effect, AL_EAXREVERB_LATE_REVERB_GAIN, other_reverb->flLateReverbGain * sqrtf(1.0f-magnitude)); + alEffectfv(other_effect, AL_EAXREVERB_REFLECTIONS_PAN, other_dir); + alEffectfv(other_effect, AL_EAXREVERB_LATE_REVERB_PAN, other_dir); + } + else + { + /* We're practically in the center of the portal. Give the panning + * vectors a 50/50 split, with Zone 0 covering the half in front of + * the normal, and Zone 1 covering the half behind. + */ + this_dir[0] = local_norm[0] / 2.0f; + this_dir[1] = local_norm[1] / 2.0f; + this_dir[2] = local_norm[2] / 2.0f; + + other_dir[0] = local_norm[0] / -2.0f; + other_dir[1] = local_norm[1] / -2.0f; + other_dir[2] = local_norm[2] / -2.0f; + + alEffectf(effects[0], AL_EAXREVERB_REFLECTIONS_GAIN, reverbs[0].flReflectionsGain * sqrtf(0.5f)); + alEffectf(effects[0], AL_EAXREVERB_LATE_REVERB_GAIN, reverbs[0].flLateReverbGain * sqrtf(0.5f)); + alEffectfv(effects[0], AL_EAXREVERB_REFLECTIONS_PAN, this_dir); + alEffectfv(effects[0], AL_EAXREVERB_LATE_REVERB_PAN, this_dir); + + alEffectf(effects[1], AL_EAXREVERB_REFLECTIONS_GAIN, reverbs[1].flReflectionsGain * sqrtf(0.5f)); + alEffectf(effects[1], AL_EAXREVERB_LATE_REVERB_GAIN, reverbs[1].flLateReverbGain * sqrtf(0.5f)); + alEffectfv(effects[1], AL_EAXREVERB_REFLECTIONS_PAN, other_dir); + alEffectfv(effects[1], AL_EAXREVERB_LATE_REVERB_PAN, other_dir); + } + + /* Finally, update the effect slots with the updated effect parameters. */ + alAuxiliaryEffectSloti(slots[0], AL_EFFECTSLOT_EFFECT, effects[0]); + alAuxiliaryEffectSloti(slots[1], AL_EFFECTSLOT_EFFECT, effects[1]); +} + int main(int argc, char **argv) { static const int MaxTransitions = 8; - EFXEAXREVERBPROPERTIES reverb0 = EFX_REVERB_PRESET_CARPETEDHALLWAY; - EFXEAXREVERBPROPERTIES reverb1 = EFX_REVERB_PRESET_BATHROOM; + EFXEAXREVERBPROPERTIES reverbs[2] = { + EFX_REVERB_PRESET_CARPETEDHALLWAY, + EFX_REVERB_PRESET_BATHROOM + }; struct timespec basetime; ALCdevice *device = NULL; ALCcontext *context = NULL; @@ -363,7 +578,7 @@ int main(int argc, char **argv) * relative to the listener. */ alGenEffects(2, effects); - if(!LoadEffect(effects[0], &reverb0) || !LoadEffect(effects[1], &reverb1)) + if(!LoadEffect(effects[0], &reverbs[0]) || !LoadEffect(effects[1], &reverbs[1])) { alDeleteEffects(2, effects); alDeleteBuffers(1, &buffer); @@ -396,10 +611,13 @@ int main(int argc, char **argv) alFilterf(direct_filter, AL_LOWPASS_GAIN, direct_gain); assert(alGetError()==AL_NO_ERROR && "Failed to set direct filter"); - /* Create the source to play the sound with. */ + /* Create the source to play the sound with, place it in front of the + * listener's path in the left zone. + */ source = 0; alGenSources(1, &source); alSourcei(source, AL_LOOPING, AL_TRUE); + alSource3f(source, AL_POSITION, -5.0f, 0.0f, -2.0f); alSourcei(source, AL_DIRECT_FILTER, direct_filter); alSourcei(source, AL_BUFFER, buffer); @@ -407,7 +625,8 @@ int main(int argc, char **argv) * to Zone 0's slot, and send 1 to Zone 1's slot. Filters can be specified * to occlude the source from each zone by varying amounts; for example, a * source within a particular zone would be unfiltered, while a source that - * can only see a zone through a window may be attenuated for that zone. + * can only see a zone through a window or thin wall may be attenuated for + * that zone. */ alSource3i(source, AL_AUXILIARY_SEND_FILTER, slots[0], 0, AL_FILTER_NULL); alSource3i(source, AL_AUXILIARY_SEND_FILTER, slots[1], 1, AL_FILTER_NULL); @@ -421,23 +640,8 @@ int main(int argc, char **argv) /* Play the sound for a while. */ alSourcePlay(source); do { - /* Individual reverb zones are connected via "portals". Each portal has - * a position (center point of the connecting area), a normal (facing - * direction), and a radius (approximate size of the connecting area). - * For this example it also has movement velocity, although normally it - * would be the listener that moves relative to the portal instead of - * the portal itself. - */ - const ALfloat portal_pos[3] = { -10.0f, 0.0f, 0.0f }; - const ALfloat portal_norm[3] = { 1.0f, 0.0f, 0.0f }; - const ALfloat portal_vel[3] = { 5.0f, 0.0f, 0.0f }; - const ALfloat portal_radius = 2.5f; - ALfloat other_dir[3], this_dir[3]; - ALfloat local_norm[3]; - ALfloat local_dir[3]; - ALfloat local_radius; - ALfloat dist, timediff; struct timespec curtime; + ALfloat timediff; /* Start a batch update, to ensure all changes apply simultaneously. */ alcSuspendContext(context); @@ -452,136 +656,25 @@ int main(int argc, char **argv) /* Avoid negative time deltas, in case of non-monotonic clocks. */ if(timediff < 0.0f) timediff = 0.0f; - else while(timediff >= 4.0f) + else while(timediff >= 4.0f*((loops&1)+1)) { - /* For this example, each transition occurs over 4 seconds. - * Decrease the delta and increase the base time to start a new - * transition. + /* For this example, each transition occurs over 4 seconds, and + * there's 2 transitions per cycle. */ - timediff -= 4.0f; - basetime.tv_sec += 4; if(++loops < MaxTransitions) printf("Transition %d of %d...\n", loops+1, MaxTransitions); - } - - /* Move the portal according to the amount of time passed. local_dir - * represents the listener-relative point to the adjacent zone. - */ - local_dir[0] = portal_pos[0] + portal_vel[0]*timediff; - local_dir[1] = portal_pos[1] + portal_vel[1]*timediff; - local_dir[2] = portal_pos[2] + portal_vel[2]*timediff; - /* A normal application would also rotate the portal's normal given the - * listener orientation, to get the listener-relative normal. - * - * For this example, the portal is always head-on but every other - * transition negates the normal. This effectively simulates a - * different portal moving in closer than the last one that faces the - * other way, switching the old adjacent zone to a new one. - */ - local_norm[0] = portal_norm[0] * ((loops&1) ? -1.0f : 1.0f); - local_norm[1] = portal_norm[1] * ((loops&1) ? -1.0f : 1.0f); - local_norm[2] = portal_norm[2] * ((loops&1) ? -1.0f : 1.0f); - - /* Calculate the distance from the listener to the portal. */ - dist = sqrtf(dot_product(local_dir, local_dir)); - if(!(dist > 0.00001f)) - { - /* We're practically in the center of the portal. Give the panning - * vectors a 50/50 split, with Zone 0 covering the half in front of - * the normal, and Zone 1 covering the half behind. - */ - this_dir[0] = local_norm[0] / 2.0f; - this_dir[1] = local_norm[1] / 2.0f; - this_dir[2] = local_norm[2] / 2.0f; - - other_dir[0] = local_norm[0] / -2.0f; - other_dir[1] = local_norm[1] / -2.0f; - other_dir[2] = local_norm[2] / -2.0f; - - alEffectf(effects[0], AL_EAXREVERB_GAIN, reverb0.flGain); - alEffectfv(effects[0], AL_EAXREVERB_REFLECTIONS_PAN, this_dir); - alEffectfv(effects[0], AL_EAXREVERB_LATE_REVERB_PAN, this_dir); - - alEffectf(effects[1], AL_EAXREVERB_GAIN, reverb1.flGain); - alEffectfv(effects[1], AL_EAXREVERB_REFLECTIONS_PAN, other_dir); - alEffectfv(effects[1], AL_EAXREVERB_LATE_REVERB_PAN, other_dir); - } - else - { - const EFXEAXREVERBPROPERTIES *other_reverb; - const EFXEAXREVERBPROPERTIES *this_reverb; - ALuint other_effect, this_effect; - ALfloat spread, attn; - - /* Normalize the direction to the portal. */ - local_dir[0] /= dist; - local_dir[1] /= dist; - local_dir[2] /= dist; - - /* Scale the radius according to its local angle. The visibility to - * the other zone reduces as the portal becomes perpendicular. - */ - local_radius = portal_radius * fabsf(dot_product(local_dir, local_norm)); - - /* Calculate distance attenuation for the other zone, using the - * standard inverse distance model with the radius as a reference. - */ - attn = local_radius / dist; - if(attn > 1.0f) attn = 1.0f; - - /* Calculate the 'spread' of the portal, which is the amount of - * coverage the other zone has around the listener. - */ - spread = atan2f(local_radius, dist) / (ALfloat)M_PI; - - /* Figure out which zone we're in, given the direction to the - * portal and its normal. - */ - if(dot_product(local_dir, local_norm) <= 0.0f) - { - /* We're in front of the portal, so we're in Zone 0. */ - this_effect = effects[0]; - other_effect = effects[1]; - this_reverb = &reverb0; - other_reverb = &reverb1; - } - else + if(!(loops&1)) { - /* We're behind the portal, so we're in Zone 1. */ - this_effect = effects[1]; - other_effect = effects[0]; - this_reverb = &reverb1; - other_reverb = &reverb0; + /* Cycle completed. Decrease the delta and increase the base + * time to start a new cycle. + */ + timediff -= 8.0f; + basetime.tv_sec += 8; } - - /* Scale the other zone's panning vector down as the portal's - * spread increases, so that it envelops the listener more. - */ - other_dir[0] = local_dir[0] * (1.0f-spread); - other_dir[1] = local_dir[1] * (1.0f-spread); - other_dir[2] = local_dir[2] * (1.0f-spread); - /* Pan the current zone to the opposite direction of the portal, - * and take the remaining percentage of the portal's spread. - */ - this_dir[0] = local_dir[0] * -spread; - this_dir[1] = local_dir[1] * -spread; - this_dir[2] = local_dir[2] * -spread; - - /* Now set the effects' panning vectors and distance attenuation. */ - alEffectf(this_effect, AL_EAXREVERB_GAIN, this_reverb->flGain); - alEffectfv(this_effect, AL_EAXREVERB_REFLECTIONS_PAN, this_dir); - alEffectfv(this_effect, AL_EAXREVERB_LATE_REVERB_PAN, this_dir); - - alEffectf(other_effect, AL_EAXREVERB_GAIN, other_reverb->flGain * attn); - alEffectfv(other_effect, AL_EAXREVERB_REFLECTIONS_PAN, other_dir); - alEffectfv(other_effect, AL_EAXREVERB_LATE_REVERB_PAN, other_dir); } - /* Finally, update the effect slots with the updated effect parameters, - * and finish the update batch. - */ - alAuxiliaryEffectSloti(slots[0], AL_EFFECTSLOT_EFFECT, effects[0]); - alAuxiliaryEffectSloti(slots[1], AL_EFFECTSLOT_EFFECT, effects[1]); + /* Update the listener and effects, and finish the batch. */ + UpdateListenerAndEffects(timediff, slots, effects, reverbs); alcProcessContext(context); al_nssleep(10000000); |