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Diffstat (limited to 'libs/fluidsynth/src/fluid_adsr_env.h')
| -rw-r--r-- | libs/fluidsynth/src/fluid_adsr_env.h | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/libs/fluidsynth/src/fluid_adsr_env.h b/libs/fluidsynth/src/fluid_adsr_env.h new file mode 100644 index 0000000000..31303a9ce9 --- /dev/null +++ b/libs/fluidsynth/src/fluid_adsr_env.h @@ -0,0 +1,162 @@ +/* FluidSynth - A Software Synthesizer + * + * Copyright (C) 2003 Peter Hanappe and others. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public License + * as published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA + */ + +#ifndef _FLUID_ADSR_ENVELOPE_H +#define _FLUID_ADSR_ENVELOPE_H + +#include "fluidsynth_priv.h" +#include "fluid_sys.h" + +/* + * envelope data + */ +struct _fluid_env_data_t { + unsigned int count; + fluid_real_t coeff; + fluid_real_t increment; + fluid_real_t min; + fluid_real_t max; +}; + +/* Indices for envelope tables */ +enum fluid_voice_envelope_index_t{ + FLUID_VOICE_ENVDELAY, + FLUID_VOICE_ENVATTACK, + FLUID_VOICE_ENVHOLD, + FLUID_VOICE_ENVDECAY, + FLUID_VOICE_ENVSUSTAIN, + FLUID_VOICE_ENVRELEASE, + FLUID_VOICE_ENVFINISHED, + FLUID_VOICE_ENVLAST +}; + +typedef enum fluid_voice_envelope_index_t fluid_adsr_env_section_t; + +typedef struct _fluid_adsr_env_t fluid_adsr_env_t; + +struct _fluid_adsr_env_t { + fluid_env_data_t data[FLUID_VOICE_ENVLAST]; + unsigned int count; + int section; + fluid_real_t val; /* the current value of the envelope */ +}; + +/* For performance, all functions are inlined */ + +static FLUID_INLINE void +fluid_adsr_env_calc(fluid_adsr_env_t* env, int is_volenv) +{ + fluid_env_data_t* env_data; + fluid_real_t x; + + env_data = &env->data[env->section]; + + /* skip to the next section of the envelope if necessary */ + while (env->count >= env_data->count) + { + // If we're switching envelope stages from decay to sustain, force the value to be the end value of the previous stage + // Hmm, should this only apply to volenv? It was so before refactoring, so keep it for now. [DH] + if (env->section == FLUID_VOICE_ENVDECAY && is_volenv) + env->val = env_data->min * env_data->coeff; + + env_data = &env->data[++env->section]; + env->count = 0; + } + + /* calculate the envelope value and check for valid range */ + x = env_data->coeff * env->val + env_data->increment; + + if (x < env_data->min) + { + x = env_data->min; + env->section++; + env->count = 0; + } + else if (x > env_data->max) + { + x = env_data->max; + env->section++; + env->count = 0; + } + + env->val = x; + env->count++; +} + +/* This one cannot be inlined since it is referenced in + the event queue */ +void +fluid_adsr_env_set_data(fluid_adsr_env_t* env, + fluid_adsr_env_section_t section, + unsigned int count, + fluid_real_t coeff, + fluid_real_t increment, + fluid_real_t min, + fluid_real_t max); + +static inline void +fluid_adsr_env_reset(fluid_adsr_env_t* env) +{ + env->count = 0; + env->section = 0; + env->val = 0.0f; +} + +static inline fluid_real_t +fluid_adsr_env_get_val(fluid_adsr_env_t* env) +{ + return env->val; +} + +static inline void +fluid_adsr_env_set_val(fluid_adsr_env_t* env, fluid_real_t val) +{ + env->val = val; +} + +static inline fluid_adsr_env_section_t +fluid_adsr_env_get_section(fluid_adsr_env_t* env) +{ + return env->section; +} + +static inline void +fluid_adsr_env_set_section(fluid_adsr_env_t* env, + fluid_adsr_env_section_t section) +{ + env->section = section; + env->count = 0; +} + +/* Used for determining which voice to kill. + Returns max amplitude from now, and forward in time. +*/ +static inline fluid_real_t +fluid_adsr_env_get_max_val(fluid_adsr_env_t* env) +{ + if (env->section > FLUID_VOICE_ENVATTACK){ + return env->val * 1000; + } else { + return env->data[FLUID_VOICE_ENVATTACK].max; + } +} + +#endif + |