text: #include "stdio.h"
  #ifndef mips
  #include "stdlib.h"
  #endif
  #include "xlisp.h"
  #include "sound.h"
  
  #include "falloc.h"
  #include "cext.h"
  #include "instrbowedfreq.h"
  
  void bowed_freq_free(snd_susp_type a_susp);
  
  
  typedef struct bowed_freq_susp_struct {
      snd_susp_node susp;
      long terminate_cnt;
      sound_type bowpress_env;
      long bowpress_env_cnt;
      sample_block_values_type bowpress_env_ptr;
      sound_type freq_env;
      long freq_env_cnt;
      sample_block_values_type freq_env_ptr;
  
      struct instr *mybow;
      int temp_ret_value;
      float bow_scale;
      double frequency;
  } bowed_freq_susp_node, *bowed_freq_susp_type;
  
  #include "instr.h"
  #include "upsample.h"
  
  
  void bowed_freq_ns_fetch(snd_susp_type a_susp, snd_list_type snd_list)
  {
      bowed_freq_susp_type susp = (bowed_freq_susp_type) a_susp;
      int cnt = 0; /* how many samples computed */
      int togo;
      int n;
      sample_block_type out;
      register sample_block_values_type out_ptr;
  
      register sample_block_values_type out_ptr_reg;
  
      register struct instr * mybow_reg;
      register float bow_scale_reg;
      register double frequency_reg;
      register sample_type freq_env_scale_reg = susp->freq_env->scale;
      register sample_block_values_type freq_env_ptr_reg;
      register sample_block_values_type bowpress_env_ptr_reg;
      falloc_sample_block(out, "bowed_freq_ns_fetch");
      out_ptr = out->samples;
      snd_list->block = out;
  
      while (cnt < max_sample_block_len) { /* outer loop */
  	/* first compute how many samples to generate in inner loop: */
  	/* don't overflow the output sample block: */
  	togo = max_sample_block_len - cnt;
  
  	/* don't run past the bowpress_env input sample block: */
  	susp_check_term_samples(bowpress_env, bowpress_env_ptr, bowpress_env_cnt);
  	togo = min(togo, susp->bowpress_env_cnt);
  
  	/* don't run past the freq_env input sample block: */
  	susp_check_samples(freq_env, freq_env_ptr, freq_env_cnt);
  	togo = min(togo, susp->freq_env_cnt);
  
  	/* don't run past terminate time */
  	if (susp->terminate_cnt != UNKNOWN &&
  	    susp->terminate_cnt <= susp->susp.current + cnt + togo) {
  	    togo = susp->terminate_cnt - (susp->susp.current + cnt);
  	    if (togo < 0) togo = 0;  /* avoids rounding errros */
  	    if (togo == 0) break;
  	}
  
  	n = togo;
  	mybow_reg = susp->mybow;
  	bow_scale_reg = susp->bow_scale;
  	frequency_reg = susp->frequency;
  	freq_env_ptr_reg = susp->freq_env_ptr;
  	bowpress_env_ptr_reg = susp->bowpress_env_ptr;
  	out_ptr_reg = out_ptr;
  	if (n) do { /* the inner sample computation loop */
              controlChange(mybow_reg, 128, bow_scale_reg * *bowpress_env_ptr_reg++);
              setFrequency(mybow_reg, frequency_reg + (freq_env_scale_reg * *freq_env_ptr_reg++));
              *out_ptr_reg++ = (sample_type) tick(mybow_reg);
  	} while (--n); /* inner loop */
  
  	susp->mybow = mybow_reg;
  	/* using freq_env_ptr_reg is a bad idea on RS/6000: */
  	susp->freq_env_ptr += togo;
  	/* using bowpress_env_ptr_reg is a bad idea on RS/6000: */
  	susp->bowpress_env_ptr += togo;
  	out_ptr += togo;
  	susp_took(bowpress_env_cnt, togo);
  	susp_took(freq_env_cnt, togo);
  	cnt += togo;
      } /* outer loop */
  
      /* test for termination */
      if (togo == 0 && cnt == 0) {
  	snd_list_terminate(snd_list);
      } else {
  	snd_list->block_len = cnt;
  	susp->susp.current += cnt;
      }
  } /* bowed_freq_ns_fetch */
  
  
  void bowed_freq_toss_fetch(snd_susp_type a_susp, snd_list_type snd_list)
      {
      bowed_freq_susp_type susp = (bowed_freq_susp_type) a_susp;
      time_type final_time = susp->susp.t0;
      long n;
  
      /* fetch samples from bowpress_env up to final_time for this block of zeros */
      while ((ROUNDBIG((final_time - susp->bowpress_env->t0) * susp->bowpress_env->sr)) >=
  	   susp->bowpress_env->current)
  	susp_get_samples(bowpress_env, bowpress_env_ptr, bowpress_env_cnt);
      /* fetch samples from freq_env up to final_time for this block of zeros */
      while ((ROUNDBIG((final_time - susp->freq_env->t0) * susp->freq_env->sr)) >=
  	   susp->freq_env->current)
  	susp_get_samples(freq_env, freq_env_ptr, freq_env_cnt);
      /* convert to normal processing when we hit final_count */
      /* we want each signal positioned at final_time */
      n = ROUNDBIG((final_time - susp->bowpress_env->t0) * susp->bowpress_env->sr -
           (susp->bowpress_env->current - susp->bowpress_env_cnt));
      susp->bowpress_env_ptr += n;
      susp_took(bowpress_env_cnt, n);
      n = ROUNDBIG((final_time - susp->freq_env->t0) * susp->freq_env->sr -
           (susp->freq_env->current - susp->freq_env_cnt));
      susp->freq_env_ptr += n;
      susp_took(freq_env_cnt, n);
      susp->susp.fetch = susp->susp.keep_fetch;
      (*(susp->susp.fetch))(a_susp, snd_list);
  }
  
  
  void bowed_freq_mark(snd_susp_type a_susp)
  {
      bowed_freq_susp_type susp = (bowed_freq_susp_type) a_susp;
      sound_xlmark(susp->bowpress_env);
      sound_xlmark(susp->freq_env);
  }
  
  
  void bowed_freq_free(snd_susp_type a_susp)
  {
      bowed_freq_susp_type susp = (bowed_freq_susp_type) a_susp;
      deleteInstrument(susp->mybow);
      sound_unref(susp->bowpress_env);
      sound_unref(susp->freq_env);
      ffree_generic(susp, sizeof(bowed_freq_susp_node), "bowed_freq_free");
  }
  
  
  void bowed_freq_print_tree(snd_susp_type a_susp, int n)
  {
      bowed_freq_susp_type susp = (bowed_freq_susp_type) a_susp;
      indent(n);
      stdputstr("bowpress_env:");
      sound_print_tree_1(susp->bowpress_env, n);
  
      indent(n);
      stdputstr("freq_env:");
      sound_print_tree_1(susp->freq_env, n);
  }
  
  
  sound_type snd_make_bowed_freq(double freq, sound_type bowpress_env, sound_type freq_env, rate_type sr)
  {
      register bowed_freq_susp_type susp;
      /* sr specified as input parameter */
      time_type t0 = bowpress_env->t0;
      sample_type scale_factor = 1.0F;
      time_type t0_min = t0;
      falloc_generic(susp, bowed_freq_susp_node, "snd_make_bowed_freq");
      susp->mybow = initInstrument(BOWED, ROUND32(sr));
      controlChange(susp->mybow, 1, 0.0);;
      susp->temp_ret_value = noteOn(susp->mybow, freq, 1.0);
      susp->bow_scale = bowpress_env->scale * BOW_CONTROL_CHANGE_CONST;
      susp->frequency = freq;
  
      /* make sure no sample rate is too high */
      if (bowpress_env->sr > sr) {
          sound_unref(bowpress_env);
          snd_badsr();
      } else if (bowpress_env->sr < sr) bowpress_env = snd_make_up(sr, bowpress_env);
      if (freq_env->sr > sr) {
          sound_unref(freq_env);
          snd_badsr();
      } else if (freq_env->sr < sr) freq_env = snd_make_up(sr, freq_env);
      susp->susp.fetch = bowed_freq_ns_fetch;
      susp->terminate_cnt = UNKNOWN;
      /* handle unequal start times, if any */
      if (t0 < bowpress_env->t0) sound_prepend_zeros(bowpress_env, t0);
      if (t0 < freq_env->t0) sound_prepend_zeros(freq_env, t0);
      /* minimum start time over all inputs: */
      t0_min = min(bowpress_env->t0, min(freq_env->t0, t0));
      /* how many samples to toss before t0: */
      susp->susp.toss_cnt = (long) ((t0 - t0_min) * sr + 0.5);
      if (susp->susp.toss_cnt > 0) {
          susp->susp.keep_fetch = susp->susp.fetch;
          susp->susp.fetch = bowed_freq_toss_fetch;
      }
  
      /* initialize susp state */
      susp->susp.free = bowed_freq_free;
      susp->susp.sr = sr;
      susp->susp.t0 = t0;
      susp->susp.mark = bowed_freq_mark;
      susp->susp.print_tree = bowed_freq_print_tree;
      susp->susp.name = "bowed_freq";
      susp->susp.log_stop_cnt = UNKNOWN;
      susp->susp.current = 0;
      susp->bowpress_env = bowpress_env;
      susp->bowpress_env_cnt = 0;
      susp->freq_env = freq_env;
      susp->freq_env_cnt = 0;
      return sound_create((snd_susp_type)susp, t0, sr, scale_factor);
  }
  
  
  sound_type snd_bowed_freq(double freq, sound_type bowpress_env, sound_type freq_env, rate_type sr)
  {
      sound_type bowpress_env_copy = sound_copy(bowpress_env);
      sound_type freq_env_copy = sound_copy(freq_env);
      return snd_make_bowed_freq(freq, bowpress_env_copy, freq_env_copy, sr);
  }
  