text: #include "stdio.h"
  #ifndef mips
  #include "stdlib.h"
  #endif
  #include "xlisp.h"
  #include "sound.h"
  
  #include "falloc.h"
  #include "cext.h"
  #include "sqrt.h"
  
  void sqrt_free();
  
  
  typedef struct sqrt_susp_struct {
      snd_susp_node susp;
      long terminate_cnt;
      boolean logically_stopped;
      sound_type input;
      long input_cnt;
      sample_block_values_type input_ptr;
  } sqrt_susp_node, *sqrt_susp_type;
  
  
  void sqrt_s_fetch(register sqrt_susp_type susp, snd_list_type snd_list)
  {
      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 sample_type input_scale_reg = susp->input->scale;
      register sample_block_values_type input_ptr_reg;
      falloc_sample_block(out, "sqrt_s_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 input input sample block: */
  	susp_check_term_log_samples(input, input_ptr, input_cnt);
  	togo = min(togo, susp->input_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) break;
  	}
  
  
  	/* don't run past logical stop time */
  	if (!susp->logically_stopped && susp->susp.log_stop_cnt != UNKNOWN) {
  	    int to_stop = susp->susp.log_stop_cnt - (susp->susp.current + cnt);
  	    /* break if to_stop == 0 (we're at the logical stop)
  	     * AND cnt > 0 (we're not at the beginning of the
  	     * output block).
  	     */
  	    if (to_stop < togo) {
  		if (to_stop == 0) {
  		    if (cnt) {
  			togo = 0;
  			break;
  		    } else /* keep togo as is: since cnt == 0, we
  		            * can set the logical stop flag on this
  		            * output block
  		            */
  			susp->logically_stopped = true;
  		} else /* limit togo so we can start a new
  		        * block at the LST
  		        */
  		    togo = to_stop;
  	    }
  	}
  
  	n = togo;
  	input_ptr_reg = susp->input_ptr;
  	out_ptr_reg = out_ptr;
  	if (n) do { /* the inner sample computation loop */
  { sample_type i = (input_scale_reg * *input_ptr_reg++); if (i < 0) i = 0; *out_ptr_reg++ = (sample_type) sqrt(i); };
  	} while (--n); /* inner loop */
  
  	/* using input_ptr_reg is a bad idea on RS/6000: */
  	susp->input_ptr += togo;
  	out_ptr += togo;
  	susp_took(input_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;
      }
      /* test for logical stop */
      if (susp->logically_stopped) {
  	snd_list->logically_stopped = true;
      } else if (susp->susp.log_stop_cnt == susp->susp.current) {
  	susp->logically_stopped = true;
      }
  } /* sqrt_s_fetch */
  
  
  void sqrt_toss_fetch(susp, snd_list)
    register sqrt_susp_type susp;
    snd_list_type snd_list;
  {
      long final_count = susp->susp.toss_cnt;
      time_type final_time = susp->susp.t0;
      long n;
  
      /* fetch samples from input up to final_time for this block of zeros */
      while ((round((final_time - susp->input->t0) * susp->input->sr)) >=
  	   susp->input->current)
  	susp_get_samples(input, input_ptr, input_cnt);
      /* convert to normal processing when we hit final_count */
      /* we want each signal positioned at final_time */
      n = round((final_time - susp->input->t0) * susp->input->sr -
           (susp->input->current - susp->input_cnt));
      susp->input_ptr += n;
      susp_took(input_cnt, n);
      susp->susp.fetch = susp->susp.keep_fetch;
      (*(susp->susp.fetch))(susp, snd_list);
  }
  
  
  void sqrt_mark(sqrt_susp_type susp)
  {
      sound_xlmark(susp->input);
  }
  
  
  void sqrt_free(sqrt_susp_type susp)
  {
      sound_unref(susp->input);
      ffree_generic(susp, sizeof(sqrt_susp_node), "sqrt_free");
  }
  
  
  void sqrt_print_tree(sqrt_susp_type susp, int n)
  {
      indent(n);
      stdputstr("input:");
      sound_print_tree_1(susp->input, n);
  }
  
  
  sound_type snd_make_sqrt(sound_type input)
  {
      register sqrt_susp_type susp;
      rate_type sr = input->sr;
      time_type t0 = input->t0;
      int interp_desc = 0;
      sample_type scale_factor = 1.0F;
      time_type t0_min = t0;
      falloc_generic(susp, sqrt_susp_node, "snd_make_sqrt");
      susp->susp.fetch = sqrt_s_fetch;
      susp->terminate_cnt = UNKNOWN;
      /* handle unequal start times, if any */
      if (t0 < input->t0) sound_prepend_zeros(input, t0);
      /* minimum start time over all inputs: */
      t0_min = min(input->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 = sqrt_toss_fetch;
      }
  
      /* initialize susp state */
      susp->susp.free = sqrt_free;
      susp->susp.sr = sr;
      susp->susp.t0 = t0;
      susp->susp.mark = sqrt_mark;
      susp->susp.print_tree = sqrt_print_tree;
      susp->susp.name = "sqrt";
      susp->logically_stopped = false;
      susp->susp.log_stop_cnt = logical_stop_cnt_cvt(input);
      susp->susp.current = 0;
      susp->input = input;
      susp->input_cnt = 0;
      return sound_create((snd_susp_type)susp, t0, sr, scale_factor);
  }
  
  
  sound_type snd_sqrt(sound_type input)
  {
      sound_type input_copy = sound_copy(input);
      return snd_make_sqrt(input_copy);
  }
  