[blockshuffle~] for shuffling samples in a block

svn path=/trunk/externals/zexy/; revision=5271

1 files changed, 148 insertions, 0 deletions

diff --git a/src/blockshuffle~.c b/src/blockshuffle~.c
new file mode 100644
index 0000000..772c792
--- /dev/null
+++ b/src/blockshuffle~.c
@@ -0,0 +1,148 @@
+/******************************************************
+ *
+ * zexy - implementation file
+ *
+ * copyleft (c) IOhannes m zmölnig
+ *
+ *   1999:forum::für::umläute:2004
+ *
+ *   institute of electronic music and acoustics (iem)
+ *
+ ******************************************************
+ *
+ * license: GNU General Public License v.2
+ *
+ ******************************************************/
+
+/*
+  1110:forum::für::umläute:1999
+*/
+
+#include "zexy.h"
+
+/* ------------------------ blockshuffle~ ----------------------------- */
+
+/* mirrors a signalblock around it's center:
+   {x[0], x[1], ... x[n-1]} --> {x[n-1], x[n-2], ... x[0]}
+*/
+
+static t_class *blockshuffle_class;
+
+typedef struct _blockshuffle
+{
+  t_object x_obj;
+
+  t_sample*blockbuf;
+  t_int*   indices;
+  int      size;
+
+  t_float *shuffle;
+  int shufflesize;
+} t_blockshuffle;
+
+static void blockshuffle_buildindex(t_blockshuffle *x, int blocksize){
+  int i=0;
+  if(blocksize!=x->size){
+    if(x->indices)freebytes(x->indices, x->size);
+    if(x->blockbuf)freebytes(x->blockbuf, x->size);
+    x->indices=getbytes (sizeof(t_int)*blocksize);
+    x->blockbuf=getbytes(sizeof(t_sample)*blocksize);
+    x->size=blocksize;
+  }
+  for(i=0;i<x->shufflesize&&i<blocksize; i++){
+    int idx=x->shuffle[i];
+    if(idx>=blocksize)idx=blocksize-1;
+    if(idx<0)idx=0;
+    x->indices[i]=idx;
+  }
+  for(;i<blocksize; i++){
+    x->indices[i]=i;
+  }
+}
+
+static void blockshuffle_list(t_blockshuffle *x, t_symbol*s, int argc, t_atom*argv)
+{
+  int i;
+  if(x->shuffle){
+    freebytes(x->shuffle, x->shufflesize);
+    x->shuffle=0;
+  }
+  x->shufflesize=argc;
+  x->shuffle=getbytes(sizeof(t_float)*argc);
+
+  for(i=0; i<argc; i++){
+    x->shuffle[i]=atom_getfloat(argv++);
+  }
+  blockshuffle_buildindex(x, x->size);
+}
+
+static t_int *blockshuffle_perform(t_int *w)
+{
+  t_blockshuffle*x = (t_blockshuffle *)(w[1]);
+  t_sample *in = (t_sample *)(w[2]);
+  t_sample *out = (t_sample *)(w[3]);
+  int n = (int)(w[4]);
+  int i=0;
+  t_sample *temp=x->blockbuf;
+  t_int    *idx =x->indices;
+
+  if(idx){
+  for(i=0; i<n; i++){
+    temp[i]=in[idx[i]];
+  }
+  temp=x->blockbuf;
+  for(i=0; i<n; i++){
+    *out++=*temp++;
+  }
+  } else
+    while(n--)*out++=*in++;
+
+  return (w+5);
+}
+
+static void blockshuffle_dsp(t_blockshuffle *x, t_signal **sp)
+{
+  blockshuffle_buildindex(x, sp[0]->s_n);
+
+  dsp_add(blockshuffle_perform, 4, x, sp[0]->s_vec, sp[1]->s_vec, sp[0]->s_n);
+}
+
+static void blockshuffle_helper(void)
+{
+  post("\n%c blockshuffle~-object for shuffling the samples within a signal-block", HEARTSYMBOL);
+  post("'help' : view this\n"
+       "signal~");
+  post("outlet : signal~");
+}
+static void blockshuffle_free(t_blockshuffle *x){
+  if(x->indices)freebytes(x->indices, x->size);
+  if(x->blockbuf)freebytes(x->blockbuf, x->size);
+  if(x->shuffle)freebytes(x->shuffle, x->shufflesize);
+}
+
+static void *blockshuffle_new(void)
+{
+  t_blockshuffle *x = (t_blockshuffle *)pd_new(blockshuffle_class);
+  outlet_new(&x->x_obj, gensym("signal"));
+  x->size=0;
+  x->blockbuf=0;
+  x->indices=0;
+  x->shuffle=0;
+  x->shufflesize=0;
+  return (x);
+}
+
+void blockshuffle_tilde_setup(void)
+{
+  blockshuffle_class = class_new(gensym("blockshuffle~"), (t_newmethod)blockshuffle_new, 
+                                 (t_method)blockshuffle_free,
+                                 sizeof(t_blockshuffle), 0, A_NULL);
+  class_addmethod(blockshuffle_class, nullfn, gensym("signal"), 0);
+  class_addmethod(blockshuffle_class, (t_method)blockshuffle_dsp, gensym("dsp"), 0);
+  
+  class_addlist(blockshuffle_class, blockshuffle_list);
+  
+  class_addmethod(blockshuffle_class, (t_method)blockshuffle_helper, gensym("help"), 0);
+  class_sethelpsymbol(blockshuffle_class, gensym("zexy/blockshuffle~"));
+  zexy_register("blockshuffle~");
+}