1 files changed, 92 insertions, 0 deletions
diff --git a/tran/ifft-old.alg b/tran/ifft-old.alg
new file mode 100644
index 0000000..442be85
--- /dev/null
+++ b/tran/ifft-old.alg
@@ -0,0 +1,92 @@
+(IFFT-ALG
+  (NAME "ifft")
+  (ARGUMENTS ("time_type" "t0") ("rate_type" "sr") ("LVAL" "src"))
+  (SUPPORT-FUNCTIONS "
+/* IMPLEMENTATION NOTE:
+ * The src argument is an XLisp object that returns either an
+ * array of samples or NIL. The output of ifft is simply the
+ * concatenation of the samples taken from the array. Later,
+ * an ifft will be plugged in and this will return overlapped
+ * adds of the ifft's.
+ */
+
+#include \"samples.h\"
+
+ /* IFFT code goes here */
+")
+
+  (SAMPLE-RATE "sr")
+  (STATE
+          ("long" "index" "0") ; samples index
+          ("long" "length" "0"); samples length
+          ("LVAL" "array" "NULL")
+        ("LVAL" "src" "src")
+        ("sample_type *" "samples" "NULL"))
+  
+  (OUTER-LOOP "
+        if (susp->src == NULL) {
+out:	    togo = 0;	/* indicate termination */
+            break;	/* we're done */
+        }
+        if (susp->index >= susp->length) {
+            long i;
+            susp->index = 0;
+            susp->array = xleval(cons(s_send, cons(susp->src, consa(s_next))));
+            susp->index = 0;
+            if (susp->array == NULL) {
+                susp->src = NULL;
+                goto out;
+            } else if (!vectorp(susp->array)) {
+                xlerror(\"array expected\", susp->array);
+            } else if (susp->samples == NULL) {
+                /* assume arrays are all the same size as first one;
+                   now that we know the size, we just have to do this
+                   first allocation.
+                 */
+                susp->length = getsize(susp->array);
+                if (susp->length < 1) xlerror(\"array has no elements\", susp->array);
+                susp->samples = 
+                    (sample_type *) calloc(susp->length,
+                                           sizeof(sample_type));
+            } else if (getsize(susp->array) != susp->length) {
+                xlerror(\"arrays must all be the same length\", susp->array);
+            }
+            /* at this point, we have a new array and a place to put samples */
+            for (i = 0; i < susp->length; i++) {
+                LVAL elem = getelement(susp->array, i);
+                if (ntype(elem) != FLONUM) {
+                    xlerror(\"flonum expected\", elem);
+                }
+                susp->samples[i] = (sample_type) getflonum(elem);
+            }
+            susp->array = NULL; /* free the array */
+            /* here is where the IFFT and windowing should take place */
+/*
+            temp_fft = (double *) malloc (susp->length * sizeof(double));
+            if (temp_fft == 0) return;
+            big_samples = (double *) malloc (susp->length * sizeof(double));
+            if (big_samples == 0) return;
+            for (i = 0; i < susp->length; i++) {
+                big_samples[i] = (double) susp->samples[i];
+            }
+            rp = rfftw_create_plan(susp->length, FFTW_COMPLEX_TO_REAL, FFTW_ESTIMATE);
+            rfftw_one(rp, big_samples, temp_fft);
+            rfftw_destroy_plan(rp);
+            free(big_samples);
+            for (i = 0; i < susp->length; i++) {
+                setelement(result, i, cvflonum(temp_fft[i]));
+            }
+            free (temp_fft);
+*/
+            
+        }
+        togo = min(togo, susp->length - susp->index);
+")
+  (INNER-LOOP "output = samples[index++];")
+  (CONSTANT "length" "samples" "array" "src")
+  (TERMINATE COMPUTED)
+  (FINALIZATION "    free(susp->samples);
+")
+
+)
+