From 5c1a81c657e5e635ff5973e53e86e77a4724df03 Mon Sep 17 00:00:00 2001
From: slack <slack@codemaniacs.com>
Date: Fri, 24 Jul 2009 23:39:14 +0200
Subject: [PATCH] added delay to synth

---
 synth.c | 22 +++++++++++++++++++++-
 synth.h |  5 +++--
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/synth.c b/synth.c
index 70bf606..56b8d4c 100644
--- a/synth.c
+++ b/synth.c
@@ -6,6 +6,11 @@
 
 extern float current_time;
 
+float noise()
+{
+    return 2.0f*(rand()/(float)RAND_MAX)-1.0f;
+}
+
 float detune(float base, int coarse, int fine)
 {
     return base*powf(2.0f, (coarse+(fine/100.0f))/12.0f);
@@ -63,7 +68,7 @@ uint8 synth(Voice *v, int len, float *mix_buf)
                         break;
                     }
                 case NOISE:
-                    v->waves[wave][i] = 2.0f*(rand()/(float)RAND_MAX)-1.0f;
+                    v->waves[wave][i] = noise();
                     break;
 
                 case SUM:
@@ -107,7 +112,22 @@ uint8 synth(Voice *v, int len, float *mix_buf)
                         v->waves[wave][i] = 1.0f - 1.0f/(1.0f+expf(-f*(time-d)));
                         break;
                     }
+                    
+                /*
 
+                case DELAY:
+                    {
+                        // op1: delay (ms), op2: volume (%)
+                        uint32 delay = op1*SAMPLE_RATE/1000.0f;
+                        float *data = (float*)(v->data[wave]+4);
+                        int *p      = (int*)(v->data[wave]);
+                        v->waves[wave][i] = (op2/100.0f)*data[*p];
+                        // circular buffer
+                        data[*p] = v->waves[wave-1][i];
+                        *p = (*p + 1)%delay;
+                        break;
+                    }
+                */
                 default:
                     goto end;
             }
diff --git a/synth.h b/synth.h
index 2383899..856f366 100644
--- a/synth.h
+++ b/synth.h
@@ -38,7 +38,7 @@ typedef struct
         // data buffer to store, for example, previous inputs/outputs for
         // filtering. It is as big as the wave buffer. Anyway, voices will be
         // created at bss, so they don't count for the file size :)
-        uint8 data[MAX_OPS][BUFFER_SIZE*sizeof(float)];
+        uint8 data[MAX_OPS][20*BUFFER_SIZE*sizeof(float)];
 
         // buffers generated by wave operations
         float waves[MAX_OPS][BUFFER_SIZE];
@@ -54,12 +54,13 @@ typedef struct
 #define HPF      7
 #define NOISE    8
 #define SIGMOID  9
+#define DELAY   10
 #define ENDI   254
 #define END    255
 
 extern uint8 synth(Voice *v, int len, float *mix_buf);
 extern float detune(float base, int coarse, int fine);
-
+extern float noise();
 
 
 #endif // SYNTH_H
-- 
2.34.1