Optimize busses

source/engine/sound/mix.c

@@ -6,37 +6,62 @@
 #include <string.h>
 
 static struct bus bus[256];
+static int first = 0; /* First bus available */
+static int first_on = -1;
 short mastermix[BUF_FRAMES*CHANNELS];
 
-struct bus *first_free_bus(struct dsp_filter in) {
+void mixer_init() {
     for (int i = 0; i < 256; i++) {
-        if (!bus[i].on) {
-            bus[i].on = 1;
-            bus[i].in = in;
-            return &bus[i];
-        }
+        bus[i].next = i+1;
+        bus[i].on = 0;
+        bus[i].id = i;
     }
 
-    return NULL;
+    bus[255].next = -1;
+}
+
+struct bus *first_free_bus(struct dsp_filter in) {
+    if (first == -1) return NULL;
+    struct bus *ret = bus[first];
+    first = ret->next;
+    ret->on = 1;
+    ret->in = in;
+
+    ret->next = first_on;
+    first_on = ret->id;
+
+    return ret;
 }
 
 void bus_free(struct bus *bus)
 {
+    bus->next = first;
     bus->on = 0;
+    first = bus->id;
 }
 
 void bus_fill_buffers(short *master, int n) {
+    int curbus = first_one
+    memset(master, 0, BUF_FRAMES*CHANNELS*sizeof(short));
+    while (bus[curbus].next != -1) {
+        dsp_run(bus[curbus].in, bus[curbus].buf, BUF_FRAMES);
+        for (int i = 0; i < BUF_FRAMES*CHANNELS; i++)
+            master[i] += bus[curbus].buf[i];
+
+        curbus = bus[curbus].next;
+    }
+
+    /*
     for (int i = 0; i < 256; i++) {
         if (bus[i].on != 1) continue;
         dsp_run(bus[i].in, bus[i].buf, BUF_FRAMES);
     }
 
-    memset(master, 0, BUF_FRAMES*CHANNELS*sizeof(short));
-
         for (int j = 0; j < 256; j++) {
             if (!bus[j].on) continue;
             for (int i = 0; i < BUF_FRAMES*CHANNELS; i++) {
                 master[i] += bus[j].buf[i];
             }
         }
+            */
 }

source/engine/sound/mix.h

@@ -7,22 +7,23 @@ struct sound;
 
 
 struct bus {
-    int on;
     struct dsp_filter in;
     short buf[BUF_FRAMES*CHANNELS];
     float gain;
-};
-
-struct listener {
-    float x;
-    float y;
-    float z;
+    int on;
+    int next; /* Next available bus */
+    int prev;
+    int id;
 };
 
 extern short mastermix[BUF_FRAMES*CHANNELS];
 
+void mixer_init();
+
 struct bus *first_free_bus(struct dsp_filter in);
 void bus_fill_buffers(short *master, int n);
+
+
 void bus_free(struct bus *bus);