Fix mixer reordering and loop handling. Fixes #580 (#581)

* Fix mixer reordering and loop handling.  Add more tests for mixer reordering and loops

* use memcpy (thanks @howard0su)

Author: PhracturedBlue

src/mixer.c

@@ -613,7 +613,7 @@ void fix_mixer_dependencies(unsigned mixer_count)
         mixers[i].src = 0;
     }
     memset(placed, 0, sizeof(placed));
-    while(mixer_count || last_count != mixer_count) {
+    while(mixer_count && last_count != mixer_count) {
         last_count = mixer_count;
         for (i = 0; i < NUM_SOURCES; i++) {
             if (placed[i])
@@ -626,7 +626,7 @@ void fix_mixer_dependencies(unsigned mixer_count)
             unsigned j;
             // determine if all dependencies have been placed
             for (j = 0; j < NUM_SOURCES; j++) {
-                if (dependencies[i] && ! placed[i]) {
+                if (dependencies[j] && ! placed[j]) {
                     ok = 0;
                     break;
                 }
@@ -639,13 +639,17 @@ void fix_mixer_dependencies(unsigned mixer_count)
             }
         }
     }
-    //mixer_count s gauranteed to be 0 when we get here
-    //if (mixer_count) {
-    //    printf("Could not place all mixers!\n");
-    //    return;
-    //}
-    for (i = 0; i < NUM_MIXERS; i++)
-        Model.mixers[i] = mixers[i];
+    if (mixer_count) {
+        // We found a mixer loop....add missing mixers to the end of the order
+        printf("Mix loop detected.  The following mixers may have a circular dependency!\n");
+        for (unsigned source = 0; source < NUM_SOURCES; source++) {
+            if (placed[source])
+                continue;
+            printf("  Mixer source: %d\n", source);
+            pos += MIXER_GetMixers(source, &mixers[pos], NUM_MIXERS);
+        }
+    }
+    memcpy(Model.mixers, mixers, sizeof(mixers));
 }
 
 int MIXER_SetMixers(struct Mixer *mixers, int count)

src/tests/test_mixer.c

@@ -686,6 +686,61 @@ void TestSetMixers(CuTest *t)
     }
 }
 
+#define TO_SOURCE(x) ((x) < 0 ? (NUM_SOURCES + 1 - (x)) : (x))
+#define FROM_SOURCE(x) ((x) > NUM_SOURCES ? -((x)-NUM_SOURCES-1) : (x))
+void TestSetMixerDepends(CuTest *t)
+{
+    int sources[]  = {-6, 1, -2,  1, -1, 1};
+    int switches[] = { 0, 0,  0, -5,  0, 0};
+    int dests[]    = { 4, 1,  6,  6,  2, 5};
+    memset(&Model, 0, sizeof(Model));
+    for (unsigned i = 0; i < sizeof(Model.templates)/sizeof(Model.templates[0]); i++) {
+        Model.templates[i] = MIXERTEMPLATE_SIMPLE;
+    }
+    for (unsigned i = 0; i < sizeof(sources)/sizeof(sources[0]); i++) {
+        Model.mixers[i].src = TO_SOURCE(sources[i]);
+        Model.mixers[i].sw = TO_SOURCE(switches[i]);
+        Model.mixers[i].dest = dests[i];
+        Model.mixers[i].scalar = i;
+        Model.mixers[i].curve.type = CURVE_FIXED;
+    }
+    MIXER_SetMixers(NULL, 0);
+    int expected[] = {1, 4, 5, 2, 3, 0};
+    for (unsigned i = 0; i < sizeof(sources)/sizeof(sources[0]); i++) {
+        //printf("%d: orig:%d src:%d sw:%d dest:%d\n",
+        //       i, Model.mixers[i].scalar, FROM_SOURCE(Model.mixers[i].src),
+        //       FROM_SOURCE(Model.mixers[i].sw), Model.mixers[i].dest);
+        CuAssertIntEquals(t, expected[i], Model.mixers[i].scalar);
+    }
+}
+
+void TestSetMixerLoop(CuTest *t)
+{
+    //negaitve values mean to use a dest as source
+    int sources[]  = {-6, 1, -2,  1, -1, 1};
+    int switches[] = { 0, 0,  0, -5,  0, 0};
+    int dests[]    = { 1, 4,  6,  6,  2, 5};
+    memset(&Model, 0, sizeof(Model));
+    for (unsigned i = 0; i < sizeof(Model.templates)/sizeof(Model.templates[0]); i++) {
+        Model.templates[i] = MIXERTEMPLATE_SIMPLE;
+    }
+    for (unsigned i = 0; i < sizeof(sources)/sizeof(sources[0]); i++) {
+        Model.mixers[i].src = TO_SOURCE(sources[i]);
+        Model.mixers[i].sw = TO_SOURCE(switches[i]);
+        Model.mixers[i].dest = dests[i];
+        Model.mixers[i].scalar = i;
+        Model.mixers[i].curve.type = CURVE_FIXED;
+    }
+    MIXER_SetMixers(NULL, 0);
+    int expected[] = {1, 5, 0, 4, 2, 3};
+    for (unsigned i = 0; i < sizeof(sources)/sizeof(sources[0]); i++) {
+        //printf("%d: orig:%d src:%d sw:%d dest:%d\n",
+        //       i, Model.mixers[i].scalar, FROM_SOURCE(Model.mixers[i].src),
+        //       FROM_SOURCE(Model.mixers[i].sw), Model.mixers[i].dest);
+        CuAssertIntEquals(t, expected[i], Model.mixers[i].scalar);
+    }
+}
+
 void TestGetLimit(CuTest *t)
 {
     struct Limit limit = {0};