1 files changed, 20 insertions, 13 deletions

diff --git a/src/spatial.c b/src/spatial.c
index 710726f..36422b8 100644
--- a/src/spatial.c
+++ b/src/spatial.c
@@ -1,7 +1,8 @@
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <inttypes.h>
 #include <math.h>
+#include <errno.h>
 
 #include <xas/spatial.h>
 
@@ -69,20 +70,22 @@ static void buffer_copy(xas_spatial_buffer *buffer,
                         size_t count) {
     int16_t *src = (int16_t *)(buffer + 1);
 
-    size_t index_i = buffer->index,
-           index_o;
+    size_t i = buffer->index,
+           o;
 
     if (count > buffer->size) {
         count = buffer->size;
     }
 
-    for (index_o=0; index_o<count; index_o++) {
-        if (index_i == buffer->size) {
-            index_i = 0;
+    for (o=0; o<count; o++) {
+        if (i == buffer->size) {
+            i = 0;
         }
 
-        dest[XAS_AUDIO_STEREO*index_o]   = src[XAS_AUDIO_STEREO*index_i];
-        dest[XAS_AUDIO_STEREO*index_o+1] = src[XAS_AUDIO_STEREO*index_i+1];
+        dest[XAS_AUDIO_STEREO*o]   = src[XAS_AUDIO_STEREO*i];
+        dest[XAS_AUDIO_STEREO*o+1] = src[XAS_AUDIO_STEREO*i+1];
+
+        i++;
     }
 }
 
@@ -155,11 +158,8 @@ next:
 
     buffer_copy(buffer, output, count);
 
-    buffer->index += count;
-
-    if (buffer->index == buffer->size) {
-        buffer->index = 0;
-    }
+    buffer->index  = index_old + count;
+    buffer->index %= buffer->size;
 
     return count;
 
@@ -246,6 +246,12 @@ xas_spatial_object *xas_spatial_scene_add_object(xas_spatial_scene *scene,
                                                      xas_audio_stream *source) {
     xas_spatial_object *object;
 
+    if (source->format.channels != XAS_AUDIO_MONO) {
+        errno = EINVAL;
+
+        goto error_invalid_source;
+    }
+
     if ((object = malloc(sizeof(*object))) == NULL) {
         goto error_malloc_object;
     }
@@ -267,6 +273,7 @@ xas_spatial_object *xas_spatial_scene_add_object(xas_spatial_scene *scene,
     return object;
 
 error_malloc_object:
+error_invalid_source:
     return NULL;
 }