fix(gfx): audio_play / audio_play_loop accept VAL_BUFFER samples (#578)

CHANGELOG.md

@@ -4,6 +4,18 @@ All notable changes to EigenScript are documented here.
 
 ## [Unreleased]
 
+### Fixed
+- **gfx audio: `audio_play` / `audio_play_loop` accept `VAL_BUFFER`
+  samples (#578).** `audio_convert_samples` was list-only, so handing a
+  buffer — the type the language recommends for bulk samples and what a
+  DAW render produces — silently returned channel `0`; consumers had to
+  convert buffer→list per play (a 3-minute stereo render is ~16M
+  appends + VAL_NUM allocations) just for the C side to re-walk it into
+  int16. Buffers now convert directly off their C double array (same
+  clamping and 64 MB cap as lists); empty buffers are rejected like
+  empty lists. Gfx-suite checks cover play, play_loop, clamping, the
+  queued length, and the empty-buffer rejection.
+
 ### Added
 - **`read_line` builtin (#558)** — blocking line read from stdin
   (`getline(3)`): returns the next line without its trailing newline

src/ext_gfx.c

@@ -730,10 +730,29 @@ static void audio_mix_callback(void *ud, uint8_t *stream, int len) {
     }
 }
 
-/* Convert a sample list (floats -1..1) to an owned int16 buffer.
- * Returns NULL on bad shape or an over-64MB clip. */
+/* Convert samples (floats -1..1) to an owned int16 buffer. Accepts a
+ * VAL_LIST or a VAL_BUFFER (#578 — the buffer is the type the language
+ * recommends for bulk samples and what a DAW render produces; forcing a
+ * buffer→list conversion per play meant millions of appends + VAL_NUM
+ * allocations just to feed the mixer). Returns NULL on bad shape or an
+ * over-64MB clip. */
 static int16_t* audio_convert_samples(Value *samples, int *out_n) {
-    if (!samples || samples->type != VAL_LIST) return NULL;
+    if (!samples) return NULL;
+    if (samples->type == VAL_BUFFER) {
+        int n = samples->data.buffer.count;
+        if (n <= 0 || (double)n * sizeof(int16_t) > 64.0 * 1024.0 * 1024.0) return NULL;
+        int16_t *buf = xmalloc_array(n, sizeof(int16_t));
+        const double *src = samples->data.buffer.data;
+        for (int i = 0; i < n; i++) {
+            double s = src[i];
+            if (s > 1.0) s = 1.0;
+            if (s < -1.0) s = -1.0;
+            buf[i] = (int16_t)(s * 32767);
+        }
+        *out_n = n;
+        return buf;
+    }
+    if (samples->type != VAL_LIST) return NULL;
     int n = samples->data.list.count;
     if (n <= 0 || (double)n * sizeof(int16_t) > 64.0 * 1024.0 * 1024.0) return NULL;
     int16_t *buf = xmalloc_array(n, sizeof(int16_t));

tests/test_audio.eigs

@@ -117,6 +117,35 @@ if d != 0:
     assert_eq of [audio_stop of chinf, 0, "stop on an inactive channel returns 0"]
     audio_clear of null
     assert_eq of [audio_queue_size of null, 0, "clear empties every channel"]
+
+    # ---- #578: VAL_BUFFER samples accepted (the bulk fast path) ----
+    # A DAW render produces C-backed double buffers; audio_play used to
+    # silently return channel 0 for them, forcing a buffer->list convert
+    # per play. Buffer and list of the same samples must both play.
+    nb is 1000
+    bclip is buffer of nb
+    bi is 0
+    loop while bi < nb:
+        bclip[bi] is 0.1
+        bi += 1
+    chb is audio_play of bclip
+    assert_eq of [(chb > 0), 1, "audio_play accepts a buffer (#578)"]
+    assert_eq of [audio_queue_size of null, nb * 2, "buffer clip queued at full length"]
+    chbl is audio_play_loop of [bclip, 3]
+    assert_eq of [(chbl > 0), 1, "audio_play_loop accepts a buffer (#578)"]
+    assert_eq of [audio_stop of chbl, 1, "buffer loop channel stoppable"]
+    # Buffer values are clamped like list values (out-of-range -> +/-1).
+    hot is buffer of 100
+    hi is 0
+    loop while hi < 100:
+        hot[hi] is 9.5
+        hi += 1
+    chh is audio_play of hot
+    assert_eq of [(chh > 0), 1, "out-of-range buffer samples clamp, still play"]
+    # Empty buffer is still rejected (0), matching the empty-list rule.
+    assert_eq of [audio_play of (buffer of 0), 0, "empty buffer rejected"]
+
+    audio_clear of null
     audio_close of null
     print of "mixer channel tests: ok"
 else: