add embed code

src/custom.zig

@@ -138,8 +138,7 @@ pub const Embed = struct {
     filepath: []const u8,
 
     sndfile: *c.SNDFILE = undefined,
-
-    // TODO add its own read buffers from snd file
+    buf: []f32 = undefined,
 
     pub fn init(allocator: *std.mem.Allocator, filepath: []const u8) @This() {
         return Embed{
@@ -157,6 +156,7 @@ pub const Embed = struct {
             .sections = c_int(0),
             .seekable = c_int(0),
         };
+
         self.sndfile = try image.sopen(
             self.allocator,
             self.filepath,
@@ -164,12 +164,29 @@ pub const Embed = struct {
             &in_fmt,
         );
 
-        // TODO allocate 1 or 2 in read buffer, but only use 1
+        self.buf = try self.allocator.alloc(f32, @intCast(usize, in_fmt.channels));
     }
 
     pub fn deinit(self: *@This()) void {}
 
     pub fn run(self: *@This(), bufs: *RunBuffers) void {
-        bufs.out[0] = 0;
+        const read_bytes = c.sf_readf_float(self.sndfile, self.buf.ptr, 1);
+
+        if (read_bytes == 0) {
+            std.debug.warn("WARN! reached EOF for embed\n");
+            return;
+        }
+
+        if (read_bytes < 0) {
+            const st: i32 = c.sf_error(self.sndfile);
+            std.debug.warn(
+                "Failed to read {} ({})\n",
+                self.filepath,
+                c.sf_error_number(st),
+            );
+            return;
+        }
+
+        bufs.out[0] = bufs.in[0] + self.buf[0];
     }
 };