Update example in readme.

README.md

@@ -17,35 +17,66 @@ Features
 
 
 
-Examples
-========
+Example
+=======
 mini_al will request and deliver audio data through callbacks.
 
 ```
-mal_uint32 on_send_audio_data(mal_device* pDevice, mal_uint32 sampleCount, void* pSamples)
+#define MAL_IMPLEMENTATION
+#include "../mini_al.h"
+
+#define DR_WAV_IMPLEMENTATION
+#include "dr_wav.h"
+
+#include <stdio.h>
+
+// This is the function that's used for sending more data to the device for playback.
+mal_uint32 on_send_frames_to_device(mal_device* pDevice, mal_uint32 frameCount, void* pSamples)
 {
-    return drwav_read_f32((drwav*)pDevice->pUserData, sampleCount, pSamples);
+    drwav* pWav = (drwav*)pDevice->pUserData;
+    if (pWav == NULL) {
+        return 0;
+    }
+    
+    return (mal_uint32)drwav_read_f32(pWav, frameCount * pDevice->channels, (float*)pSamples) / pDevice->channels;
 }
 
-int main()
+int main(int argc, char** argv)
 {
-    mal_uint32 channels = 2;
-    mal_uint32 sampleRate = 44100;
-    mal_uint32 bufferSizeInFrames = 512;
-    mal_uint32 periods = 2;
-
-    mal_device playbackDevice;
-    if (mal_device_init(&playbackDevice, mal_device_type_playback, NULL, mal_format_f32, channels, sampleRate, bufferSizeInFrames, periods) != MAL_SUCCESS) {
+    if (argc < 2) {
+        printf("No input file.");
         return -1;
     }
-    
-    mal_device_set_send_callback(&playbackDevice, on_send_audio_data);
-    mal_device_start(&playbackDevice);
 
-    printf("Press Enter to quit...\n");
+    drwav wav;
+    if (!drwav_init_file(&wav, argv[1])) {
+        printf("Not a valid WAV file.");
+        return -2;
+    }
+    
+    // In this example we use the default playback device with a default buffer size and period count.
+    mal_device device;
+    if (mal_device_init(&device, mal_device_type_playback, NULL, mal_format_f32, wav.channels, wav.sampleRate, 0, 0, NULL) != MAL_SUCCESS) {
+        printf("Failed to open playback device.");
+        drwav_uninit(&wav);
+        return -3;
+    }
+    
+    // The pUserData member of mal_device is reserved for you.
+    device.pUserData = &wav;
+    
+    // This is the callback for sending data to a playback device when it needs more. Make sure
+    // it's set before playing the device otherwise you'll end up with silence for the first
+    // bunch of frames.
+    mal_device_set_send_callback(&device, on_send_frames_to_device);
+    mal_device_start(&device);
+    
+    printf("Press Enter to quit...");
     getchar();
-
-    mal_device_uninit(&playbackDevice);
+    
+    mal_device_uninit(&device);
+    drwav_uninit(&wav);
+    
     return 0;
-} 
+}
 ```
\ No newline at end of file