Add initial callback/timer API.

Subversion-branch: /branches/opl-branch
Subversion-revision: 1538

1 files changed, 72 insertions, 22 deletions

diff --git a/opl/examples/droplay.c b/opl/examples/droplay.c
index 5f09fe11..89cf6862 100644
--- a/opl/examples/droplay.c
+++ b/opl/examples/droplay.c
@@ -116,44 +116,51 @@ void Shutdown(void)
     OPL_Shutdown();
 }
 
-void PlayFile(char *filename)
+struct timer_data
 {
-    FILE *stream;
-    char buf[8];
-
-    stream = fopen(filename, "rb");
+    int running;
+    FILE *fstream;
+};
 
-    if (fread(buf, 1, 8, stream) < 8)
-    {
-        fprintf(stderr, "failed to read raw OPL header\n");
-        exit(-1);
-    }
+void TimerCallback(void *data)
+{
+    struct timer_data *timer_data = data;
+    int delay;
 
-    if (strncmp(buf, HEADER_STRING, 8) != 0)
+    if (!timer_data->running)
     {
-        fprintf(stderr, "Raw OPL header not found\n");
-        exit(-1);
+        return;
     }
 
-    fseek(stream, 28, SEEK_SET);
+    // Read data until we must make a delay.
 
-    while (!feof(stream))
+    for (;;)
     {
         int reg, val;
 
-        reg = fgetc(stream);
-        val = fgetc(stream);
+        // End of file?
 
-        // Delay?
+        if (feof(timer_data->fstream))
+        {
+            timer_data->running = 0;
+            return;
+        }
+
+        reg = fgetc(timer_data->fstream);
+        val = fgetc(timer_data->fstream);
+
+        // Register value of 0 or 1 indicates a delay.
 
         if (reg == 0x00)
         {
-            SDL_Delay(val);
+            delay = val;
+            break;
         }
         else if (reg == 0x01)
         {
-            val |= (fgetc(stream) << 8);
-            SDL_Delay(val);
+            val |= (fgetc(timer_data->fstream) << 8);
+            delay = val;
+            break;
         }
         else
         {
@@ -161,7 +168,50 @@ void PlayFile(char *filename)
         }
     }
 
-    fclose(stream);
+    // Schedule the next timer callback.
+
+    OPL_SetCallback(delay, TimerCallback, timer_data);
+}
+
+void PlayFile(char *filename)
+{
+    struct timer_data timer_data;
+    int running;
+    char buf[8];
+
+    timer_data.fstream = fopen(filename, "rb");
+
+    if (fread(buf, 1, 8, timer_data.fstream) < 8)
+    {
+        fprintf(stderr, "failed to read raw OPL header\n");
+        exit(-1);
+    }
+
+    if (strncmp(buf, HEADER_STRING, 8) != 0)
+    {
+        fprintf(stderr, "Raw OPL header not found\n");
+        exit(-1);
+    }
+
+    fseek(timer_data.fstream, 28, SEEK_SET);
+    timer_data.running = 1;
+
+    // Start callback loop sequence.
+
+    OPL_SetCallback(0, TimerCallback, &timer_data);
+
+    // Sleep until the playback finishes.
+
+    do
+    {
+        OPL_Lock();
+        running = timer_data.running;
+        OPL_Unlock();
+
+        SDL_Delay(100);
+    } while (running);
+
+    fclose(timer_data.fstream);
 }
 
 int main(int argc, char *argv[])