Implement a countdown clock in the timer

Updated the HUD to show the time.

1 files changed, 40 insertions, 5 deletions

diff --git a/src/timer.c b/src/timer.c
index d7810b6..ae76037 100644
--- a/src/timer.c
+++ b/src/timer.c
@@ -4,14 +4,31 @@
 #include <dpmi.h>
 
 volatile uint32_t ticks = 0;
-volatile static uint32_t ticks_to = 0;
+volatile uint32_t clock = 0;
+volatile uint8_t clock_secs = 0;
+volatile uint8_t clock_enabled = 0;
+volatile uint8_t *clock_updated = NULL;
 
 static _go32_dpmi_seginfo old_handler, new_handler;
 
 static void timer_handler()
 {
     ticks++;
-    ticks_to++;
+
+    if (clock_enabled)
+    {
+        clock += 5494;
+        if (clock > 100000)
+        {
+            clock -= 100000;
+            if (clock_secs)
+            {
+                clock_secs--;
+                if (clock_updated)
+                    *clock_updated = 1;
+            }
+        }
+    }
 }
 
 void timer_init()
@@ -28,8 +45,26 @@ void timer_free()
         fprintf(stderr, "Failed to free the timer :(\n");
 }
 
-void timer_wait(uint8_t t)
+void timer_start(uint8_t secs, uint8_t *updated)
+{
+    *updated = 0;
+    clock_updated = updated;
+    clock_secs = secs;
+    clock_enabled = 1;
+}
+
+uint8_t timer_value()
+{
+    *clock_updated = 0;
+    return clock_secs;
+}
+
+void timer_stop()
+{
+    clock_enabled = 0;
+}
+
+void timer_resume()
 {
-    while (ticks_to < t);
-    ticks_to = 0;
+    clock_enabled = 1;
 }