#931 Correct for overshoot value when returning delta_system_time for…

… interval systems

flecs.c

@@ -18260,9 +18260,10 @@ void ProgressTimers(ecs_iter_t *it) {
                 t = 0;
             }
 
-            timer[i].time = t; /* Initialize with remainder */            
+            timer[i].time = t; /* Initialize with remainder */
             tick_source[i].tick = true;
-            tick_source[i].time_elapsed = time_elapsed;
+            tick_source[i].time_elapsed = time_elapsed - timer[i].overshoot;
+            timer[i].overshoot = t;
 
             if (timer[i].single_shot) {
                 timer[i].active = false;

flecs.h

@@ -10067,6 +10067,7 @@ extern "C" {
 typedef struct EcsTimer {
     ecs_ftime_t timeout;         /**< Timer timeout period */
     ecs_ftime_t time;            /**< Incrementing time value */
+    ecs_ftime_t overshoot;       /**< Used to correct returned interval time */
     int32_t fired_count;         /**< Number of times ticked */
     bool active;                 /**< Is the timer active or not */
     bool single_shot;            /**< Is this a single shot timer */

include/flecs/addons/timer.h

@@ -35,6 +35,7 @@ extern "C" {
 typedef struct EcsTimer {
     ecs_ftime_t timeout;         /**< Timer timeout period */
     ecs_ftime_t time;            /**< Incrementing time value */
+    ecs_ftime_t overshoot;       /**< Used to correct returned interval time */
     int32_t fired_count;         /**< Number of times ticked */
     bool active;                 /**< Is the timer active or not */
     bool single_shot;            /**< Is this a single shot timer */

src/addons/timer.c

@@ -42,9 +42,10 @@ void ProgressTimers(ecs_iter_t *it) {
                 t = 0;
             }
 
-            timer[i].time = t; /* Initialize with remainder */            
+            timer[i].time = t; /* Initialize with remainder */
             tick_source[i].tick = true;
-            tick_source[i].time_elapsed = time_elapsed;
+            tick_source[i].time_elapsed = time_elapsed - timer[i].overshoot;
+            timer[i].overshoot = t;
 
             if (timer[i].single_shot) {
                 timer[i].active = false;