util: Allow event hooks to start/stop drawing

2 files changed, 14 insertions, 0 deletions

diff --git a/util.c b/util.c
index 21b5ed0..3c32245 100644
--- a/util.c
+++ b/util.c
@@ -270,6 +270,15 @@ ru_engine_main_loop(ru_engine_t *engine) {
             need_resize = false;
         }
 
+        switch (engine->draw_mode) {
+            case RU_DRAW_MODE_CONTINUOUS:
+            case RU_DRAW_MODE_ONCE:
+                need_draw = true;
+                break;
+            case RU_DRAW_MODE_PAUSED:
+                break;
+        }
+
         if (exposed && need_draw) {
             engine->draw(engine);
             SDL_GL_SwapWindow(engine->window);
@@ -279,6 +288,10 @@ ru_engine_main_loop(ru_engine_t *engine) {
             case RU_DRAW_MODE_CONTINUOUS:
                 break;
             case RU_DRAW_MODE_ONCE:
+                engine->draw_mode = RU_DRAW_MODE_PAUSED;
+                need_draw = false;
+                break;
+            case RU_DRAW_MODE_PAUSED:
                 need_draw = false;
                 break;
         }
diff --git a/util.h b/util.h
index 21bd9a9..9869140 100644
--- a/util.h
+++ b/util.h
@@ -58,6 +58,7 @@ typedef struct ru_engine ru_engine_t;
 enum ru_draw_mode {
     RU_DRAW_MODE_CONTINUOUS,
     RU_DRAW_MODE_ONCE,
+    RU_DRAW_MODE_PAUSED,
 };
 
 struct ru_engine {