cache SDL_GetTicks()

2 files changed, 7 insertions, 7 deletions

diff --git a/src/sdl/draw.c b/src/sdl/draw.c
index f27a6be..f7f9ff7 100644
--- a/src/sdl/draw.c
+++ b/src/sdl/draw.c
@@ -139,9 +139,7 @@ draw_on_home(
   void * const data
 ) {
   draw_ctx_t * const draw_ctx = data;
-  const bool is_done = sok_ctx_is_done(draw_ctx->ctx);
-  const Uint32 ticks = SDL_GetTicks();
-  const double angle = is_done ? (10 * sin(ticks * M_2_PI / 1000.0)) : 0;
+  const double angle = sok_ctx_is_done(draw_ctx->ctx) ? (10 * sin(draw_ctx->ticks * M_2_PI / 1000.0)) : 0;
 
   draw_cell(draw_ctx, pos, SPRITE_HOME, angle);
 
@@ -156,9 +154,7 @@ draw_on_box(
   void * const data
 ) {
   draw_ctx_t * const draw_ctx = data;
-  const Uint32 ticks = SDL_GetTicks();
-  const bool is_done = sok_ctx_is_done(draw_ctx->ctx);
-  const double angle = is_done ? (5 * sin((100 * (pos.y + pos.x) + ticks) * M_2_PI / 1000.0)) : 0;
+  const double angle = sok_ctx_is_done(draw_ctx->ctx) ? (5 * sin((100 * (pos.y + pos.x) + draw_ctx->ticks) * M_2_PI / 1000.0)) : 0;
 
   draw_cell(draw_ctx, pos, SPRITE_BOX, angle);
 
@@ -279,7 +275,7 @@ draw_bg(
   // get color
   const SDL_Color c = bg_style_get_color(
     BG_STYLES + (sok_ctx_is_done(draw_ctx->ctx) ? 1 : 0),
-    SDL_GetTicks()
+    draw_ctx->ticks
   );
 
   // set color
@@ -295,6 +291,9 @@ void
 draw(
   draw_ctx_t * const draw_ctx
 ) {
+  // update timestamp
+  draw_ctx->ticks = SDL_GetTicks();
+
   // clear background
   draw_bg(draw_ctx);
 
diff --git a/src/sdl/draw.h b/src/sdl/draw.h
index b8aeed4..19d8837 100644
--- a/src/sdl/draw.h
+++ b/src/sdl/draw.h
@@ -22,6 +22,7 @@ typedef struct {
 
   // render offset
   int render_ofs_x, render_ofs_y;
+  Uint32 ticks;
 } draw_ctx_t;
 
 void draw(draw_ctx_t * const);