controller_t: Reduce memory usage using bitwise

5 files changed, 73 insertions, 51 deletions

diff --git a/Makefile b/Makefile
index 2433900..2a46725 100644
--- a/Makefile
+++ b/Makefile
@@ -44,7 +44,7 @@ $(TEST_DIR)/%: $(TEST_DIR)/%-test
 test: lib/libmunit.so $(BUILD_DIR) $(TESTS) 
 
 lib/libmunit.so: $(LIB_DIR) third_party/munit/munit.c
-	$(CC) -Wall -Werror -fpic -c third_party/munit/munit.c -shared -o lib/libmunit.so
+	$(CC) -Wall -fpic -c third_party/munit/munit.c -shared -o lib/libmunit.so
 
 clean:
 	@rm -rf $(BUILD_DIR)
diff --git a/src/controller.c b/src/controller.c
index 09757c4..4e488e9 100644
--- a/src/controller.c
+++ b/src/controller.c
@@ -38,39 +38,59 @@ controller_update(controller_t *self,
 {
   if (event->type == SDL_KEYDOWN) {
     switch (event->key.keysym.sym) {
-      case SDLK_UP:
-        self->up = true;
-        break;
-      case SDLK_DOWN:
-        self->down = true;
-        break;
-      case SDLK_LEFT:
-        self->left = true;
-        break;
-      case SDLK_RIGHT:
-        self->right = true;
-        break;
+    case SDLK_UP:
+      self->pressed_buttons |= BTN_UP;
+      break;
+    case SDLK_DOWN:
+      self->pressed_buttons |= BTN_DOWN;
+      break;
+    case SDLK_LEFT:
+      self->pressed_buttons |= BTN_LEFT;
+      break;
+    case SDLK_RIGHT:
+      self->pressed_buttons |= BTN_RIGHT;
+      break;
     }
   }
 
   if (event->type == SDL_KEYUP) {
     switch (event->key.keysym.sym) {
-      case SDLK_UP:
-        self->up = false;
-        break;
+    case SDLK_UP:
+      self->pressed_buttons ^= BTN_UP;
+      break;
+    case SDLK_DOWN:
+      self->pressed_buttons ^= BTN_DOWN;
+      break;
+    case SDLK_LEFT:
+      self->pressed_buttons ^= BTN_LEFT;
+      break;
+    case SDLK_RIGHT:
+      self->pressed_buttons ^= BTN_RIGHT;
+      break;
+    }
+  }
+}
 
-      case SDLK_DOWN:
-        self->down = false;
-        break;
+bool
+controller_is_up_pressed(controller_t *self)
+{
+  return self->pressed_buttons & BTN_UP;
+}
 
-      case SDLK_LEFT:
-        self->left = false;
-        break;
+bool
+controller_is_down_pressed(controller_t *self)
+{
+  return self->pressed_buttons & BTN_DOWN;
+}
 
-      case SDLK_RIGHT:
-        self->right = false;
-        break;
-    }
-  }
+bool
+controller_is_right_pressed(controller_t *self)
+{
+  return self->pressed_buttons & BTN_RIGHT;
 }
 
+bool
+controller_is_left_pressed(controller_t *self)
+{
+  return self->pressed_buttons & BTN_LEFT;
+}
diff --git a/src/controller.h b/src/controller.h
index 736b9e6..ecc0389 100644
--- a/src/controller.h
+++ b/src/controller.h
@@ -33,23 +33,25 @@
 
 #include <SDL.h>
 #include <stdbool.h>
+#include <stdint.h>
 
-#ifdef __cplusplus
-extern "C" {
-#endif
+enum btn_t {
+  BTN_UP    = 1 << 0,
+  BTN_DOWN  = 1 << 1,
+  BTN_RIGHT = 1 << 2,
+  BTN_LEFT  = 1 << 3
+};
 
 typedef struct controller_t {
-  bool up;
-  bool down;
-  bool left;
-  bool right;
+  uint8_t pressed_buttons;
 } controller_t;
 
 void controller_update(controller_t *self,
                        SDL_Event    *event);
 
-#ifdef __cplusplus
-}
-#endif
+bool controller_is_up_pressed(controller_t *self);
+bool controller_is_down_pressed(controller_t *self);
+bool controller_is_right_pressed(controller_t *self);
+bool controller_is_left_pressed(controller_t *self);
 
 #endif /* CONTROLLER_H */
diff --git a/src/main.c b/src/main.c
index 2c71864..b8e723b 100644
--- a/src/main.c
+++ b/src/main.c
@@ -74,7 +74,7 @@ main (int   argc,
   SDL_Rect rect = { .x = 0, .y = 0, .w = 20, .h = 20 };
 
   bool quit = false;
-  controller_t controller = {0};
+  controller_t ctrl = {0};
 
   while (!quit) {
     screenSurface = SDL_GetWindowSurface(window);
@@ -89,13 +89,13 @@ main (int   argc,
       if (event.type == SDL_QUIT) {
         quit = true;
       }
-      controller_update(&controller, &event);
+      controller_update(&ctrl, &event);
     }
 
-    if (controller.up)    rect.y -= 1;
-    if (controller.down)  rect.y += 1;
-    if (controller.left)  rect.x -= 1;
-    if (controller.right) rect.x += 1;
+    if (controller_is_up_pressed(&ctrl))    rect.y -= 1;
+    if (controller_is_down_pressed(&ctrl))  rect.y += 1;
+    if (controller_is_left_pressed(&ctrl))  rect.x -= 1;
+    if (controller_is_right_pressed(&ctrl)) rect.x += 1;
 
     SDL_FillRect(
         screenSurface,
diff --git a/test/controller-test.c b/test/controller-test.c
index d6c1455..c271756 100644
--- a/test/controller-test.c
+++ b/test/controller-test.c
@@ -47,11 +47,11 @@ press_and_release_up(const MunitParameter params[], void* fixture)
 
     SDL_Event event = an_event(SDL_KEYDOWN, SDLK_UP);
     controller_update(&ctrl, &event);
-    assert_true(ctrl.up);
+    assert_true(controller_is_up_pressed(&ctrl));
 
     event = an_event(SDL_KEYUP, SDLK_UP);
     controller_update(&ctrl, &event);
-    assert_false(ctrl.up);
+    assert_false(controller_is_up_pressed(&ctrl));
     return MUNIT_OK;
 }
 
@@ -62,11 +62,11 @@ press_and_release_down(const MunitParameter params[], void* fixture)
 
     SDL_Event event = an_event(SDL_KEYDOWN, SDLK_DOWN);
     controller_update(&ctrl, &event);
-    assert_true(ctrl.down);
+    assert_true(controller_is_down_pressed(&ctrl));
 
     event = an_event(SDL_KEYUP, SDLK_DOWN);
     controller_update(&ctrl, &event);
-    assert_false(ctrl.down);
+    assert_false(controller_is_down_pressed(&ctrl));
     return MUNIT_OK;
 }
 
@@ -77,11 +77,11 @@ press_and_release_right(const MunitParameter params[], void* fixture)
 
     SDL_Event event = an_event(SDL_KEYDOWN, SDLK_RIGHT);
     controller_update(&ctrl, &event);
-    assert_true(ctrl.right);
+    assert_true(controller_is_right_pressed(&ctrl));
 
     event = an_event(SDL_KEYUP, SDLK_RIGHT);
     controller_update(&ctrl, &event);
-    assert_false(ctrl.right);
+    assert_false(controller_is_right_pressed(&ctrl));
     return MUNIT_OK;
 }
 
@@ -92,11 +92,11 @@ press_and_release_left(const MunitParameter params[], void* fixture)
 
     SDL_Event event = an_event(SDL_KEYDOWN, SDLK_LEFT);
     controller_update(&ctrl, &event);
-    assert_true(ctrl.left);
+    assert_true(controller_is_left_pressed(&ctrl));
 
     event = an_event(SDL_KEYUP, SDLK_LEFT);
     controller_update(&ctrl, &event);
-    assert_false(ctrl.left);
+    assert_false(controller_is_left_pressed(&ctrl));
     return MUNIT_OK;
 }