Added proper hit test with rotation and pivoting

include/app/app.h

@@ -15,6 +15,7 @@ struct Element {
   Type type;
   Vec2<float> position = {0, 0};
   float rotation = 0;
+  Vec2<float> pivot = {0, 0};
   Vec2<float> scale = {1, 1};
   float alpha = 1.0f;
   float z = 0;
@@ -24,7 +25,7 @@ struct Element {
   Element(Type type) : type(type) {}
   virtual ~Element() = default;
   virtual void render(Window &window, uint64_t abs_time) = 0;
-  virtual Vec2<float> size(Window *window) = 0;
+  virtual Vec2<float> size() = 0;
 
   void click() {
     on_click.call();
@@ -43,11 +44,11 @@ struct EImage : Element {
       animation_pool.release(animation_id);
   }
 
-  Vec2<float> size(Window *window) override {
+  Vec2<float> size() override {
     Animation &animation = *animation_pool[animation_id];
     if (animation.frames.empty())
       return {0, 0};
-    return window->get_image_size(animation.frames[0]);
+    return window.get_image_size(animation.frames[0]);
   }
 
   void render(Window &window, uint64_t abs_time) override {
@@ -55,7 +56,7 @@ struct EImage : Element {
     if (animation.frames.empty())
       return;
     int frame_index = (int)((abs_time * animation.frame_rate) / 1e9) % animation.frames.size();
-    window.draw(animation.frames[frame_index], position, z, rotation, scale, alpha);
+    window.draw(animation.frames[frame_index], position, z, rotation, pivot, scale, alpha);
   }
 };
 
@@ -86,10 +87,10 @@ struct EText : Element {
     last_key = UINT16_MAX;
   }
 
-  Vec2<float> size(Window *window) override {
+  Vec2<float> size() override {
     if (text_id == UINT64_MAX)
       return {0, 0};
-    return window->get_text_size(text_id);
+    return window.get_text_size(text_id);
   };
 
   void render(Window &window, uint64_t) override {
@@ -106,7 +107,7 @@ struct EText : Element {
       last_key = key;
       last_color = color;
     }
-    window.write(text_id, position, z, rotation, scale, alpha);
+    window.write(text_id, position, z, rotation, pivot, scale, alpha);
   }
 
 private:
@@ -119,14 +120,14 @@ private:
 struct ERect : Element {
   Vec2<float> shape = {0, 0};
   Color color = {255, 255, 255};
-  Vec2<float> size(Window *) override {
+  Vec2<float> size() override {
     return shape;
   };
 
   ERect(Vec2<float> shape, Color color) : Element(Type::RECT), shape(shape), color(color) {}
 
   void render(Window &window, uint64_t) override {
-    window.draw_rect(Rect::from_size(position, shape), color, z, rotation, scale, alpha);
+    window.draw_rect(Rect::from(position, shape), color, z, rotation, pivot, scale, alpha);
   }
 };
 
@@ -177,16 +178,19 @@ struct Scene {
       element_pool[id]->click();
   }
 
-#warning "This does not take rotation into account \
+  void render(Window &window, uint64_t abs_time) {
-reference and use reverse-transform on point then AABB check instead"
+    for (const uint64_t &e : element_ids)
+      element_pool[e]->render(window, abs_time);
+  }
+
   std::vector<uint64_t> elements_at(Vec2<float> position) {
     std::vector<uint64_t> result;
 
     for (auto it = element_ids.rbegin(); it != element_ids.rend(); ++it) {
       Element *e = element_pool[*it];
-      Vec2<float> size = e->size(&window);
+      Vec2<float> size = e->size();
-      Rect rect = Rect::from_size(e->position, size * e->scale);
+      Rect rect = Rect::from(size);
-      if (rect.contains(position)) {
+      if (rect.contains(world_to_local(position, e))) {
         result.push_back(*it);
         if (e->click_through)
           continue;
@@ -198,9 +202,25 @@ reference and use reverse-transform on point then AABB check instead"
     return result;
   }
 
-  void render(Window &window, uint64_t abs_time) {
+  Vec2<float> world_to_local(Vec2<float> p, Element *e) {
-    for (const uint64_t &e : element_ids)
+    Vec2<float> size = e->size();
-      element_pool[e]->render(window, abs_time);
+    Vec2<float> pivot = e->pivot * size * e->scale;
+    p = p - e->position;
+
+    float rad = -e->rotation * (M_PI / 180.0f);
+    float c = cos(rad);
+    float s = sin(rad);
+
+    p = p - pivot;
+    p = {
+      p.x * c - p.y * s,
+      p.x * s + p.y * c
+    };
+
+    p = p + pivot;
+    p = p / e->scale;
+
+    return p;
   }
 };
 

include/binding/definitions.h

@@ -317,7 +317,9 @@ static mrb_value ElementText_init(mrb_state *mrb, mrb_value self) {
     return mrb_nil_value();
   }
 
-  float x = 0, y = 0, z = 0, rotation = 0, scale_x = 1, scale_y = 1, alpha = 1;
+  float x = 0, y = 0, z = 0, rotation = 0;
+  float scale_x = 1, scale_y = 1, alpha = 1;
+  float pivot_x = 0.5, pivot_y = 0.5;
   bool click_through = false;
   if (!mrb_nil_p(kwargs)) {
     mrb_value pos_hash = HASH_GET(kwargs, position);
@@ -332,6 +334,12 @@ static mrb_value ElementText_init(mrb_state *mrb, mrb_value self) {
       HASH_FLOAT(scale_hash, y, scale_y);
     }
 
+    mrb_value pivot_hash = HASH_GET(kwargs, pivot);
+    if (!mrb_nil_p(pivot_hash)) {
+      HASH_FLOAT(pivot_hash, x, pivot_x);
+      HASH_FLOAT(pivot_hash, y, pivot_y);
+    }
+
     HASH_FLOAT(kwargs, z, z);
     HASH_FLOAT(kwargs, rotation, rotation);
     HASH_FLOAT(kwargs, alpha, alpha);
@@ -351,6 +359,7 @@ static mrb_value ElementText_init(mrb_state *mrb, mrb_value self) {
   element->position = {x, y};
   element->scale = {scale_x, scale_y};
   element->rotation = rotation;
+  element->pivot = {pivot_x, pivot_y};
   element->alpha = alpha;
   element->z = z;
   element->click_through = click_through;
@@ -533,6 +542,28 @@ static mrb_value element_text_rotation_set(mrb_state *mrb, mrb_value self) {
   return mrb_nil_value();
 }
 
+static mrb_value element_text_pivot_get(mrb_state *mrb, mrb_value self) {
+  uint64_t id = get_id_ElementText(mrb, self);
+  app::EText *element = (app::EText *)app::element_pool[id];
+  mrb_value pivot_hash = mrb_hash_new(mrb);
+  HASH_SET(pivot_hash, x, mrb_float_value(mrb, element->pivot.x));
+  HASH_SET(pivot_hash, y, mrb_float_value(mrb, element->pivot.y));
+  return pivot_hash;
+}
+
+static mrb_value element_text_pivot_set(mrb_state *mrb, mrb_value self) {
+  mrb_value pivot_hash;
+  mrb_get_args(mrb, "H", &pivot_hash);
+
+  uint64_t id = get_id_ElementText(mrb, self);
+  app::EText *element = (app::EText *)app::element_pool[id];
+
+  HASH_FLOAT(pivot_hash, x, element->pivot.x);
+  HASH_FLOAT(pivot_hash, y, element->pivot.y);
+
+  return mrb_nil_value();
+}
+
 static mrb_value element_text_scale_get(mrb_state *mrb, mrb_value self) {
   uint64_t id = get_id_ElementText(mrb, self);
   app::EText *element = (app::EText *)app::element_pool[id];
@@ -609,13 +640,13 @@ static mrb_value element_text_click_through_set(mrb_state *mrb, mrb_value self)
 static mrb_value element_text_width(mrb_state *mrb, mrb_value self) {
   uint64_t id = get_id_ElementText(mrb, self);
   app::EText *element = (app::EText *)app::element_pool[id];
-  return mrb_float_value(mrb, element->size(&window).x);
+  return mrb_float_value(mrb, element->size().x);
 }
 
 static mrb_value element_text_height(mrb_state *mrb, mrb_value self) {
   uint64_t id = get_id_ElementText(mrb, self);
   app::EText *element = (app::EText *)app::element_pool[id];
-  return mrb_float_value(mrb, element->size(&window).y);
+  return mrb_float_value(mrb, element->size().y);
 }
 
 static void ElementRect_free(mrb_state *mrb, void *ptr) {
@@ -643,7 +674,8 @@ static mrb_value ElementRect_init(mrb_state *mrb, mrb_value self) {
   mrb_value kwargs;
   mrb_get_args(mrb, "ffi|H", &w, &h, &color_i, &kwargs);
 
-  float x = 0, y = 0, z = 0, rotation = 0, scale_x = 1, scale_y = 1, alpha = 1;
+  float x = 0, y = 0, z = 0, rotation = 0;
+  float scale_x = 1, scale_y = 1, alpha = 1, pivot_x = 0.5, pivot_y = 0.5;
   bool click_through = false;
   if (!mrb_nil_p(kwargs)) {
     mrb_value pos_hash = HASH_GET(kwargs, position);
@@ -658,6 +690,12 @@ static mrb_value ElementRect_init(mrb_state *mrb, mrb_value self) {
       HASH_FLOAT(scale_hash, y, scale_y);
     }
 
+    mrb_value pivot_hash = HASH_GET(kwargs, pivot);
+    if (!mrb_nil_p(pivot_hash)) {
+      HASH_FLOAT(pivot_hash, x, pivot_x);
+      HASH_FLOAT(pivot_hash, y, pivot_y);
+    }
+
     HASH_FLOAT(kwargs, z, z);
     HASH_FLOAT(kwargs, rotation, rotation);
     HASH_FLOAT(kwargs, alpha, alpha);
@@ -679,6 +717,7 @@ static mrb_value ElementRect_init(mrb_state *mrb, mrb_value self) {
   element->position = {x, y};
   element->scale = {scale_x, scale_y};
   element->rotation = rotation;
+  element->pivot = {pivot_x, pivot_y};
   element->alpha = alpha;
   element->z = z;
   element->click_through = click_through;
@@ -829,6 +868,28 @@ static mrb_value element_rect_rotation_set(mrb_state *mrb, mrb_value self) {
   return mrb_nil_value();
 }
 
+static mrb_value element_rect_pivot_get(mrb_state *mrb, mrb_value self) {
+  uint64_t id = get_id_ElementRect(mrb, self);
+  app::ERect *element = (app::ERect *)app::element_pool[id];
+  mrb_value pivot_hash = mrb_hash_new(mrb);
+  HASH_SET(pivot_hash, x, mrb_float_value(mrb, element->pivot.x));
+  HASH_SET(pivot_hash, y, mrb_float_value(mrb, element->pivot.y));
+  return pivot_hash;
+}
+
+static mrb_value element_rect_pivot_set(mrb_state *mrb, mrb_value self) {
+  mrb_value pivot_hash;
+  mrb_get_args(mrb, "H", &pivot_hash);
+
+  uint64_t id = get_id_ElementRect(mrb, self);
+  app::ERect *element = (app::ERect *)app::element_pool[id];
+
+  HASH_FLOAT(pivot_hash, x, element->pivot.x);
+  HASH_FLOAT(pivot_hash, y, element->pivot.y);
+
+  return mrb_nil_value();
+}
+
 static mrb_value element_rect_scale_get(mrb_state *mrb, mrb_value self) {
   uint64_t id = get_id_ElementRect(mrb, self);
   app::ERect *element = (app::ERect *)app::element_pool[id];
@@ -938,7 +999,8 @@ static mrb_value ElementImage_init(mrb_state *mrb, mrb_value self) {
     return mrb_nil_value();
   }
 
-  float x = 0, y = 0, z = 0, rotation = 0, scale_x = 1, scale_y = 1, alpha = 1;
+  float x = 0, y = 0, z = 0, rotation = 0;
+  float scale_x = 1, scale_y = 1, alpha = 1, pivot_x = 0.5, pivot_y = 0.5;
   bool click_through = false;
   if (!mrb_nil_p(kwargs)) {
     mrb_value pos_hash = HASH_GET(kwargs, position);
@@ -953,6 +1015,12 @@ static mrb_value ElementImage_init(mrb_state *mrb, mrb_value self) {
       HASH_FLOAT(scale_hash, y, scale_y);
     }
 
+    mrb_value pivot_hash = HASH_GET(kwargs, pivot);
+    if (!mrb_nil_p(pivot_hash)) {
+      HASH_FLOAT(pivot_hash, x, pivot_x);
+      HASH_FLOAT(pivot_hash, y, pivot_y);
+    }
+
     HASH_FLOAT(kwargs, z, z);
     HASH_FLOAT(kwargs, rotation, rotation);
     HASH_FLOAT(kwargs, alpha, alpha);
@@ -965,6 +1033,7 @@ static mrb_value ElementImage_init(mrb_state *mrb, mrb_value self) {
   element->position = {x, y};
   element->scale = {scale_x, scale_y};
   element->rotation = rotation;
+  element->pivot = {pivot_x, pivot_y};
   element->alpha = alpha;
   element->z = z;
   element->click_through = click_through;
@@ -1098,6 +1167,28 @@ static mrb_value element_image_rotation_set(mrb_state *mrb, mrb_value self) {
   return mrb_nil_value();
 }
 
+static mrb_value element_image_pivot_get(mrb_state *mrb, mrb_value self) {
+  uint64_t id = get_id_ElementImage(mrb, self);
+  app::EImage *element = (app::EImage *)app::element_pool[id];
+  mrb_value pivot_hash = mrb_hash_new(mrb);
+  HASH_SET(pivot_hash, x, mrb_float_value(mrb, element->pivot.x));
+  HASH_SET(pivot_hash, y, mrb_float_value(mrb, element->pivot.y));
+  return pivot_hash;
+}
+
+static mrb_value element_image_pivot_set(mrb_state *mrb, mrb_value self) {
+  mrb_value pivot_hash;
+  mrb_get_args(mrb, "H", &pivot_hash);
+
+  uint64_t id = get_id_ElementImage(mrb, self);
+  app::EImage *element = (app::EImage *)app::element_pool[id];
+
+  HASH_FLOAT(pivot_hash, x, element->pivot.x);
+  HASH_FLOAT(pivot_hash, y, element->pivot.y);
+
+  return mrb_nil_value();
+}
+
 static mrb_value element_image_scale_get(mrb_state *mrb, mrb_value self) {
   uint64_t id = get_id_ElementImage(mrb, self);
   app::EImage *element = (app::EImage *)app::element_pool[id];
@@ -1572,14 +1663,18 @@ inline void setup() {
   ADD_METHOD(ElementText, "color", element_text_color_get, MRB_ARGS_NONE());
   ADD_METHOD(ElementText, "font=", element_text_font_set, MRB_ARGS_REQ(1));
   ADD_METHOD(ElementText, "font", element_text_font_get, MRB_ARGS_NONE());
+#warning "Make text params a proper class instead of using a hash for text params"
   ADD_METHOD(ElementText, "params", element_text_params, MRB_ARGS_NONE());
   ADD_METHOD(ElementText, "params!", element_text_params_load, MRB_ARGS_NONE());
+#warning "Make vector a proper class instead of using a hash for vectors"
   ADD_METHOD(ElementText, "position=", element_text_position_set, MRB_ARGS_REQ(1));
   ADD_METHOD(ElementText, "position", element_text_position_get, MRB_ARGS_NONE());
   ADD_METHOD(ElementText, "scale=", element_text_scale_set, MRB_ARGS_REQ(1));
   ADD_METHOD(ElementText, "scale", element_text_scale_get, MRB_ARGS_NONE());
   ADD_METHOD(ElementText, "rotation=", element_text_rotation_set, MRB_ARGS_REQ(1));
   ADD_METHOD(ElementText, "rotation", element_text_rotation_get, MRB_ARGS_NONE());
+  ADD_METHOD(ElementText, "pivot=", element_text_pivot_set, MRB_ARGS_REQ(1));
+  ADD_METHOD(ElementText, "pivot", element_text_pivot_get, MRB_ARGS_NONE());
   ADD_METHOD(ElementText, "alpha=", element_text_alpha_set, MRB_ARGS_REQ(1));
   ADD_METHOD(ElementText, "alpha", element_text_alpha_get, MRB_ARGS_NONE());
   ADD_METHOD(ElementText, "z=", element_text_z_set, MRB_ARGS_REQ(1));
@@ -1608,6 +1703,8 @@ inline void setup() {
   ADD_METHOD(ElementRect, "scale", element_rect_scale_get, MRB_ARGS_NONE());
   ADD_METHOD(ElementRect, "rotation=", element_rect_rotation_set, MRB_ARGS_REQ(1));
   ADD_METHOD(ElementRect, "rotation", element_rect_rotation_get, MRB_ARGS_NONE());
+  ADD_METHOD(ElementRect, "pivot=", element_rect_pivot_set, MRB_ARGS_REQ(1));
+  ADD_METHOD(ElementRect, "pivot", element_rect_pivot_get, MRB_ARGS_NONE());
   ADD_METHOD(ElementRect, "alpha=", element_rect_alpha_set, MRB_ARGS_REQ(1));
   ADD_METHOD(ElementRect, "alpha", element_rect_alpha_get, MRB_ARGS_NONE());
   ADD_METHOD(ElementRect, "z=", element_rect_z_set, MRB_ARGS_REQ(1));
@@ -1630,6 +1727,8 @@ inline void setup() {
   ADD_METHOD(ElementImage, "scale", element_image_scale_get, MRB_ARGS_NONE());
   ADD_METHOD(ElementImage, "rotation=", element_image_rotation_set, MRB_ARGS_REQ(1));
   ADD_METHOD(ElementImage, "rotation", element_image_rotation_get, MRB_ARGS_NONE());
+  ADD_METHOD(ElementImage, "pivot=", element_image_pivot_set, MRB_ARGS_REQ(1));
+  ADD_METHOD(ElementImage, "pivot", element_image_pivot_get, MRB_ARGS_NONE());
   ADD_METHOD(ElementImage, "alpha=", element_image_alpha_set, MRB_ARGS_REQ(1));
   ADD_METHOD(ElementImage, "alpha", element_image_alpha_get, MRB_ARGS_NONE());
   ADD_METHOD(ElementImage, "z=", element_image_z_set, MRB_ARGS_REQ(1));

include/binding/ruby.h

@@ -103,6 +103,7 @@ DEF_SYM(italic)
 DEF_SYM(underline)
 DEF_SYM(position)
 DEF_SYM(rotation)
+DEF_SYM(pivot)
 DEF_SYM(scale)
 DEF_SYM(alpha)
 DEF_SYM(fps)

include/utils.h

@@ -80,6 +80,7 @@ struct Line {
   Vec2<float> start;
   Vec2<float> end;
 
+  Line() = default;
   Line(Vec2<float> start, Vec2<float> end) : start(start), end(end) {}
 
   bool intersects(const Line &other) const {
@@ -98,7 +99,7 @@ struct Line {
 struct Rect {
   Line diagonal; // from top-left to bottom-right
 
-  Rect(Vec2<float> a, Vec2<float> b) : diagonal(a, b) {
+  Rect(Vec2<float> a, Vec2<float> b) {
     diagonal.start = {
       MIN(a.x, b.x),
       MIN(a.y, b.y)
@@ -109,7 +110,11 @@ struct Rect {
     };
   }
 
-  static Rect from_size(Vec2<float> position, Vec2<float> size) {
+  static Rect from(Vec2<float> size) {
+    return Rect({0, 0}, size);
+  }
+
+  static Rect from(Vec2<float> position, Vec2<float> size) {
     return Rect(position, position + size);
   }
 

include/window/window.h

@@ -320,11 +320,11 @@ public:
   uint64_t create_text(uint64_t font_id, const char *text, uint32_t length, Color color);
   Vec2<float> get_text_size(uint64_t text_id);
 
-  bool write(uint64_t text_id, Vec2<float> position, float z, float angle, Vec2<float> scale, float alpha);
+  bool write(uint64_t text_id, Vec2<float> position, float z, float angle, Vec2<float> pivot, Vec2<float> scale, float alpha);
 
-  bool draw(uint64_t image_id, Vec2<float> position, float z, float angle, Vec2<float> scale, float alpha);
+  bool draw(uint64_t image_id, Vec2<float> position, float z, float angle, Vec2<float> pivot, Vec2<float> scale, float alpha);
 
-  bool draw_rect(Rect rect, Color color, float z, float angle, Vec2<float> scale, float alpha);
+  bool draw_rect(Rect rect, Color color, float z, float angle, Vec2<float> pivot, Vec2<float> scale, float alpha);
 
   void render(); // the rest of the calls only build the instruction list, this actually renders everything added to the screen (following z order)
 
@@ -366,6 +366,7 @@ private:
 
     float z;
     float angle;
+    Vec2<float> pivot;
     Vec2<float> scale;
     float alpha;
 

samples/button.rb

@@ -14,10 +14,12 @@ App.localize(:en, :btn_text, "Click %{name}!")
 
 text = ElementText.new :btn_text, default_font, 0xFFFF00, {name: "Me"}, position: {x: 50, y: 50}, z: 1, click_through: true, alpha: 1
 
-rect = ElementRect.new 100, 25, 0xFF0000, position: {x: 50, y: 50}, z: 0, rotation: 60, scale: { x: 1.5, y: 1 }, alpha: 0.4
+rect = ElementRect.new 100, 25, 0xFF0000, position: {x: 50, y: 50}, z: 0, rotation: 60, pivot: {x: 0.5, y: 0.5}, scale: { x: 1, y: 1 }, alpha: 0.4
 
 image_element = ElementImage.new bg_animation, position: {x: 0, y: 0}, z: -1, click_through: true, alpha: 1
 
+pp text, rect, image_element
+
 rect.on_click do
   rect.color = rect.color == 0xFF0000 ?
     0x00FF00 :
@@ -47,7 +49,7 @@ main_scene.on_update do |delta_time|
 
   pp App.text_input if App.text_input != ""
 
-  next unless App.pressed?(:press)
+  next unless App.down?(:press)
   
   pp "#{App.pressed?(:press)}, #{App.down?(:press)}, #{App.released?(:press)}"
 

src/window/window.cc

@@ -155,7 +155,7 @@ Vec2<float> Window::get_text_size(uint64_t text_id) {
   return text_pool[text_id]->size;
 }
 
-bool Window::write(uint64_t text_id, Vec2<float> position, float z, float angle, Vec2<float> scale, float alpha) {
+bool Window::write(uint64_t text_id, Vec2<float> position, float z, float angle, Vec2<float> pivot, Vec2<float> scale, float alpha) {
   if (!text_pool.is_valid(text_id)) {
     fprintf(stderr, "(Write) Invalid text ID: %llu\n", (unsigned long long)text_id);
     return false;
@@ -165,6 +165,7 @@ bool Window::write(uint64_t text_id, Vec2<float> position, float z, float angle,
     {.type = RenderInstruction::DRAW_TEXT,
      .z = z,
      .angle = angle,
+     .pivot = pivot,
      .scale = scale,
      .alpha = alpha,
      .draw_text = {
@@ -176,7 +177,7 @@ bool Window::write(uint64_t text_id, Vec2<float> position, float z, float angle,
   return true;
 };
 
-bool Window::draw(uint64_t image_id, Vec2<float> position, float z, float angle, Vec2<float> scale, float alpha) {
+bool Window::draw(uint64_t image_id, Vec2<float> position, float z, float angle, Vec2<float> pivot, Vec2<float> scale, float alpha) {
   if (!image_pool.is_valid(image_id)) {
     fprintf(stderr, "Invalid image ID: %llu\n", (unsigned long long)image_id);
     return false;
@@ -186,6 +187,7 @@ bool Window::draw(uint64_t image_id, Vec2<float> position, float z, float angle,
     {.type = RenderInstruction::DRAW_IMAGE,
      .z = z,
      .angle = angle,
+     .pivot = pivot,
      .scale = scale,
      .alpha = alpha,
      .draw_image = {
@@ -197,11 +199,12 @@ bool Window::draw(uint64_t image_id, Vec2<float> position, float z, float angle,
   return true;
 };
 
-bool Window::draw_rect(Rect rect, Color color, float z, float angle, Vec2<float> scale, float alpha) {
+bool Window::draw_rect(Rect rect, Color color, float z, float angle, Vec2<float> pivot, Vec2<float> scale, float alpha) {
   render_instructions.push_back(
     {.type = RenderInstruction::DRAW_RECT,
      .z = z,
      .angle = angle,
+     .pivot = pivot,
      .scale = scale,
      .alpha = alpha,
      .draw_rect = {
@@ -279,13 +282,18 @@ void Window::render() {
 
       SDL_SetTextureAlphaModFloat(texture, instruction.alpha);
 
+      SDL_FPoint pivot_point = {
+        instruction.pivot.x * scale_x,
+        instruction.pivot.y * scale_y
+      };
+
       SDL_RenderTextureRotated(
         renderer,
         texture,
         nullptr,
         &dst_rect,
         instruction.angle,
-        nullptr,
+        &pivot_point,
         flip
       );
     } break;
@@ -311,13 +319,18 @@ void Window::render() {
 
       SDL_SetTextureAlphaModFloat(image->texture, instruction.alpha);
 
+      SDL_FPoint pivot_point = {
+        instruction.pivot.x * scale_x,
+        instruction.pivot.y * scale_y
+      };
+
       SDL_RenderTextureRotated(
         renderer,
         image->texture,
         nullptr,
         &dst_rect,
         instruction.angle,
-        nullptr,
+        &pivot_point,
         flip
       );
     } break;
@@ -338,13 +351,18 @@ void Window::render() {
 
       SDL_SetTextureAlphaModFloat(white_tex, instruction.alpha);
 
+      SDL_FPoint pivot_point = {
+        instruction.pivot.x * dst_rect.w,
+        instruction.pivot.y * dst_rect.h
+      };
+
       SDL_RenderTextureRotated(
         renderer,
         white_tex,
         nullptr,
         &dst_rect,
         instruction.angle,
-        nullptr,
+        &pivot_point,
         SDL_FLIP_NONE
       );
     } break;