Fixes the bad calculation of margin & anchors when child of Node2D

2 files changed, 68 insertions, 109 deletions

diff --git a/scene/gui/control.cpp b/scene/gui/control.cpp
index d07b5a9f65..ebe54681a8 100644
--- a/scene/gui/control.cpp
+++ b/scene/gui/control.cpp
@@ -1268,21 +1268,23 @@ bool Control::has_constant(const StringName &p_name, const StringName &p_type) c
 	return Theme::get_default()->has_constant(p_name, type);
 }
 
-Size2 Control::get_parent_area_size() const {
-
-	ERR_FAIL_COND_V(!is_inside_tree(), Size2());
-
-	Size2 parent_size;
+Rect2 Control::get_parent_anchorable_rect() const {
+	if (!is_inside_tree())
+		return Rect2();
 
+	Rect2 parent_rect;
 	if (data.parent_canvas_item) {
-
-		parent_size = data.parent_canvas_item->_edit_get_rect().size;
+		parent_rect = data.parent_canvas_item->get_anchorable_rect();
 	} else {
-
-		parent_size = get_viewport()->get_visible_rect().size;
+		parent_rect = get_viewport()->get_visible_rect();
 	}
 
-	return parent_size;
+	return parent_rect;
+}
+
+Size2 Control::get_parent_area_size() const {
+
+	return get_parent_anchorable_rect().size;
 }
 
 void Control::_size_changed() {
@@ -1290,13 +1292,13 @@ void Control::_size_changed() {
 	if (!is_inside_tree())
 		return;
 
-	Size2 parent_size = get_parent_area_size();
+	Rect2 parent_rect = get_parent_anchorable_rect();
 
 	float margin_pos[4];
 
 	for (int i = 0; i < 4; i++) {
 
-		float area = parent_size[i & 1];
+		float area = parent_rect.size[i & 1];
 		margin_pos[i] = data.margin[i] + (data.anchor[i] * area);
 	}
 
@@ -1350,43 +1352,9 @@ void Control::_size_changed() {
 	}
 }
 
-float Control::_get_parent_range(int p_idx) const {
-
-	if (!is_inside_tree()) {
-
-		return 0;
-	}
-	if (data.parent_canvas_item) {
-
-		return data.parent_canvas_item->_edit_get_rect().size[p_idx & 1];
-	} else {
-		return get_viewport()->get_visible_rect().size[p_idx & 1];
-	}
-
-	return 0;
-}
-
-float Control::_get_range(int p_idx) const {
-
-	p_idx &= 1;
-
-	float parent_range = _get_parent_range(p_idx);
-	float from = _a2s(data.margin[p_idx], data.anchor[p_idx], parent_range);
-	float to = _a2s(data.margin[p_idx + 2], data.anchor[p_idx + 2], parent_range);
-
-	return to - from;
-}
-
-float Control::_s2a(float p_val, float p_anchor, float p_range) const {
-	return p_val - (p_anchor * p_range);
-}
-
-float Control::_a2s(float p_val, float p_anchor, float p_range) const {
-	return Math::floor(p_val + (p_anchor * p_range));
-}
-
 void Control::set_anchor(Margin p_margin, float p_anchor, bool p_keep_margin, bool p_push_opposite_anchor) {
-	float parent_range = _get_parent_range((p_margin == MARGIN_LEFT || p_margin == MARGIN_RIGHT) ? 0 : 1);
+	Rect2 parent_rect = get_parent_anchorable_rect();
+	float parent_range = (p_margin == MARGIN_LEFT || p_margin == MARGIN_RIGHT) ? parent_rect.size.x : parent_rect.size.y;
 	float previous_margin_pos = data.margin[p_margin] + data.anchor[p_margin] * parent_range;
 	float previous_opposite_margin_pos = data.margin[(p_margin + 2) % 4] + data.anchor[(p_margin + 2) % 4] * parent_range;
 
@@ -1402,9 +1370,9 @@ void Control::set_anchor(Margin p_margin, float p_anchor, bool p_keep_margin, bo
 	}
 
 	if (!p_keep_margin) {
-		data.margin[p_margin] = _s2a(previous_margin_pos, data.anchor[p_margin], parent_range);
+		data.margin[p_margin] = previous_margin_pos - data.anchor[p_margin] * parent_range;
 		if (p_push_opposite_anchor) {
-			data.margin[(p_margin + 2) % 4] = _s2a(previous_opposite_margin_pos, data.anchor[(p_margin + 2) % 4], parent_range);
+			data.margin[(p_margin + 2) % 4] = previous_opposite_margin_pos - data.anchor[(p_margin + 2) % 4] * parent_range;
 		}
 	}
 	if (is_inside_tree()) {
@@ -1558,8 +1526,7 @@ void Control::set_margins_preset(LayoutPreset p_preset, LayoutPresetMode p_resiz
 		new_size.y = min_size.y;
 	}
 
-	float pw = _get_parent_range(0);
-	float ph = _get_parent_range(1);
+	Rect2 parent_rect = get_parent_anchorable_rect();
 
 	//Left
 	switch (p_preset) {
@@ -1571,21 +1538,21 @@ void Control::set_margins_preset(LayoutPreset p_preset, LayoutPresetMode p_resiz
 		case PRESET_LEFT_WIDE:
 		case PRESET_HCENTER_WIDE:
 		case PRESET_WIDE:
-			data.margin[0] = pw * (0.0 - data.anchor[0]) + p_margin;
+			data.margin[0] = parent_rect.size.x * (0.0 - data.anchor[0]) + p_margin + parent_rect.position.x;
 			break;
 
 		case PRESET_CENTER_TOP:
 		case PRESET_CENTER_BOTTOM:
 		case PRESET_CENTER:
 		case PRESET_VCENTER_WIDE:
-			data.margin[0] = pw * (0.5 - data.anchor[0]) - new_size.x / 2;
+			data.margin[0] = parent_rect.size.x * (0.5 - data.anchor[0]) - new_size.x / 2 + parent_rect.position.x;
 			break;
 
 		case PRESET_TOP_RIGHT:
 		case PRESET_BOTTOM_RIGHT:
 		case PRESET_CENTER_RIGHT:
 		case PRESET_RIGHT_WIDE:
-			data.margin[0] = pw * (1.0 - data.anchor[0]) - new_size.x - p_margin;
+			data.margin[0] = parent_rect.size.x * (1.0 - data.anchor[0]) - new_size.x - p_margin + parent_rect.position.x;
 			break;
 	}
 
@@ -1599,21 +1566,21 @@ void Control::set_margins_preset(LayoutPreset p_preset, LayoutPresetMode p_resiz
 		case PRESET_TOP_WIDE:
 		case PRESET_VCENTER_WIDE:
 		case PRESET_WIDE:
-			data.margin[1] = ph * (0.0 - data.anchor[1]) + p_margin;
+			data.margin[1] = parent_rect.size.y * (0.0 - data.anchor[1]) + p_margin + parent_rect.position.y;
 			break;
 
 		case PRESET_CENTER_LEFT:
 		case PRESET_CENTER_RIGHT:
 		case PRESET_CENTER:
 		case PRESET_HCENTER_WIDE:
-			data.margin[1] = ph * (0.5 - data.anchor[1]) - new_size.y / 2;
+			data.margin[1] = parent_rect.size.y * (0.5 - data.anchor[1]) - new_size.y / 2 + parent_rect.position.y;
 			break;
 
 		case PRESET_BOTTOM_LEFT:
 		case PRESET_BOTTOM_RIGHT:
 		case PRESET_CENTER_BOTTOM:
 		case PRESET_BOTTOM_WIDE:
-			data.margin[1] = ph * (1.0 - data.anchor[1]) - new_size.y - p_margin;
+			data.margin[1] = parent_rect.size.y * (1.0 - data.anchor[1]) - new_size.y - p_margin + parent_rect.position.y;
 			break;
 	}
 
@@ -1623,14 +1590,14 @@ void Control::set_margins_preset(LayoutPreset p_preset, LayoutPresetMode p_resiz
 		case PRESET_BOTTOM_LEFT:
 		case PRESET_CENTER_LEFT:
 		case PRESET_LEFT_WIDE:
-			data.margin[2] = pw * (0.0 - data.anchor[2]) + new_size.x + p_margin;
+			data.margin[2] = parent_rect.size.x * (0.0 - data.anchor[2]) + new_size.x + p_margin + parent_rect.position.x;
 			break;
 
 		case PRESET_CENTER_TOP:
 		case PRESET_CENTER_BOTTOM:
 		case PRESET_CENTER:
 		case PRESET_VCENTER_WIDE:
-			data.margin[2] = pw * (0.5 - data.anchor[2]) + new_size.x / 2;
+			data.margin[2] = parent_rect.size.x * (0.5 - data.anchor[2]) + new_size.x / 2 + parent_rect.position.x;
 			break;
 
 		case PRESET_TOP_RIGHT:
@@ -1641,7 +1608,7 @@ void Control::set_margins_preset(LayoutPreset p_preset, LayoutPresetMode p_resiz
 		case PRESET_BOTTOM_WIDE:
 		case PRESET_HCENTER_WIDE:
 		case PRESET_WIDE:
-			data.margin[2] = pw * (1.0 - data.anchor[2]) - p_margin;
+			data.margin[2] = parent_rect.size.x * (1.0 - data.anchor[2]) - p_margin + parent_rect.position.x;
 			break;
 	}
 
@@ -1651,14 +1618,14 @@ void Control::set_margins_preset(LayoutPreset p_preset, LayoutPresetMode p_resiz
 		case PRESET_TOP_RIGHT:
 		case PRESET_CENTER_TOP:
 		case PRESET_TOP_WIDE:
-			data.margin[3] = ph * (0.0 - data.anchor[3]) + new_size.y + p_margin;
+			data.margin[3] = parent_rect.size.y * (0.0 - data.anchor[3]) + new_size.y + p_margin + parent_rect.position.y;
 			break;
 
 		case PRESET_CENTER_LEFT:
 		case PRESET_CENTER_RIGHT:
 		case PRESET_CENTER:
 		case PRESET_HCENTER_WIDE:
-			data.margin[3] = ph * (0.5 - data.anchor[3]) + new_size.y / 2;
+			data.margin[3] = parent_rect.size.y * (0.5 - data.anchor[3]) + new_size.y / 2 + parent_rect.position.y;
 			break;
 
 		case PRESET_BOTTOM_LEFT:
@@ -1669,7 +1636,7 @@ void Control::set_margins_preset(LayoutPreset p_preset, LayoutPresetMode p_resiz
 		case PRESET_BOTTOM_WIDE:
 		case PRESET_VCENTER_WIDE:
 		case PRESET_WIDE:
-			data.margin[3] = ph * (1.0 - data.anchor[3]) - p_margin;
+			data.margin[3] = parent_rect.size.y * (1.0 - data.anchor[3]) - p_margin + parent_rect.position.y;
 			break;
 	}
 
@@ -1748,31 +1715,29 @@ void Control::set_global_position(const Point2 &p_point) {
 	set_position(inv.xform(p_point));
 }
 
-void Control::set_position(const Size2 &p_point) {
-
-	float pw = _get_parent_range(0);
-	float ph = _get_parent_range(1);
+Rect2 Control::_compute_child_rect(const float p_anchors[4], const float p_margins[4]) const {
 
-	float x = _a2s(data.margin[0], data.anchor[0], pw);
-	float y = _a2s(data.margin[1], data.anchor[1], ph);
-	float x2 = _a2s(data.margin[2], data.anchor[2], pw);
-	float y2 = _a2s(data.margin[3], data.anchor[3], ph);
+	Rect2 anchorable = get_parent_anchorable_rect();
+	Rect2 result = anchorable;
+	for (int i = 0; i < 4; i++) {
+		result.grow_margin((Margin)i, p_anchors[i] * anchorable.get_size()[i % 2] + p_margins[i]);
+	}
 
-	Size2 ret = Size2(x2 - x, y2 - y);
-	Size2 min = get_combined_minimum_size();
+	return result;
+}
 
-	Size2 size = Size2(MAX(min.width, ret.width), MAX(min.height, ret.height));
-	float w = size.x;
-	float h = size.y;
+void Control::_compute_margins(Rect2 p_rect, const float p_anchors[4], float (&r_margins)[4]) {
 
-	x = p_point.x;
-	y = p_point.y;
+	Size2 parent_rect_size = get_parent_anchorable_rect().size;
+	r_margins[0] = Math::floor(p_rect.position.x - (p_anchors[0] * parent_rect_size.x));
+	r_margins[1] = Math::floor(p_rect.position.y - (p_anchors[1] * parent_rect_size.y));
+	r_margins[2] = Math::floor(p_rect.position.x + p_rect.size.x - (p_anchors[2] * parent_rect_size.x));
+	r_margins[3] = Math::floor(p_rect.position.y + p_rect.size.y - (p_anchors[3] * parent_rect_size.y));
+}
 
-	data.margin[0] = _s2a(x, data.anchor[0], pw);
-	data.margin[1] = _s2a(y, data.anchor[1], ph);
-	data.margin[2] = _s2a(x + w, data.anchor[2], pw);
-	data.margin[3] = _s2a(y + h, data.anchor[3], ph);
+void Control::set_position(const Size2 &p_point) {
 
+	_compute_margins(Rect2(p_point, data.size_cache), data.anchor, data.margin);
 	_size_changed();
 }
 
@@ -1785,18 +1750,7 @@ void Control::set_size(const Size2 &p_size) {
 	if (new_size.y < min.y)
 		new_size.y = min.y;
 
-	float pw = _get_parent_range(0);
-	float ph = _get_parent_range(1);
-
-	float x = _a2s(data.margin[0], data.anchor[0], pw);
-	float y = _a2s(data.margin[1], data.anchor[1], ph);
-
-	float w = new_size.width;
-	float h = new_size.height;
-
-	data.margin[2] = _s2a(x + w, data.anchor[2], pw);
-	data.margin[3] = _s2a(y + h, data.anchor[3], ph);
-
+	_compute_margins(Rect2(data.pos_cache, new_size), data.anchor, data.margin);
 	_size_changed();
 }
 
@@ -1827,6 +1781,11 @@ Rect2 Control::get_rect() const {
 	return Rect2(get_position(), get_size());
 }
 
+Rect2 Control::get_anchorable_rect() const {
+
+	return Rect2(Point2(), get_size());
+}
+
 void Control::add_icon_override(const StringName &p_name, const Ref<Texture> &p_icon) {
 
 	ERR_FAIL_COND(p_icon.is_null());
@@ -2326,12 +2285,11 @@ Control *Control::_get_focus_neighbour(Margin p_margin, int p_count) {
 	Point2 points[4];
 
 	Transform2D xform = get_global_transform();
-	Rect2 rect = _edit_get_rect();
 
-	points[0] = xform.xform(rect.position);
-	points[1] = xform.xform(rect.position + Point2(rect.size.x, 0));
-	points[2] = xform.xform(rect.position + rect.size);
-	points[3] = xform.xform(rect.position + Point2(0, rect.size.y));
+	points[0] = xform.xform(Point2());
+	points[1] = xform.xform(Point2(get_size().x, 0));
+	points[2] = xform.xform(get_size());
+	points[3] = xform.xform(Point2(0, get_size().y));
 
 	const Vector2 dir[4] = {
 		Vector2(-1, 0),
@@ -2385,12 +2343,11 @@ void Control::_window_find_focus_neighbour(const Vector2 &p_dir, Node *p_at, con
 		Point2 points[4];
 
 		Transform2D xform = c->get_global_transform();
-		Rect2 rect = c->_edit_get_rect();
 
-		points[0] = xform.xform(rect.position);
-		points[1] = xform.xform(rect.position + Point2(rect.size.x, 0));
-		points[2] = xform.xform(rect.position + rect.size);
-		points[3] = xform.xform(rect.position + Point2(0, rect.size.y));
+		points[0] = xform.xform(Point2());
+		points[1] = xform.xform(Point2(get_size().x, 0));
+		points[2] = xform.xform(get_size());
+		points[3] = xform.xform(Point2(0, get_size().y));
 
 		float min = 1e7;
 
diff --git a/scene/gui/control.h b/scene/gui/control.h
index 9124256624..ddd55128c3 100644
--- a/scene/gui/control.h
+++ b/scene/gui/control.h
@@ -220,10 +220,6 @@ private:
 
 	void _set_anchor(Margin p_margin, float p_anchor);
 
-	float _get_parent_range(int p_idx) const;
-	float _get_range(int p_idx) const;
-	float _s2a(float p_val, float p_anchor, float p_range) const;
-	float _a2s(float p_val, float p_anchor, float p_range) const;
 	void _propagate_theme_changed(CanvasItem *p_at, Control *p_owner, bool p_assign = true);
 	void _theme_changed();
 
@@ -233,6 +229,9 @@ private:
 	void _update_scroll();
 	void _resize(const Size2 &p_size);
 
+	Rect2 _compute_child_rect(const float p_anchors[4], const float p_margins[4]) const;
+	void _compute_margins(Rect2 p_rect, const float p_anchors[4], float (&r_margins)[4]);
+
 	void _size_changed();
 	String _get_tooltip() const;
 
@@ -283,6 +282,7 @@ public:
 
 	};
 
+	/* EDITOR */
 	virtual Dictionary _edit_get_state() const;
 	virtual void _edit_set_state(const Dictionary &p_state);
 
@@ -358,6 +358,7 @@ public:
 	Rect2 get_rect() const;
 	Rect2 get_global_rect() const;
 	Rect2 get_window_rect() const; ///< use with care, as it blocks waiting for the visual server
+	Rect2 get_anchorable_rect() const;
 
 	void set_rotation(float p_radians);
 	void set_rotation_degrees(float p_degrees);
@@ -465,6 +466,7 @@ public:
 	bool is_toplevel_control() const;
 
 	Size2 get_parent_area_size() const;
+	Rect2 get_parent_anchorable_rect() const;
 
 	void grab_click_focus();