diff --git a/#backups/scripts/canvas_tool_brush/canvas_tool_brush.gml.backup0 b/#backups/scripts/canvas_tool_brush/canvas_tool_brush.gml.backup0
index 2132dd44b..b5c6477d6 100644
--- a/#backups/scripts/canvas_tool_brush/canvas_tool_brush.gml.backup0
+++ b/#backups/scripts/canvas_tool_brush/canvas_tool_brush.gml.backup0
@@ -1,4 +1,4 @@
-// 2024-04-14 18:56:07
+// 2024-04-18 15:44:33
 function canvas_tool_brush(brush, eraser = false) : canvas_tool() constructor {
 	self.brush = brush;
 	isEraser   = eraser;
@@ -12,6 +12,12 @@ function canvas_tool_brush(brush, eraser = false) : canvas_tool() constructor {
 	mouse_pre_draw_x = undefined;
 	mouse_pre_draw_y = undefined;
 	
+	mouse_line_drawing = false;
+	mouse_line_x0 = 0;
+	mouse_line_y0 = 0;
+	mouse_line_x1 = 0;
+	mouse_line_y1 = 0;
+	
 	function step(hover, active, _x, _y, _s, _mx, _my, _snx, _sny) {
 		
 		mouse_cur_x = round((_mx - _x) / _s - 0.5);
@@ -30,13 +36,13 @@ function canvas_tool_brush(brush, eraser = false) : canvas_tool() constructor {
 		if(mouse_press(mb_left, active)) {
 				
 			surface_set_shader(drawing_surface, noone);
-				canvas_draw_point_size(brush, mouse_cur_x, mouse_cur_y, true);
+				canvas_draw_point_brush(brush, mouse_cur_x, mouse_cur_y, true);
 			surface_reset_shader();
 				
 			mouse_holding = true;
 			if(mouse_pre_draw_x != undefined && mouse_pre_draw_y != undefined && key_mod_press(SHIFT)) { ///////////////// shift line
 				surface_set_shader(drawing_surface, noone, true, BLEND.alpha);
-					canvas_draw_line_size(brush, mouse_pre_draw_x, mouse_pre_draw_y, mouse_cur_x, mouse_cur_y, true);
+					canvas_draw_line_brush(brush, mouse_pre_draw_x, mouse_pre_draw_y, mouse_cur_x, mouse_cur_y, true);
 				surface_reset_shader();
 				mouse_holding = false;
 					
@@ -55,8 +61,8 @@ function canvas_tool_brush(brush, eraser = false) : canvas_tool() constructor {
 				
 			if(_move || !_1stp) {
 				surface_set_shader(drawing_surface, noone, false, BLEND.alpha);
-					if(_1stp) canvas_draw_point_size(brush, mouse_cur_x, mouse_cur_y, true);
-					canvas_draw_line_size(brush, mouse_pre_draw_x, mouse_pre_draw_y, mouse_cur_x, mouse_cur_y, true);
+					if(_1stp) canvas_draw_point_brush(brush, mouse_cur_x, mouse_cur_y, true);
+					canvas_draw_line_brush(brush, mouse_pre_draw_x, mouse_pre_draw_y, mouse_cur_x, mouse_cur_y, true);
 				surface_reset_shader();
 			}
 				
@@ -79,9 +85,42 @@ function canvas_tool_brush(brush, eraser = false) : canvas_tool() constructor {
 	function drawPreview(hover, active, _x, _y, _s, _mx, _my, _snx, _sny) {
 		if(isEraser) draw_set_color(c_white);
 		
-		if(mouse_pre_draw_x != undefined && mouse_pre_draw_y != undefined && key_mod_press(SHIFT)) 
-			canvas_draw_line_size(brush, mouse_pre_draw_x, mouse_pre_draw_y, mouse_cur_x, mouse_cur_y);
-		else
-			canvas_draw_point_size(brush, mouse_cur_x, mouse_cur_y);
+		mouse_line_drawing = false;
+		
+		if(mouse_pre_draw_x != undefined && mouse_pre_draw_y != undefined && key_mod_press(SHIFT)) {
+			
+			canvas_draw_line_brush(brush, mouse_pre_draw_x, mouse_pre_draw_y, mouse_cur_x, mouse_cur_y);
+			mouse_line_drawing = true;
+			mouse_line_x0 = min(mouse_cur_x, mouse_pre_draw_x);
+			mouse_line_y0 = min(mouse_cur_y, mouse_pre_draw_y);
+			mouse_line_x1 = max(mouse_cur_x, mouse_pre_draw_x) + 1;
+			mouse_line_y1 = max(mouse_cur_y, mouse_pre_draw_y) + 1;
+			
+		} else
+			canvas_draw_point_brush(brush, mouse_cur_x, mouse_cur_y);
 	}
+	
+	function drawPostOverlay(hover, active, _x, _y, _s, _mx, _my, _snx, _sny) {
+		
+		if(mouse_line_drawing && !brush.brush_sizing && node.attributes.show_slope_check) {
+			var _x0 = _x + mouse_line_x0 * _s;
+			var _y0 = _y + mouse_line_y0 * _s;
+			var _x1 = _x + mouse_line_x1 * _s;
+			var _y1 = _y + mouse_line_y1 * _s;
+			
+			var _w  = mouse_line_x1 - mouse_line_x0;
+			var _h  = mouse_line_y1 - mouse_line_y0;
+			var _as = max(_w, _h) % min(_w, _h) == 0;
+			
+			draw_set_color(_as? COLORS._main_value_positive : COLORS._main_accent);
+			draw_rectangle(_x0, _y0, _x1, _y1, true);
+			
+			draw_set_text(f_p3, fa_center, fa_top);
+			draw_text((_x0 + _x1) / 2, _y1 + 8, _w);
+			
+			draw_set_text(f_p3, fa_left, fa_center);
+			draw_text(_x1 + 8, (_y0 + _y1) / 2, _h);
+		}
+	}
+	
 }
\ No newline at end of file
diff --git a/#backups/scripts/canvas_tool_brush/canvas_tool_brush.gml.backup1 b/#backups/scripts/canvas_tool_brush/canvas_tool_brush.gml.backup1
index 3d2386700..41f74fb69 100644
--- a/#backups/scripts/canvas_tool_brush/canvas_tool_brush.gml.backup1
+++ b/#backups/scripts/canvas_tool_brush/canvas_tool_brush.gml.backup1
@@ -1,4 +1,4 @@
-// 2024-04-14 14:45:30
+// 2024-04-18 15:43:04
 function canvas_tool_brush(brush, eraser = false) : canvas_tool() constructor {
 	self.brush = brush;
 	isEraser   = eraser;
@@ -12,6 +12,12 @@ function canvas_tool_brush(brush, eraser = false) : canvas_tool() constructor {
 	mouse_pre_draw_x = undefined;
 	mouse_pre_draw_y = undefined;
 	
+	mouse_line_drawing = false;
+	mouse_line_x0 = 0;
+	mouse_line_y0 = 0;
+	mouse_line_x1 = 0;
+	mouse_line_y1 = 0;
+	
 	function step(hover, active, _x, _y, _s, _mx, _my, _snx, _sny) {
 		
 		mouse_cur_x = round((_mx - _x) / _s - 0.5);
@@ -28,17 +34,15 @@ function canvas_tool_brush(brush, eraser = false) : canvas_tool() constructor {
 		}
 			
 		if(mouse_press(mb_left, active)) {
-			brush_next_dist = 0;
 				
 			surface_set_shader(drawing_surface, noone);
-				canvas_draw_point_size(brush, mouse_cur_x, mouse_cur_y, true);
+				canvas_draw_point_brush(brush, mouse_cur_x, mouse_cur_y, true);
 			surface_reset_shader();
 				
 			mouse_holding = true;
 			if(mouse_pre_draw_x != undefined && mouse_pre_draw_y != undefined && key_mod_press(SHIFT)) { ///////////////// shift line
 				surface_set_shader(drawing_surface, noone, true, BLEND.alpha);
-					brush_next_dist = 0;
-					canvas_draw_line_size(brush, mouse_pre_draw_x, mouse_pre_draw_y, mouse_cur_x, mouse_cur_y, true);
+					canvas_draw_line_brush(brush, mouse_pre_draw_x, mouse_pre_draw_y, mouse_cur_x, mouse_cur_y, true);
 				surface_reset_shader();
 				mouse_holding = false;
 					
@@ -57,8 +61,8 @@ function canvas_tool_brush(brush, eraser = false) : canvas_tool() constructor {
 				
 			if(_move || !_1stp) {
 				surface_set_shader(drawing_surface, noone, false, BLEND.alpha);
-					if(_1stp) canvas_draw_point_size(brush, mouse_cur_x, mouse_cur_y, true);
-					canvas_draw_line_size(brush, mouse_pre_draw_x, mouse_pre_draw_y, mouse_cur_x, mouse_cur_y, true);
+					if(_1stp) canvas_draw_point_brush(brush, mouse_cur_x, mouse_cur_y, true);
+					canvas_draw_line_brush(brush, mouse_pre_draw_x, mouse_pre_draw_y, mouse_cur_x, mouse_cur_y, true);
 				surface_reset_shader();
 			}
 				
@@ -81,9 +85,42 @@ function canvas_tool_brush(brush, eraser = false) : canvas_tool() constructor {
 	function drawPreview(hover, active, _x, _y, _s, _mx, _my, _snx, _sny) {
 		if(isEraser) draw_set_color(c_white);
 		
-		if(mouse_pre_draw_x != undefined && mouse_pre_draw_y != undefined && key_mod_press(SHIFT)) 
-			canvas_draw_line_size(brush, mouse_pre_draw_x, mouse_pre_draw_y, mouse_cur_x, mouse_cur_y);
-		else
-			canvas_draw_point_size(brush, mouse_cur_x, mouse_cur_y);
+		mouse_line_drawing = false;
+		
+		if(mouse_pre_draw_x != undefined && mouse_pre_draw_y != undefined && key_mod_press(SHIFT)) {
+			
+			canvas_draw_line_brush(brush, mouse_pre_draw_x, mouse_pre_draw_y, mouse_cur_x, mouse_cur_y);
+			mouse_line_drawing = true;
+			mouse_line_x0 = min(mouse_cur_x, mouse_pre_draw_x);
+			mouse_line_y0 = min(mouse_cur_y, mouse_pre_draw_y);
+			mouse_line_x1 = max(mouse_cur_x, mouse_pre_draw_x) + 1;
+			mouse_line_y1 = max(mouse_cur_y, mouse_pre_draw_y) + 1;
+			
+		} else
+			canvas_draw_point_brush(brush, mouse_cur_x, mouse_cur_y);
 	}
+	
+	function drawPostOverlay(hover, active, _x, _y, _s, _mx, _my, _snx, _sny) {
+		
+		if(mouse_line_drawing && !brush.brush_sizing) {
+			var _x0 = _x + mouse_line_x0 * _s;
+			var _y0 = _y + mouse_line_y0 * _s;
+			var _x1 = _x + mouse_line_x1 * _s;
+			var _y1 = _y + mouse_line_y1 * _s;
+			
+			var _w  = mouse_line_x1 - mouse_line_x0;
+			var _h  = mouse_line_y1 - mouse_line_y0;
+			var _as = max(_w, _h) % min(_w, _h) == 0;
+			
+			draw_set_color(_as? COLORS._main_value_positive : COLORS._main_accent);
+			draw_rectangle(_x0, _y0, _x1, _y1, true);
+			
+			draw_set_text(f_p3, fa_center, fa_top);
+			draw_text((_x0 + _x1) / 2, _y1 + 8, _w);
+			
+			draw_set_text(f_p3, fa_left, fa_center);
+			draw_text(_x1 + 8, (_y0 + _y1) / 2, _h);
+		}
+	}
+	
 }
\ No newline at end of file
diff --git a/#backups/scripts/node_canvas/node_canvas.gml.backup0 b/#backups/scripts/node_canvas/node_canvas.gml.backup0
index 9af37958b..2a796d67d 100644
--- a/#backups/scripts/node_canvas/node_canvas.gml.backup0
+++ b/#backups/scripts/node_canvas/node_canvas.gml.backup0
@@ -1,4 +1,4 @@
-// 2024-04-18 15:00:59
+// 2024-04-18 16:15:18
 function Node_Canvas(_x, _y, _group = noone) : Node(_x, _y, _group) constructor {
 	name	= "Canvas";
 	color	= COLORS.node_blend_canvas;
@@ -184,6 +184,9 @@ function Node_Canvas(_x, _y, _group = noone) : Node(_x, _y, _group) constructor
 		
 		draw_stack = ds_list_create();
 		
+		attributes.show_slope_check = true;
+		array_push(attributeEditors, "Display");
+		array_push(attributeEditors, [ "Slope Check", function() { return attributes.show_slope_check; }, new checkBox(function() { attributes.show_slope_check = !attributes.show_slope_check; }) ]);
 	#endregion
 	
 	#region ++++ tool object ++++
diff --git a/#backups/scripts/node_canvas/node_canvas.gml.backup1 b/#backups/scripts/node_canvas/node_canvas.gml.backup1
index 356b8182b..58799db9b 100644
--- a/#backups/scripts/node_canvas/node_canvas.gml.backup1
+++ b/#backups/scripts/node_canvas/node_canvas.gml.backup1
@@ -1,4 +1,4 @@
-// 2024-04-18 15:00:58
+// 2024-04-18 16:15:08
 function Node_Canvas(_x, _y, _group = noone) : Node(_x, _y, _group) constructor {
 	name	= "Canvas";
 	color	= COLORS.node_blend_canvas;
@@ -184,6 +184,9 @@ function Node_Canvas(_x, _y, _group = noone) : Node(_x, _y, _group) constructor
 		
 		draw_stack = ds_list_create();
 		
+		attributes.show_slope_check = true;
+		array_push(attributeEditors, "Display");
+		array_push(attributeEditors, [ "Slope Check", function() { return attributes.show_slope_check; }, new checkBox(function() { attributes.show_slope_check = !attributes.show_slope_check; }) ]);
 	#endregion
 	
 	#region ++++ tool object ++++
diff --git a/scripts/canvas_tool_brush/canvas_tool_brush.gml b/scripts/canvas_tool_brush/canvas_tool_brush.gml
index 87667a87f..edb38b065 100644
--- a/scripts/canvas_tool_brush/canvas_tool_brush.gml
+++ b/scripts/canvas_tool_brush/canvas_tool_brush.gml
@@ -11,6 +11,12 @@ function canvas_tool_brush(brush, eraser = false) : canvas_tool() constructor {
 	mouse_pre_draw_x = undefined;
 	mouse_pre_draw_y = undefined;
 	
+	mouse_line_drawing = false;
+	mouse_line_x0 = 0;
+	mouse_line_y0 = 0;
+	mouse_line_x1 = 0;
+	mouse_line_y1 = 0;
+	
 	function step(hover, active, _x, _y, _s, _mx, _my, _snx, _sny) {
 		
 		mouse_cur_x = round((_mx - _x) / _s - 0.5);
@@ -78,9 +84,42 @@ function canvas_tool_brush(brush, eraser = false) : canvas_tool() constructor {
 	function drawPreview(hover, active, _x, _y, _s, _mx, _my, _snx, _sny) {
 		if(isEraser) draw_set_color(c_white);
 		
-		if(mouse_pre_draw_x != undefined && mouse_pre_draw_y != undefined && key_mod_press(SHIFT)) 
+		mouse_line_drawing = false;
+		
+		if(mouse_pre_draw_x != undefined && mouse_pre_draw_y != undefined && key_mod_press(SHIFT)) {
+			
 			canvas_draw_line_brush(brush, mouse_pre_draw_x, mouse_pre_draw_y, mouse_cur_x, mouse_cur_y);
-		else
+			mouse_line_drawing = true;
+			mouse_line_x0 = min(mouse_cur_x, mouse_pre_draw_x);
+			mouse_line_y0 = min(mouse_cur_y, mouse_pre_draw_y);
+			mouse_line_x1 = max(mouse_cur_x, mouse_pre_draw_x) + 1;
+			mouse_line_y1 = max(mouse_cur_y, mouse_pre_draw_y) + 1;
+			
+		} else
 			canvas_draw_point_brush(brush, mouse_cur_x, mouse_cur_y);
 	}
+	
+	function drawPostOverlay(hover, active, _x, _y, _s, _mx, _my, _snx, _sny) {
+		
+		if(mouse_line_drawing && !brush.brush_sizing && node.attributes.show_slope_check) {
+			var _x0 = _x + mouse_line_x0 * _s;
+			var _y0 = _y + mouse_line_y0 * _s;
+			var _x1 = _x + mouse_line_x1 * _s;
+			var _y1 = _y + mouse_line_y1 * _s;
+			
+			var _w  = mouse_line_x1 - mouse_line_x0;
+			var _h  = mouse_line_y1 - mouse_line_y0;
+			var _as = max(_w, _h) % min(_w, _h) == 0;
+			
+			draw_set_color(_as? COLORS._main_value_positive : COLORS._main_accent);
+			draw_rectangle(_x0, _y0, _x1, _y1, true);
+			
+			draw_set_text(f_p3, fa_center, fa_top);
+			draw_text((_x0 + _x1) / 2, _y1 + 8, _w);
+			
+			draw_set_text(f_p3, fa_left, fa_center);
+			draw_text(_x1 + 8, (_y0 + _y1) / 2, _h);
+		}
+	}
+	
 }
\ No newline at end of file
diff --git a/scripts/node_canvas/node_canvas.gml b/scripts/node_canvas/node_canvas.gml
index e55d2d9df..2c5e6fa5b 100644
--- a/scripts/node_canvas/node_canvas.gml
+++ b/scripts/node_canvas/node_canvas.gml
@@ -183,6 +183,9 @@ function Node_Canvas(_x, _y, _group = noone) : Node(_x, _y, _group) constructor
 		
 		draw_stack = ds_list_create();
 		
+		attributes.show_slope_check = true;
+		array_push(attributeEditors, "Display");
+		array_push(attributeEditors, [ "Slope Check", function() { return attributes.show_slope_check; }, new checkBox(function() { attributes.show_slope_check = !attributes.show_slope_check; }) ]);
 	#endregion
 	
 	#region ++++ tool object ++++