Merge pull request #72880 from dalexeev/optimize-draw-dashed-line-and-draw-rect

Optimize `draw_dashed_line()` and `draw_rect()`

scene/main/canvas_item.cpp

@@ -530,10 +530,18 @@ void CanvasItem::draw_dashed_line(const Point2 &p_from, const Point2 &p_to, cons
 	if (p_aligned) {
 		off += (p_to - p_from).normalized() * (length - steps * p_dash) / 2.0;
 	}
+
+	Vector<Vector2> points;
+	points.resize(steps + 1);
 	for (int i = 0; i < steps; i += 2) {
-		RenderingServer::get_singleton()->canvas_item_add_line(canvas_item, (i == 0) ? p_from : off, (p_aligned && i == steps - 1) ? p_to : (off + step), p_color, p_width);
+		points.write[i] = (i == 0) ? p_from : off;
+		points.write[i + 1] = (p_aligned && i == steps - 1) ? p_to : (off + step);
 		off += step * 2;
 	}
+
+	Vector<Color> colors = { p_color };
+
+	RenderingServer::get_singleton()->canvas_item_add_multiline(canvas_item, points, colors, p_width);
 }
 
 void CanvasItem::draw_line(const Point2 &p_from, const Point2 &p_to, const Color &p_color, real_t p_width, bool p_antialiased) {
@@ -599,38 +607,17 @@ void CanvasItem::draw_rect(const Rect2 &p_rect, const Color &p_color, bool p_fil
 	} else if (p_width >= rect.size.width || p_width >= rect.size.height) {
 		RenderingServer::get_singleton()->canvas_item_add_rect(canvas_item, rect.grow(0.5f * p_width), p_color);
 	} else {
-		// Thick lines are offset depending on their width to avoid partial overlapping.
-		// Thin lines are drawn without offset. The result may not be perfect.
-		real_t offset = (p_width >= 0) ? 0.5f * p_width : 0.0f;
-
-		// Top line.
-		RenderingServer::get_singleton()->canvas_item_add_line(
-				canvas_item,
-				rect.position + Size2(-offset, 0),
-				rect.position + Size2(-offset + rect.size.width, 0),
-				p_color,
-				p_width);
-		// Right line.
-		RenderingServer::get_singleton()->canvas_item_add_line(
-				canvas_item,
-				rect.position + Size2(rect.size.width, -offset),
-				rect.position + Size2(rect.size.width, -offset + rect.size.height),
-				p_color,
-				p_width);
-		// Bottom line.
-		RenderingServer::get_singleton()->canvas_item_add_line(
-				canvas_item,
-				rect.position + Size2(offset + rect.size.width, rect.size.height),
-				rect.position + Size2(offset, rect.size.height),
-				p_color,
-				p_width);
-		// Left line.
-		RenderingServer::get_singleton()->canvas_item_add_line(
-				canvas_item,
-				rect.position + Size2(0, offset + rect.size.height),
-				rect.position + Size2(0, offset),
-				p_color,
-				p_width);
+		Vector<Vector2> points;
+		points.resize(5);
+		points.write[0] = rect.position;
+		points.write[1] = rect.position + Vector2(rect.size.x, 0);
+		points.write[2] = rect.position + rect.size;
+		points.write[3] = rect.position + Vector2(0, rect.size.y);
+		points.write[4] = rect.position;
+
+		Vector<Color> colors = { p_color };
+
+		RenderingServer::get_singleton()->canvas_item_add_polyline(canvas_item, points, colors, p_width);
 	}
 }