From ab2c6092e8e68c0fdb9a3a952c1c25a4e8271b1f Mon Sep 17 00:00:00 2001
From: Haibo <nomango@qq.com>
Date: Tue, 20 Nov 2018 15:56:56 +0800
Subject: [PATCH] add: the method of drawing arcs

---
 core/base/Canvas.cpp   | 16 ++++++++++++++++
 core/base/Canvas.h     |  9 +++++++++
 core/base/Geometry.cpp | 16 ++++++++++++++++
 core/base/Geometry.h   |  9 +++++++++
 4 files changed, 50 insertions(+)

diff --git a/core/base/Canvas.cpp b/core/base/Canvas.cpp
index 4b8be4e9..78e7d4dd 100644
--- a/core/base/Canvas.cpp
+++ b/core/base/Canvas.cpp
@@ -452,6 +452,22 @@ namespace easy2d
 		}
 	}
 
+	void Canvas::AddArc(Point const & point, Point const & radius, float rotation, bool clockwise, bool is_small)
+	{
+		if (current_sink_)
+		{
+			current_sink_->AddArc(
+				D2D1::ArcSegment(
+					point,
+					D2D1_SIZE_F{ radius.x, radius.y },
+					rotation,
+					clockwise ? D2D1_SWEEP_DIRECTION_CLOCKWISE : D2D1_SWEEP_DIRECTION_COUNTER_CLOCKWISE,
+					is_small ? D2D1_ARC_SIZE_SMALL : D2D1_ARC_SIZE_LARGE
+				)
+			);
+		}
+	}
+
 	void Canvas::StrokePath()
 	{
 		render_target_->DrawGeometry(
diff --git a/core/base/Canvas.h b/core/base/Canvas.h
index 5e4375f3..ed6b4f7e 100644
--- a/core/base/Canvas.h
+++ b/core/base/Canvas.h
@@ -157,6 +157,15 @@ namespace easy2d
 			Point const& point3		/* 贝塞尔曲线的终点 */
 		);
 
+		// 添加弧线
+		void AddArc(
+			Point const& point,		/* 终点 */
+			Point const& radius,	/* 椭圆半径 */
+			float rotation,			/* 椭圆旋转角度 */
+			bool clockwise = true,	/* 顺时针 or 逆时针 */
+			bool is_small = true	/* 是否取小于 180° 的弧 */
+		);
+
 		// 路径描边
 		void StrokePath();
 
diff --git a/core/base/Geometry.cpp b/core/base/Geometry.cpp
index f0f326a8..a0dc3102 100644
--- a/core/base/Geometry.cpp
+++ b/core/base/Geometry.cpp
@@ -392,6 +392,22 @@ namespace easy2d
 		}
 	}
 
+	void PathGeometry::AddArc(Point const & point, Point const & radius, float rotation, bool clockwise, bool is_small)
+	{
+		if (current_sink_)
+		{
+			current_sink_->AddArc(
+				D2D1::ArcSegment(
+					point,
+					D2D1_SIZE_F{ radius.x, radius.y },
+					rotation,
+					clockwise ? D2D1_SWEEP_DIRECTION_CLOCKWISE : D2D1_SWEEP_DIRECTION_COUNTER_CLOCKWISE,
+					is_small ? D2D1_ARC_SIZE_SMALL : D2D1_ARC_SIZE_LARGE
+				)
+			);
+		}
+	}
+
 	void PathGeometry::ClearPath()
 	{
 		geo_ = nullptr;
diff --git a/core/base/Geometry.h b/core/base/Geometry.h
index 20043850..31c572e1 100644
--- a/core/base/Geometry.h
+++ b/core/base/Geometry.h
@@ -258,6 +258,15 @@ namespace easy2d
 			Point const& point3		/* 贝塞尔曲线的终点 */
 		);
 
+		// 添加弧线
+		void AddArc(
+			Point const& point,		/* 终点 */
+			Point const& radius,	/* 椭圆半径 */
+			float rotation,			/* 椭圆旋转角度 */
+			bool clockwise = true,	/* 顺时针 or 逆时针 */
+			bool is_small = true	/* 是否取小于 180° 的弧 */
+		);
+
 		// 清除路径
 		void ClearPath();