using Delta.Utilities.Datatypes;



namespace Delta.Rendering.Basics.Drawing

{

	/// <summary>

	/// Draw 2D rectangles with help of this class. They can be drawn as only

	/// outline, filled shape and with rotation. This has the advantage of

	/// optimizing it better.

	/// </summary>

	public static class Rect

	{

		#region Constants

		/// <summary>

		/// Helper for the Rectangle method that allows rotated rectangle drawing.

		/// </summary>

		private static readonly Point[] rotatedEdgePoints = new Point[4];

		#endregion



		#region DrawOutline (Static)

		/// <summary>

		/// Draws a rectangle box with lines

		/// </summary>

		/// <param name="rect">Rectangle to draw</param>

		/// <param name="lineColor">Line color</param>

		public static void DrawOutline(Rectangle rect, Color lineColor)

		{

			// Skip if the drawArea is certainly outside of the quadratic space.

			// Checking the screen area would work too, but is a little slower and

			// won't exclude much more anyway.

			if (rect.Left >= 1.0f ||

			    rect.Top >= 1.0f ||

			    rect.Left < -rect.Width ||

			    rect.Top < -rect.Height)

			{

				// Skip this material rendering, not visible this frame.

				return;

			}



			DrawManager drawInstance = DrawManager.Instance;

			Point topRight = rect.TopRight;

			Point bottomRight = rect.BottomRight;

			Point bottomLeft = rect.BottomLeft;

			drawInstance.Draw2DLine(ref rect.TopLeft, ref topRight, ref lineColor);

			drawInstance.Draw2DLine(ref topRight, ref bottomRight, ref lineColor);

			drawInstance.Draw2DLine(ref bottomRight, ref bottomLeft, ref lineColor);

			drawInstance.Draw2DLine(ref bottomLeft, ref rect.TopLeft, ref lineColor);

		}



		/// <summary>

		/// Draws a rotated rectangle box with lines.

		/// </summary>

		/// <param name="rect">Rectangle to draw</param>

		/// <param name="lineColor">Line color</param>

		/// <param name="rotation">Rotation of the rectangle</param>

		public static void DrawOutline(Rectangle rect, Color lineColor,

			float rotation)

		{

			// Skip if the drawArea is certainly outside of the quadratic space.

			// Checking the screen area would work too, but is a little slower and

			// won't exclude much more anyway.

			if (rect.Left >= 1.0f ||

			    rect.Top >= 1.0f ||

			    rect.Left < -rect.Width ||

			    rect.Top < -rect.Height)

			{

				// Skip this material rendering, not visible this frame.

				return;

			}



			// Rotate the original rectangle

			rect.Rotate(rotation, rotatedEdgePoints);

			// And draw it out same way as above: top left, right, bottom right, left

			DrawManager drawInstance = DrawManager.Instance;

			drawInstance.Draw2DLine(ref rotatedEdgePoints[0],

				ref rotatedEdgePoints[1], ref lineColor);

			drawInstance.Draw2DLine(ref rotatedEdgePoints[1],

				ref rotatedEdgePoints[2], ref lineColor);

			drawInstance.Draw2DLine(ref rotatedEdgePoints[2],

				ref rotatedEdgePoints[3], ref lineColor);

			drawInstance.Draw2DLine(ref rotatedEdgePoints[3],

				ref rotatedEdgePoints[0], ref lineColor);

		}

		#endregion



		#region DrawFilled (Static)

		/// <summary>

		/// Draw filled rectangle at the given position with the given color.

		/// </summary>

		/// <param name="rect">The rect.</param>

		/// <param name="color">The color.</param>

		public static void DrawFilled(Rectangle rect, Color color)

		{

			// Skip if the drawArea is certainly outside of the quadratic space.

			// Checking the screen area would work too, but is a little slower and

			// won't exclude much more anyway.

			if (rect.Left >= 1.0f ||

			    rect.Top >= 1.0f ||

			    rect.Left < -rect.Width ||

			    rect.Top < -rect.Height)

			{

				// Skip this material rendering, not visible this frame.

				return;

			}



			// A rectangle is just 2 polygons

			DrawManager drawInstance = DrawManager.Instance;

			Point bottomRight = rect.BottomRight;

			Point topRight = rect.TopRight;

			Point bottomLeft = rect.BottomLeft;

			drawInstance.DrawPolygon(ref rect.TopLeft, ref bottomRight,

				ref topRight, ref color);

			drawInstance.DrawPolygon(ref rect.TopLeft, ref bottomLeft,

				ref bottomRight, ref color);

		}



		/// <summary>

		/// Draw filled rectangle at the given position with the given color.

		/// </summary>

		/// <param name="rect">The rect.</param>

		/// <param name="color">The color.</param>

		/// <param name="rotation">The rotation.</param>

		public static void DrawFilled(Rectangle rect, Color color,

			float rotation)

		{

			// Skip if the drawArea is certainly outside of the quadratic space.

			// Checking the screen area would work too, but is a little slower and

			// won't exclude much more anyway.

			if (rect.Left >= 1.0f ||

			    rect.Top >= 1.0f ||

			    rect.Left < -rect.Width ||

			    rect.Top < -rect.Height)

			{

				// Skip this material rendering, not visible this frame.

				return;

			}



			// A rectangle is 2 polygons, but rotate the original rectangle first

			rect.Rotate(rotation, rotatedEdgePoints);

			// And draw it out same way as above

			DrawManager drawInstance = DrawManager.Instance;

			drawInstance.DrawPolygon(ref rotatedEdgePoints[0],

				ref rotatedEdgePoints[2], ref rotatedEdgePoints[1], ref color);

			drawInstance.DrawPolygon(ref rotatedEdgePoints[0],

				ref rotatedEdgePoints[3], ref rotatedEdgePoints[2], ref color);

		}

		#endregion

	}

}