Tutorial-Draw A Line At XNA(Window Phone)

如果沒有使用 DrawPrimitive Methods做的話，XNA 並無提供簡單產生出一個線段，因此在這裡提供一下簡易 2D線段的方法。

 

The XNA dosen’t provide a way to Draw a Line if you don’t use 3D DrawPrimitive Methods

 

第一步:
產生一個 1X1 Texture。
產生下列Code

Texture2D pixel;
Vector2 firstPosition;
Vector2 secondPosition;
float rotation;
float length;
//At LoadContet Method
protected override void LoadContent()
{

..

pixel = Content.Load<Texture>("Your Texture Location");

..

base.Initialize();

}
現在我們要選擇兩個點去產生線段，我們必須算出角度和長度來決定線段
protected override void Draw(GameTime gameTime)
{

...

distance = Vector2.Distance(secondPosition,firstPosition);

rotation = (float)Math.Atan2(secondPosition.Y - firstPosition.Y,secondPosition.X - firstPosition.X);

spriteBatch.Begin();

spriteBatch.Draw(pixel,firstPosition,null,Color.Black,rotation,Vector2.Zero,new Vector2(distance,5),SpriteEffects.None,0);

spriteBatch.End();

...

}
這樣大致在XNA上完成畫線動作了，windowPhone可以使用GestureSample是取的tap的位置 firstPosition 和 secondPosition位置。
--------------------------------------------------------------------------------------------------------------------------------
That’s Begin
Create a 1x1 Texture
And Coding
Texture2D pixel;
Vector2 firstPosition;
Vector2 secondPosition;
float rotation;
float length;
//At LoadContet Method
protected override void LoadContent()
{

..

pixel = Content.Load<Texture>("Your Texture Location");

..

base.Initialize();

}
We need to know length between firstPosition and secondPosition.
And caculatr Rotation angle between firstPosition and secondPosition.
protected override void Draw(GameTime gameTime)
{

...

distance = Vector2.Distance(secondPosition,firstPosition);

rotation = (float)Math.Atan2(secondPosition.Y - firstPosition.Y,secondPosition.X - firstPosition.X);

spriteBatch.Begin();

spriteBatch.Draw(pixel,firstPosition,null,Color.Black,rotation,Vector2.Zero,new Vector2(distance,5),SpriteEffects.None,0);

spriteBatch.End();

...

}
And see result is Perfect.
if you want do in Window Phone then you can use GestureSample 's GestureType.Tap to make two postion to create a line.