Working with primitives in XNA

Question

Perhaps I am trying to use XNA in a way that it was not designed, but I would very much like to be able to draw my own primitives and save them as a bitmap, or a texture2D, or anything that will hold a few 2d lines for me. My goal is to program a game where the textures are created procedurally, instead of just being loaded from the content manager.

If it helps to know, I've made a Shape class that stores polygons, and I probably could just tell spriteBatch to draw each line out, but I'm trying to optimize by storing commonly used shapes somewhere, instead.

Petr Abdulin Petr Abdulin · Accepted Answer · 2012-12-11T05:33:32

You can use a RenderTarget for your task. Something like this:

// var to store your drawing
Texture2D newShape;

// drawing will be on this target
RenderTarget2D rt = new RenderTarget2D(GraphicsDevice, width, height);
SpriteBatch sb = new SpriteBatch(GraphicsDevice);

// set to render all to render target
GraphicsDevice.SetRenderTarget(rt); 

GraphicsDevice.Clear(Color.Transparent); 

sb.Begin();

// Draw what you want here.

sb.End()

// Return to drawing on "main" buffer
GraphicsDevice.SetRenderTarget(null);

// Save the texture you just drawn
newShape = rt;

Working with primitives in XNA

1 Answers