How do you draw shapes, such as Rectangles and Circles, in MonoGame without having to save the a predrawn shape in the Content folder?
DrawRectangle() and DrawEllipse() are for Windows Form and do not work in OpenGL, which is what I am using.
EDIT
You can learn basic things for MonoGame with tutorials I've put on GitHub : https://github.com/aybe/MonoGameSamples
Here's a simple example with explanations
I define a 10x10 rectangle and set the world matrix to make it look like a 2D projection :
Note : the BasicEffect
is what draws your primitive
protected override void LoadContent()
{
_vertexPositionColors = new[]
{
new VertexPositionColor(new Vector3(0, 0, 1), Color.White),
new VertexPositionColor(new Vector3(10, 0, 1), Color.White),
new VertexPositionColor(new Vector3(10, 10, 1), Color.White),
new VertexPositionColor(new Vector3(0, 10, 1), Color.White)
};
_basicEffect = new BasicEffect(GraphicsDevice);
_basicEffect.World = Matrix.CreateOrthographicOffCenter(
0, GraphicsDevice.Viewport.Width, GraphicsDevice.Viewport.Height, 0, 0, 1);
}
Then I draw the whole thing :D
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.CornflowerBlue);
EffectTechnique effectTechnique = _basicEffect.Techniques[0];
EffectPassCollection effectPassCollection = effectTechnique.Passes;
foreach (EffectPass pass in effectPassCollection)
{
pass.Apply();
GraphicsDevice.DrawUserPrimitives(PrimitiveType.LineStrip, _vertexPositionColors, 0, 4);
}
base.Draw(gameTime);
}
There you have your rectangle !
Now this is just the tip the of the iceberg,
Or as mentioned in one of the posts above you could use a shader that does it instead ...
I needed to draw a Superellipse a while ago and ended up sketching this shader :
Drawing a SuperEllipse in HLSL
As you can see in the post a Superellipse not only draws ellipse but also other shapes and maybe even circles (I did not test) so you might be interested in it.
Ultimately you will want some class/methods to hide all these details so you just have to invoke something like DrawCircle()
.
Tip : by posting @ https://gamedev.stackexchange.com/ you will likely get more answers for Monogame-related questions
:D