Hi,
I’m having some trouble renedering simples shapes with Monogame.
Im on Windows 10 and im using the monogame directX template.
I have a basic code that is supposed to draw just a rectangle on screen and rotate it around.
I’m trying to use a vertex buffer and a index buffer and render the whole thing as a TriangleStrip.
I’ve came up with this :
And then i coded it. I understand the fact that monogame is culling my vertex in a counter clock wise direction.
So i indexed them using clock ward direction (points 0-1-2 for the first triangle and 2-3-0 for the second one).
The thing is, when i try to render it on my screen, i get one of them displaying properly and another that is being drawn in the opposite way.
Maybe there is an issue with monogame or (more probably) i didnt understood the concept of indexed primitives correctly.
Here is the result : (for some reasons the gif isnt showing except if you click on it, on my computer at least)
Its supposed to be a simple rectangle rotating on the screen and disapearing when you see his backward face but instead i have 2 triangles facing opposite direction, even tho im respecting the counter clock wise culling thing.
And here is the basic code i used to do it :
public class Game1 : Game
{
GraphicsDeviceManager graphics;
VertexBuffer VertexBuffer { get; set; }
IndexBuffer IndexBuffer { get; set; }
BasicEffect effect;
public Game1()
{
graphics = new GraphicsDeviceManager(this);
}
protected override void Initialize()
{
// Create the shape into the buffers
VertexPositionColor[] vertices = new VertexPositionColor[4];
vertices[0] = new VertexPositionColor(new Vector3(-1, 1, 0), Color.Red);
vertices[1] = new VertexPositionColor(new Vector3(1, 1, 0), Color.Green);
vertices[2] = new VertexPositionColor(new Vector3(1, -1, 0), Color.Blue);
vertices[3] = new VertexPositionColor(new Vector3(-1, -1, 0), Color.Yellow);
VertexBuffer = new VertexBuffer(graphics.GraphicsDevice, typeof(VertexPositionColor), 4, BufferUsage.WriteOnly);
VertexBuffer.SetData(vertices);
short[] indices = new short[6];
indices[0] = 0; indices[1] = 1; indices[2] = 2;
indices[3] = 2; indices[4] = 3; indices[5] = 0;
IndexBuffer = new IndexBuffer(graphics.GraphicsDevice, typeof(short), 6, BufferUsage.WriteOnly);
IndexBuffer.SetData(indices);
base.Initialize();
}
protected override void LoadContent()
{
System.Console.WriteLine(GraphicsDevice.RasterizerState);
effect = new BasicEffect(GraphicsDevice);
}
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.CornflowerBlue);
// Draw the shape
GraphicsDevice.SetVertexBuffer(VertexBuffer);
GraphicsDevice.Indices = IndexBuffer;
effect.World = Matrix.CreateTranslation(Vector3.Zero) * Matrix.CreateRotationY((float)gameTime.TotalGameTime.TotalSeconds);
effect.View = Matrix.CreateLookAt(new Vector3(0, 0, -10), Vector3.Zero, Vector3.UnitY);
effect.Projection = Matrix.CreatePerspectiveFieldOfView(
MathHelper.PiOver4,
Window.ClientBounds.Width / (float)Window.ClientBounds.Height,
1,
100);
effect.VertexColorEnabled = true;
foreach (var pass in effect.CurrentTechnique.Passes)
{
pass.Apply();
graphics.GraphicsDevice.DrawIndexedPrimitives(PrimitiveType.TriangleStrip, 0, 0, 4);
}
base.Draw(gameTime);
}
}
Can someone tell me where i fucked up ?
