75 lines
2.4 KiB
C#

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Syntriax.Engine.Core;
namespace Syntriax.Engine.Integration.MonoGame;
public class TriangleBatch : ITriangleBatch
{
private readonly GraphicsDevice graphicsDevice;
private VertexBuffer vertexBuffer = default!;
private readonly VertexPositionColor[] vertices = new VertexPositionColor[1024];
private int verticesIndex = 0;
private Matrix _view;
private Matrix _projection;
private readonly BasicEffect basicEffect;
public TriangleBatch(GraphicsDevice graphicsDevice)
{
this.graphicsDevice = graphicsDevice;
this.graphicsDevice.RasterizerState = new RasterizerState() { CullMode = CullMode.None };
basicEffect = new(graphicsDevice);
basicEffect.VertexColorEnabled = true;
}
public void Draw(Triangle triangle, ColorRGBA colorRGBA)
{
if (verticesIndex + 3 >= vertices.Length)
Flush();
Vector2 A = triangle.A.ToDisplayVector2();
Vector2 B = triangle.B.ToDisplayVector2();
Vector2 C = triangle.C.ToDisplayVector2();
Color color = colorRGBA.ToColor();
vertices[verticesIndex++] = new(new(A.X, A.Y, 0f), color);
vertices[verticesIndex++] = new(new(B.X, B.Y, 0f), color);
vertices[verticesIndex++] = new(new(C.X, C.Y, 0f), color);
}
public void Begin(Matrix? view = null, Matrix? projection = null)
{
if (view != null)
_view = view.Value;
else
_view = Matrix.Identity;
if (projection != null)
_projection = projection.Value;
else
{
Viewport viewport = graphicsDevice.Viewport;
_projection = Matrix.CreateOrthographicOffCenter(viewport.X, viewport.Width, viewport.Height, viewport.Y, 0, 1);
}
}
public void End() => Flush();
private void Flush()
{
basicEffect.Projection = _projection;
basicEffect.View = _view;
vertexBuffer = new VertexBuffer(graphicsDevice, typeof(VertexPositionColor), 1024, BufferUsage.WriteOnly);
vertexBuffer.SetData(vertices);
graphicsDevice.SetVertexBuffer(vertexBuffer);
foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes)
pass.Apply();
graphicsDevice.DrawPrimitives(PrimitiveType.TriangleList, 0, verticesIndex / 3);
verticesIndex = 0;
}
}