feat: basic MonoGame integration implementations added

Engine.Integration/Engine.Integration.MonoGame/TriangleBatch.cs

@@ -0,0 +1,74 @@
+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;
+    }
+}