Organização

1 files changed, 115 insertions, 0 deletions

diff --git a/scripts/Map/FieldOfView.cs b/scripts/Map/FieldOfView.cs
new file mode 100644
index 0000000..40df320
--- /dev/null
+++ b/scripts/Map/FieldOfView.cs
@@ -0,0 +1,115 @@
+using Godot;
+
+namespace TheLegendOfGustav.Map;
+
+// Copiado e adaptado deste cara aqui: https://www.roguebasin.com/index.php?title=C%2B%2B_shadowcasting_implementation e deste também https://selinadev.github.io/08-rogueliketutorial-04/
+
+// Eu não vou mentir, li como o algoritmo funciona, mas mesmo assim não entendi.
+
+public partial class FieldOfView : Node
+{
+
+	private Godot.Collections.Array<Tile> fov = [];
+
+	private static readonly int[,] multipliers = new int[4, 8]{
+		{1, 0, 0, -1, -1, 0, 0, 1},
+		{0, 1, -1, 0, 0, -1, 1, 0},
+		{0, 1, 1, 0, 0, -1, -1, 0},
+		{1, 0, 0, 1, -1, 0, 0, -1}
+	};
+	private void CastLight(MapData data, Vector2I pos, int radius, int row, float startSlope, float endSlope, int xx, int xy, int yx, int yy)
+	{
+		if (startSlope < endSlope)
+		{
+			return;
+		}
+
+		float nextStartSlope = startSlope;
+		for (int i = row; i <= radius; i++)
+		{
+			bool blocked = false;
+			for (int dx = -i, dy = -i; dx <= 0; dx++)
+			{
+				float lSlope = (float)((dx - 0.5) / (dy + 0.5));
+				float rSlope = (float)((dx + 0.5) / (dy - 0.5));
+
+				if (startSlope < rSlope)
+				{
+					continue;
+				}
+				else if (endSlope > lSlope)
+				{
+					break;
+				}
+
+				int sax = dx * xx + dy * xy;
+				int say = dx * yx + dy * yy;
+
+				if ((sax < 0 && int.Abs(sax) > pos.X) || (say < 0 && int.Abs(say) > pos.Y))
+				{
+					continue;
+				}
+				int ax = pos.X + sax;
+				int ay = pos.Y + say;
+
+				if (ax >= data.Width || ay >= data.Height)
+				{
+					continue;
+				}
+
+				Tile currentTile = data.GetTile(ax, ay);
+				int radius2 = radius * radius;
+				if ((dx * dx + dy * dy) < radius2)
+				{
+					currentTile.IsInView = true;
+					fov.Add(currentTile);
+				}
+
+				if (blocked)
+				{
+					if (!currentTile.IsTransparent)
+					{
+						nextStartSlope = rSlope;
+						continue;
+					}
+					else
+					{
+						blocked = false;
+						startSlope = nextStartSlope;
+					}
+				}
+				else if (!currentTile.IsTransparent)
+				{
+					blocked = true;
+					nextStartSlope = rSlope;
+					CastLight(data, pos, radius, i + 1, startSlope, lSlope, xx, xy, yx, yy);
+				}
+			}
+			if (blocked)
+			{
+				break;
+			}
+		}
+	}
+
+	private void ClearFOV()
+	{
+		foreach (Tile tile in fov)
+		{
+			tile.IsInView = false;
+		}
+		fov.Clear();
+	}
+
+	public void UpdateFOV(MapData data, Vector2I position, int radius)
+	{
+		ClearFOV();
+		Tile start = data.GetTile(position);
+		start.IsInView = true;
+		fov.Add(start);
+		for (int i = 0; i < 8; i++)
+		{
+			CastLight(data, position, radius, 1, 1.0f, 0.0f, multipliers[0, i], multipliers[1, i], multipliers[2, i], multipliers[3, i]);
+		}
+	}
+}