using System.Numerics;
using System.Runtime.CompilerServices;
using Dalamud.Interface.Utility;

namespace Auspex.Rendering.ImGuiFallback;

internal static class FallbackClipMath
{
	public enum LineClipStatus
	{
		NotVisible,
		NotClipped,
		A_Clipped,
		B_Clipped
	}

	public static Vector3 XYZ(this Vector4 v)
	{
		return new Vector3(v.X, v.Y, v.Z);
	}

	public static LineClipStatus ClipLineToPlane(Vector4 plane, ref Vector3 a, ref Vector3 b, out float t)
	{
		t = 0f;
		float num = Vector4.Dot(new Vector4(a, 1f), plane);
		float num2 = Vector4.Dot(new Vector4(b, 1f), plane);
		bool flag = num < 0f;
		bool flag2 = num2 < 0f;
		if (flag && flag2)
		{
			return LineClipStatus.NotClipped;
		}
		if (!flag && !flag2)
		{
			return LineClipStatus.NotVisible;
		}
		Vector3 vector = b - a;
		t = (0f - num) / Vector3.Dot(vector, plane.XYZ());
		Vector3 vector2 = a + vector * t;
		if (flag)
		{
			b = vector2;
			return LineClipStatus.B_Clipped;
		}
		a = vector2;
		return LineClipStatus.A_Clipped;
	}

	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public static void TransformCoordinate(in Vector3 coordinate, in Matrix4x4 transform, out Vector3 result)
	{
		result.X = coordinate.X * transform.M11 + coordinate.Y * transform.M21 + coordinate.Z * transform.M31 + transform.M41;
		result.Y = coordinate.X * transform.M12 + coordinate.Y * transform.M22 + coordinate.Z * transform.M32 + transform.M42;
		result.Z = coordinate.X * transform.M13 + coordinate.Y * transform.M23 + coordinate.Z * transform.M33 + transform.M43;
		float num = 1f / (coordinate.X * transform.M14 + coordinate.Y * transform.M24 + coordinate.Z * transform.M34 + transform.M44);
		result *= num;
	}

	public static Vector2 WorldToScreenOld(in Matrix4x4 viewProj, in Vector3 worldPos)
	{
		TransformCoordinate(in worldPos, in viewProj, out var result);
		return new Vector2(0.5f * ImGuiHelpers.MainViewport.Size.X * (1f + result.X), 0.5f * ImGuiHelpers.MainViewport.Size.Y * (1f - result.Y)) + ImGuiHelpers.MainViewport.Pos;
	}
}