spritebatch.cs

 private void PushSprite(Rectangle dest, Rectangle src, Vector2 origin, double rotation, bool flipH = false, bool flipV = false, float depth = 0f)
        {
            //if (depth <= 0.0f)
            {
                //Console.WriteLine($"Depth: {depth}");
            }
            float cos = (float) Math.Cos(rotation);
            float sin = (float) Math.Sin(rotation);
            //if (Game.Instance.Debug)
                //Console.WriteLine($"cos/sin: {cos} {sin}");
            float texLeft = (float)src.Left / Texture.Width;
            float texRight = (float)src.Right / Texture.Width;
            float texTop = (float)src.Top / Texture.Height;
            float texBottom = (float)src.Bottom / Texture.Height;

            //float originCorrectionX = origin.X * dest.Width;
            //float originCorrectionY = origin.Y * dest.Height;

            float cornerX = -origin.X * dest.Width;
            float cornerY = -origin.Y * dest.Height;
            float xOffset = (-sin * cornerY) + (cos * cornerX);// + originCorrectionX;
            float yOffset = (cos * cornerY) + (sin * cornerX);// + originCorrectionY;
            Vertex topLeft = new Vertex {
                x = dest.X + xOffset,
                y = dest.Y + yOffset,
                z = depth,
                u = flipH ? texRight : texLeft,
                v = flipV ? texBottom : texTop };

            cornerX = (1.0f - origin.X) * dest.Width;
            cornerY = -origin.Y * dest.Height;
            xOffset = (-sin * cornerY) + (cos * cornerX);// + originCorrectionX;
            yOffset = (cos * cornerY) + (sin * cornerX);// + originCorrectionY;
            Vertex topRight = new Vertex {
                x = dest.X + xOffset,
                y = dest.Y + yOffset,
                z = depth,
                u = flipH ? texLeft : texRight,
                v = flipV ? texBottom : texTop };

            cornerX = (1.0f - origin.X) * dest.Width;
            cornerY = (1.0f - origin.Y) * dest.Height;
            xOffset = (-sin * cornerY) + (cos * cornerX);// + originCorrectionX;
            yOffset = (cos * cornerY) + (sin * cornerX);// + originCorrectionY;
            Vertex bottomRight = new Vertex {
                x = dest.X + xOffset,
                y = dest.Y + yOffset,
                z = depth,
                u = flipH ? texLeft : texRight,
                v = flipV ? texTop : texBottom };

            cornerX = (-origin.X) * dest.Width;
            cornerY = (1.0f - origin.Y) * dest.Height;
            xOffset = (-sin * cornerY) + (cos * cornerX);// + originCorrectionX;
            yOffset = (cos * cornerY) + (sin * cornerX);// + originCorrectionY;
            Vertex bottomLeft = new Vertex {
                x = dest.X + xOffset,
                y = dest.Y + yOffset,
                z = depth,
                u = flipH ? texRight : texLeft,
                v = flipV ? texTop : texBottom };

            Vertex[] newVertices = new Vertex[]{topLeft, topRight, bottomRight, bottomLeft};
            newVertices.CopyTo(Vertices, VerticesIndex);

            ushort[] NewIndices = new ushort[] {
                (ushort)(VerticesIndex + 0), (ushort)(VerticesIndex + 1), (ushort)(VerticesIndex + 2),
                (ushort)(VerticesIndex + 2), (ushort)(VerticesIndex + 3), (ushort)(VerticesIndex + 0),
            };

            NewIndices.CopyTo(Indices, IndicesIndex);

            VerticesIndex += newVertices.Length;
            IndicesIndex += NewIndices.Length;
            NumSprites += 1;
        }