System.Drawing.Drawing2D.PathGradientBrush.RasterizeTriangle C# (CSharp) Method

        internal void RasterizeTriangle(CGContext context, PointF vt1, PointF vt2, PointF vt3, Color colorV1, Color colorV2, Color colorV3)
        {
            // get the bounding box of the triangle
            int maxX = (int)Math.Max(vt1.X, Math.Max(vt2.X, vt3.X));
            int minX = (int)Math.Min(vt1.X, Math.Min(vt2.X, vt3.X));
            int maxY = (int)Math.Max(vt1.Y, Math.Max(vt2.Y, vt3.Y));
            int minY = (int)Math.Min(vt1.Y, Math.Min(vt2.Y, vt3.Y));

            // Barycentric coordinates at minX/minY corner
            PointF pm = new PointF( minX, minY );

            var edge32 = new Edge(vt3, vt2, vt1, pm, colorV1);
            var edge13 = new Edge (vt1, vt3, vt2, pm, colorV2);
            var edge21 = new Edge (vt2, vt1, vt3, pm, colorV3);

            int span32 = edge32.EdgeOrigin;
            int span13 = edge13.EdgeOrigin;
            int span21 = edge21.EdgeOrigin;

            edge32Red = colorV1.R;
            edge32Green = colorV1.G;
            edge32Blue = colorV1.B;
            edge32Alpha = colorV1.A;

            edge13Red = colorV2.R;
            edge13Green = colorV2.G;
            edge13Blue = colorV2.B;
            edge13Alpha = colorV2.A;

            edge21Red = colorV3.R;
            edge21Green = colorV3.G;
            edge21Blue = colorV3.B;
            edge21Alpha = colorV3.A;

            int span32XOffset = 0;
            int span13XOffset = 0;
            int span21XOffset = 0;

            bool inside = false;
            int mask = 0;
            //  Iterate over each pixel of bounding box and check if it's inside
            //  the triangle using the barycentirc approach.
            for (int y = minY; y <= maxY; y += Edge.StepYSize)
            {
                // Barycentric coordinates at start of row
                span32XOffset = span32;
                span13XOffset = span13;
                span21XOffset = span21;

                inside = false;
                for (int x = minX; x <= maxX; x += Edge.StepXSize)
                {

                    mask = span32XOffset | span13XOffset | span21XOffset;

                    // If p is on or inside all edges for any pixels,
                    // render those pixels.
                    if (mask >= 0)
                    {
                        if (!inside)
                        {
                            inside = true;
                        }
                        RenderPixels(context, x, y, edge32, edge13, edge21, span32XOffset, span13XOffset, span21XOffset);
                    }

                    // Step to the right
                    span32XOffset += edge32.StepX;
                    span13XOffset += edge13.StepX;
                    span21XOffset += edge21.StepX;
                    if (mask < 0 && inside)
                    {
                        inside = false;
                        break;
                    }

                }

                // Row step
                span32 += edge32.StepY;
                span13 += edge13.StepY;
                span21 += edge21.StepY;
            }
        }