Beispiel #1
0
        public void Draw1(int w, int h, Matrix3D projection,
                          Mesh mesh,
                          Action <int, int, int> setFacePixel,
                          Action <int, int, int> setEdgePixel
                          )
        {
            for (var fi = 0; fi < mesh.Indices.Count; ++fi)
            {
                var face = mesh.Indices[fi];

                if (face.Count < 3)
                {
                    continue;                 // nothing to draw
                }
                // check normal
                var v0 = projection * mesh.Points[face[0]];
                var v1 = projection * mesh.Points[face[1]];
                var v2 = projection * mesh.Points[face[2]];
                if (Vector3D.Cross(v0 - v1, v2 - v1).Z < 0)
                {
                    continue;
                }

                // projected points
                var ppts = new List <Vector3D>();
                for (var i = 0; i < face.Count; ++i)
                {
                    ppts.Add(projection * mesh.Points[face[i]]);
                }
                ppts.Add(ppts[0]); // double up on last one

                // draw filled polygon
                // get min, max y
                int minY = int.MaxValue, maxY = int.MinValue;
                foreach (var pt in ppts)
                {
                    minY = Math.Min(minY, (int)pt.Y);
                    maxY = Math.Max(maxY, (int)pt.Y);
                }
                // space for left, right ends
                var left  = new int[maxY - minY + 1];
                var right = new int[maxY - minY + 1];
                // initialize them
                for (var i = 0; i < left.Length; ++i)
                {
                    left[i]  = int.MaxValue;
                    right[i] = int.MinValue;
                }
                // now walk all edges, setting left and right at each y value
                for (var i = 0; i < ppts.Count - 1; ++i)
                {
                    var p1 = ppts[i];
                    var p2 = ppts[i + 1];
                    int x1 = (int)p1.X, y1 = (int)p1.Y;
                    int x2 = (int)p2.X, y2 = (int)p2.Y;
                    DDA.Compute(x1, y1, x2, y2, (x, y) =>
                    {
                        left[y - minY]  = Math.Min(left[y - minY], x);
                        right[y - minY] = Math.Max(right[y - minY], x);
                    }
                                );
                }
                // now walk and fill
                var color = mesh.FaceColors[fi];
                for (var j = 0; j < left.Length; ++j)
                {
                    for (var i = left[j]; i <= right[j]; ++i)
                    {
                        setFacePixel(i, j + minY, fi);
                    }
                }


                // draw wireframe
                for (var i = 0; i < ppts.Count - 1; ++i)
                {
                    var p1 = ppts[i];
                    var p2 = ppts[i + 1];
                    int x1 = (int)p1.X, y1 = (int)p1.Y;
                    int x2 = (int)p2.X, y2 = (int)p2.Y;
                    Draw.Line(x1, y1, x2, y2, (i1, j1) => setEdgePixel(i1, j1, fi));
                }
            }
        }
Beispiel #2
0
 public static void Line(int x1, int y1, int x2, int y2, Action <int, int> setPixel)
 {
     DDA.Compute(x1, y1, x2, y2, (x, y) => setPixel(x, y));
 }