| 1 |
using System; |
| 2 |
using System.Collections.Generic; |
| 3 |
using Oni.Collections; |
| 4 |
|
| 5 |
namespace Oni.Dae |
| 6 |
{ |
| 7 |
internal class FaceConverter |
| 8 |
{ |
| 9 |
private Node root; |
| 10 |
private int maxEdges = 3; |
| 11 |
|
| 12 |
public static void Triangulate(Node root) |
| 13 |
{ |
| 14 |
var converter = new FaceConverter { |
| 15 |
root = root |
| 16 |
}; |
| 17 |
|
| 18 |
converter.Convert(); |
| 19 |
} |
| 20 |
|
| 21 |
private void Convert() |
| 22 |
{ |
| 23 |
ConvertNode(root); |
| 24 |
} |
| 25 |
|
| 26 |
private void ConvertNode(Node node) |
| 27 |
{ |
| 28 |
foreach (var instance in node.Instances) |
| 29 |
ConvertInstance(instance); |
| 30 |
|
| 31 |
foreach (var child in node.Nodes) |
| 32 |
ConvertNode(child); |
| 33 |
} |
| 34 |
|
| 35 |
private void ConvertInstance(Instance instance) |
| 36 |
{ |
| 37 |
var geometryInstance = instance as GeometryInstance; |
| 38 |
|
| 39 |
if (geometryInstance != null) |
| 40 |
{ |
| 41 |
ConvertGeometry(geometryInstance.Target); |
| 42 |
return; |
| 43 |
} |
| 44 |
} |
| 45 |
|
| 46 |
private void ConvertGeometry(Geometry geometry) |
| 47 |
{ |
| 48 |
foreach (var primitives in geometry.Primitives) |
| 49 |
{ |
| 50 |
if (primitives.PrimitiveType != MeshPrimitiveType.Polygons) |
| 51 |
continue; |
| 52 |
|
| 53 |
if (primitives.VertexCounts.All(c => c == 3)) |
| 54 |
continue; |
| 55 |
|
| 56 |
ConvertPolygons(geometry, primitives); |
| 57 |
} |
| 58 |
} |
| 59 |
|
| 60 |
private void ConvertPolygons(Geometry geometry, MeshPrimitives primitives) |
| 61 |
{ |
| 62 |
var positionInput = primitives.Inputs.FirstOrDefault(i => i.Semantic == Semantic.Position); |
| 63 |
|
| 64 |
if (positionInput == null) |
| 65 |
{ |
| 66 |
Console.Error.WriteLine("{0}: cannot find position input", geometry.Name); |
| 67 |
return; |
| 68 |
} |
| 69 |
|
| 70 |
var newFaces = new List<int>(primitives.VertexCounts.Count * 2); |
| 71 |
var newVertexCounts = new List<int>(primitives.VertexCounts.Count * 2); |
| 72 |
int voffset = 0; |
| 73 |
|
| 74 |
foreach (int vcount in primitives.VertexCounts) |
| 75 |
{ |
| 76 |
if (vcount < 3) |
| 77 |
{ |
| 78 |
Console.Error.WriteLine("{0}: skipping bad face (line)", geometry.Name); |
| 79 |
} |
| 80 |
else if (vcount <= maxEdges) |
| 81 |
{ |
| 82 |
for (int i = 0; i < vcount; i++) |
| 83 |
newFaces.Add(voffset + i); |
| 84 |
|
| 85 |
newVertexCounts.Add(vcount); |
| 86 |
} |
| 87 |
else |
| 88 |
{ |
| 89 |
ConvertPolygon(geometry, positionInput, voffset, vcount, newFaces, newVertexCounts); |
| 90 |
} |
| 91 |
|
| 92 |
voffset += vcount; |
| 93 |
} |
| 94 |
|
| 95 |
primitives.VertexCounts.Clear(); |
| 96 |
primitives.VertexCounts.AddRange(newVertexCounts); |
| 97 |
|
| 98 |
var oldIndices = new int[primitives.Inputs.Count][]; |
| 99 |
|
| 100 |
for (int i = 0; i < primitives.Inputs.Count; i++) |
| 101 |
{ |
| 102 |
var input = primitives.Inputs[i]; |
| 103 |
oldIndices[i] = input.Indices.ToArray(); |
| 104 |
input.Indices.Clear(); |
| 105 |
} |
| 106 |
|
| 107 |
for (int i = 0; i < primitives.Inputs.Count; i++) |
| 108 |
{ |
| 109 |
var ni = primitives.Inputs[i].Indices; |
| 110 |
var oi = oldIndices[i]; |
| 111 |
|
| 112 |
foreach (int v in newFaces) |
| 113 |
ni.Add(oi[v]); |
| 114 |
} |
| 115 |
} |
| 116 |
|
| 117 |
private void ConvertPolygon(Geometry geometry, IndexedInput input, int offset, int vcount, List<int> newFaces, List<int> newVertexCounts) |
| 118 |
{ |
| 119 |
var points = new Vector3[vcount]; |
| 120 |
|
| 121 |
for (int i = 0; i < vcount; i++) |
| 122 |
points[i] = Dae.Source.ReadVector3(input.Source, input.Indices[offset + i]); |
| 123 |
|
| 124 |
int concave = -1; |
| 125 |
|
| 126 |
for (int i = 0; i < vcount; i++) |
| 127 |
{ |
| 128 |
Vector3 p0 = points[i]; |
| 129 |
Vector3 p1 = points[(i + 1) % vcount]; |
| 130 |
|
| 131 |
if (Vector3.Dot(p0, p1) < 0.0f) |
| 132 |
{ |
| 133 |
concave = i; |
| 134 |
break; |
| 135 |
} |
| 136 |
} |
| 137 |
|
| 138 |
if (concave == -1) |
| 139 |
{ |
| 140 |
for (int i = 0; i < vcount - 2; i++) |
| 141 |
{ |
| 142 |
newFaces.Add(offset + 0); |
| 143 |
newFaces.Add(offset + 1 + i); |
| 144 |
newFaces.Add(offset + 2 + i); |
| 145 |
newVertexCounts.Add(3); |
| 146 |
} |
| 147 |
|
| 148 |
return; |
| 149 |
} |
| 150 |
|
| 151 |
if (vcount == 4) |
| 152 |
{ |
| 153 |
newFaces.Add(offset + concave); |
| 154 |
newFaces.Add(offset + (concave + 1) % vcount); |
| 155 |
newFaces.Add(offset + (concave + 2) % vcount); |
| 156 |
newVertexCounts.Add(3); |
| 157 |
|
| 158 |
newFaces.Add(offset + (concave + vcount - 1) % vcount); |
| 159 |
newFaces.Add(offset + (concave + vcount - 2) % vcount); |
| 160 |
newFaces.Add(offset + concave); |
| 161 |
newVertexCounts.Add(3); |
| 162 |
|
| 163 |
return; |
| 164 |
} |
| 165 |
|
| 166 |
Console.Error.WriteLine("{0}: skipping bad face (concave {1}-gon)", geometry.Name, vcount); |
| 167 |
} |
| 168 |
} |
| 169 |
} |
