Singularity/Library/PackageCache/com.unity.render-pipelines..../Runtime/2D/UTess2D/Tessellator.cs
2024-05-06 11:45:45 -07:00

913 lines
29 KiB
C#

using System;
using Unity.Profiling;
using Unity.Collections;
using Unity.Mathematics;
using Unity.Collections.LowLevel.Unsafe;
namespace UnityEngine.Rendering.Universal.UTess
{
// Constrained Delaunay Triangulation.
struct Tessellator
{
// For Processing.
NativeArray<int2> m_Edges;
NativeArray<UStar> m_Stars;
NativeArray<int3> m_Cells;
int m_CellCount;
// For Storage.
NativeArray<int> m_ILArray;
NativeArray<int> m_IUArray;
NativeArray<int> m_SPArray;
int m_NumEdges;
int m_NumHulls;
int m_NumPoints;
int m_StarCount;
// Intermediates.
NativeArray<int> m_Flags;
NativeArray<int> m_Neighbors;
NativeArray<int> m_Constraints;
Allocator m_Allocator;
struct TestHullPointL : ICondition2<UHull, float2>
{
public bool Test(UHull h, float2 p, ref float t)
{
t = ModuleHandle.OrientFast(h.a, h.b, p);
return t < 0;
}
}
struct TestHullPointU : ICondition2<UHull, float2>
{
public bool Test(UHull h, float2 p, ref float t)
{
t = ModuleHandle.OrientFast(h.a, h.b, p);
return t > 0;
}
}
static float FindSplit(UHull hull, UEvent edge)
{
float d = 0;
if (hull.a.x < edge.a.x)
{
d = ModuleHandle.OrientFast(hull.a, hull.b, edge.a);
}
else
{
d = ModuleHandle.OrientFast(edge.b, edge.a, hull.a);
}
if (0 != d)
{
return d;
}
if (edge.b.x < hull.b.x)
{
d = ModuleHandle.OrientFast(hull.a, hull.b, edge.b);
}
else
{
d = ModuleHandle.OrientFast(edge.b, edge.a, hull.b);
}
if (0 != d)
{
return d;
}
return hull.idx - edge.idx;
}
struct TestHullEventLe : ICondition2<UHull, UEvent>
{
public bool Test(UHull h, UEvent p, ref float t)
{
t = FindSplit(h, p);
return t <= 0;
}
}
struct TestHullEventE : ICondition2<UHull, UEvent>
{
public bool Test(UHull h, UEvent p, ref float t)
{
t = FindSplit(h, p);
return t == 0;
}
}
void SetAllocator(Allocator allocator)
{
m_Allocator = allocator;
}
bool AddPoint(NativeArray<UHull> hulls, int hullCount, NativeArray<float2> points, float2 p, int idx)
{
int l = ModuleHandle.GetLower(hulls, hullCount, p, new TestHullPointL());
int u = ModuleHandle.GetUpper(hulls, hullCount, p, new TestHullPointU());
if (l < 0 || u < 0)
return false;
for (int i = l; i < u; ++i)
{
UHull hull = hulls[i];
int m = hull.ilcount;
while (m > 1 && ModuleHandle.OrientFast(points[hull.ilarray[m - 2]], points[hull.ilarray[m - 1]], p) > 0)
{
int3 c = new int3();
c.x = hull.ilarray[m - 1];
c.y = hull.ilarray[m - 2];
c.z = idx;
m_Cells[m_CellCount++] = c;
m -= 1;
}
hull.ilcount = m + 1;
if (hull.ilcount > hull.ilarray.Length)
return false;
hull.ilarray[m] = idx;
m = hull.iucount;
while (m > 1 && ModuleHandle.OrientFast(points[hull.iuarray[m - 2]], points[hull.iuarray[m - 1]], p) < 0)
{
int3 c = new int3();
c.x = hull.iuarray[m - 2];
c.y = hull.iuarray[m - 1];
c.z = idx;
m_Cells[m_CellCount++] = c;
m -= 1;
}
hull.iucount = m + 1;
if (hull.iucount > hull.iuarray.Length)
return false;
hull.iuarray[m] = idx;
hulls[i] = hull;
}
return true;
}
static void InsertHull(NativeArray<UHull> Hulls, int Pos, ref int Count, UHull Value)
{
if (Count < Hulls.Length - 1)
{
for (int i = Count; i > Pos; --i)
Hulls[i] = Hulls[i - 1];
Hulls[Pos] = Value;
Count++;
}
}
static void EraseHull(NativeArray<UHull> Hulls, int Pos, ref int Count)
{
if (Count < Hulls.Length)
{
for (int i = Pos; i < Count - 1; ++i)
Hulls[i] = Hulls[i + 1];
Count--;
}
}
bool SplitHulls(NativeArray<UHull> hulls, ref int hullCount, NativeArray<float2> points, UEvent evt)
{
int index = ModuleHandle.GetLower(hulls, hullCount, evt, new TestHullEventLe());
if (index < 0)
return false;
UHull hull = hulls[index];
UHull newHull;
newHull.a = evt.a;
newHull.b = evt.b;
newHull.idx = evt.idx;
int y = hull.iuarray[hull.iucount - 1];
newHull.iuarray = new ArraySlice<int>(m_IUArray, newHull.idx * m_NumHulls, m_NumHulls);
newHull.iucount = hull.iucount;
for (int i = 0; i < newHull.iucount; ++i)
newHull.iuarray[i] = hull.iuarray[i];
hull.iuarray[0] = y;
hull.iucount = 1;
hulls[index] = hull;
newHull.ilarray = new ArraySlice<int>(m_ILArray, newHull.idx * m_NumHulls, m_NumHulls);
newHull.ilarray[0] = y;
newHull.ilcount = 1;
InsertHull(hulls, index + 1, ref hullCount, newHull);
return true;
}
bool MergeHulls(NativeArray<UHull> hulls, ref int hullCount, NativeArray<float2> points, UEvent evt)
{
float2 temp = evt.a;
evt.a = evt.b;
evt.b = temp;
int index = ModuleHandle.GetEqual(hulls, hullCount, evt, new TestHullEventE());
if (index < 0)
return false;
UHull upper = hulls[index];
UHull lower = hulls[index - 1];
lower.iucount = upper.iucount;
for (int i = 0; i < lower.iucount; ++i)
lower.iuarray[i] = upper.iuarray[i];
hulls[index - 1] = lower;
EraseHull(hulls, index, ref hullCount);
return true;
}
static void InsertUniqueEdge(NativeArray<int2> edges, int2 e, ref int edgeCount)
{
TessEdgeCompare edgeComparer = new TessEdgeCompare();
var validEdge = true;
for (int j = 0; validEdge && j < edgeCount; ++j)
if (edgeComparer.Compare(e, edges[j]) == 0)
validEdge = false;
if (validEdge)
edges[edgeCount++] = e;
}
void PrepareDelaunay(NativeArray<int2> edges, int edgeCount)
{
m_StarCount = m_CellCount * 3;
m_Stars = new NativeArray<UStar>(m_StarCount, m_Allocator);
m_SPArray = new NativeArray<int>(m_StarCount * m_StarCount, m_Allocator);
var UEdgeCount = 0;
var UEdges = new NativeArray<int2>(m_StarCount, m_Allocator);
// Input Edges.
for (int i = 0; i < edgeCount; ++i)
{
int2 e = edges[i];
e.x = (edges[i].x < edges[i].y) ? edges[i].x : edges[i].y;
e.y = (edges[i].x > edges[i].y) ? edges[i].x : edges[i].y;
edges[i] = e;
InsertUniqueEdge(UEdges, e, ref UEdgeCount);
}
m_Edges = new NativeArray<int2>(UEdgeCount, m_Allocator);
for (int i = 0; i < UEdgeCount; ++i)
m_Edges[i] = UEdges[i];
UEdges.Dispose();
unsafe
{
ModuleHandle.InsertionSort<int2, TessEdgeCompare>(
NativeArrayUnsafeUtility.GetUnsafeBufferPointerWithoutChecks(m_Edges), 0, m_Edges.Length - 1,
new TessEdgeCompare());
}
// Init Stars.
for (int i = 0; i < m_StarCount; ++i)
{
UStar s = m_Stars[i];
s.points = new ArraySlice<int>(m_SPArray, i * m_StarCount, m_StarCount);
s.pointCount = 0;
m_Stars[i] = s;
}
// Fill stars.
for (int i = 0; i < m_CellCount; ++i)
{
int a = m_Cells[i].x;
int b = m_Cells[i].y;
int c = m_Cells[i].z;
UStar sa = m_Stars[a];
UStar sb = m_Stars[b];
UStar sc = m_Stars[c];
sa.points[sa.pointCount++] = b;
sa.points[sa.pointCount++] = c;
sb.points[sb.pointCount++] = c;
sb.points[sb.pointCount++] = a;
sc.points[sc.pointCount++] = a;
sc.points[sc.pointCount++] = b;
m_Stars[a] = sa;
m_Stars[b] = sb;
m_Stars[c] = sc;
}
}
int OppositeOf(int a, int b)
{
ArraySlice<int> points = m_Stars[b].points;
for (int k = 1, n = m_Stars[b].pointCount; k < n; k += 2)
if (points[k] == a)
return points[k - 1];
return -1;
}
struct TestEdgePointE : ICondition2<int2, int2>
{
public bool Test(int2 h, int2 p, ref float t)
{
TessEdgeCompare tc = new TessEdgeCompare();
t = tc.Compare(h, p);
return t == 0;
}
}
int FindConstraint(int a, int b)
{
int2 e;
e.x = a < b ? a : b;
e.y = a > b ? a : b;
return ModuleHandle.GetEqual(m_Edges, m_Edges.Length, e, new TestEdgePointE());
}
void AddTriangle(int i, int j, int k)
{
UStar si = m_Stars[i];
UStar sj = m_Stars[j];
UStar sk = m_Stars[k];
si.points[si.pointCount++] = j;
si.points[si.pointCount++] = k;
sj.points[sj.pointCount++] = k;
sj.points[sj.pointCount++] = i;
sk.points[sk.pointCount++] = i;
sk.points[sk.pointCount++] = j;
m_Stars[i] = si;
m_Stars[j] = sj;
m_Stars[k] = sk;
}
void RemovePair(int r, int j, int k)
{
UStar s = m_Stars[r];
ArraySlice<int> points = s.points;
for (int i = 1, n = s.pointCount; i < n; i += 2)
{
if (points[i - 1] == j && points[i] == k)
{
points[i - 1] = points[n - 2];
points[i] = points[n - 1];
s.points = points;
s.pointCount = s.pointCount - 2;
m_Stars[r] = s;
return;
}
}
}
void RemoveTriangle(int i, int j, int k)
{
RemovePair(i, j, k);
RemovePair(j, k, i);
RemovePair(k, i, j);
}
void EdgeFlip(int i, int j)
{
int a = OppositeOf(i, j);
int b = OppositeOf(j, i);
RemoveTriangle(i, j, a);
RemoveTriangle(j, i, b);
AddTriangle(i, b, a);
AddTriangle(j, a, b);
}
bool Flip(NativeArray<float2> points, ref NativeArray<int> stack, ref int stackCount, int a, int b, int x)
{
int y = OppositeOf(a, b);
if (y < 0)
{
return true;
}
if (b < a)
{
int tmp = a;
a = b;
b = tmp;
tmp = x;
x = y;
y = tmp;
}
if (FindConstraint(a, b) != -1)
{
return true;
}
if (ModuleHandle.IsInsideCircle(points[a], points[b], points[x], points[y]))
{
if ((2 + stackCount) >= stack.Length)
return false;
stack[stackCount++] = a;
stack[stackCount++] = b;
}
return true;
}
NativeArray<int3> GetCells(ref int count)
{
NativeArray<int3> cellsOut = new NativeArray<int3>(m_NumPoints * (m_NumPoints + 1), m_Allocator);
count = 0;
for (int i = 0, n = m_Stars.Length; i < n; ++i)
{
ArraySlice<int> points = m_Stars[i].points;
for (int j = 0, m = m_Stars[i].pointCount; j < m; j += 2)
{
int s = points[j];
int t = points[j + 1];
if (i < math.min(s, t))
{
int3 c = new int3();
c.x = i;
c.y = s;
c.z = t;
cellsOut[count++] = c;
}
}
}
return cellsOut;
}
internal bool ApplyDelaunay(NativeArray<float2> points, NativeArray<int2> edges)
{
// Early out if cannot find any valid cells.
if (0 == m_CellCount)
return false;
NativeArray<int> stack = new NativeArray<int>(m_NumPoints * (m_NumPoints + 1), m_Allocator);
int stackCount = 0;
var valid = true;
PrepareDelaunay(edges, m_NumEdges);
for (int a = 0; valid && (a < m_NumPoints); ++a)
{
UStar star = m_Stars[a];
for (int j = 1; j < star.pointCount; j += 2)
{
int b = star.points[j];
if (b < a)
{
continue;
}
if (FindConstraint(a, b) >= 0)
{
continue;
}
int x = star.points[j - 1], y = -1;
for (int k = 1; k < star.pointCount; k += 2)
{
if (star.points[k - 1] == b)
{
y = star.points[k];
break;
}
}
if (y < 0)
{
continue;
}
if (ModuleHandle.IsInsideCircle(points[a], points[b], points[x], points[y]))
{
if ((2 + stackCount) >= stack.Length)
{
valid = false;
break;
}
stack[stackCount++] = a;
stack[stackCount++] = b;
}
}
}
var flipFlops = m_NumPoints * m_NumPoints;
while (stackCount > 0 && valid)
{
int b = stack[stackCount - 1];
stackCount--;
int a = stack[stackCount - 1];
stackCount--;
int x = -1, y = -1;
UStar star = m_Stars[a];
for (int i = 1; i < star.pointCount; i += 2)
{
int s = star.points[i - 1];
int t = star.points[i];
if (s == b)
{
y = t;
}
else if (t == b)
{
x = s;
}
}
if (x < 0 || y < 0)
{
continue;
}
if (!ModuleHandle.IsInsideCircle(points[a], points[b], points[x], points[y]))
{
continue;
}
EdgeFlip(a, b);
valid = Flip(points, ref stack, ref stackCount, x, a, y);
valid = valid && Flip(points, ref stack, ref stackCount, a, y, x);
valid = valid && Flip(points, ref stack, ref stackCount, y, b, x);
valid = valid && Flip(points, ref stack, ref stackCount, b, x, y);
valid = valid && (--flipFlops > 0);
}
stack.Dispose();
return valid;
}
struct TestCellE : ICondition2<int3, int3>
{
public bool Test(int3 h, int3 p, ref float t)
{
TessCellCompare tc = new TessCellCompare();
t = tc.Compare(h, p);
return t == 0;
}
}
int FindNeighbor(NativeArray<int3> cells, int count, int a, int b, int c)
{
int x = a, y = b, z = c;
if (b < c)
{
if (b < a)
{
x = b;
y = c;
z = a;
}
}
else if (c < a)
{
x = c;
y = a;
z = b;
}
if (x < 0)
{
return -1;
}
int3 key;
key.x = x;
key.y = y;
key.z = z;
return ModuleHandle.GetEqual(cells, count, key, new TestCellE());
}
NativeArray<int3> Constrain(ref int count)
{
var cells = GetCells(ref count);
int nc = count;
for (int i = 0; i < nc; ++i)
{
int3 c = cells[i];
int x = c.x, y = c.y, z = c.z;
if (y < z)
{
if (y < x)
{
c.x = y;
c.y = z;
c.z = x;
}
}
else if (z < x)
{
c.x = z;
c.y = x;
c.z = y;
}
cells[i] = c;
}
unsafe
{
ModuleHandle.InsertionSort<int3, TessCellCompare>(
NativeArrayUnsafeUtility.GetUnsafeBufferPointerWithoutChecks(cells), 0, m_CellCount - 1,
new TessCellCompare());
}
// Out
m_Flags = new NativeArray<int>(nc, m_Allocator);
m_Neighbors = new NativeArray<int>(nc * 3, m_Allocator);
m_Constraints = new NativeArray<int>(nc * 3, m_Allocator);
var next = new NativeArray<int>(nc * 3, m_Allocator);
var active = new NativeArray<int>(nc * 3, m_Allocator);
int side = 1, nextCount = 0, activeCount = 0;
for (int i = 0; i < nc; ++i)
{
int3 c = cells[i];
for (int j = 0; j < 3; ++j)
{
int x = j, y = (j + 1) % 3;
x = (x == 0) ? c.x : (j == 1) ? c.y : c.z;
y = (y == 0) ? c.x : (y == 1) ? c.y : c.z;
int o = OppositeOf(y, x);
int a = m_Neighbors[3 * i + j] = FindNeighbor(cells, count, y, x, o);
int b = m_Constraints[3 * i + j] = (-1 != FindConstraint(x, y)) ? 1 : 0;
if (a < 0)
{
if (0 != b)
{
next[nextCount++] = i;
}
else
{
active[activeCount++] = i;
m_Flags[i] = 1;
}
}
}
}
while (activeCount > 0 || nextCount > 0)
{
while (activeCount > 0)
{
int t = active[activeCount - 1];
activeCount--;
if (m_Flags[t] == -side)
{
continue;
}
m_Flags[t] = side;
int3 c = cells[t];
for (int j = 0; j < 3; ++j)
{
int f = m_Neighbors[3 * t + j];
if (f >= 0 && m_Flags[f] == 0)
{
if (0 != m_Constraints[3 * t + j])
{
next[nextCount++] = f;
}
else
{
active[activeCount++] = f;
m_Flags[f] = side;
}
}
}
}
for (int e = 0; e < nextCount; e++)
active[e] = next[e];
activeCount = nextCount;
nextCount = 0;
side = -side;
}
active.Dispose();
next.Dispose();
return cells;
}
internal NativeArray<int3> RemoveExterior(ref int cellCount)
{
int constrainedCount = 0;
NativeArray<int3> constrained = Constrain(ref constrainedCount);
NativeArray<int3> cellsOut = new NativeArray<int3>(constrainedCount, m_Allocator);
cellCount = 0;
for (int i = 0; i < constrainedCount; ++i)
{
if (m_Flags[i] == -1)
{
cellsOut[cellCount++] = constrained[i];
}
}
constrained.Dispose();
return cellsOut;
}
internal NativeArray<int3> RemoveInterior(int cellCount)
{
int constrainedCount = 0;
NativeArray<int3> constrained = Constrain(ref constrainedCount);
NativeArray<int3> cellsOut = new NativeArray<int3>(constrainedCount, m_Allocator);
cellCount = 0;
for (int i = 0; i < constrainedCount; ++i)
{
if (m_Flags[i] == 1)
{
cellsOut[cellCount++] = constrained[i];
}
}
constrained.Dispose();
return cellsOut;
}
internal bool Triangulate(NativeArray<float2> points, int pointCount, NativeArray<int2> edges, int edgeCount)
{
m_NumEdges = edgeCount;
m_NumHulls = edgeCount * 2;
m_NumPoints = pointCount;
m_CellCount = 0;
m_Cells = new NativeArray<int3>(ModuleHandle.kMaxTriangleCount, m_Allocator);
m_ILArray = new NativeArray<int>(m_NumHulls * (m_NumHulls + 1), m_Allocator); // Make room for -1 node.
m_IUArray = new NativeArray<int>(m_NumHulls * (m_NumHulls + 1), m_Allocator); // Make room for -1 node.
NativeArray<UHull> hulls = new NativeArray<UHull>(m_NumPoints * 8, m_Allocator);
int hullCount = 0;
NativeArray<UEvent> events = new NativeArray<UEvent>(m_NumPoints + (m_NumEdges * 2), m_Allocator);
int eventCount = 0;
for (int i = 0; i < m_NumPoints; ++i)
{
UEvent evt = new UEvent();
evt.a = points[i];
evt.b = new float2();
evt.idx = i;
evt.type = (int)UEventType.EVENT_POINT;
events[eventCount++] = evt;
}
for (int i = 0; i < m_NumEdges; ++i)
{
int2 e = edges[i];
float2 a = points[e.x];
float2 b = points[e.y];
if (a.x < b.x)
{
UEvent _s = new UEvent();
_s.a = a;
_s.b = b;
_s.idx = i;
_s.type = (int)UEventType.EVENT_START;
UEvent _e = new UEvent();
_e.a = b;
_e.b = a;
_e.idx = i;
_e.type = (int)UEventType.EVENT_END;
events[eventCount++] = _s;
events[eventCount++] = _e;
}
else if (a.x > b.x)
{
UEvent _s = new UEvent();
_s.a = b;
_s.b = a;
_s.idx = i;
_s.type = (int)UEventType.EVENT_START;
UEvent _e = new UEvent();
_e.a = a;
_e.b = b;
_e.idx = i;
_e.type = (int)UEventType.EVENT_END;
events[eventCount++] = _s;
events[eventCount++] = _e;
}
}
unsafe
{
ModuleHandle.InsertionSort<UEvent, TessEventCompare>(
NativeArrayUnsafeUtility.GetUnsafeBufferPointerWithoutChecks(events), 0, eventCount - 1,
new TessEventCompare());
;
}
var hullOp = true;
float minX = events[0].a.x - (1 + math.abs(events[0].a.x)) * math.pow(2.0f, -16.0f);
UHull hull;
hull.a.x = minX;
hull.a.y = 1;
hull.b.x = minX;
hull.b.y = 0;
hull.idx = -1;
hull.ilarray = new ArraySlice<int>(m_ILArray, m_NumHulls * m_NumHulls, m_NumHulls); // Last element
hull.iuarray = new ArraySlice<int>(m_IUArray, m_NumHulls * m_NumHulls, m_NumHulls);
hull.ilcount = 0;
hull.iucount = 0;
hulls[hullCount++] = hull;
for (int i = 0, numEvents = eventCount; i < numEvents; ++i)
{
switch (events[i].type)
{
case (int) UEventType.EVENT_POINT:
{
hullOp = AddPoint(hulls, hullCount, points, events[i].a, events[i].idx);
}
break;
case (int) UEventType.EVENT_START:
{
hullOp = SplitHulls(hulls, ref hullCount, points, events[i]);
}
break;
default:
{
hullOp = MergeHulls(hulls, ref hullCount, points, events[i]);
}
break;
}
if (!hullOp)
break;
}
events.Dispose();
hulls.Dispose();
return hullOp;
}
internal static bool Tessellate(Allocator allocator, NativeArray<float2> pgPoints, int pgPointCount, NativeArray<int2> pgEdges, int pgEdgeCount, ref NativeArray<float2> outputVertices, ref int vertexCount, ref NativeArray<int> outputIndices, ref int indexCount)
{
// Process.
Tessellator tess = new Tessellator();
tess.SetAllocator(allocator);
int maxCount = 0, triCount = 0;
var valid = true;
valid = tess.Triangulate(pgPoints, pgPointCount, pgEdges, pgEdgeCount);
valid = valid && tess.ApplyDelaunay(pgPoints, pgEdges);
if (valid)
{
// Output.
NativeArray<int3> cells = tess.RemoveExterior(ref triCount);
for (var i = 0; i < triCount; ++i)
{
var a = (UInt16)cells[i].x;
var b = (UInt16)cells[i].y;
var c = (UInt16)cells[i].z;
if (a != b && b != c && a != c)
{
outputIndices[indexCount++] = a;
outputIndices[indexCount++] = c;
outputIndices[indexCount++] = b;
}
maxCount = math.max(math.max(math.max(cells[i].x, cells[i].y), cells[i].z), maxCount);
}
maxCount = (maxCount != 0) ? (maxCount + 1) : 0;
for (var i = 0; i < maxCount; ++i)
outputVertices[vertexCount++] = pgPoints[i];
cells.Dispose();
}
tess.Cleanup();
return valid;
}
internal void Cleanup()
{
if (m_Edges.IsCreated) m_Edges.Dispose();
if (m_Stars.IsCreated) m_Stars.Dispose();
if (m_SPArray.IsCreated) m_SPArray.Dispose();
if (m_Cells.IsCreated) m_Cells.Dispose();
if (m_ILArray.IsCreated) m_ILArray.Dispose();
if (m_IUArray.IsCreated) m_IUArray.Dispose();
if (m_Flags.IsCreated) m_Flags.Dispose();
if (m_Neighbors.IsCreated) m_Neighbors.Dispose();
if (m_Constraints.IsCreated) m_Constraints.Dispose();
}
}
}