private void AddRibbonSegmentIndices(RibbonSegment ribbonSegment, int firstSegmentVertIdx, List <int> indices)
{
int v = firstSegmentVertIdx;
// Startcap
if (ribbonSegment.hasStartCap)
{
indices.Add(v + 0);
indices.Add(v + 1);
indices.Add(v + 2);
indices.Add(v + 0);
indices.Add(v + 2);
indices.Add(v + 3);
v += 4; // having a startcap offsets the expected vertex index for this segment
// Side up
indices.Add(v + 0);
indices.Add(v + 1);
indices.Add(v + 9);
indices.Add(v + 0);
indices.Add(v + 9);
indices.Add(v + 8);
// Side right
indices.Add(v + 2);
indices.Add(v + 3);
indices.Add(v + 11);
indices.Add(v + 2);
indices.Add(v + 11);
indices.Add(v + 10);
// Side down
indices.Add(v + 4);
indices.Add(v + 5);
indices.Add(v + 13);
indices.Add(v + 4);
indices.Add(v + 13);
indices.Add(v + 12);
// Side left
indices.Add(v + 6);
indices.Add(v + 7);
indices.Add(v + 15);
indices.Add(v + 6);
indices.Add(v + 15);
indices.Add(v + 14);
}
else
{
// With no startcap, side tris connect to previous segment's verts.
// Side up
indices.Add(v + 0);
indices.Add(v - 8);
indices.Add(v + 1);
indices.Add(v + 1);
indices.Add(v - 8);
indices.Add(v - 7);
// Side right
indices.Add(v + 2);
indices.Add(v - 6);
indices.Add(v + 3);
indices.Add(v + 3);
indices.Add(v - 6);
indices.Add(v - 5);
// Side down
indices.Add(v + 4);
indices.Add(v - 4);
indices.Add(v + 5);
indices.Add(v + 5);
indices.Add(v - 4);
indices.Add(v - 3);
// Side left
indices.Add(v + 6);
indices.Add(v - 2);
indices.Add(v + 7);
indices.Add(v + 7);
indices.Add(v - 2);
indices.Add(v - 1);
}
// Endcap
if (ribbonSegment.hasEndCap)
{
if (ribbonSegment.hasStartCap)
{
v += 16;
}
else
{
v += 8;
}
indices.Add(v + 0);
indices.Add(v + 1);
indices.Add(v + 2);
indices.Add(v + 0);
indices.Add(v + 2);
indices.Add(v + 3);
}
}
public void UpdateRenderer(List <StrokePoint> stroke, int maxChangedFromEnd)
{
if (stroke.Count <= 1 || maxChangedFromEnd == 0)
{
return;
}
if (OnUpdateRenderer != null)
{
OnUpdateRenderer(stroke, maxChangedFromEnd);
}
int startIdx = Mathf.Max(0, (stroke.Count - 1) - maxChangedFromEnd - 1);
int endIdx = stroke.Count - 1;
// Lop off outdated vertices and indices.
int expectedNewNumRibbons = stroke.Count - 1;
int firstChangedRibbonIndex = expectedNewNumRibbons - 1 - maxChangedFromEnd;
int numRibbonSegmentsOutdated = _ribbonSegments.Count - firstChangedRibbonIndex;
int numVertsOutdated = 0;
int numRibbonVertsAccountFor = 0;
int numIndicesOutdated = 0;
for (int i = 0; i < numRibbonSegmentsOutdated; i++)
{
if (i >= 0 && i < _ribbonSegments.Count)
{
numVertsOutdated += _ribbonSegments[_ribbonSegments.Count - 1 - i].NumVerts();
numRibbonVertsAccountFor++;
numIndicesOutdated += _ribbonSegments[_ribbonSegments.Count - 1 - i].NumIndices();
}
}
for (int i = 0; i < numVertsOutdated; i++)
{
if (_verts.Count > 0)
{
_verts.RemoveAt(_verts.Count - 1);
_colors.RemoveAt(_colors.Count - 1);
_normals.RemoveAt(_normals.Count - 1);
}
}
for (int i = 0; i < numIndicesOutdated; i++)
{
if (_indices.Count > 0)
{
_indices.RemoveAt(_indices.Count - 1);
}
}
// Update Ribbon Segment representation.
for (int i = startIdx; i < endIdx; i++)
{
// Define the current ribbon segment.
StrokePoint curPoint = stroke[i];
StrokePoint nextPoint = stroke[i + 1];
Vector3 curSegmentDirection = (nextPoint.position - curPoint.position).normalized;
Vector3 prevSegmentDirection = curSegmentDirection;
bool hasPrevSegment = (i > 0);
if (hasPrevSegment)
{
prevSegmentDirection = (stroke[i].position - stroke[i - 1].position).normalized;
}
Vector3 nextSegmentDirection = curSegmentDirection;
bool hasNextSegment = (i < endIdx - 1);
if (hasNextSegment)
{
nextSegmentDirection = (stroke[i + 2].position - stroke[i + 1].position).normalized;
}
bool curSegmentHasStartCap = i == 0;
if (hasPrevSegment)
{
curSegmentHasStartCap = (Vector3.Dot(prevSegmentDirection, curSegmentDirection) < -0.8F);
}
Vector3 startFacing, startNormal;
if (curSegmentHasStartCap)
{
startFacing = -curSegmentDirection;
startNormal = curPoint.normal;
}
else
{
startFacing = -(prevSegmentDirection + curSegmentDirection).normalized;
startNormal = (stroke[i - 1].normal + curPoint.normal).normalized;
}
bool curSegmentHasEndCap = i == stroke.Count - 2;
if (hasNextSegment)
{
curSegmentHasEndCap = (Vector3.Dot(curSegmentDirection, nextSegmentDirection) < -0.8F);
}
Vector3 endFacing, endNormal;
if (curSegmentHasEndCap)
{
endFacing = curSegmentDirection;
endNormal = curPoint.normal;
}
else
{
endFacing = (curSegmentDirection + nextSegmentDirection).normalized;
endNormal = (curPoint.normal + nextPoint.normal).normalized;
}
RibbonSegment curRibbonSegment = new RibbonSegment(
curPoint.position,
startFacing,
startNormal,
curPoint.thickness,
nextPoint.position,
endFacing,
endNormal,
nextPoint.thickness,
curSegmentHasStartCap,
curSegmentHasEndCap
);
// Add or modify the constructed ribbon segment
if (i > _ribbonSegments.Count - 1)
{
// Add a new ribbon segment definition.
_ribbonSegments.Add(curRibbonSegment);
}
else
{
// Modify an existing ribbon segment definition.
_ribbonSegments[i] = curRibbonSegment;
}
}
// Construct and add new vertices and indices per RibbonSegment.
for (int i = startIdx; i < endIdx; i++)
{
AddRibbonSegmentIndices(_ribbonSegments[i], _verts.Count, _indices);
AddRibbonSegmentVerts(_ribbonSegments[i], _verts, _normals);
for (int j = 0; j < _ribbonSegments[i].NumVerts(); j++) // color vertices
{
_colors.Add(stroke[i].color);
}
}
_mesh.Clear();
_mesh.SetVertices(_verts);
_mesh.SetTriangles(_indices, 0);
_mesh.SetNormals(_normals);
_mesh.SetColors(_colors);
_mesh.RecalculateBounds();
_mesh.RecalculateNormals();
_mesh.UploadMeshData(false);
_cachedStrokeRenderered = stroke;
}
private void AddRibbonSegmentVerts(RibbonSegment ribbonSegment, List <Vector3> verts, List <Vector3> normals)
{
// Vertex order:
// Side up, right, down, left
// Startcap (if any)
// Endcap (if any)
Vector3 startPos = ribbonSegment.startPos;
Vector3 startFaceLeftDir = Vector3.Cross(ribbonSegment.startFacing, ribbonSegment.startNormal).normalized;
Vector3 startFaceUpDir = ribbonSegment.startNormal;
float startXThickness = ribbonSegment.startThickness;
float startYThickness = ribbonSegment.startThickness * VERTICAL_THICKNESS_MULTIPLIER;
Vector3 endPos = ribbonSegment.endPos;
Vector3 endFaceLeftDir = Vector3.Cross(ribbonSegment.endNormal, ribbonSegment.endFacing).normalized; // "left" looking at/through the start face
Vector3 endFaceUpDir = ribbonSegment.endNormal;
float endXThickness = ribbonSegment.endThickness;
float endYThickness = ribbonSegment.endThickness * VERTICAL_THICKNESS_MULTIPLIER;
Vector3 startLeft = startFaceLeftDir * startXThickness;
Vector3 startRight = -startLeft;
Vector3 startUp = startFaceUpDir * startYThickness;
Vector3 startDown = -startUp;
Vector3 endLeft = endFaceLeftDir * endXThickness;
Vector3 endRight = -endLeft;
Vector3 endUp = endFaceUpDir * endYThickness;
Vector3 endDown = -endUp;
// Startcap
if (ribbonSegment.hasStartCap)
{
verts.Add(startPos + startLeft + startDown);
verts.Add(startPos + startRight + startDown);
verts.Add(startPos + startRight + startUp);
verts.Add(startPos + startLeft + startUp);
normals.Add(ribbonSegment.startFacing);
normals.Add(ribbonSegment.startFacing);
normals.Add(ribbonSegment.startFacing);
normals.Add(ribbonSegment.startFacing);
// Start side up
verts.Add(startPos + startLeft + startUp);
verts.Add(startPos + startRight + startUp);
normals.Add(startUp);
normals.Add(startUp);
// Start side right
verts.Add(startPos + startRight + startUp);
verts.Add(startPos + startRight + startDown);
normals.Add(startRight);
normals.Add(startRight);
// Start side down
verts.Add(startPos + startRight + startDown);
verts.Add(startPos + startLeft + startDown);
normals.Add(startDown);
normals.Add(startDown);
// Start side left
verts.Add(startPos + startLeft + startDown);
verts.Add(startPos + startLeft + startUp);
normals.Add(startLeft);
normals.Add(startLeft);
}
// End side up
verts.Add(endPos + endLeft + endUp);
verts.Add(endPos + endRight + endUp);
normals.Add(endUp);
normals.Add(endUp);
// End side right
verts.Add(endPos + endRight + endUp);
verts.Add(endPos + endRight + endDown);
normals.Add(endRight);
normals.Add(endRight);
// End side down
verts.Add(endPos + endRight + endDown);
verts.Add(endPos + endLeft + endDown);
normals.Add(endDown);
normals.Add(endDown);
// End side left
verts.Add(endPos + endLeft + endDown);
verts.Add(endPos + endLeft + endUp);
normals.Add(endLeft);
normals.Add(endLeft);
// Endcap
if (ribbonSegment.hasEndCap)
{
verts.Add(endPos + endLeft + endUp);
verts.Add(endPos + endRight + endUp);
verts.Add(endPos + endRight + endDown);
verts.Add(endPos + endLeft + endDown);
normals.Add(ribbonSegment.endFacing);
normals.Add(ribbonSegment.endFacing);
normals.Add(ribbonSegment.endFacing);
normals.Add(ribbonSegment.endFacing);
}
}
