float[] ComputeWorldPositions (PathAttachment path, int spacesCount, bool tangents, bool percentPosition,
bool percentSpacing) {
Slot target = this.target;
float position = this.position;
float[] spaces = this.spaces.Items, output = this.positions.Resize(spacesCount * 3 + 2).Items, world;
bool closed = path.Closed;
int verticesLength = path.WorldVerticesLength, curveCount = verticesLength / 6, prevCurve = NONE;
float pathLength;
if (!path.ConstantSpeed) {
float[] lengths = path.Lengths;
curveCount -= closed ? 1 : 2;
pathLength = lengths[curveCount];
if (percentPosition) position *= pathLength;
if (percentSpacing) {
for (int i = 0; i < spacesCount; i++)
spaces[i] *= pathLength;
}
world = this.world.Resize(8).Items;
for (int i = 0, o = 0, curve = 0; i < spacesCount; i++, o += 3) {
float space = spaces[i];
position += space;
float p = position;
if (closed) {
p %= pathLength;
if (p < 0) p += pathLength;
curve = 0;
} else if (p < 0) {
if (prevCurve != BEFORE) {
prevCurve = BEFORE;
path.ComputeWorldVertices(target, 2, 4, world, 0);
}
AddBeforePosition(p, world, 0, output, o);
continue;
} else if (p > pathLength) {
if (prevCurve != AFTER) {
prevCurve = AFTER;
path.ComputeWorldVertices(target, verticesLength - 6, 4, world, 0);
}
AddAfterPosition(p - pathLength, world, 0, output, o);
continue;
}
// Determine curve containing position.
for (;; curve++) {
float length = lengths[curve];
if (p > length) continue;
if (curve == 0)
p /= length;
else {
float prev = lengths[curve - 1];
p = (p - prev) / (length - prev);
}
break;
}
if (curve != prevCurve) {
prevCurve = curve;
if (closed && curve == curveCount) {
path.ComputeWorldVertices(target, verticesLength - 4, 4, world, 0);
path.ComputeWorldVertices(target, 0, 4, world, 4);
} else
path.ComputeWorldVertices(target, curve * 6 + 2, 8, world, 0);
}
AddCurvePosition(p, world[0], world[1], world[2], world[3], world[4], world[5], world[6], world[7], output, o,
tangents || (i > 0 && space == 0));
}
return output;
}
// World vertices.
if (closed) {
verticesLength += 2;
world = this.world.Resize(verticesLength).Items;
path.ComputeWorldVertices(target, 2, verticesLength - 4, world, 0);
path.ComputeWorldVertices(target, 0, 2, world, verticesLength - 4);
world[verticesLength - 2] = world[0];
world[verticesLength - 1] = world[1];
} else {
curveCount--;
verticesLength -= 4;
world = this.world.Resize(verticesLength).Items;
path.ComputeWorldVertices(target, 2, verticesLength, world, 0);
}
// Curve lengths.
float[] curves = this.curves.Resize(curveCount).Items;
pathLength = 0;
float x1 = world[0], y1 = world[1], cx1 = 0, cy1 = 0, cx2 = 0, cy2 = 0, x2 = 0, y2 = 0;
float tmpx, tmpy, dddfx, dddfy, ddfx, ddfy, dfx, dfy;
for (int i = 0, w = 2; i < curveCount; i++, w += 6) {
cx1 = world[w];
cy1 = world[w + 1];
cx2 = world[w + 2];
cy2 = world[w + 3];
x2 = world[w + 4];
y2 = world[w + 5];
tmpx = (x1 - cx1 * 2 + cx2) * 0.1875f;
tmpy = (y1 - cy1 * 2 + cy2) * 0.1875f;
dddfx = ((cx1 - cx2) * 3 - x1 + x2) * 0.09375f;
dddfy = ((cy1 - cy2) * 3 - y1 + y2) * 0.09375f;
ddfx = tmpx * 2 + dddfx;
ddfy = tmpy * 2 + dddfy;
dfx = (cx1 - x1) * 0.75f + tmpx + dddfx * 0.16666667f;
dfy = (cy1 - y1) * 0.75f + tmpy + dddfy * 0.16666667f;
pathLength += (float)Math.Sqrt(dfx * dfx + dfy * dfy);
dfx += ddfx;
dfy += ddfy;
ddfx += dddfx;
ddfy += dddfy;
pathLength += (float)Math.Sqrt(dfx * dfx + dfy * dfy);
dfx += ddfx;
dfy += ddfy;
pathLength += (float)Math.Sqrt(dfx * dfx + dfy * dfy);
dfx += ddfx + dddfx;
dfy += ddfy + dddfy;
pathLength += (float)Math.Sqrt(dfx * dfx + dfy * dfy);
curves[i] = pathLength;
x1 = x2;
y1 = y2;
}
if (percentPosition) position *= pathLength;
if (percentSpacing) {
for (int i = 0; i < spacesCount; i++)
spaces[i] *= pathLength;
}
float[] segments = this.segments;
float curveLength = 0;
for (int i = 0, o = 0, curve = 0, segment = 0; i < spacesCount; i++, o += 3) {
float space = spaces[i];
position += space;
float p = position;
if (closed) {
p %= pathLength;
if (p < 0) p += pathLength;
curve = 0;
} else if (p < 0) {
AddBeforePosition(p, world, 0, output, o);
continue;
} else if (p > pathLength) {
AddAfterPosition(p - pathLength, world, verticesLength - 4, output, o);
continue;
}
// Determine curve containing position.
for (;; curve++) {
float length = curves[curve];
if (p > length) continue;
if (curve == 0)
p /= length;
else {
float prev = curves[curve - 1];
p = (p - prev) / (length - prev);
}
break;
}
// Curve segment lengths.
if (curve != prevCurve) {
prevCurve = curve;
int ii = curve * 6;
x1 = world[ii];
y1 = world[ii + 1];
cx1 = world[ii + 2];
cy1 = world[ii + 3];
cx2 = world[ii + 4];
cy2 = world[ii + 5];
x2 = world[ii + 6];
y2 = world[ii + 7];
tmpx = (x1 - cx1 * 2 + cx2) * 0.03f;
tmpy = (y1 - cy1 * 2 + cy2) * 0.03f;
dddfx = ((cx1 - cx2) * 3 - x1 + x2) * 0.006f;
dddfy = ((cy1 - cy2) * 3 - y1 + y2) * 0.006f;
ddfx = tmpx * 2 + dddfx;
ddfy = tmpy * 2 + dddfy;
dfx = (cx1 - x1) * 0.3f + tmpx + dddfx * 0.16666667f;
dfy = (cy1 - y1) * 0.3f + tmpy + dddfy * 0.16666667f;
curveLength = (float)Math.Sqrt(dfx * dfx + dfy * dfy);
segments[0] = curveLength;
for (ii = 1; ii < 8; ii++) {
dfx += ddfx;
dfy += ddfy;
ddfx += dddfx;
ddfy += dddfy;
curveLength += (float)Math.Sqrt(dfx * dfx + dfy * dfy);
segments[ii] = curveLength;
}
dfx += ddfx;
dfy += ddfy;
curveLength += (float)Math.Sqrt(dfx * dfx + dfy * dfy);
segments[8] = curveLength;
dfx += ddfx + dddfx;
dfy += ddfy + dddfy;
curveLength += (float)Math.Sqrt(dfx * dfx + dfy * dfy);
segments[9] = curveLength;
segment = 0;
}
// Weight by segment length.
p *= curveLength;
for (;; segment++) {
float length = segments[segment];
if (p > length) continue;
if (segment == 0)
p /= length;
else {
float prev = segments[segment - 1];
p = segment + (p - prev) / (length - prev);
}
break;
}
AddCurvePosition(p * 0.1f, x1, y1, cx1, cy1, cx2, cy2, x2, y2, output, o, tangents || (i > 0 && space == 0));
}
return output;
}
