[subset] Finish out hb-subset-instancer-solver.cc
diff --git a/src/hb-subset-instancer-solver.cc b/src/hb-subset-instancer-solver.cc
index 89360d0..b7d6538 100644
--- a/src/hb-subset-instancer-solver.cc
+++ b/src/hb-subset-instancer-solver.cc
@@ -28,8 +28,6 @@
*
* https://github.com/fonttools/fonttools/blob/f73220816264fc383b8a75f2146e8d69e455d398/Lib/fontTools/varLib/instancer/solver.py
*
- * See XXX markers for unfinished parts.
- *
* Where that file returns None for a triple, we return Triple{}.
* This should be safe.
*/
@@ -45,6 +43,13 @@
Triple (float minimum_, float middle_, float maximum_) :
minimum (minimum_), middle (middle_), maximum (maximum_) {}
+ bool operator == (const Triple &o)
+ {
+ return minimum == o.minimum &&
+ middle == o.middle &&
+ maximum == o.maximum;
+ }
+
float minimum;
float middle;
float maximum;
@@ -53,6 +58,31 @@
static inline Triple _reverse_negate(const Triple &v)
{ return {-v.maximum, -v.middle, -v.minimum}; }
+
+static inline float supportScalar (float coord, const Triple &tent)
+{
+ /* Copied from VarRegionAxis::evaluate() */
+ float start = tent.minimum, peak = tent.middle, end = tent.maximum;
+
+ if (unlikely (start > peak || peak > end))
+ return 1.;
+ if (unlikely (start < 0 && end > 0 && peak != 0))
+ return 1.;
+
+ if (peak == 0 || coord == peak)
+ return 1.;
+
+ if (coord <= start || end <= coord)
+ return 0.;
+
+ /* Interpolate */
+ if (coord < peak)
+ return (coord - start) / (peak - start);
+ else
+ return (end - coord) / (end - peak);
+}
+
+
using result_item_t = hb_pair_t<float, Triple>;
using result_t = hb_vector_t<result_item_t>;
@@ -124,7 +154,7 @@
*/
if (axisMax < peak)
{
- float mult = 1.f; //XXX supportScalar({"tag": axisMax}, {"tag": tent})
+ float mult = supportScalar (axisMax, tent);
tent = Triple{lower, axisMax, axisMax};
result_t vec = _solve (tent, axisLimit);
@@ -137,13 +167,13 @@
// lower <= axisDef <= peak <= axisMax
- float gain = 1.0f; // XXX supportScalar({"tag": axisDef}, {"tag": tent})
+ float gain = supportScalar (axisDef, tent);
result_t out {hb_pair (gain, Triple{})};
// First, the positive side
// outGain is the scalar of axisMax at the tent.
- float outGain = 1.f; // XXX supportScalar({"tag": axisMax}, {"tag": tent})
+ float outGain = supportScalar (axisMax, tent);
/* Case 3a: Gain is more than outGain. The tent down-slope crosses
* the axis into negative. We have to split it into multiples.
@@ -183,7 +213,7 @@
if (upper >= axisMax)
{
Triple loc {crossing, axisMax, axisMax};
- float scalar = 1.f; // XXX supportScalar({"tag": axisMax}, {"tag": tent})
+ float scalar = supportScalar (axisMax, tent);
out.push (hb_pair (scalar - gain, loc));
}
@@ -294,7 +324,7 @@
float scalar1 = 1.f;
Triple loc2 {peak, axisMax, axisMax};
- float scalar2 = 1.f; // XXX supportScalar({"tag": axisMax}, {"tag": tent})
+ float scalar2 = supportScalar (axisMax, tent);
out.push (hb_pair (scalar1 - gain, loc1));
// Don't add a dirac delta!
@@ -321,7 +351,7 @@
if (lower <= axisMin)
{
Triple loc {axisMin, axisMin, axisDef};
- float scalar = 1.f; // XXX supportScalar({"tag": axisMin}, {"tag": tent})
+ float scalar = supportScalar (axisMin, tent);
out.push (hb_pair (scalar - gain, loc));
}
@@ -362,6 +392,36 @@
return out;
}
+/* Normalizes value based on a min/default/max triple. */
+static inline float normalizeValue (float v, const Triple &triple, bool extrapolate = false)
+{
+ /*
+ >>> normalizeValue(400, (100, 400, 900))
+ 0.0
+ >>> normalizeValue(100, (100, 400, 900))
+ -1.0
+ >>> normalizeValue(650, (100, 400, 900))
+ 0.5
+ */
+ float lower = triple.minimum, def = triple.middle, upper = triple.maximum;
+ assert (lower <= def && def <= upper);
+
+ if (!extrapolate)
+ v = hb_max (hb_min (v, upper), lower);
+
+ if ((v == def) || (lower == upper))
+ return 0.f;
+
+ if ((v < def && lower != def) || (v > def && upper == def))
+ return (v - def) / (def - lower);
+ else
+ {
+ assert ((v > def && upper != def) ||
+ (v < def && lower == def));
+ return (v - def) / (upper - def);
+ }
+}
+
/* Given a tuple (lower,peak,upper) "tent" and new axis limits
* (axisMin,axisDefault,axisMax), solves how to represent the tent
* under the new axis configuration. All values are in normalized
@@ -391,15 +451,21 @@
result_t sols = _solve (tent, axisLimit);
-#if 0
- // XXX
- n = lambda v: normalizeValue(v, axisLimit, extrapolate=True)
- sols = [
- (scalar, (n(v[0]), n(v[1]), n(v[2])) if v is not None else None)
- for scalar, v in sols
- if scalar
- ]
-#endif
+ auto n = [&axisLimit] (float v) { return normalizeValue (v, axisLimit, true); };
+
+ result_t out;
+ for (auto &p : sols)
+ {
+ if (!p.first) continue;
+ if (p.second == Triple{})
+ {
+ out.push (p);
+ continue;
+ }
+ Triple t = p.second;
+ out.push (hb_pair (p.first,
+ Triple{n (t.minimum), n (t.middle), n (t.maximum)}));
+ }
return sols;
}
