Add some useful lerp lib functions made use of in the polytrails branch and in mods

diff --git a/qcsrc/lib/math.qh b/qcsrc/lib/math.qh
index d8f19906a3eb26b1d9003e74f4493450f4b018d8..ac23325000995f50ef2e1fdde945686ff741401f 100644 (file)
--- a/qcsrc/lib/math.qh
+++ b/qcsrc/lib/math.qh
@@ -71,6 +71,39 @@ vector vsnap(vector point, float fsize)
        return vret;
 }
 
+ERASEABLE
+float lerpratio(float f0, float f1, float ratio)
+{
+       return f0 * (1 - ratio) + f1 * ratio;
+}
+
+ERASEABLE
+float lerp(float t0, float f0, float t1, float f1, float t)
+{
+       return lerpratio(f0, f1, (t - t0) / (t1 - t0));
+}
+
+ERASEABLE
+float lerp3ratio(float f0, float f1, float f2, float ratio)
+{
+       float mid = 0.5;
+       return ratio < mid ? lerpratio(f0, f1, ratio / mid) : ratio > mid ? lerpratio(f1, f2, (ratio - mid) / mid) : f1;
+}
+
+
+ERASEABLE
+vector lerpvratio(vector f0, vector f1, float ratio)
+{
+       return f0 * (1 - ratio) + f1 * ratio;
+}
+
+ERASEABLE
+vector lerpv3ratio(vector f0, vector f1, vector f2, float ratio)
+{
+       float mid = 0.5;
+       return ratio < mid ? lerpvratio(f0, f1, ratio / mid) : ratio > mid ? lerpvratio(f1, f2, (ratio - mid) / mid) : f1;
+}
+
 ERASEABLE
 vector lerpv(float t0, vector v0, float t1, vector v1, float t)
 {