Add simd::crossfade. Make MinBlepGenerator generic.

include/dsp/minblep.hpp

@@ -15,9 +15,9 @@ https://www.cs.cmu.edu/~eli/papers/icmc01-hardsync.pdf
 void minBlepImpulse(int z, int o, float *output);
 
 
-template <int Z, int O>
+template <int Z, int O, typename T = float>
 struct MinBlepGenerator {
-	float buf[2 * Z] = {};
+	T buf[2 * Z] = {};
 	int pos = 0;
 	float impulse[2 * Z * O + 1];
 
@@ -27,7 +27,7 @@ struct MinBlepGenerator {
 	}
 
 	/** Places a discontinuity with magnitude `x` at -1 < p <= 0 relative to the current frame */
-	void insertDiscontinuity(float p, float x) {
+	void insertDiscontinuity(float p, T x) {
 		if (!(-1 < p && p <= 0))
 			return;
 		for (int j = 0; j < 2 * Z; j++) {
@@ -37,9 +37,9 @@ struct MinBlepGenerator {
 		}
 	}
 
-	float process() {
-		float v = buf[pos];
-		buf[pos] = 0.f;
+	T process() {
+		T v = buf[pos];
+		buf[pos] = T(0);
 		pos = (pos + 1) % (2 * Z);
 		return v;
 	}

include/simd/functions.hpp

@@ -172,6 +172,12 @@ inline float_4 rescale(float_4 x, float_4 xMin, float_4 xMax, float_4 yMin, floa
 	return yMin + (x - xMin) / (xMax - xMin) * (yMax - yMin);
 }
 
+using math::crossfade;
+
+inline float_4 crossfade(float_4 a, float_4 b, float_4 p) {
+	return a + (b - a) * p;
+}
+
 using math::sgn;
 
 inline float_4 sgn(float_4 x) {