[breaking change] Sample signals from query onset, rather than midpoint (#1278)

This changes almost everything involving signals, including all use of random numbers.

packages/core/signal.mjs

@@ -16,7 +16,7 @@ export function steady(value) {
 }
 
 export const signal = (func) => {
-  const query = (state) => [new Hap(undefined, state.span, func(state.span.midpoint()))];
+  const query = (state) => [new Hap(undefined, state.span, func(state.span.begin))];
   return new Pattern(query);
 };
 
@@ -158,7 +158,7 @@ const timeToRands = (t, n) => timeToRandsPrime(timeToIntSeed(t), n);
  * n(run(4)).scale("C4:pentatonic")
  * // n("0 1 2 3").scale("C4:pentatonic")
  */
-export const run = (n) => saw.range(0, n).floor().segment(n);
+export const run = (n) => saw.range(0, n).round().segment(n);
 
 /**
  * Creates a pattern from a binary number.

packages/core/test/pattern.test.mjs

@@ -736,21 +736,15 @@ describe('Pattern', () => {
   describe('signal()', () => {
     it('Can make saw/saw2', () => {
       expect(saw.struct(true, true, true, true).firstCycle()).toStrictEqual(
-        sequence(1 / 8, 3 / 8, 5 / 8, 7 / 8).firstCycle(),
+        sequence(0, 1 / 4, 1 / 2, 3 / 4).firstCycle(),
       );
 
-      expect(saw2.struct(true, true, true, true).firstCycle()).toStrictEqual(
-        sequence(-3 / 4, -1 / 4, 1 / 4, 3 / 4).firstCycle(),
-      );
+      expect(saw2.struct(true, true, true, true).firstCycle()).toStrictEqual(sequence(-1, -0.5, 0, 0.5).firstCycle());
     });
     it('Can make isaw/isaw2', () => {
-      expect(isaw.struct(true, true, true, true).firstCycle()).toStrictEqual(
-        sequence(7 / 8, 5 / 8, 3 / 8, 1 / 8).firstCycle(),
-      );
+      expect(isaw.struct(true, true, true, true).firstCycle()).toStrictEqual(sequence(1, 0.75, 0.5, 0.25).firstCycle());
 
-      expect(isaw2.struct(true, true, true, true).firstCycle()).toStrictEqual(
-        sequence(3 / 4, 1 / 4, -1 / 4, -3 / 4).firstCycle(),
-      );
+      expect(isaw2.struct(true, true, true, true).firstCycle()).toStrictEqual(sequence(1, 0.5, 0, -0.5).firstCycle());
     });
   });
   describe('_setContext()', () => {
@@ -888,7 +882,7 @@ describe('Pattern', () => {
           .squeezeJoin()
           .queryArc(3, 4)
           .map((x) => x.value),
-      ).toStrictEqual([Fraction(3.5)]);
+      ).toStrictEqual([Fraction(3)]);
     });
   });
   describe('ply', () => {