Replace light presets with shared hue, temperature and brightness sliders

tests/test_light_controls.cpp

@@ -0,0 +1,23 @@
+#define LIGHT_CONTROLS_TEST
+#include "../light_controls.h"
+#include <cassert>
+int main() {
+  using namespace light_controls;
+  float value = -1;
+  for (auto text : {"[120.5, 100]", "(120.5, 80.0)", "120.5"}) {
+    assert(first_number(text, value)); assert(value == 120.5f);
+  }
+  for (auto text : {"None", "unknown", "unavailable", "[]", "nan", "inf", ""}) assert(!first_number(text, value));
+  State a, b;
+  a.update(0, "[239.6, 80]"); assert(a.hue == 240); assert(b.hue == 0);
+  a.update(0, "None"); a.update(0, "[720, 100]"); assert(a.hue == 240);
+  a.update(1, "2700"); a.update(1, "unavailable"); assert(a.kelvin == 2700);
+  assert(!a.temperature_ready()); a.update(2, "2200"); assert(!a.temperature_ready());
+  a.update(3, "5000"); assert(a.temperature_ready());
+  assert(clamp(1800, a.minimum, a.maximum) == 2200);
+  assert(clamp(6500, a.minimum, a.maximum) == 5000);
+  a.update(3, "2000"); assert(!a.temperature_ready());
+  a.update(3, "1e30"); assert(!a.temperature_ready());
+  a.update(3, "5000"); assert(a.temperature_ready());
+  assert(clamp(-1, 0, 360) == 0); assert(clamp(999, 0, 360) == 360);
+}