Add Oneiroi docs

Tweak EvenVCO so oscillators have same phase relationship as before

docs/Oneiroi.md

@@ -0,0 +1,16 @@
+# Befaco Oneiroi
+
+Based on [Befaco Oneiroi](http://www.befaco.org/oneiroi) Eurorack module. For the official manual, see [here](https://befaco.org/docs/Oneiroi/Oneiroi_User_Manual.pdf).
+
+
+## Differences with hardware
+
+* Randomisation can optionally be applied to every parameter using the built in VCV randomisation
+* Input gain switch (available on hardware) has been removed as this makes no sense in VCV
+* Undo/redo is natively handled by VCV Rack
+* .wav files can be loaded from the context menu (naive loading no sample rate conversion!)
+* Additional LED indicators have been added for filter type, filter position, modulation type and oscillator octave
+* Distinct virtual knobs are used for each parameter so parameter catch-up (used on hardware) is not needed. 
+* As yet, slew of parameter values on randomize is not supported
+
+![Oneiroi](img/Oneiroi.png)

src/EvenVCO.cpp

@@ -169,14 +169,14 @@ struct EvenVCO : Module {
 
 				if (outputs[SINE_OUTPUT].isConnected() || outputs[EVEN_OUTPUT].isConnected()) {
 					// sin doesn't need PDW
-					osBufferSin[i] = -simd::cos(2.0 * M_PI * phase[c / 4]);
+					osBufferSin[i] = -simd::cos(M_PI + 2.0 * M_PI * phase[c / 4]);
 				}
 
 				if (outputs[TRI_OUTPUT].isConnected()) {
 					const float_4 dpwOrder1 = 1.0 - 2.0 * simd::abs(2 * phase[c / 4] - 1.0);
 					const float_4 dpwOrder3 = aliasSuppressedTri(phases) * denominatorInv;
 
-					osBufferTri[i] = simd::ifelse(lowFreqRegime, dpwOrder1, dpwOrder3);
+					osBufferTri[i] = -simd::ifelse(lowFreqRegime, dpwOrder1, dpwOrder3);
 				}
 
 				if (outputs[SAW_OUTPUT].isConnected()) {