Refactored rate curve into file of its own.

Improved scaling of rate curves

js/RateCurve.js

@@ -0,0 +1,106 @@
+'use strict';
+
+var minRc = 1000;
+var midRc = 1500;
+var maxRc = 2000;
+
+var RateCurve = function (useLegacyCurve) {
+    this.useLegacyCurve = useLegacyCurve;
+
+    function constrain(value, min, max) {
+        return Math.max(min, Math.min(value, max));
+    }
+
+    function rcCommand(rcData, rcRate, rcExpo) {
+        var tmp = Math.min(Math.abs(rcData - midRc), 500) / 100;
+
+	var result = ((2500 + rcExpo * (tmp * tmp - 25)) * tmp * rcRate / 2500).toFixed(0);
+	if (rcData < midRc) {
+            result = -result;
+        }
+
+        return result;
+    }
+
+    this.rcCommandRawToDegreesPerSecond = function (rcData, rate, rcRate, rcExpo, superExpoActive) {
+        var inputValue = rcCommand(rcData, rcRate, rcExpo);
+
+        var angleRate;
+        if (superExpoActive) {
+            var rcFactor = Math.abs(inputValue) / (500 * rcRate / 100);
+            rcFactor = 1 / constrain(1 - rcFactor * rate / 100, 0.01, 1);
+
+            angleRate = rcFactor * 27 * inputValue / 16;
+        } else {
+            angleRate = (rate + 27) * inputValue / 16;
+        }
+
+        angleRate = constrain(angleRate, -8190, 8190); // Rate limit protection
+        return angleRate >> 2; // the shift by 2 is to counterbalance the divide by 4 that occurs on the gyro to calculate the error
+    };
+
+    this.drawRateCurve = function (rate, rcRate, rcExpo, superExpoActive, maxAngularVel, context, width, height) {
+        rate = rate * 100;
+	rcRate = rcRate * 100;
+	rcExpo = rcExpo * 100;
+
+        var canvasHeightScale = height / (2 * maxAngularVel);
+
+        var stepWidth = context.lineWidth;
+
+        context.save();
+        context.translate(width / 2, height / 2);
+
+        context.beginPath();
+        var rcData = minRc;
+        context.moveTo(-500, -canvasHeightScale * this.rcCommandRawToDegreesPerSecond(rcData, rate, rcRate, rcExpo, superExpoActive));
+        rcData = rcData + stepWidth;
+        while (rcData <= maxRc) {
+            context.lineTo(rcData - midRc, -canvasHeightScale * this.rcCommandRawToDegreesPerSecond(rcData, rate, rcRate, rcExpo, superExpoActive));
+
+            rcData = rcData + stepWidth;
+        }
+        context.stroke();
+
+        context.restore();
+    }
+
+    this.drawLegacyRateCurve = function (rate, rcRate, rcExpo, context, width, height) {
+        // math magic by englishman
+        var rateY = height * rcRate;
+        rateY = rateY + (1 / (1 - ((rateY / height) * rate)))
+
+        // draw
+        context.beginPath();
+        context.moveTo(0, height);
+        context.quadraticCurveTo(width * 11 / 20, height - ((rateY / 2) * (1 - rcExpo)), width, height - rateY);
+        context.stroke();
+    }
+}
+
+RateCurve.prototype.getMaxAngularVel = function (rate, rcRate, rcExpo, superExpoActive) {
+    var maxAngularVel;
+    if (rate !== undefined && rcRate !== undefined && rcExpo !== undefined
+        && !this.useLegacyCurve) {
+        rate = rate * 100;
+	rcRate = rcRate * 100;
+	rcExpo = rcExpo * 100;
+
+        maxAngularVel = this.rcCommandRawToDegreesPerSecond(maxRc, rate, rcRate, rcExpo, superExpoActive);
+    }
+
+    return maxAngularVel;
+}
+
+RateCurve.prototype.draw = function (rate, rcRate, rcExpo, superExpoActive, maxAngularVel, context) {
+    if (rate !== undefined && rcRate !== undefined && rcExpo !== undefined) {
+        var height = context.canvas.height;
+        var width = context.canvas.width;
+
+        if (this.useLegacyCurve) {
+            this.drawLegacyRateCurve(rate, rcRate, rcExpo, context, width, height);
+        } else {
+            this.drawRateCurve(rate, rcRate, rcExpo, superExpoActive, maxAngularVel, context, width, height);
+        }
+    }
+}