Added not finished air breaks

doc/links.md

@@ -47,6 +47,7 @@ Following list of external sources was used to develop this application and can
   * <https://decodoppler.wordpress.com/2012/08/02/air-breaks-what-are-they-and-do-people-take-them-for-the-wrong-reason/>
   * <https://www.diverite.com/uncategorized/oxygen-toxicity-and-ccr-rebreather-diving/>
   * <https://www.diverite.com/articles/oxygen-toxicity-signs-and-symptoms/>
+  * <https://www.diverite.com/uncategorized/oxygen-toxicity-and-ccr-rebreather-diving/>
   * Diverite and decodopler: 20min./5 min.
 * Gas blender
   * https://github.com/atdotde/realblender

doc/roadmap.md

@@ -12,6 +12,8 @@ Following list of features and improvements ordered by priority is under develop
 
 ## Improvements / Features
 
+* TRIMIX support
+    * Add air breaks
 * Gas blender:
   * Add use case to identify mix when adding only top mix without adding he or oxygen
 * Fix PWA issues https://www.pwabuilder.com/
@@ -34,8 +36,6 @@ Following list of features and improvements ordered by priority is under develop
     * [Z factor](https://www.divegearexpress.com/library/articles/calculating-scuba-cylinder-capacities)
     * <https://youtu.be/OI4ZzqJLQjw>
 * Add undo/redo to all pages
-* TRIMIX support
-  * Add air breaks
 * Add CCR support
 * Add localizations
 * Add calculation trainings

projects/scuba-physics/src/lib/AlgorithmContext.ts

@@ -8,6 +8,7 @@ import { Segment, Segments } from './Segments';
 import { Options } from './Options';
 import { DepthConverter } from './depth-converter';
 import { Time } from './Time';
+import { StandardGases } from './StandardGases';
 
 export interface ContextMemento {
     tissues: Tissue[];
@@ -20,9 +21,10 @@ export interface ContextMemento {
 export class AlgorithmContext {
     public tissues: Tissues;
     public ceilings: Ceiling[] = [];
-    public currentGas: Gas;
     /** in seconds */
     public runTime = 0;
+    private _oxygenStarted = 0;
+    private _currentGas: Gas;
     private gradients: GradientFactors;
     private bestGasOptions: BestGasOptions;
     private speeds: AscentSpeeds;
@@ -39,7 +41,7 @@ export class AlgorithmContext {
         // this.gradients = new SimpleGradientFactors(depthConverter, options, this.tissues, this.segments);
         this.gradients = new SubSurfaceGradientFactors(depthConverter, options, this.tissues);
         const last = segments.last();
-        this.currentGas = last.gas;
+        this._currentGas = last.gas;
 
         this.bestGasOptions = {
             currentDepth: this.currentDepth,
@@ -54,6 +56,10 @@ export class AlgorithmContext {
         this.gasSource = new OCGasSource(gases, options);
     }
 
+    public get currentGas(): Gas {
+        return this._currentGas;
+    }
+
     public get ascentSpeed(): number {
         return this.speeds.ascent(this.currentDepth);
     }
@@ -62,10 +68,6 @@ export class AlgorithmContext {
         return this.segments.currentDepth;
     }
 
-    public get ambientPressure(): number {
-        return this.depthConverter.toBar(this.currentDepth);
-    }
-
     public get addSafetyStop(): boolean {
         return this.levels.addSafetyStop(this.currentDepth, this.segments.maxDepth);
     }
@@ -78,6 +80,23 @@ export class AlgorithmContext {
         return this.segments.last().endDepth === 0;
     }
 
+    public get runTimeOnOxygen(): number {
+        return this.runTime - this._oxygenStarted;
+    }
+
+    public get isBreathingOxygen(): boolean {
+        // Correct is to compare ppO2 >= 1.3, but it may happen also on deep stops, which we want to avoid
+        return this.currentGas.compositionEquals(StandardGases.oxygen);
+    }
+
+    public set currentGas(newValue: Gas) {
+        this._currentGas = newValue;
+
+        if (newValue.compositionEquals(StandardGases.oxygen)) {
+            this._oxygenStarted = this.runTime;
+        }
+    }
+
     /** use this just before calculating ascent to be able calculate correct speeds */
     public markAverageDepth(): void {
         this.speeds.markAverageDepth(this.segments);

projects/scuba-physics/src/lib/BuhlmannAlgorithm.airbreaks.spec.ts

@@ -140,4 +140,5 @@ xdescribe('Buhlmann Algorithm - Air breaks', () => {
     // behavior notes:
     // * safety stop is also counted to the air break
     // TODO add warning if unable to switch to air break if back gas not breathable at 6m
+    // TODO add test for small depths without deco, but with oxygen - shouldn't add air break
 });

projects/scuba-physics/src/lib/BuhlmannAlgorithm.ts

@@ -151,7 +151,6 @@ export class BuhlmannAlgorithm {
         while (nextStop >= 0 && !context.isAtSurface) {
             // Next steps need to be in this order
             this.tryGasSwitch(context); // multiple gas switches may happen before first deco stop
-            // TODO add air breaks - https://www.diverite.com/uncategorized/oxygen-toxicity-and-ccr-rebreather-diving/
             this.stayAtDecoStop(context, nextStop);
             this.stayAtSafetyStop(context);
             this.ascentToNextStop(context, nextStop);
@@ -229,12 +228,31 @@ export class BuhlmannAlgorithm {
             // the algorithm returns lowest value, so the last second where the deco isn't enough
             // so we need to add one more second to be safe and adjust it to the required rounding
             const stopDuration = interval.search(searchContext) + Time.oneSecond;
-            const rounded = Precision.ceilDistance(stopDuration, context.decoStopDuration);
-            this.swimDecoStop(context, memento, rounded);
-            // we don't restore last search iteration, we keep the deco stop segment
+            const roundedStopDuration = Precision.ceilDistance(stopDuration, context.decoStopDuration);
+
+            if(context.isBreathingOxygen) {
+                // TODO this.swimOxygenStop(context, roundedStopDuration);
+                this.swimDecoStop(context, memento, roundedStopDuration);
+            } else {
+                // we don't restore last search iteration, we keep the deco stop segment
+                this.swimDecoStop(context, memento, roundedStopDuration);
+            }
         }
     }
 
+    /** Includes air breaks */
+    private swimOxygenStop(context: AlgorithmContext, totalStopDuration: number): void {
+        // TODO apply settings for air breaks
+        // TODO air breaks prolong the deco, so we need to adjust the stop duration,
+        // but we want to avoid another stop estimation, because it is performance heavy
+        // easy solution is to use recursion and call the stayAtDecoStop once again
+        const remainingOxygenTime = totalStopDuration - context.runTimeOnOxygen;
+        const stopDuration = remainingOxygenTime > 0 ? remainingOxygenTime : 20;
+        const decoStop = context.addDecoStopSegment();
+        decoStop.duration = stopDuration;
+        this.swim(context, decoStop);
+    }
+
     private swimDecoStop(context: AlgorithmContext, memento: ContextMemento, stopDuration: number): void {
         context.restore(memento);
         const decoStop = context.addDecoStopSegment();