feat: detect bass cleff on Guitar Pro 3-5 files (#2483)

Author: Danielku15

packages/alphatab/src/importer/Gp3To5Importer.ts

@@ -37,17 +37,17 @@ import { TripletFeel } from '@coderline/alphatab/model/TripletFeel';
 import { VibratoType } from '@coderline/alphatab/model/VibratoType';
 import { Voice } from '@coderline/alphatab/model/Voice';
 
-import { Logger } from '@coderline/alphatab/Logger';
-import { ModelUtils } from '@coderline/alphatab/model/ModelUtils';
 import type { IWriteable } from '@coderline/alphatab/io/IWriteable';
-import { FadeType } from '@coderline/alphatab/model/FadeType';
-import { Rasgueado } from '@coderline/alphatab/model/Rasgueado';
+import { Logger } from '@coderline/alphatab/Logger';
+import { AccidentalType } from '@coderline/alphatab/model/AccidentalType';
 import { Direction } from '@coderline/alphatab/model/Direction';
-import { BeamDirection } from '@coderline/alphatab/rendering/utils/BeamDirection';
+import { FadeType } from '@coderline/alphatab/model/FadeType';
+import { ModelUtils } from '@coderline/alphatab/model/ModelUtils';
 import { Ottavia } from '@coderline/alphatab/model/Ottavia';
-import { WahPedal } from '@coderline/alphatab/model/WahPedal';
-import { AccidentalType } from '@coderline/alphatab/model/AccidentalType';
+import { Rasgueado } from '@coderline/alphatab/model/Rasgueado';
 import { TremoloPickingEffect } from '@coderline/alphatab/model/TremoloPickingEffect';
+import { WahPedal } from '@coderline/alphatab/model/WahPedal';
+import { BeamDirection } from '@coderline/alphatab/rendering/utils/BeamDirection';
 
 /**
  * @internal
@@ -434,6 +434,11 @@ export class Gp3To5Importer extends ScoreImporter {
         }
     }
 
+    /**
+     * Guitar Pro 3-6 changes to a bass clef if any string tuning is below B2;
+     */
+    private static readonly _bassClefTuningThreshold = ModelUtils.parseTuning('B2')!.realValue;
+
     public readTrack(): void {
         const newTrack: Track = new Track();
         newTrack.ensureStaveCount(1);
@@ -527,10 +532,10 @@ export class Gp3To5Importer extends ScoreImporter {
 
             // `12` for all tunings which have bass clefs
             const clefMode = IOHelper.readInt32LE(this.data);
-            if (clefMode === 12) {
-                this._clefsPerTrack.set(index, Clef.F4);
+            if (clefMode === 12 || tuning[tuning.length - 1] < Gp3To5Importer._bassClefTuningThreshold) {
+                this._clefsPerTrack.set(newTrack.index, Clef.F4);
             } else {
-                this._clefsPerTrack.set(index, Clef.G2);
+                this._clefsPerTrack.set(newTrack.index, Clef.G2);
             }
 
             // Unknown, no UI setting seem to affect this
@@ -570,10 +575,10 @@ export class Gp3To5Importer extends ScoreImporter {
                 GpBinaryHelpers.gpReadStringIntByte(this.data, this.settings.importer.encoding);
             }
         } else {
-            if (GeneralMidi.isBass(newTrack.playbackInfo.program)) {
-                this._clefsPerTrack.set(index, Clef.F4);
+            if (tuning[tuning.length - 1] < Gp3To5Importer._bassClefTuningThreshold) {
+                this._clefsPerTrack.set(newTrack.index, Clef.F4);
             } else {
-                this._clefsPerTrack.set(index, Clef.G2);
+                this._clefsPerTrack.set(newTrack.index, Clef.G2);
             }
         }
     }

packages/alphatab/test-data/guitarpro5/bass-tuning.gp5

@@ -8,6 +8,7 @@ import { TextAlign } from '@coderline/alphatab/platform/ICanvas';
 import { BeamDirection } from '@coderline/alphatab/rendering/utils/BeamDirection';
 import { GpImporterTestHelper } from 'test/importer/GpImporterTestHelper';
 import { expect } from 'chai';
+import { Clef } from '@coderline/alphatab/model/Clef';
 
 describe('Gp5ImporterTest', () => {
     it('score-info', async () => {
@@ -544,4 +545,12 @@ describe('Gp5ImporterTest', () => {
         expect(score.tracks[1].playbackInfo.program).to.equal(25);
         expect(score.tracks[1].playbackInfo.bank).to.equal(77);
     });
+
+    it('tuning-bass-clef', async () => {
+        const score = (await GpImporterTestHelper.prepareImporterWithFile('guitarpro5/bass-tuning.gp5')).readScore();
+        expect(score.tracks[0].staves[0].bars[0].clef).to.equal(Clef.F4);
+        expect(score.tracks[1].staves[0].bars[0].clef).to.equal(Clef.F4);
+        expect(score.tracks[2].staves[0].bars[0].clef).to.equal(Clef.F4);
+        expect(score.tracks[3].staves[0].bars[0].clef).to.equal(Clef.F4);
+    });
 });

packages/alphatab/test/importer/Gp5Importer.test.ts

@@ -152,10 +152,41 @@ export default abstract class AstPrinterBase {
             d.isStatic &&
             !d.setAccessor &&
             cs.isPrimitiveTypeNode(d.type) &&
-            !!d.initializer &&
+            this._isConstantExpression(d.initializer) &&
             (!d.getAccessor || !d.getAccessor.body)
         );
     }
+    private _isConstantExpression(expression: cs.Expression | undefined): boolean {
+        if (expression === undefined) {
+            return false;
+        }
+
+        switch (expression.nodeType) {
+            case cs.SyntaxKind.PrefixUnaryExpression:
+                return this._isConstantExpression((expression as cs.PrefixUnaryExpression).operand);
+            case cs.SyntaxKind.PostfixUnaryExpression:
+                return this._isConstantExpression((expression as cs.PostfixUnaryExpression).operand);
+            case cs.SyntaxKind.NullLiteral:
+            case cs.SyntaxKind.TrueLiteral:
+            case cs.SyntaxKind.FalseLiteral:
+            case cs.SyntaxKind.StringLiteral:
+            case cs.SyntaxKind.NumericLiteral:
+            case cs.SyntaxKind.DefaultExpression:
+                return true;
+            case cs.SyntaxKind.BinaryExpression:
+                return (
+                    this._isConstantExpression((expression as cs.BinaryExpression).left) &&
+                    this._isConstantExpression((expression as cs.BinaryExpression).right)
+                );
+            case cs.SyntaxKind.ParenthesizedExpression:
+                return this._isConstantExpression((expression as cs.ParenthesizedExpression).expression);
+            // case cs.SyntaxKind.MemberAccessExpression:
+            // case cs.SyntaxKind.Identifier:
+            // maybe detect enums and other constant declarations?
+        }
+
+        return false;
+    }
 
     protected writePropertyAsField(d: cs.PropertyDeclaration) {
         if (