klx_teacher/KulexiuForTeacher/KulexiuForTeacher/Common/MediaMerge/AudioMerge/MergeAudioAnimation/KSSpectrumView.m

//
//  KSSpectrumView.m
//  KulexiuSchoolStudent
//
//  Created by 王智 on 2024/7/29.
//

#import "KSSpectrumView.h"

@interface KSSpectrumView ()

@property (nonatomic, strong) CAGradientLayer *combinedGradientLayer;

@end

@implementation KSSpectrumView

- (instancetype)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if (self) {
        [self setupView];
    }
    return self;
}


- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    self = [super initWithCoder:aDecoder];
    if (self) {
        [self setupView];
    }
    return self;
}

- (void)setupView {
    self.barWidth = 3.0;
    self.space = 1.0;

    self.combinedGradientLayer = [CAGradientLayer layer];
    self.combinedGradientLayer.colors = @[
        (__bridge id)HexRGBAlpha(0xffffff, 0.32f).CGColor,
        (__bridge id)HexRGBAlpha(0xffffff, 0.32f).CGColor
    ];
    self.combinedGradientLayer.locations = @[@0.6, @1.0];
    [self.layer addSublayer:self.combinedGradientLayer];
}

- (void)resetLayer {
    self.spectra = [NSArray array];
}

- (void)setSpectra:(NSArray<NSArray<NSNumber *> *> *)spectra {
    _spectra = spectra;
    if (spectra) {
        NSUInteger spectraCount = [spectra[0] count];
        NSMutableArray<NSNumber *> *combinedSpectrum = [NSMutableArray arrayWithCapacity:spectraCount];
        // 取两个声道数据中的最大值
        for (NSUInteger i = 0; i < spectraCount; i++) {
            NSNumber *leftAmplitude = spectra[0][i];
            NSNumber *rightAmplitude = spectra.count > 1 ? spectra[1][i] : @0;
            CGFloat maxAmplitude = MAX(leftAmplitude.floatValue, rightAmplitude.floatValue);
            [combinedSpectrum addObject:@(maxAmplitude)];
        }
        
        CGFloat viewHeight = self.bounds.size.height;
        CGFloat viewWidth = self.bounds.size.width;
        CGFloat middleY = viewHeight / 2.0;
        CGFloat barHeight = (viewHeight) / 2.0;
        CGFloat cornerRadius = viewWidth / 2.0f;
        CGFloat xIncrement = self.barWidth + self.space;
        UIBezierPath *combinedPath = [UIBezierPath bezierPath];

        // Left channel
        for (NSUInteger i = 0; i < spectraCount; i++) {
            CGFloat x = i * xIncrement + self.space;
            CGFloat amplitudeValue = combinedSpectrum[i].floatValue;
            CGFloat height = amplitudeValue * barHeight;
            CGFloat y = middleY - height/2.0; // Centered vertically
            
            CGRect rect = CGRectMake(x, y, self.barWidth, height);
            UIBezierPath *barPath = [UIBezierPath bezierPathWithRoundedRect:rect cornerRadius:cornerRadius];
            [combinedPath appendPath:barPath];
        }
        
        CAShapeLayer *combinedMaskLayer = [CAShapeLayer layer];
        combinedMaskLayer.path = combinedPath.CGPath;
        self.combinedGradientLayer.frame = CGRectMake(0, 0, viewWidth, viewHeight);
        self.combinedGradientLayer.mask = combinedMaskLayer;

    }
}

- (CGFloat)translateAmplitudeToYPosition:(float)amplitude {
    CGFloat barHeight = amplitude * self.bounds.size.height;
    return self.bounds.size.height - barHeight;
}

- (void)dealloc {
    NSLog(@"---- KSSpectrumView dealloc");
}
/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
    // Drawing code
}
*/

@end