添加等速弹幕的功能

OCBarrage/OCBarrage/OCBarrageDescriptor.h

@@ -17,7 +17,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 @property (nonatomic, assign, nullable) Class barrageCellClass;
 @property (nonatomic, assign) OCBarragePositionPriority positionPriority;//显示位置normal型的渲染在low型的上面, height型的渲染在normal上面
-@property (nonatomic, assign) CGFloat animationDuration;
+@property (nonatomic, assign) CGFloat animationDuration;//动画时间, 时间越长速度越慢, 时间越短速度越快
+@property (nonatomic, assign) CGFloat fixedSpeed;//固定速度, 可以防止弹幕在有空闲轨道的情况下重叠, 取值0.0~100.0, animationDuration与fixedSpeed只能选择一个, fixedSpeed设置之后可以不用设置animationDuration
 
 @property (nonatomic, copy, nullable) OCBarrageTouchAction touchAction DEPRECATED_MSG_ATTRIBUTE("use OCBarrageCellTouchedAction instead");
 @property (nonatomic, copy, nullable) OCBarrageCellTouchedAction cellTouchedAction;//新属性里回传了被点击的cell, 可以在代码块里更改被点击的cell的属性, 比如之前有用户需要在弹幕被点击的时候修改被点击的弹幕的文字颜色等等. 用来替代旧版本的touchAction
@@ -27,7 +28,6 @@ NS_ASSUME_NONNULL_BEGIN
 
 @property (nonatomic, assign) NSRange renderRange;//渲染范围, 最终渲染出来的弹幕的Y坐标最小不小于renderRange.location, 最大不超过renderRange.length-barrageCell.height
 
-
 @end
 
 NS_ASSUME_NONNULL_END

OCBarrage/OCBarrage/OCBarrageTextCell.m

@@ -62,10 +62,18 @@ - (void)addBarrageAnimationWithDelegate:(id<CAAnimationDelegate>)animationDelega
     CGPoint startCenter = CGPointMake(CGRectGetMaxX(self.superview.bounds) + CGRectGetWidth(self.bounds)/2, self.center.y);
     CGPoint endCenter = CGPointMake(-(CGRectGetWidth(self.bounds)/2), self.center.y);
 
+    CGFloat animationDuration = self.barrageDescriptor.animationDuration;
+    if (self.barrageDescriptor.fixedSpeed > 0.0) {//如果是固定速度那就用固定速度
+        if (self.barrageDescriptor.fixedSpeed > 100.0) {
+            self.barrageDescriptor.fixedSpeed = 100.0;
+        }
+        animationDuration = (startCenter.x - endCenter.x)/([UIScreen mainScreen].scale*2)/self.barrageDescriptor.fixedSpeed;
+    }
+
     CAKeyframeAnimation *walkAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"];
     walkAnimation.values = @[[NSValue valueWithCGPoint:startCenter], [NSValue valueWithCGPoint:endCenter]];
     walkAnimation.keyTimes = @[@(0.0), @(1.0)];
-    walkAnimation.duration = self.barrageDescriptor.animationDuration;
+    walkAnimation.duration = animationDuration;
     walkAnimation.repeatCount = 1;
     walkAnimation.delegate =  animationDelegate;
     walkAnimation.removedOnCompletion = NO;

OCBarrage/ViewController.m

@@ -94,7 +94,7 @@ - (void)viewDidDisappear:(BOOL)animated {
 
 - (void)addBarrage {
     [self performSelector:@selector(addNormalBarrage) withObject:nil afterDelay:0.5];
-    [self performSelector:@selector(addGradientBackgroundColorBarrage) withObject:nil afterDelay:0.5];
+    [self performSelector:@selector(addFixedSpeedAnimationCell) withObject:nil afterDelay:0.5];//添加等速的弹幕, 等速弹幕速度相同不会重叠
     [self performSelector:@selector(addWalkBannerBarrage) withObject:nil afterDelay:0.5];
     [self performSelector:@selector(addStopoverBarrage) withObject:nil afterDelay:0.5];
     [self performSelector:@selector(addMixedImageAndTextBarrage) withObject:nil afterDelay:0.5];
@@ -120,21 +120,21 @@ - (void)addNormalBarrage {
     [self performSelector:@selector(addNormalBarrage) withObject:nil afterDelay:0.25];
 }
 
-- (void)addGradientBackgroundColorBarrage {
+- (void)addFixedSpeedAnimationCell {
     OCBarrageGradientBackgroundColorDescriptor *gradientBackgroundDescriptor = [[OCBarrageGradientBackgroundColorDescriptor alloc] init];
-    gradientBackgroundDescriptor.text = [NSString stringWithFormat:@"~全民直播~"];
+    gradientBackgroundDescriptor.text = [NSString stringWithFormat:@"~等速弹幕~"];
     gradientBackgroundDescriptor.textColor = [UIColor whiteColor];
     gradientBackgroundDescriptor.positionPriority = OCBarragePositionLow;
     gradientBackgroundDescriptor.textFont = [UIFont systemFontOfSize:17.0];
     gradientBackgroundDescriptor.strokeColor = [[UIColor blackColor] colorWithAlphaComponent:0.3];
     gradientBackgroundDescriptor.strokeWidth = -1;
-    gradientBackgroundDescriptor.animationDuration = arc4random()%5 + 5;
+    gradientBackgroundDescriptor.fixedSpeed = 50.0;//用fixedSpeed属性设定速度
     gradientBackgroundDescriptor.barrageCellClass = [OCBarrageGradientBackgroundColorCell class];
     gradientBackgroundDescriptor.gradientColor = kRandomColor;
 
     [self.barrageManager renderBarrageDescriptor:gradientBackgroundDescriptor];
 
-    [self performSelector:@selector(addGradientBackgroundColorBarrage) withObject:nil afterDelay:0.5];
+    [self performSelector:@selector(addFixedSpeedAnimationCell) withObject:nil afterDelay:0.5];
 }
 
 - (void)addWalkBannerBarrage {