fix time up or down

src/workspace/Timestep.cpp

@@ -1,5 +1,7 @@
 #include "workspace/Timestep.h"
 
+#include <algorithm>
+
 #include <QFile>
 #include <QTextStream>
 
@@ -14,6 +16,10 @@ Timestep::Timestep(const std::vector<double>& steps, const QString& path, WorkSp
     , path_(path)
     , workSpace_(parent) {
     maxTime_ = *steps_.rbegin();
+    // 初始化为 1.0x，如果列表中没有 1.0，则取最接近中间的默认索引
+    auto it = std::find(speedLevels_.begin(), speedLevels_.end(), 1.0);
+    speedIndex_ = it != speedLevels_.end() ? int(std::distance(speedLevels_.begin(), it)) : speedIndex_;
+    currentStep_ = speedLevels_[speedIndex_];
 }
 
 Timestep* Timestep::Load(const QString& path, WorkSpace* workSpace) {
@@ -91,6 +97,11 @@ void Timestep::Start() {
         return;
     }
     workSpace_->Begin();
+    // 重置速度为 1x 并通知 UI
+    auto it = std::find(speedLevels_.begin(), speedLevels_.end(), 1.0);
+    speedIndex_ = it != speedLevels_.end() ? int(std::distance(speedLevels_.begin(), it)) : speedIndex_;
+    currentStep_ = speedLevels_[speedIndex_];
+    emit StepChanged(currentStep_);
     emit StatusChanged((int)playStatus_);
 }
 
@@ -123,17 +134,28 @@ void Timestep::Stop() {
         return;
     }
     workSpace_->End();
+    // 停止时也恢复为 1x，避免停后再次播放仍是异常倍率
+    auto it = std::find(speedLevels_.begin(), speedLevels_.end(), 1.0);
+    speedIndex_ = it != speedLevels_.end() ? int(std::distance(speedLevels_.begin(), it)) : speedIndex_;
+    currentStep_ = speedLevels_[speedIndex_];
+    emit StepChanged(currentStep_);
     emit StatusChanged((int)playStatus_);
 }
 
 void Timestep::Up() {
-    currentSpeed *= 2;
-    currentStep_ *= currentSpeed;
-    emit StepChanged(currentSpeed);
+    // 提升到下一个倍率（封顶）
+    if (speedIndex_ < int(speedLevels_.size()) - 1) {
+        ++speedIndex_;
+    }
+    currentStep_ = speedLevels_[speedIndex_];
+    emit StepChanged(currentStep_);
 }
 
 void Timestep::Down() {
-    currentSpeed *= 0.5;
-    currentStep_ *= currentSpeed;
-    emit StepChanged(currentSpeed);
+    // 降到上一个倍率（保底）
+    if (speedIndex_ > 0) {
+        --speedIndex_;
+    }
+    currentStep_ = speedLevels_[speedIndex_];
+    emit StepChanged(currentStep_);
 }

src/workspace/Timestep.h

@@ -43,7 +43,7 @@ public:
 	void Stop();
 
 	void Up();
-	void Down();
+    void Down();
 
 	WorkSpace* GetWorkSpace() const {
 		return workSpace_;
@@ -56,15 +56,18 @@ Q_SIGNALS:
 	
 
 private:
-	std::vector<double> steps_;
-	QString path_;
-	double current_{ 0.0 };
-	double maxTime_{ 0.0 };
-	double currentStep_{ 1.0 };
-	double currentSpeed = { 1.0 };
+    std::vector<double> steps_;
+    QString path_;
+    double current_{ 0.0 };
+    double maxTime_{ 0.0 };
+    // 播放速度（倍率），与 UI 显示一致，比如 0.5x、1x、2x
+    double currentStep_{ 1.0 };
+    // 有限倍率列表，防止无限放大/缩小导致无法恢复
+    std::vector<double> speedLevels_{ 0.25, 0.5, 1.0, 2.0, 4.0, 8.0 };
+    int speedIndex_{ 2 }; // 默认指向 1.0x
 
 	
-	PlayStatus playStatus_{ PlayStatus::PS_Stoped };
-	WorkSpace* workSpace_{ nullptr };
+    PlayStatus playStatus_{ PlayStatus::PS_Stoped };
+    WorkSpace* workSpace_{ nullptr };
 };