Make preset transitions use TimeKeeper instead of the system clock

src/libprojectM/ProjectM.cpp

@@ -150,7 +150,7 @@ void ProjectM::RenderFrame(uint32_t targetFramebufferObject /*= 0*/)
 
     if (m_transition != nullptr && m_transitioningPreset != nullptr)
     {
-        if (m_transition->IsDone())
+        if (m_transition->IsDone(m_timeKeeper->GetFrameTime()))
         {
             m_activePreset = std::move(m_transitioningPreset);
             m_transitioningPreset.reset();
@@ -170,7 +170,7 @@ void ProjectM::RenderFrame(uint32_t targetFramebufferObject /*= 0*/)
 
     if (m_transition != nullptr && m_transitioningPreset != nullptr)
     {
-        m_transition->Draw(*m_activePreset, *m_transitioningPreset, renderContext, audioData);
+        m_transition->Draw(*m_activePreset, *m_transitioningPreset, renderContext, audioData, m_timeKeeper->GetFrameTime());
     }
     else
     {
@@ -254,7 +254,7 @@ void ProjectM::StartPresetTransition(std::unique_ptr<Preset>&& preset, bool hard
     {
         m_transitioningPreset = std::move(preset);
         m_timeKeeper->StartSmoothing();
-        m_transition = std::make_unique<Renderer::PresetTransition>(m_transitionShaderManager->RandomTransition(), m_softCutDuration);
+        m_transition = std::make_unique<Renderer::PresetTransition>(m_transitionShaderManager->RandomTransition(), m_softCutDuration, m_timeKeeper->GetFrameTime());
     }
 }
 

src/libprojectM/Renderer/PresetTransition.cpp

@@ -11,9 +11,10 @@ namespace Renderer {
 
 constexpr double PI = 3.14159265358979323846;
 
-PresetTransition::PresetTransition(const std::shared_ptr<Shader>& transitionShader, double durationSeconds)
+PresetTransition::PresetTransition(const std::shared_ptr<Shader>& transitionShader, double durationSeconds, double transitionStartTime)
     : m_transitionShader(transitionShader)
     , m_durationSeconds(durationSeconds)
+    , m_transitionStartTime(transitionStartTime)
 {
     std::mt19937 rand32(m_randomDevice());
     m_staticRandomValues = {rand32(), rand32(), rand32(), rand32()};
@@ -33,19 +34,18 @@ void PresetTransition::InitVertexAttrib()
     glBufferData(GL_ARRAY_BUFFER, sizeof(points), points.data(), GL_STATIC_DRAW);
 }
 
-auto PresetTransition::IsDone() const -> bool
+auto PresetTransition::IsDone(double currentFrameTime) const -> bool
 {
-    const auto secondsSinceStart = std::chrono::duration<double>(std::chrono::system_clock::now() - m_transitionStartTime).count();
+    const auto secondsSinceStart = currentFrameTime - m_transitionStartTime;
     return m_durationSeconds <= 0.0 || secondsSinceStart >= m_durationSeconds;
 }
 
 void PresetTransition::Draw(const Preset& oldPreset,
                             const Preset& newPreset,
                             const RenderContext& context,
-                            const libprojectM::Audio::FrameAudioData& audioData)
+                            const libprojectM::Audio::FrameAudioData& audioData,
+                            double currentFrameTime)
 {
-    using namespace std::chrono_literals;
-
     if (m_transitionShader == nullptr)
     {
         return;
@@ -54,7 +54,7 @@ void PresetTransition::Draw(const Preset& oldPreset,
     std::mt19937 rand32(m_randomDevice());
 
     // Calculate progress values
-    const auto secondsSinceStart = std::chrono::duration<double>(std::chrono::system_clock::now() - m_transitionStartTime).count();
+    const auto secondsSinceStart = currentFrameTime - m_transitionStartTime;
 
     // If duration is zero,
     double linearProgress{1.0};
@@ -81,7 +81,7 @@ void PresetTransition::Draw(const Preset& oldPreset,
                                                             m_durationSeconds});
 
     m_transitionShader->SetUniformFloat2("timeParams", {secondsSinceStart,
-                                                        std::chrono::duration<float>(std::chrono::system_clock::now() - m_lastFrameTime).count()});
+                                                        currentFrameTime - m_lastFrameTime});
 
     m_transitionShader->SetUniformInt4("iRandStatic", m_staticRandomValues);
 
@@ -130,7 +130,7 @@ void PresetTransition::Draw(const Preset& oldPreset,
     Shader::Unbind();
 
     // Update last frame time.
-    m_lastFrameTime = std::chrono::system_clock::now();
+    m_lastFrameTime = currentFrameTime;
 }
 
 } // namespace Renderer

src/libprojectM/Renderer/PresetTransition.hpp

@@ -8,7 +8,6 @@
 
 #include <glm/glm.hpp>
 
-#include <chrono>
 #include <random>
 
 namespace libprojectM {
@@ -22,27 +21,38 @@ class PresetTransition : public RenderItem
 public:
     PresetTransition() = delete;
 
-    explicit PresetTransition(const std::shared_ptr<Shader>& transitionShader, double durationSeconds);
+    /**
+     * Constructor.
+     * @param transitionShader The transition shader program.
+     * @param durationSeconds Transition duration in seconds.
+     * @param transitionStartTime The time in seconds since start of projectM.
+     */
+    explicit PresetTransition(const std::shared_ptr<Shader>& transitionShader,
+                              double durationSeconds,
+                              double transitionStartTime);
 
     void InitVertexAttrib() override;
 
     /**
      * @brief Returns true if the transition is done.
+     * @param currentFrameTime The time in seconds since start of the current frame.
      * @return false if the transition is still in progress, true if it's done.
      */
-    auto IsDone() const -> bool;
+    auto IsDone(double currentFrameTime) const -> bool;
 
     /**
      * @brief Updates the transition variables and renders the shader quad to the current FBO.
      * @param oldPreset A reference to the old (fading out) preset.
      * @param newPreset A reference to the new (fading in) preset.
      * @param context The rendering context used to render the presets.
      * @param audioData Current audio data and beat detection values.
+     * @param currentFrameTime The time in seconds since start of the current frame.
      */
     void Draw(const Preset& oldPreset,
               const Preset& newPreset,
               const RenderContext& context,
-              const libprojectM::Audio::FrameAudioData& audioData);
+              const libprojectM::Audio::FrameAudioData& audioData,
+              double currentFrameTime);
 
 private:
     std::vector<std::string> m_noiseTextureNames{"noise_lq",
@@ -59,9 +69,9 @@ class PresetTransition : public RenderItem
     std::shared_ptr<Shader> m_transitionShader;                                                       //!< The compiled shader used for this transition.
     std::shared_ptr<Sampler> m_presetSampler{std::make_shared<Sampler>(GL_CLAMP_TO_EDGE, GL_LINEAR)}; //!< Sampler for preset textures. Uses bilinear interpolation and no repeat.
 
-    double m_durationSeconds{3.0};                                                                              //!< Transition duration in seconds.
-    std::chrono::time_point<std::chrono::system_clock> m_transitionStartTime{std::chrono::system_clock::now()}; //!< Start time of this transition. Duration is measured from this point.
-    std::chrono::time_point<std::chrono::system_clock> m_lastFrameTime{std::chrono::system_clock::now()};       //!< Time when the previous frame was rendered.
+    double m_durationSeconds{3.0};  //!< Transition duration in seconds.
+    double m_transitionStartTime{}; //!< Start time of this transition. Duration is measured from this point.
+    double m_lastFrameTime{};       //!< Time when the previous frame was rendered.
 
     glm::ivec4 m_staticRandomValues{}; //!< Four random integers, remaining static during the whole transition.