diff options
Diffstat (limited to 'src/crepe/api/LoopTimer.cpp')
-rw-r--r-- | src/crepe/api/LoopTimer.cpp | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/src/crepe/api/LoopTimer.cpp b/src/crepe/api/LoopTimer.cpp new file mode 100644 index 0000000..8f09e41 --- /dev/null +++ b/src/crepe/api/LoopTimer.cpp @@ -0,0 +1,86 @@ +#include <chrono> + +#include "../facade/SDLContext.h" +#include "../util/log.h" + +#include "LoopTimer.h" + +using namespace crepe; + +LoopTimer::LoopTimer() { dbg_trace(); } + +LoopTimer & LoopTimer::get_instance() { + static LoopTimer instance; + return instance; +} + +void LoopTimer::start() { + this->last_frame_time = std::chrono::steady_clock::now(); + this->elapsed_time = std::chrono::milliseconds(0); + this->elapsed_fixed_time = std::chrono::milliseconds(0); + this->delta_time = std::chrono::milliseconds(0); +} + +void LoopTimer::update() { + auto current_frame_time = std::chrono::steady_clock::now(); + // Convert to duration in seconds for delta time + this->delta_time + = std::chrono::duration_cast<std::chrono::duration<double>>( + current_frame_time - last_frame_time); + + if (this->delta_time > this->maximum_delta_time) { + this->delta_time = this->maximum_delta_time; + } + + this->delta_time *= this->game_scale; + this->elapsed_time += this->delta_time; + this->last_frame_time = current_frame_time; +} + +double LoopTimer::get_delta_time() const { return this->delta_time.count(); } + +double LoopTimer::get_current_time() const { + return this->elapsed_time.count(); +} + +void LoopTimer::advance_fixed_update() { + this->elapsed_fixed_time += this->fixed_delta_time; +} + +double LoopTimer::get_fixed_delta_time() const { + return this->fixed_delta_time.count(); +} + +void LoopTimer::set_fps(int fps) { + this->fps = fps; + // target time per frame in seconds + this->frame_target_time = std::chrono::seconds(1) / fps; +} + +int LoopTimer::get_fps() const { return this->fps; } + +void LoopTimer::set_game_scale(double value) { this->game_scale = value; } + +double LoopTimer::get_game_scale() const { return this->game_scale; } +void LoopTimer::enforce_frame_rate() { + std::chrono::steady_clock::time_point current_frame_time + = std::chrono::steady_clock::now(); + std::chrono::milliseconds frame_duration + = std::chrono::duration_cast<std::chrono::milliseconds>( + current_frame_time - this->last_frame_time); + + if (frame_duration < this->frame_target_time) { + std::chrono::milliseconds delay_time + = std::chrono::duration_cast<std::chrono::milliseconds>( + this->frame_target_time - frame_duration); + if (delay_time.count() > 0) { + SDLContext::get_instance().delay(delay_time.count()); + } + } + + this->last_frame_time = current_frame_time; +} + +double LoopTimer::get_lag() const { + return (this->elapsed_time - this->elapsed_fixed_time).count(); +} |