forked from jaildesigner-jailgames/jaildoctors_dilemma
39 lines
1.2 KiB
C++
39 lines
1.2 KiB
C++
#include "utils/delta_timer.hpp"
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DeltaTimer::DeltaTimer() noexcept
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: last_counter_(SDL_GetPerformanceCounter()),
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perf_freq_(static_cast<double>(SDL_GetPerformanceFrequency())),
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time_scale_(1.0F) {
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}
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auto DeltaTimer::tick() noexcept -> float {
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const Uint64 NOW = SDL_GetPerformanceCounter();
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const Uint64 DIFF = (NOW > last_counter_) ? (NOW - last_counter_) : 0;
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last_counter_ = NOW;
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const double SECONDS = static_cast<double>(DIFF) / perf_freq_;
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return static_cast<float>(SECONDS * static_cast<double>(time_scale_));
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}
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auto DeltaTimer::peek() const noexcept -> float {
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const Uint64 NOW = SDL_GetPerformanceCounter();
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const Uint64 DIFF = (NOW > last_counter_) ? (NOW - last_counter_) : 0;
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const double SECONDS = static_cast<double>(DIFF) / perf_freq_;
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return static_cast<float>(SECONDS * static_cast<double>(time_scale_));
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}
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void DeltaTimer::reset(Uint64 counter) noexcept {
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if (counter == 0) {
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last_counter_ = SDL_GetPerformanceCounter();
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} else {
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last_counter_ = counter;
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}
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}
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void DeltaTimer::setTimeScale(float scale) noexcept {
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time_scale_ = std::max(scale, 0.0F);
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}
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auto DeltaTimer::getTimeScale() const noexcept -> float {
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return time_scale_;
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}
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