Now have a timer for animations that does ticks with deltatime...maybe it works.

animate2.cpp

@@ -76,6 +76,38 @@ namespace animate2 {
     $transform.lerp($sequence, pos, scale);
   }
 
+  void Timer::start() {
+    clock.start();
+  }
+
+  void Timer::reset() {
+    clock.reset();
+  }
+
+  void Timer::restart() {
+    clock.restart();
+  }
+
+  sf::Time Timer::getElapsedTime() {
+    return clock.getElapsedTime();
+  }
+
+  void Timer::begin() {
+    prev_time = clock.getElapsedTime().asSeconds();
+  }
+
+  std::pair<int, double> Timer::commit() {
+    current_time = clock.getElapsedTime().asSeconds();
+    frame_duration = current_time - prev_time;
+    accumulator += frame_duration;
+
+    double tick_count = accumulator / DELTA;
+    double alpha = modf(tick_count, &tick_count);
+    accumulator -= tick_count * DELTA;
+
+    return {int(tick_count), alpha};
+  }
+
   float Transform::twitching(Sequence& seq) {
     float tick = 1 - std::powf(ease_rate, seq.subframe + 0.0001);
     return easing(tick);

animate2.hpp

@@ -7,6 +7,7 @@
 #include <SFML/System/Time.hpp>
 #include <functional>
 #include "ease2.hpp"
+#include <fmt/core.h>
 
 namespace animate2 {
   struct Sheet {
@@ -16,13 +17,30 @@ namespace animate2 {
     int frame_height{0};
   };
 
+  struct Timer {
+    double DELTA = 1.0/60.0;
+    double accumulator = 0.0;
+    double prev_time = 0.0;
+    double current_time = 0.0;
+    double frame_duration = 0.0;
+    double alpha = 0.0;
+    sf::Clock clock{};
+
+    void begin();
+    std::pair<int, double> commit();
+    void start();
+    void reset();
+    void restart();
+    sf::Time getElapsedTime();
+  };
+
   struct Sequence {
     std::vector<int> frames{};
     std::vector<std::chrono::milliseconds> durations{};
     size_t current{0};
     int loop_count{0};
     size_t frame_count{frames.size()};
-    sf::Clock timer{};
+    Timer timer{};
     float subframe{0.0f};
   };
 

simplefsm.hpp

@@ -5,7 +5,7 @@
 #ifndef FSM_DEBUG
 #define FSM_STATE(C, S, E, ...) case C::S: S(E, ##__VA_ARGS__); break
 #else
-int last_event=-1;
+static int last_event=-1;
 #define FSM_STATE(C, S, E, ...) case C::S: if(last_event != int(E)) { last_event = int(E); fmt::println(">> " #C " " #S " event={}, state={}", int(E), int($state));}; S(E, ##__VA_ARGS__); break
 #endif
 

tests/animate2.cpp

@@ -51,12 +51,16 @@ Animate2 crafter() {
   return {sheet, sequence, transform};
 }
 
+void FAKE_RENDER() {
+  std::this_thread::sleep_for(Random::milliseconds(5, 32));
+}
+
 void PLAY_TEST(Animate2 &anim) {
   anim.play();
 
   while(anim.playing) {
     anim.update();
-    std::this_thread::sleep_for(Random::milliseconds(1, 100));
+    FAKE_RENDER();
   }
 
   REQUIRE(anim.playing == false);
@@ -114,6 +118,7 @@ TEST_CASE("new animation system", "[animation-new]") {
   };
 }
 
+
 TEST_CASE("confirm frame sequencing works", "[animation-new]") {
   textures::init();
   animation::init();
@@ -165,15 +170,37 @@ TEST_CASE("confirm transition changes work", "[animation-new]") {
 
   anim.play();
 
+  sf::Clock clock;
+  clock.start();
+  sf::Time start;
+  sf::Time delta;
+
+
   while(anim.playing) {
+    start = clock.getElapsedTime();
+
     anim.update();
     anim.motion(pos, scale);
     std::this_thread::sleep_for(10ms);
     fmt::println("POSITION: {},{}; SCALE: {},{}; current: {}; subframe: {}",
         pos.x, pos.y, scale.x, scale.y, anim.$sequence.current, anim.$sequence.subframe);
+
+    delta = clock.getElapsedTime() - start;
+    fmt::println("FRAME RATE {}", 1.0f / delta.asSeconds());
   }
 
   REQUIRE(anim.playing == false);
   REQUIRE(pos != sf::Vector2f{0,0});
   REQUIRE(scale != sf::Vector2f{0,0});
 }
+
+TEST_CASE("playing with delta time", "[animation-new]") {
+  animate2::Timer timer;
+
+  for(int i = 0; i < 20; i++) {
+    timer.begin();
+    FAKE_RENDER();
+    auto [tick_count, alpha] = timer.commit();
+    fmt::println("tick: {}, alpha: {}", tick_count, alpha);
+  }
+}

tools/animator.cpp

@@ -1,3 +1,4 @@
+#define FSM_DEBUG 1
 #include "sound.hpp"
 #include "ai.hpp"
 #include "animation.hpp"
@@ -11,6 +12,9 @@
 #include <guecs/ui.hpp>
 #include "gui/event_router.hpp"
 #include "gui/guecstra.hpp"
+#include "animate2.hpp"
+
+bool YES_SYNC=true;
 
 namespace animator {
   struct UI {
@@ -53,6 +57,7 @@ namespace animator {
 
   enum class State {
     START=__LINE__,
+    ANIMATE=__LINE__,
     END=__LINE__,
   };
 
@@ -63,21 +68,42 @@ namespace animator {
 
     void init(const std::string &sprite_name) {
       $ui.init(sprite_name);
+
+      if(YES_SYNC) {
         $window.setVerticalSyncEnabled(VSYNC);
         if(FRAME_LIMIT) $window.setFramerateLimit(FRAME_LIMIT);
+      }
+
       $window.setPosition({0,0});
     }
 
     void event(game::Event ev, std::any data={}) {
       switch($state) {
         FSM_STATE(State, START, ev);
+        FSM_STATE(State, ANIMATE, ev);
         FSM_STATE(State, END, ev);
       }
     }
 
     void START(game::Event ev) {
+      switch(ev) {
+        case game::Event::TICK:
+          state(State::ANIMATE);
+          break;
+        default:
           state(State::START);
       }
+    }
+
+    void ANIMATE(game::Event ev) {
+      switch(ev) {
+        case game::Event::TICK:
+          // stuff
+          break;
+        default:
+          state(State::START);
+      }
+    }
 
     void END(game::Event ev) {
     }
@@ -132,8 +158,20 @@ int main(int argc, char* argv[]) {
   animator::FSM main;
   main.init(argv[1]);
 
+  animate2::Timer timer;
+  timer.start();
+
   while(main.active()) {
+    timer.begin();
     main.render();
+    auto [ticks, alpha] = timer.commit();
+    fmt::println("TICK: {}, alpha: {}", ticks, alpha);
+
+    for(int i = 0; i < ticks; i++) {
+      main.event(game::Event::TICK, {});
+    }
+
+    // do something with alpha....
     main.handle_keyboard_mouse();
   }