animation.h

/* *   Copyright (c) 2011-2017 Luke Benstead https://simulant-engine.appspot.com
 *
 *     This file is part of Simulant.
 *
 *     Simulant is free software: you can redistribute it and/or modify
 *     it under the terms of the GNU Lesser General Public License as published by
 *     the Free Software Foundation, either version 3 of the License, or
 *     (at your option) any later version.
 *
 *     Simulant is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU Lesser General Public License for more details.
 *
 *     You should have received a copy of the GNU Lesser General Public License
 *     along with Simulant.  If not, see <http://www.gnu.org/licenses/>.
 */
 
#pragma once
 
#include <cmath>
#include <unordered_map>
#include <memory>
#include <vector>
#include <string>
#include "signals/signal.h"
#include "utils/throttle.h"
 
namespace smlt {
 
struct AnimationSequenceStage {
    std::string animation_name;
    float duration;
};
 
class KeyFrameAnimated;
 
typedef sig::signal<void (KeyFrameAnimated*, const std::string&)> SignalAnimationAdded;
 
class KeyFrameAnimated {
    DEFINE_SIGNAL(SignalAnimationAdded, signal_animation_added);
public:
    virtual ~KeyFrameAnimated() {}
 
    void add_sequence(const std::string& name, const std::vector<AnimationSequenceStage>& stages);
    void add_animation(const std::string& name, uint32_t start_frame, uint32_t end_frame, float fps);
    void add_animation(const std::string& name, uint32_t start_frame, uint32_t end_frame);
 
    bool has_animations() const { return !animations_.empty(); }
    std::size_t animation_count() const { return animations_.size(); }
 
    void set_default_fps(float fps);
    float default_fps() const;
protected:
    //Animation stuff
    friend class KeyFrameAnimationState;
 
    struct Animation {
        Animation():
            duration(0) {}
 
        Animation(float duration, uint32_t start, uint32_t end):
            duration(duration),
            frames(std::make_pair(start, end)) {}
 
        float duration;
        std::pair<uint32_t, uint32_t> frames;
    };
 
    typedef std::unordered_map<std::string, std::shared_ptr<Animation> > AnimationMap;
    AnimationMap animations_;
    std::string first_animation_;
 
    Animation* animation(const std::string& name) {
        auto it = animations_.find(name);
        if(it == animations_.end()) return nullptr;
 
        return (*it).second.get();
    }
 
private:
    float default_fps_ = 7.0f;  // This is a common frame rate on MD2 models
};
 
// args: current_frame, next_frame, interp
typedef std::function<void (int32_t, int32_t, float)> AnimationUpdatedCallback;
 
class KeyFrameAnimationState {
public:
    KeyFrameAnimationState(
        KeyFrameAnimated* animatable,
        AnimationUpdatedCallback refresh_animation_state
    );
 
    virtual ~KeyFrameAnimationState() {
        on_animation_added_.disconnect();
    }
 
    void play_first_animation();
    void play_animation(const std::string& name);
    void queue_next_animation(const std::string& name);
    void play_sequence(const std::string& name);
 
    void override_playing_animation_duration(const float new_duration);
    void update(float dt);
 
    uint32_t current_frame() const { return current_frame_; }
    uint32_t next_frame() const { return next_frame_; }
    float interp() const { return interp_; }
 
private:
    KeyFrameAnimated* animatable_;
 
    KeyFrameAnimated::Animation* current_animation_ = nullptr;
    KeyFrameAnimated::Animation* next_animation_ = nullptr;
    float current_animation_duration_ = 0.0f;
 
    uint32_t current_frame_ = 0;
    uint32_t next_frame_ = 0;
    float interp_ = 0.0f;
 
    AnimationUpdatedCallback refresh_animation_state_;
    sig::connection on_animation_added_;
 
    Throttle throttle_ = Throttle(60);
};
 
 
}