njin_fx.h

#pragma once
#include "_math.h"
#include "_types.h"
#include "njin_particles.h"
#include <entt/entity/fwd.hpp>
 
namespace njin {
struct context;



struct shake_config {
  f32 max_offset = 16.0f; 
  f32 max_angle = 3.0f;   
  f32 frequency = 30.0f;  
  f32 decay = 1.5f;       
};

void camera_shake(context &ctx, f32 trauma);

void camera_shake_config(context &ctx, const shake_config &config);

f32 camera_shake_amount(const context &ctx);

void hitstop(context &ctx, f32 seconds);

bool hitstop_active(const context &ctx);

void screen_flash(context &ctx, rgba color, f32 duration);


struct flash_fx {
  rgba color{1.0f, 1.0f, 1.0f, 1.0f}; 
  f32 duration = 0.1f; 
  f32 time = 0.0f;     
  bool fade = true;    
};

void sprite_flash(context &ctx, entt::entity entity,
                  rgba color = {1.0f, 1.0f, 1.0f, 1.0f}, f32 duration = 0.1f);


struct dissolve_fx {
  rgba edge_color{1.0f, 0.55f, 0.1f, 1.0f}; 
  f32 edge_width = 0.08f; 
  f32 grain = 2.0f;       
  f32 seed = 0.0f;        
  f32 duration = 0.6f;    
  f32 time = 0.0f;        
  bool reverse = false;   
  bool destroy_when_done = false; 
};

void sprite_dissolve(context &ctx, entt::entity entity, f32 duration = 0.6f,
                     rgba edge_color = {1.0f, 0.55f, 0.1f, 1.0f});

namespace fx {
inline particle_emitter explosion() {
  particle_emitter e{};
  e.life = {0.35f, 0.8f};
  e.speed = {120.0f, 420.0f};
  e.drag = 4.0f;
  e.size_start = 18.0f;
  e.size_end = 2.0f;
  e.size_jitter = {0.6f, 1.4f};
  e.color_start = {1.0f, 0.85f, 0.35f, 1.0f};
  e.color_end = {0.7f, 0.1f, 0.05f, 0.0f};
  e.blend = blend_additive;
  e.area = {8.0f, 8.0f};
  return e;
}

inline particle_emitter sparks() {
  particle_emitter e{};
  e.life = {0.2f, 0.5f};
  e.speed = {200.0f, 500.0f};
  e.gravity = {0.0f, 900.0f};
  e.drag = 1.5f;
  e.size_start = 4.0f;
  e.size_end = 1.0f;
  e.color_start = {1.0f, 0.95f, 0.6f, 1.0f};
  e.color_end = {1.0f, 0.45f, 0.1f, 0.0f};
  e.shape = particle_square;
  e.blend = blend_additive;
  return e;
}

inline particle_emitter dust() {
  particle_emitter e{};
  e.life = {0.3f, 0.6f};
  e.speed = {20.0f, 70.0f};
  e.angle = -90.0f;
  e.spread = 140.0f;
  e.gravity = {0.0f, -20.0f};
  e.drag = 3.0f;
  e.size_start = 6.0f;
  e.size_end = 12.0f;
  e.size_jitter = {0.7f, 1.3f};
  e.color_start = {0.75f, 0.7f, 0.62f, 0.7f};
  e.color_end = {0.75f, 0.7f, 0.62f, 0.0f};
  e.area = {16.0f, 2.0f};
  return e;
}

inline particle_emitter smoke() {
  particle_emitter e{};
  e.rate = 20.0f;
  e.life = {1.2f, 2.2f};
  e.speed = {20.0f, 45.0f};
  e.angle = -90.0f;
  e.spread = 30.0f;
  e.drag = 0.5f;
  e.spin = {-40.0f, 40.0f};
  e.size_start = 10.0f;
  e.size_end = 36.0f;
  e.color_start = {0.55f, 0.55f, 0.58f, 0.5f};
  e.color_end = {0.35f, 0.35f, 0.38f, 0.0f};
  e.area = {6.0f, 2.0f};
  return e;
}

inline particle_emitter fire() {
  particle_emitter e{};
  e.rate = 70.0f;
  e.life = {0.4f, 0.8f};
  e.speed = {50.0f, 120.0f};
  e.angle = -90.0f;
  e.spread = 25.0f;
  e.size_start = 22.0f;
  e.size_end = 2.0f;
  e.size_jitter = {0.7f, 1.2f};
  e.color_start = {1.0f, 0.8f, 0.3f, 0.9f};
  e.color_end = {0.9f, 0.15f, 0.05f, 0.0f};
  e.blend = blend_additive;
  e.area = {14.0f, 4.0f};
  return e;
}

inline particle_emitter sparkle() {
  particle_emitter e{};
  e.life = {0.4f, 0.9f};
  e.speed = {30.0f, 120.0f};
  e.drag = 2.5f;
  e.gravity = {0.0f, -30.0f};
  e.spin = {-360.0f, 360.0f};
  e.size_start = 7.0f;
  e.size_end = 0.0f;
  e.color_start = {1.0f, 1.0f, 0.75f, 1.0f};
  e.color_end = {0.5f, 0.8f, 1.0f, 0.0f};
  e.shape = particle_square;
  e.blend = blend_additive;
  e.area = {12.0f, 12.0f};
  return e;
}

inline particle_emitter debris() {
  particle_emitter e{};
  e.life = {0.6f, 1.1f};
  e.speed = {120.0f, 320.0f};
  e.angle = -90.0f;
  e.spread = 120.0f;
  e.gravity = {0.0f, 1100.0f};
  e.spin = {-540.0f, 540.0f};
  e.size_start = 7.0f;
  e.size_end = 5.0f;
  e.size_jitter = {0.6f, 1.4f};
  e.color_start = {0.55f, 0.4f, 0.25f, 1.0f};
  e.color_end = {0.45f, 0.32f, 0.2f, 0.0f};
  e.shape = particle_square;
  return e;
}

inline particle_emitter splash() {
  particle_emitter e{};
  e.life = {0.35f, 0.7f};
  e.speed = {100.0f, 300.0f};
  e.spread = 70.0f;
  e.gravity = {0.0f, 900.0f};
  e.size_start = 6.0f;
  e.size_end = 2.0f;
  e.size_jitter = {0.6f, 1.3f};
  e.color_start = {0.75f, 0.05f, 0.08f, 1.0f};
  e.color_end = {0.45f, 0.0f, 0.02f, 0.0f};
  return e;
}

inline particle_emitter rain() {
  particle_emitter e{};
  e.rate = 250.0f;
  e.max_particles = 1500;
  e.life = {0.6f, 0.9f};
  e.speed = {700.0f, 900.0f};
  e.angle = 100.0f;
  e.spread = 4.0f;
  e.size_start = 3.0f;
  e.size_end = 3.0f;
  e.color_start = {0.7f, 0.8f, 1.0f, 0.55f};
  e.color_end = {0.7f, 0.8f, 1.0f, 0.3f};
  e.shape = particle_square;
  e.area = {1400.0f, 10.0f};
  return e;
}

inline particle_emitter snow() {
  particle_emitter e{};
  e.rate = 60.0f;
  e.max_particles = 1500;
  e.life = {6.0f, 9.0f};
  e.speed = {30.0f, 70.0f};
  e.angle = 90.0f;
  e.spread = 50.0f;
  e.size_start = 4.0f;
  e.size_end = 4.0f;
  e.size_jitter = {0.5f, 1.3f};
  e.color_start = {1.0f, 1.0f, 1.0f, 0.9f};
  e.color_end = {1.0f, 1.0f, 1.0f, 0.0f};
  e.area = {1400.0f, 10.0f};
  return e;
}

inline particle_emitter trail() {
  particle_emitter e{};
  e.rate = 80.0f;
  e.life = {0.25f, 0.4f};
  e.speed = {0.0f, 8.0f};
  e.size_start = 8.0f;
  e.size_end = 0.0f;
  e.color_start = {1.0f, 1.0f, 1.0f, 0.8f};
  e.color_end = {0.6f, 0.8f, 1.0f, 0.0f};
  e.blend = blend_additive;
  return e;
}
} // namespace fx

} // namespace njin