Reorganize source files into logical subdirectories

Co-authored-by: Hirek193 <23196899+Hirek193@users.noreply.github.com>

rendering/particles.h

@@ -0,0 +1,243 @@
+/*
+This Source Code Form is subject to the
+terms of the Mozilla Public License, v.
+2.0. If a copy of the MPL was not
+distributed with this file, You can
+obtain one at
+http://mozilla.org/MPL/2.0/.
+*/
+
+#pragma once
+
+#include "Classes.h"
+#include "scene.h"
+
+// particle specialized for drawing smoke
+// given smoke features we can take certain shortcuts
+// -- there's no need to sort the particles, can be drawn in any order with depth write turned off
+// -- the colour remains consistent throughout, only opacity changes
+// -- randomized particle rotation
+// -- initial velocity reduced over time to slow drift upwards (drift speed depends on particle and air temperature difference)
+// -- size increased over time
+struct smoke_particle {
+
+    glm::dvec3 position; // meters, 3d space;
+    float rotation; // radians; local z axis angle
+    glm::vec3 velocity; // meters per second, 3d space; current velocity
+    float size; // multiplier, billboard size
+//    glm::vec4 color; // 0-1 range, rgba; geometry color and opacity
+    float opacity; // 0-1 range
+//    glm::vec2 uv_offset; // 0-1 range, uv space; for texture animation
+    float age; // seconds; time elapsed since creation
+//    double distance; // meters; distance between particle and camera
+};
+
+enum value_limit {
+    min = 0,
+    max = 1
+};
+
+// helper, adjusts provided variable by fixed amount, keeping resulting value between limits
+template <typename Type_>
+class fixedstep_modifier {
+
+public:
+// methods
+    void
+        deserialize( cParser &Input );
+    // updates state of provided variable
+    void
+        update( Type_ &Variable, double const Timedelta ) const;
+    void
+        bind( Type_ const *Modifier ) {
+            m_valuechangemodifier = Modifier; }
+    Type_
+        value_change() const {
+            return (
+                m_valuechangemodifier == nullptr ?
+                    m_valuechange :
+                    m_valuechange / *( m_valuechangemodifier ) ); }
+
+private:
+//types
+// methods
+// members
+//    Type_ m_intialvalue { Type_( 0 ) }; // meters per second; velocity applied to freshly spawned particles
+    Type_ m_valuechange { Type_( 0 ) }; // meters per second; change applied to initial velocity
+    Type_ m_valuelimits[ 2 ] { Type_( std::numeric_limits<Type_>::lowest() ), Type_( std::numeric_limits<Type_>::max() ) };
+    Type_ const *m_valuechangemodifier{ nullptr }; // optional modifier applied to value change
+};
+
+
+// particle emitter
+class smoke_source {
+// located in scenery
+// new particles emitted if distance of source < double view range
+// existing particles are updated until dead no matter the range (presumed to have certain lifespan)
+// during update pass dead particle slots are filled with new instances, if there's no particles queued the slot is swapped with the last particle in the list
+// bounding box/sphere calculated based on position of all owned particles, used by the renderer to include/discard data in a draw pass
+    friend class particle_manager;
+
+public:
+// types
+    using particle_sequence = std::vector<smoke_particle>;
+// methods
+    bool
+        deserialize( cParser &Input );
+    void
+        initialize();
+    void
+        bind( TDynamicObject const *Vehicle );
+    void
+        bind( TAnimModel const *Node );
+    // updates state of owned particles
+    void
+        update( double const Timedelta, bool const Onlydespawn );
+    glm::vec3 const &
+        color() const {
+            return m_emitter.color; }
+    glm::dvec3
+        location() const;
+    // provides access to bounding area data
+    scene::bounding_area const &
+        area() const {
+            return m_area; }
+    particle_sequence const &
+        sequence() const {
+            return m_particles; }
+
+private:
+// types
+    enum class owner_type {
+        none = 0,
+        vehicle,
+        node
+    };
+
+    struct particle_emitter {
+        float inclination[ 2 ] { 0.f, 0.f };
+        float velocity[ 2 ] { 1.f, 1.f };
+        float size[ 2 ] { 1.f, 1.f };
+        float opacity[ 2 ] { 1.f, 1.f };
+        glm::vec3 color { 16.f / 255.f };
+
+        void deserialize( cParser &Input );
+        void initialize( smoke_particle &Particle );
+    };
+
+    using bounding_box = glm::dvec3[ 2 ]; // bounding box of owned particles
+
+// methods
+    // imports member data pair from the config file
+    bool
+        deserialize_mapping( cParser &Input );
+    void
+        initialize( smoke_particle &Particle );
+    // updates state of provided particle and bounding box. returns: true if particle is still alive afterwards, false otherwise
+    bool
+        update( smoke_particle &Particle, bounding_box &Boundingbox, double const Timedelta );
+// members
+    // config/inputs
+    // TBD: union and indicator, or just plain owner variables?
+    owner_type m_ownertype { owner_type::none };
+    union {
+        TDynamicObject const * vehicle;
+        TAnimModel const * node;
+    } m_owner { nullptr }; // optional, scene item carrying this source
+    glm::dvec3 m_offset; // meters, 3d space; relative position of the source, either from the owner or the region centre
+    float m_spawnrate { 0.f }; // number of particles to spawn per second
+    particle_emitter m_emitter;
+//    bool m_inheritvelocity { false }; // whether spawned particle should receive velocity of its owner
+    // TODO: replace modifiers with configurable interpolator item allowing keyframe-based changes over time
+    fixedstep_modifier<float> m_sizemodifier; // particle billboard size
+//    fixedstep_modifier<glm::vec3> m_colormodifier; // particle billboard color and opacity
+    fixedstep_modifier<float> m_opacitymodifier;
+//    texture_handle m_texture { -1 }; // texture assigned to particle billboards
+    // current state
+    float m_spawncount { 0.f }; // number of particles to spawn during next update
+    particle_sequence m_particles; // collection of spawned particles
+    std::size_t m_max_particles; // maximum number of particles existing
+    scene::bounding_area m_area; // bounding sphere of owned particles
+};
+
+
+// holds all particle emitters defined in the scene and updates their state
+class particle_manager {
+
+    friend opengl_renderer;
+
+public:
+// types
+    using source_sequence = std::vector<smoke_source>;
+// constructors
+    particle_manager() = default;
+// destructor
+//    ~particle_manager();
+// methods
+    // adds a new particle source of specified type, placing it in specified world location. returns: true on success, false if the specified type definition couldn't be located
+    bool
+        insert( std::string const &Sourcetemplate, glm::dvec3 const Location );
+    bool
+        insert( std::string const &Sourcetemplate, TDynamicObject const *Vehicle, glm::dvec3 const Location );
+    bool
+        insert( std::string const &Sourcetemplate, TAnimModel const *Node, glm::dvec3 const Location );
+    // updates state of all owned emitters
+    void
+        update();
+    // data access
+    source_sequence &
+        sequence() {
+            return m_sources; }
+
+// members
+
+private:
+// types
+    using source_map = std::unordered_map<std::string, smoke_source>;
+// methods
+    smoke_source *
+        find( std::string const &Template );
+// members
+    source_map m_sourcetemplates; // cached particle emitter configurations
+    source_sequence m_sources; // all owned particle emitters
+};
+
+
+
+template <typename Type_>
+void
+fixedstep_modifier<Type_>::update( Type_ &Variable, double const Timedelta ) const {
+    // HACK: float cast to avoid vec3 and double mismatch
+    // TBD, TODO: replace with vector types specialization
+    auto const valuechange { (
+        m_valuechangemodifier == nullptr ?
+            m_valuechange :
+            m_valuechange / *( m_valuechangemodifier ) ) };
+    Variable += ( valuechange * static_cast<float>( Timedelta ) );
+    // clamp down to allowed value range
+    Variable = glm::max( Variable, m_valuelimits[ value_limit::min ] );
+    Variable = glm::min( Variable, m_valuelimits[ value_limit::max ] );
+}
+
+template <typename Type_>
+void
+fixedstep_modifier<Type_>::deserialize( cParser &Input ) {
+
+    if( Input.getToken<std::string>() != "{" ) { return; }
+
+    std::unordered_map<std::string, Type_ &> const variablemap {
+        { "step:", m_valuechange },
+        { "min:", m_valuelimits[ value_limit::min ] },
+        { "max:", m_valuelimits[ value_limit::max ] } };
+
+    std::string key;
+
+    while( ( false == ( ( key = Input.getToken<std::string>( true, "\n\r\t  ,;[]" ) ).empty() ) )
+        && ( key != "}" ) ) {
+
+        auto const lookup { variablemap.find( key ) };
+        if( lookup == variablemap.end() ) { continue; }
+
+        lookup->second = Input.getToken<Type_>( true, "\n\r\t  ,;[]" );
+    }
+}