submesh.h

#pragma once
 
#include "../interfaces/boundable.h"
#include "../generic/property.h"
#include "../generic/managed.h"
#include "../interfaces/nameable.h"
 
namespace smlt {
 
class VertexData;
class IndexData;
class Mesh;
class Renderer;
 
enum MaterialSlot : uint8_t {
    MATERIAL_SLOT0 = 0,
    MATERIAL_SLOT1,
    MATERIAL_SLOT2,
    MATERIAL_SLOT3,
    MATERIAL_SLOT4,
    MATERIAL_SLOT5,
    MATERIAL_SLOT6,
    MATERIAL_SLOT7,
    MATERIAL_SLOT_MAX
};
 
enum SubmeshType {
    SUBMESH_TYPE_INDEXED,
    SUBMESH_TYPE_RANGED,
};
 
struct VertexRange {
    uint32_t start;
    uint32_t count;
};
 
typedef std::vector<VertexRange> VertexRangeList;
 
 
class SubMesh:
    public RefCounted<SubMesh>,
    public Nameable {
 
public:
    /* Indexed submesh constructor */
    SubMesh(Mesh* parent,
        const std::string& name,
        MaterialPtr material,
        std::shared_ptr<IndexData>& index_data,
        MeshArrangement arrangement = MESH_ARRANGEMENT_TRIANGLES
    );
 
    /* Ranged submesh constructor */
    SubMesh(Mesh* parent,
        const std::string& name,
        MaterialPtr material,
        MeshArrangement arrangement = MESH_ARRANGEMENT_TRIANGLES
    );
 
    virtual ~SubMesh();
 
    SubmeshType type() const;
 
    bool add_vertex_range(uint32_t start, uint32_t count);
    void mark_changed();
 
    const VertexRange* vertex_ranges() const {
        return &vertex_ranges_[0];
    }
 
    std::size_t vertex_range_count() const {
        return vertex_ranges_.size();
    }
 
    void remove_all_vertex_ranges();
 
    void set_material(const MaterialPtr &material);
    void set_material_at_slot(MaterialSlot var, const MaterialPtr& material);
 
    MaterialPtr material() const;
    MaterialPtr material_at_slot(MaterialSlot var, bool fallback=false) const;
 
    MeshArrangement arrangement() const { return arrangement_; }
 
    bool reverse_winding();
 
    void generate_texture_coordinates_cube(uint32_t texture=0);
 
    /* Goes through the indexes in this submesh and changes the diffuse colour of the vertices
     * they point to */
    void set_diffuse(const Colour &colour);
 
    /*
     * Whether or not this submesh contributes to the adjacency info attached to the mesh
     * which is used for silhouettes
     */
    void set_contributes_to_edge_list(bool v=true) {
        contributes_to_edge_list_ = v;
    }
 
    bool contributes_to_edge_list() const {
        return contributes_to_edge_list_;
    }
 
    /*
     * Iterates the submesh indexes and breaks them into triangles (a, b, c). In the case of lines
     * index c will be the same as index a.
     */
    void each_triangle(std::function<void (uint32_t, uint32_t, uint32_t)> cb);
 
    const AABB& aabb() const;
 
public:
    typedef sig::signal<void (SubMeshPtr, MaterialSlot, MaterialID, MaterialID)> MaterialChangedCallback;
 
    MaterialChangedCallback& signal_material_changed() {
        return signal_material_changed_;
    }
 
private:
    friend class Mesh;
 
    sig::connection material_change_connection_;
 
    Mesh* parent_;
    SubmeshType type_;
    sig::connection parent_update_connection_;
 
    std::array<MaterialPtr, MATERIAL_SLOT_MAX> materials_;
 
    MeshArrangement arrangement_;
 
    std::shared_ptr<IndexData> index_data_;
    VertexRangeList vertex_ranges_;
 
    void _recalc_bounds(AABB& bounds);
    void _recalc_bounds_indexed(AABB& bounds);
    void _recalc_bounds_ranged(AABB& bounds);
 
    void _each_triangle_indexed(std::function<void (uint32_t, uint32_t, uint32_t)> cb);
    void _each_triangle_ranged(std::function<void (uint32_t, uint32_t, uint32_t)> cb);
 
    MaterialChangedCallback signal_material_changed_;
 
    bool contributes_to_edge_list_ = true;
 
    /* This is updated and maintained by Mesh, it only lives here so
     * there's a fast lookup for each submesh */
    AABB bounds_;
 
public:
    S_DEFINE_PROPERTY(mesh, &SubMesh::parent_);
    S_DEFINE_PROPERTY(index_data, &SubMesh::index_data_);
};
 
}