axmol/core/3d/MeshRenderer.h

/****************************************************************************
 Copyright (c) 2014-2016 Chukong Technologies Inc.
 Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.
 Copyright (c) 2022 Bytedance Inc.

 https://axmolengine.github.io/

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#ifndef __AX_MESH_RENDERER_H__
#define __AX_MESH_RENDERER_H__

#include <unordered_map>

#include "base/Vector.h"
#include "base/Types.h"
#include "base/Protocols.h"
#include "2d/Node.h"
#include "renderer/MeshCommand.h"
#include "3d/Skeleton3D.h"  // needs to be included for lua-bindings
#include "3d/AABB.h"
#include "3d/Bundle3DData.h"
#include "3d/MeshVertexIndexData.h"

NS_AX_BEGIN

/**
 * @addtogroup _3d
 * @{
 */

class Mesh;
class Texture2D;
class MeshSkin;
class AttachNode;
struct NodeData;
/** @brief MeshRenderer: A mesh can be loaded from model files, .obj, .c3t, .c3b
 *and a mesh renderer renders a list of these loaded meshes with specified materials
 */
class AX_DLL MeshRenderer : public Node, public BlendProtocol
{
public:
    /**
     * Creates an empty MeshRenderer without a mesh or a texture.
     * Can be used to create procedural meshes on runtime.
     *
     * @return An autoreleased MeshRenderer object.
     */
    static MeshRenderer* create();

    /** creates a MeshRenderer with a specified path */
    static MeshRenderer* create(std::string_view modelPath);

    /** creates a MeshRenderer. A mesh can only have one texture, the default texture can be overridden with 'texturePath' */
    static MeshRenderer* create(std::string_view modelPath, std::string_view texturePath);

    /** create 3d mesh asynchronously
     * If the 3d model was previously loaded, it will create a new 3d mesh and the callback will be called once.
     * Otherwise it will load the model file in a new thread, and when the 3d mesh is loaded, the callback will be
     * called with the created MeshRenderer and a user-defined parameter. The callback will be called from the main thread,
     * so it is safe to create any object from the callback.
     * @param modelPath model to be loaded
     * @param callback callback when loading is finished
     * @param callbackparam user-defined parameter for the callback
     */
    static void createAsync(std::string_view modelPath,
                            const std::function<void(MeshRenderer*, void*)>& callback,
                            void* callbackparam);

    static void createAsync(std::string_view modelPath,
                            std::string_view texturePath,
                            const std::function<void(MeshRenderer*, void*)>& callback,
                            void* callbackparam);

    /** set diffuse texture, set the first mesh's texture if multiple textures exist */
    void setTexture(std::string_view texFile);
    void setTexture(Texture2D* texture);

    /** get Mesh by index */
    Mesh* getMeshByIndex(int index) const;

    /** get Mesh by Name, returns the first one if there are more than one mesh with the same name */
    Mesh* getMeshByName(std::string_view name) const;

    /**
     * get mesh array by name, returns all meshes with the given name
     *
     * @lua NA
     */
    std::vector<Mesh*> getMeshArrayByName(std::string_view name) const;

    /** get mesh at index 0 which is the default mesh */
    Mesh* getMesh() const;

    /** get mesh count */
    ssize_t getMeshCount() const { return _meshes.size(); }

    Skeleton3D* getSkeleton() const { return _skeleton; }

    /** return an AttachNode by bone name. Otherwise, return nullptr if it doesn't exist */
    AttachNode* getAttachNode(std::string_view boneName);

    /** remove an attached node */
    void removeAttachNode(std::string_view boneName);

    /** remove all attached nodes */
    void removeAllAttachNode();

    // overrides
    virtual void setBlendFunc(const BlendFunc& blendFunc) override;
    virtual const BlendFunc& getBlendFunc() const override;

    // overrides
    /** Sets ProgramState, attributes should be bound by the user */
    bool setProgramState(backend::ProgramState* programState, bool needsRetain = true) override;

    /*
     * Get AABB
     * If the mesh has animations, it can't be calculated accurately,
     * because a bone can transform the vertices, and the untransformed vertices are used
     * to calculate the AABB.
     */
    const AABB& getAABB() const;

    /*
     * Get AABB Recursively
     * Because sometimes we may have an empty MeshRenderer Node as parent, If
     * the MeshRenderer doesn't contain any meshes, then we use getAABB()
     */
    AABB getAABBRecursively();

    /**
     * Executes an action, and returns the action that is executed. For the MeshRenderer special logic is needed to take
     * care of Fading.
     *
     * This node becomes the action's target. Refer to Action::getTarget()
     * @warning Actions don't retain their target.
     *
     * @return a pointer to Action 
     */
    virtual Action* runAction(Action* action) override;

    /**
     * Force depth buffer writing, this is useful if you want to achieve effects like fading.
     */
    void setForceDepthWrite(bool value) { _forceDepthWrite = value; }
    bool isForceDepthWrite() const { return _forceDepthWrite; };

    /**
     * Returns a 2d bounding-box
     * Note: the bounding-box is taken from the mesh's AABB with Z-axis ignored.
     */
    virtual Rect getBoundingBox() const override;

    // set face culling side, CullFaceSide::BACK, CullFaceSide::FRONT and CullFaceSide::NONE.
    virtual void setCullFace(CullFaceSide side);
    // set face culling enabled.
    void setCullFaceEnabled(bool enable);

    /** light mask getter & setter, lighting only works when _lightmask & light's flag are set to true, the default
     value of _lightmask is 0xffff */
    void setLightMask(unsigned int mask) { _lightMask = mask; }
    unsigned int getLightMask() const { return _lightMask; }

    /** enables wireframe rendering mode for this mesh renderer only, this can be very useful for debugging and
     understanding generated meshes. */
    void setWireframe(bool value) { _wireframe = value; }
    bool isWireframe() const { return _wireframe; }

    /** render all meshes within this mesh renderer */
    virtual void draw(Renderer* renderer, const Mat4& transform, uint32_t flags) override;

    /** Adds a new material to this mesh renderer.
     The Material will be applied to all the meshes that belong to the mesh renderer.
     It will internally call `setMaterial(material,-1)`
     */
    void setMaterial(Material* material);

    /** Adds a new material to a particular mesh in this mesh renderer.
     * if meshIndex == -1, then it will be applied to all the meshes that belong to this mesh renderer.
     * 
     * @param meshIndex Index of the mesh to apply the material to.
     */
    void setMaterial(Material* material, int meshIndex);

    /** Gets the material of a specific mesh in this mesh renderer.
     * 
     * @param meshIndex Index of the mesh to get the material from. 0 is the default index.
     */
    Material* getMaterial(int meshIndex = 0) const;

    /** Get list of meshes used in this mesh renderer. */
    const Vector<Mesh*>& getMeshes() const { return _meshes; }

    MeshRenderer();
    virtual ~MeshRenderer();

    virtual bool init() override;

    bool initWithFile(std::string_view path);

    bool initFrom(const NodeDatas& nodedatas, const MeshDatas& meshdatas, const MaterialDatas& materialdatas);

    /** load a mesh renderer from cache, returns true if succeeded, false otherwise. */
    bool loadFromCache(std::string_view path);

    /** load a file and feed it's content into meshedatas, nodedatas and materialdatas, obj file and .mtl file
     should be in the same directory. */
    bool loadFromFile(std::string_view path, NodeDatas* nodedatas, MeshDatas* meshdatas, MaterialDatas* materialdatas);

    /**
     * Visits this MeshRenderer's children and draws them recursively.
     * Note: all children will be rendered in 3D space with depth, this behaviour can be changed using
     * setForce2DQueue()
     */
    virtual void visit(Renderer* renderer, const Mat4& parentTransform, uint32_t parentFlags) override;

    /** generate default material. */
    void genMaterial(bool useLight = false);

    void createNode(NodeData* nodedata, Node* root, const MaterialDatas& materialdatas, bool singleMesh);
    void createAttachMeshRendererNode(NodeData* nodedata, const MaterialDatas& materialdatas);
    MeshRenderer* createMeshRendererNode(NodeData* nodedata, ModelData* modeldata, const MaterialDatas& materialdatas);

    /** get MeshIndexData by Id */
    MeshIndexData* getMeshIndexData(std::string_view indexId) const;

    void addMesh(Mesh* mesh);

    void onAABBDirty() { _aabbDirty = true; }

    void afterAsyncLoad(void* param);

    static AABB getAABBRecursivelyImp(Node* node);

protected:
    /** set specific mesh texture, for private use (create mesh stage) only */
    Texture2D* setMeshTexture(Mesh* mesh,
                              std::string_view texPath,
                              NTextureData::Usage usage = NTextureData::Usage::Diffuse);

    /** set model texture from model path when model file not contains texture and texPath is empty
    * only for create mesh renderer
    */
    void setModelTexture(std::string_view modelPath, std::string_view texPath);

    Skeleton3D* _skeleton;

    Vector<MeshVertexData*> _meshVertexDatas;

    hlookup::string_map<AttachNode*> _attachments;

    BlendFunc _blend;

    Vector<Mesh*> _meshes;

    mutable AABB _aabb;                  // cache current aabb
    mutable Mat4 _nodeToWorldTransform;  // cache current matrix
    unsigned int _lightMask;
    mutable bool _aabbDirty;
    bool _shaderUsingLight;  // Is the current shader using lighting?
    bool _forceDepthWrite;   // Always write to depth buffer
    bool _wireframe;         // render in wireframe mode
    bool _usingAutogeneratedGLProgram;
    bool _transparentMaterialHint; // Generate transparent materials when building from files
    unsigned short _meshTextureHint; // Whether model file has texture config

    struct AsyncLoadParam
    {
        std::function<void(MeshRenderer*, void*)> afterLoadCallback;  // callback after loading is finished
        void* callbackParam;
        bool result;  // mesh renderer loading result
        std::string modelPath;
        std::string modelFullPath;
        std::string texPath;
        MeshDatas* meshdatas;
        MaterialDatas* materialdatas;
        NodeDatas* nodeDatas;
    };
    AsyncLoadParam _asyncLoadParam;
};

///////////////////////////////////////////////////////
/**
 * @brief MeshRendererCache: the cache data of MeshRenderer, used to speed up the creation process of MeshRenderer
 */
class AX_DLL MeshRendererCache
{
public:
    struct MeshRenderData
    {
        Vector<MeshVertexData*> meshVertexDatas;
        Vector<backend::ProgramState*> programStates;
        NodeDatas* nodedatas;
        MaterialDatas* materialdatas;
        ~MeshRenderData()
        {
            if (nodedatas)
                delete nodedatas;
            if (materialdatas)
                delete materialdatas;
            meshVertexDatas.clear();
            programStates.clear();
        }
    };

    static MeshRendererCache* getInstance();
    static void destroyInstance();

    /**
     * get a MeshData object by key
     *
     * @lua NA
     */
    MeshRenderData* getMeshRenderData(std::string_view key) const;

    /**
     * add a MeshData object into the MeshRenderer with a specified key
     *
     * @lua NA
     */
    bool addMeshRenderData(std::string_view key, MeshRenderData* meshdata);

    /** remove a MeshData from the MeshRenderer with a specified key */
    void removeMeshRenderData(std::string_view key);

    /** remove all the MeshData objects from the MeshRenderer */
    void removeAllMeshRenderData();

    MeshRendererCache();
    ~MeshRendererCache();

protected:
    static MeshRendererCache* _cacheInstance;
    hlookup::string_map<MeshRenderData*> _meshDatas;  // cached mesh data
};

// end of 3d group
/// @}

NS_AX_END
#endif  // __AX_MESH_RENDERER_H__