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/** @file scene.h
 *  @brief Defines the data structures in which the imported scene is returned.
 */
#pragma once
#ifndef AI_SCENE_H_INC
#define AI_SCENE_H_INC

#include "types.h"
#include "texture.h"
#include "mesh.h"
#include "light.h"
#include "camera.h"
#include "material.h"
#include "anim.h"
#include "metadata.h"

#ifdef __cplusplus
extern "C" {
#endif

// -------------------------------------------------------------------------------
/** 
 * A node in the imported hierarchy.
 *
 * Each node has name, a parent node (except for the root node),
 * a transformation relative to its parent and possibly several child nodes.
 * Simple file formats don't support hierarchical structures - for these formats
 * the imported scene does consist of only a single root node without children.
 */
// -------------------------------------------------------------------------------
struct aiNode
{
    /** The name of the node.
     *
     * The name might be empty (length of zero) but all nodes which
     * need to be referenced by either bones or animations are named.
     * Multiple nodes may have the same name, except for nodes which are referenced
     * by bones (see #aiBone and #aiMesh::mBones). Their names *must* be unique.
     *
     * Cameras and lights reference a specific node by name - if there
     * are multiple nodes with this name, they are assigned to each of them.
     * <br>
     * There are no limitations with regard to the characters contained in
     * the name string as it is usually taken directly from the source file.
     *
     * Implementations should be able to handle tokens such as whitespace, tabs,
     * line feeds, quotation marks, ampersands etc.
     *
     * Sometimes assimp introduces new nodes not present in the source file
     * into the hierarchy (usually out of necessity because sometimes the
     * source hierarchy format is simply not compatible). Their names are
     * surrounded by @verbatim <> @endverbatim e.g.
     *  @verbatim<DummyRootNode> @endverbatim.
     */
    C_STRUCT aiString mName;

    /** The transformation relative to the node's parent. */
    C_STRUCT aiMatrix4x4 mTransformation;

    /** Parent node. NULL if this node is the root node. */
    C_STRUCT aiNode* mParent;

    /** The number of child nodes of this node. */
    unsigned int mNumChildren;

    /** The child nodes of this node. NULL if mNumChildren is 0. */
    C_STRUCT aiNode** mChildren;

    /** The number of meshes of this node. */
    unsigned int mNumMeshes;

    /** The meshes of this node. Each entry is an index into the
      * mesh list of the #aiScene.
      */
    unsigned int* mMeshes;

    /** Metadata associated with this node or NULL if there is no metadata.
      *  Whether any metadata is generated depends on the source file format. See the
      * @link importer_notes @endlink page for more information on every source file
      * format. Importers that don't document any metadata don't write any.
      */
    C_STRUCT aiMetadata* mMetaData;

#ifdef __cplusplus
    /** Constructor */
    aiNode()
        // set all members to zero by default
        : mName("")
        , mParent(NULL)
        , mNumChildren(0)
        , mChildren(NULL)
        , mNumMeshes(0)
        , mMeshes(NULL)
        , mMetaData(NULL)
    {
    }


    /** Construction from a specific name */
    explicit aiNode(const std::string& name)
        // set all members to zero by default
        : mName(name)
        , mParent(NULL)
        , mNumChildren(0)
        , mChildren(NULL)
        , mNumMeshes(0)
        , mMeshes(NULL)
        , mMetaData(NULL)
    {
    }

    /** Destructor */
    ~aiNode()
    {
        // delete all children recursively
        // to make sure we won't crash if the data is invalid ...
        if (mChildren && mNumChildren)
        {
            for( unsigned int a = 0; a < mNumChildren; a++)
                delete mChildren[a];
        }
        delete [] mChildren;
        delete [] mMeshes;
        delete mMetaData;
    }


    /** Searches for a node with a specific name, beginning at this
     *  nodes. Normally you will call this method on the root node
     *  of the scene.
     *
     *  @param name Name to search for
     *  @return NULL or a valid Node if the search was successful.
     */
    inline const aiNode* FindNode(const aiString& name) const
    {
        return FindNode(name.data);
    }


    inline aiNode* FindNode(const aiString& name)
    {
        return FindNode(name.data);
    }


    inline const aiNode* FindNode(const char* name) const
    {
        if (!::strcmp( mName.data,name))return this;
        for (unsigned int i = 0; i < mNumChildren;++i)
        {
            const aiNode* const p = mChildren[i]->FindNode(name);
            if (p) {
                return p;
            }
        }
        // there is definitely no sub-node with this name
        return NULL;
    }

    inline aiNode* FindNode(const char* name)
    {
        if (!::strcmp( mName.data,name))return this;
        for (unsigned int i = 0; i < mNumChildren;++i)
        {
            aiNode* const p = mChildren[i]->FindNode(name);
            if (p) {
                return p;
            }
        }
        // there is definitely no sub-node with this name
        return NULL;
    }

#endif // __cplusplus
};


// -------------------------------------------------------------------------------
/**
 * Specifies that the scene data structure that was imported is not complete.
 * This flag bypasses some internal validations and allows the import
 * of animation skeletons, material libraries or camera animation paths
 * using Assimp. Most applications won't support such data.
 */
#define AI_SCENE_FLAGS_INCOMPLETE   0x1

/**
 * This flag is set by the validation postprocess-step (aiPostProcess_ValidateDS)
 * if the validation is successful. In a validated scene you can be sure that
 * any cross references in the data structure (e.g. vertex indices) are valid.
 */
#define AI_SCENE_FLAGS_VALIDATED    0x2

/**
 * This flag is set by the validation postprocess-step (aiPostProcess_ValidateDS)
 * if the validation is successful but some issues have been found.
 * This can for example mean that a texture that does not exist is referenced
 * by a material or that the bone weights for a vertex don't sum to 1.0 ... .
 * In most cases you should still be able to use the import. This flag could
 * be useful for applications which don't capture Assimp's log output.
 */
#define AI_SCENE_FLAGS_VALIDATION_WARNING   0x4

/**
 * This flag is currently only set by the aiProcess_JoinIdenticalVertices step.
 * It indicates that the vertices of the output meshes aren't in the internal
 * verbose format anymore. In the verbose format all vertices are unique,
 * no vertex is ever referenced by more than one face.
 */
#define AI_SCENE_FLAGS_NON_VERBOSE_FORMAT   0x8

 /**
 * Denotes pure height-map terrain data. Pure terrains usually consist of quads,
 * sometimes triangles, in a regular grid. The x,y coordinates of all vertex
 * positions refer to the x,y coordinates on the terrain height map, the z-axis
 * stores the elevation at a specific point.
 *
 * TER (Terragen) and HMP (3D Game Studio) are height map formats.
 * @note Assimp is probably not the best choice for loading *huge* terrains -
 * fully triangulated data takes extremely much free store and should be avoided
 * as long as possible (typically you'll do the triangulation when you actually
 * need to render it).
 */
#define AI_SCENE_FLAGS_TERRAIN 0x10

 /**
 * Specifies that the scene data can be shared between structures. For example:
 * one vertex in few faces. \ref AI_SCENE_FLAGS_NON_VERBOSE_FORMAT can not be
 * used for this because \ref AI_SCENE_FLAGS_NON_VERBOSE_FORMAT has internal
 * meaning about postprocessing steps.
 */
#define AI_SCENE_FLAGS_ALLOW_SHARED			0x20

// -------------------------------------------------------------------------------
/** The root structure of the imported data.
 *
 *  Everything that was imported from the given file can be accessed from here.
 *  Objects of this class are generally maintained and owned by Assimp, not
 *  by the caller. You shouldn't want to instance it, nor should you ever try to
 *  delete a given scene on your own.
 */
// -------------------------------------------------------------------------------
struct aiScene
{
    /** Any combination of the AI_SCENE_FLAGS_XXX flags. By default
    * this value is 0, no flags are set. Most applications will
    * want to reject all scenes with the AI_SCENE_FLAGS_INCOMPLETE
    * bit set.
    */
    unsigned int mFlags;

    /** The root node of the hierarchy.
    *
    * There will always be at least the root node if the import
    * was successful (and no special flags have been set).
    * Presence of further nodes depends on the format and content
    * of the imported file.
    */
    C_STRUCT aiNode* mRootNode;

    /** The number of meshes in the scene. */
    unsigned int mNumMeshes;

    /** The array of meshes.
    *
    * Use the indices given in the aiNode structure to access
    * this array. The array is mNumMeshes in size. If the
    * AI_SCENE_FLAGS_INCOMPLETE flag is not set there will always
    * be at least ONE material.
    */
    C_STRUCT aiMesh** mMeshes;

    /** The number of materials in the scene. */
    unsigned int mNumMaterials;

    /** The array of materials.
    *
    * Use the index given in each aiMesh structure to access this
    * array. The array is mNumMaterials in size. If the
    * AI_SCENE_FLAGS_INCOMPLETE flag is not set there will always
    * be at least ONE material.
    */
    C_STRUCT aiMaterial** mMaterials;

    /** The number of animations in the scene. */
    unsigned int mNumAnimations;

    /** The array of animations.
    *
    * All animations imported from the given file are listed here.
    * The array is mNumAnimations in size.
    */
    C_STRUCT aiAnimation** mAnimations;

    /** The number of textures embedded into the file */
    unsigned int mNumTextures;

    /** The array of embedded textures.
    *
    * Not many file formats embed their textures into the file.
    * An example is Quake's MDL format (which is also used by
    * some GameStudio versions)
    */
    C_STRUCT aiTexture** mTextures;

    /** The number of light sources in the scene. Light sources
    * are fully optional, in most cases this attribute will be 0
        */
    unsigned int mNumLights;

    /** The array of light sources.
    *
    * All light sources imported from the given file are
    * listed here. The array is mNumLights in size.
    */
    C_STRUCT aiLight** mLights;

    /** The number of cameras in the scene. Cameras
    * are fully optional, in most cases this attribute will be 0
        */
    unsigned int mNumCameras;

    /** The array of cameras.
    *
    * All cameras imported from the given file are listed here.
    * The array is mNumCameras in size. The first camera in the
    * array (if existing) is the default camera view into
    * the scene.
    */
    C_STRUCT aiCamera** mCameras;

#ifdef __cplusplus

    //! Default constructor - set everything to 0/NULL
    ASSIMP_API aiScene();

    //! Destructor
    ASSIMP_API ~aiScene();

    //! Check whether the scene contains meshes
    //! Unless no special scene flags are set this will always be true.
    inline bool HasMeshes() const { 
        return mMeshes != NULL && mNumMeshes > 0; 
    }

    //! Check whether the scene contains materials
    //! Unless no special scene flags are set this will always be true.
    inline bool HasMaterials() const { 
        return mMaterials != NULL && mNumMaterials > 0; 
    }

    //! Check whether the scene contains lights
    inline bool HasLights() const { 
        return mLights != NULL && mNumLights > 0; 
    }

    //! Check whether the scene contains textures
    inline bool HasTextures() const {
        return mTextures != NULL && mNumTextures > 0; 
    }

    //! Check whether the scene contains cameras
    inline bool HasCameras() const {
        return mCameras != NULL && mNumCameras > 0; 
    }

    //! Check whether the scene contains animations
    inline bool HasAnimations() const { 
        return mAnimations != NULL && mNumAnimations > 0; 
    }

#endif // __cplusplus

    /**  Internal data, do not touch */
#ifdef __cplusplus
    void* mPrivate;
#else
    char* mPrivate;
#endif

};

#ifdef __cplusplus
} //! namespace Assimp
#endif

#endif // AI_SCENE_H_INC
