Kelsidavis-WoWee/include/pipeline/wmo_loader.hpp

#pragma once

#include <vector>
#include <string>
#include <unordered_map>
#include <glm/glm.hpp>
#include <glm/gtc/quaternion.hpp>

namespace wowee {
namespace pipeline {

/**
 * WMO (World Model Object) Format
 *
 * WMO files contain buildings, dungeons, and large structures.
 * Structure:
 * - Root WMO file: Contains groups, materials, doodad sets
 * - Group WMO files: Individual rooms/sections (_XXX.wmo)
 *
 * Reference: https://wowdev.wiki/WMO
 */

// WMO Material
struct WMOMaterial {
    uint32_t flags;
    uint32_t shader;
    uint32_t blendMode;
    uint32_t texture1;          // Diffuse texture index
    uint32_t color1;
    uint32_t texture2;          // Environment/detail texture
    uint32_t color2;
    uint32_t texture3;
    uint32_t color3;
    float runtime[4];           // Runtime data
};

// WMO Group Info
struct WMOGroupInfo {
    uint32_t flags;
    glm::vec3 boundingBoxMin;
    glm::vec3 boundingBoxMax;
    int32_t nameOffset;         // Group name in MOGN chunk
};

// WMO Light
struct WMOLight {
    uint32_t type;              // 0=omni, 1=spot, 2=directional, 3=ambient
    uint8_t useAttenuation;
    uint8_t pad[3];
    glm::vec4 color;
    glm::vec3 position;
    float intensity;
    float attenuationStart;
    float attenuationEnd;
    float unknown[4];
};

// WMO Doodad Set (collection of M2 models placed in WMO)
struct WMODoodadSet {
    char name[20];
    uint32_t startIndex;        // First doodad in MODD
    uint32_t count;             // Number of doodads
    uint32_t padding;
};

// WMO Doodad Instance
struct WMODoodad {
    uint32_t nameIndex;         // Index into MODN (doodad names)
    glm::vec3 position;
    glm::quat rotation;         // Quaternion rotation
    float scale;
    glm::vec4 color;           // BGRA color
};

// WMO Fog
struct WMOFog {
    uint32_t flags;
    glm::vec3 position;
    float smallRadius;
    float largeRadius;
    float endDist;
    float startFactor;
    glm::vec4 color1;          // End fog color
    float endDist2;
    float startFactor2;
    glm::vec4 color2;          // Start fog color (blend with color1)
};

// WMO Portal
struct WMOPortal {
    uint16_t startVertex;
    uint16_t vertexCount;
    uint16_t planeIndex;
    uint16_t padding;
};

// WMO Portal Plane
struct WMOPortalPlane {
    glm::vec3 normal;
    float distance;
};

// WMO Group Vertex
struct WMOVertex {
    glm::vec3 position;
    glm::vec3 normal;
    glm::vec2 texCoord;
    glm::vec4 color;           // Vertex color
};

// WMO Batch (render batch)
struct WMOBatch {
    uint32_t startIndex;   // First index (this is uint32 in file format)
    uint16_t indexCount;   // Number of indices
    uint16_t startVertex;
    uint16_t lastVertex;
    uint8_t flags;
    uint8_t materialId;
};

// WMO Group (individual room/section)
struct WMOGroup {
    uint32_t flags;
    glm::vec3 boundingBoxMin;
    glm::vec3 boundingBoxMax;
    uint16_t portalStart;
    uint16_t portalCount;
    uint16_t batchCountA;
    uint16_t batchCountB;
    uint32_t fogIndices[4];     // Fog references
    uint32_t liquidType;
    uint32_t groupId;

    // Geometry
    std::vector<WMOVertex> vertices;
    std::vector<uint16_t> indices;
    std::vector<WMOBatch> batches;

    // Portals
    std::vector<WMOPortal> portals;
    std::vector<glm::vec3> portalVertices;

    // BSP tree (for collision - optional)
    std::vector<uint8_t> bspNodes;

    std::string name;
    std::string description;
};

// Complete WMO Model
struct WMOModel {
    // Root WMO data
    uint32_t version;
    uint32_t nGroups;
    uint32_t nPortals;
    uint32_t nLights;
    uint32_t nDoodadNames;
    uint32_t nDoodadDefs;
    uint32_t nDoodadSets;

    glm::vec3 boundingBoxMin;
    glm::vec3 boundingBoxMax;

    // Materials and textures
    std::vector<WMOMaterial> materials;
    std::vector<std::string> textures;
    std::unordered_map<uint32_t, uint32_t> textureOffsetToIndex;  // MOTX offset -> texture array index

    // Groups (rooms/sections)
    std::vector<WMOGroupInfo> groupInfo;
    std::vector<WMOGroup> groups;

    // Portals (visibility culling)
    std::vector<WMOPortal> portals;
    std::vector<WMOPortalPlane> portalPlanes;
    std::vector<glm::vec3> portalVertices;

    // Lights
    std::vector<WMOLight> lights;

    // Doodads (M2 models placed in WMO)
    // Keyed by byte offset into MODN chunk (nameIndex in MODD references these offsets)
    std::unordered_map<uint32_t, std::string> doodadNames;
    std::vector<WMODoodad> doodads;
    std::vector<WMODoodadSet> doodadSets;

    // Fog
    std::vector<WMOFog> fogs;

    // Group names
    std::vector<std::string> groupNames;

    bool isValid() const {
        return nGroups > 0 && !groups.empty();
    }
};

class WMOLoader {
public:
    /**
     * Load root WMO file
     *
     * @param wmoData Raw WMO file bytes
     * @return Parsed WMO model (without group geometry)
     */
    static WMOModel load(const std::vector<uint8_t>& wmoData);

    /**
     * Load WMO group file
     *
     * @param groupData Raw WMO group file bytes
     * @param model Model to populate with group data
     * @param groupIndex Group index to load
     * @return True if successful
     */
    static bool loadGroup(const std::vector<uint8_t>& groupData,
                         WMOModel& model,
                         uint32_t groupIndex);
};

} // namespace pipeline
} // namespace wowee