/**
 * @file llface.h
 * @brief LLFace class definition
 *
 * $LicenseInfo:firstyear=2001&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#ifndef LL_LLFACE_H
#define LL_LLFACE_H

#include "llstrider.h"
#include "llrender.h"
#include "v2math.h"
#include "v3math.h"
#include "v4math.h"
#include "m4math.h"
#include "v4coloru.h"
#include "llquaternion.h"
#include "xform.h"
#include "llvertexbuffer.h"
#include "llviewertexture.h"
#include "lldrawable.h"

class LLFacePool;
class LLVolume;
class LLViewerTexture;
class LLTextureEntry;
class LLVertexProgram;
class LLViewerTexture;
class LLGeometryManager;
class LLDrawInfo;
class LLMeshSkinInfo;

const F32 MIN_ALPHA_SIZE = 1024.f;
const F32 MIN_TEX_ANIM_SIZE = 512.f;
const U8 FACE_DO_NOT_BATCH_TEXTURES = 255;

class alignas(16) LLFace
{
    LL_ALIGN_NEW
public:
    LLFace(const LLFace& rhs)
    {
        *this = rhs;
    }

    const LLFace& operator=(const LLFace& rhs)
    {
        LL_ERRS() << "Illegal operation!" << LL_ENDL;
        return *this;
    }

    enum EMasks
    {
        LIGHT           = 0x0001,
        GLOBAL          = 0x0002,
        FULLBRIGHT      = 0x0004,
        HUD_RENDER      = 0x0008,
        USE_FACE_COLOR  = 0x0010,
        TEXTURE_ANIM    = 0x0020,
        RIGGED          = 0x0040,
        PARTICLE        = 0x0080,
    };

public:
    LLFace(LLDrawable* drawablep, LLViewerObject* objp)
    {
        LL_PROFILE_ZONE_SCOPED;
        init(drawablep, objp);
    }
    ~LLFace()  { destroy(); }

    const LLMatrix4& getWorldMatrix()   const   { return mVObjp->getWorldMatrix(mXform); }
    const LLMatrix4& getRenderMatrix() const;
    U32             getIndicesCount()   const   { return mIndicesCount; };
    S32             getIndicesStart()   const   { return mIndicesIndex; };
    U16             getGeomCount()      const   { return mGeomCount; }      // vertex count for this face
    U16             getGeomIndex()      const   { return mGeomIndex; }      // index into draw pool
    U16             getGeomStart()      const   { return mGeomIndex; }      // index into draw pool
    void            setTextureIndex(U8 index);
    U8              getTextureIndex() const     { return mTextureIndex; }
    void            setTexture(U32 ch, LLViewerTexture* tex);
    void            setTexture(LLViewerTexture* tex) ;
    void            setDiffuseMap(LLViewerTexture* tex);
    void            setNormalMap(LLViewerTexture* tex);
    void            setSpecularMap(LLViewerTexture* tex);
    void            setAlternateDiffuseMap(LLViewerTexture* tex);
    void            switchTexture(U32 ch, LLViewerTexture* new_texture);
    void            dirtyTexture();
    LLXformMatrix*  getXform()          const   { return mXform; }
    bool            hasGeometry()       const   { return mGeomCount > 0; }
    LLVector3       getPositionAgent()  const;
    LLVector2       surfaceToTexture(LLVector2 surface_coord, const LLVector4a& position, const LLVector4a& normal);
    void            getPlanarProjectedParams(LLQuaternion* face_rot, LLVector3* face_pos, F32* scale) const;
    bool            calcAlignedPlanarTE(const LLFace* align_to, LLVector2* st_offset,
                                        LLVector2* st_scale, F32* st_rot, LLRender::eTexIndex map = LLRender::DIFFUSE_MAP) const;

    U32             getState()          const   { return mState; }
    void            setState(U32 state)         { mState |= state; }
    void            clearState(U32 state)       { mState &= ~state; }
    bool            isState(U32 state)  const   { return (mState & state) != 0; }
    void            setVirtualSize(F32 size) { mVSize = size; }
    void            setPixelArea(F32 area)  { mPixelArea = area; }
    F32             getVirtualSize() const { return mVSize; }
    F32             getPixelArea() const { return mPixelArea; }

    S32             getIndexInTex(U32 ch) const      { llassert(ch < LLRender::NUM_TEXTURE_CHANNELS); return mIndexInTex[ch]; }
    void            setIndexInTex(U32 ch, S32 index) { llassert(ch < LLRender::NUM_TEXTURE_CHANNELS); mIndexInTex[ch] = index; }

    void            setWorldMatrix(const LLMatrix4& mat);
    const LLTextureEntry* getTextureEntry() const { return mVObjp->getTE(mTEOffset); }

    LLFacePool*     getPool()           const   { return mDrawPoolp; }
    U32             getPoolType()       const   { return mPoolType; }
    LLDrawable*     getDrawable()       const   { return mDrawablep; }
    LLViewerObject* getViewerObject()   const   { return mVObjp; }
    S32             getLOD()            const   { return mVObjp.notNull() ? mVObjp->getLOD() : 0; }
    void            setPoolType(U32 type)       { mPoolType = type; }
    S32             getTEOffset()       const   { return mTEOffset; }
    LLViewerTexture*    getTexture(U32 ch = LLRender::DIFFUSE_MAP) const;

    void            setViewerObject(LLViewerObject* object);
    void            setPool(LLFacePool *pool, LLViewerTexture *texturep);
    void            setPool(LLFacePool* pool);

    void            setDrawable(LLDrawable *drawable);
    void            setTEOffset(const S32 te_offset);

    void            renderIndexed();

    void            setFaceColor(const LLColor4& color); // override material color
    void            unsetFaceColor(); // switch back to material color
    const LLColor4& getFaceColor() const { return mFaceColor; }


    //for volumes
    void updateRebuildFlags();
    bool canRenderAsMask(); // logic helper
    bool getGeometryVolume(const LLVolume& volume,
                            S32 face_index,
                            const LLMatrix4& mat_vert,
                            const LLMatrix3& mat_normal,
                            U16 index_offset,
                            bool force_rebuild = false,
                            bool no_debug_assert = false,
                            bool rebuild_for_gltf = false);

    // For avatar
    U16          getGeometryAvatar(
                                    LLStrider<LLVector3> &vertices,
                                    LLStrider<LLVector3> &normals,
                                    LLStrider<LLVector2> &texCoords,
                                    LLStrider<F32>       &vertex_weights,
                                    LLStrider<LLVector4> &clothing_weights);

    // For volumes, etc.
    U16             getGeometry(LLStrider<LLVector3> &vertices,
                                LLStrider<LLVector3> &normals,
                                LLStrider<LLVector2> &texCoords,
                                LLStrider<U16>  &indices);

    S32 getColors(LLStrider<LLColor4U> &colors);
    S32 getIndices(LLStrider<U16> &indices);

    void        setSize(S32 numVertices, S32 num_indices = 0, bool align = false);

    bool        genVolumeBBoxes(const LLVolume &volume, S32 f,
                                    const LLMatrix4& mat_vert_in, bool global_volume = false);

    void        init(LLDrawable* drawablep, LLViewerObject* objp);
    void        destroy();
    void        update();

    void        updateCenterAgent(); // Update center when xform has changed.
    void        renderSelectedUV();

    void        renderSelected(LLViewerTexture *image, const LLColor4 &color);
    void        renderOneWireframe(const LLColor4 &color, F32 fogCfx, bool wireframe_selection, bool bRenderHiddenSelections, bool shader);

    F32         getKey()                    const   { return mDistance; }

    S32         getReferenceIndex()         const   { return mReferenceIndex; }
    void        setReferenceIndex(const S32 index)  { mReferenceIndex = index; }

    bool        verify(const U32* indices_array = NULL) const;
    void        printDebugInfo() const;

    void        setGeomIndex(U16 idx);
    void        setIndicesIndex(S32 idx);
    void        setDrawInfo(LLDrawInfo* draw_info);

    F32         getTextureVirtualSize() ;
    void        resetVirtualSize();

    void        setHasMedia(bool has_media)  { mHasMedia = has_media ;}
    bool        hasMedia() const ;

    void        setMediaAllowed(bool is_media_allowed)  { mIsMediaAllowed = is_media_allowed; }
    bool        isMediaAllowed() const { return mIsMediaAllowed; }

    bool        switchTexture() ;

    //vertex buffer tracking
    void setVertexBuffer(LLVertexBuffer* buffer);
    void clearVertexBuffer(); //sets mVertexBuffer to NULL
    LLVertexBuffer* getVertexBuffer()   const   { return mVertexBuffer; }
    S32 getRiggedIndex(U32 type) const;

    // used to preserve draw order of faces that are batched together.
    // Allows content creators to manipulate linked sets and face ordering
    // for consistent alpha sorting results, particularly for rigged attachments
    void setDrawOrderIndex(U32 index) { mDrawOrderIndex = index; }
    U32 getDrawOrderIndex() const { return mDrawOrderIndex; }

    // return true if this face is in an alpha draw pool
    bool isInAlphaPool() const;
public: //aligned members

    // bounding box of face in drawable space
    LLVector4a      mExtents[2];

    // cached bounding box of rigged face in world space
    // calculated on-demand by LLFace::calcPixelArea and may not be up-to-date
    LLVector4a  mRiggedExtents[2] = { LLVector4a(0,0,0), LLVector4a(0,0,0) };

private:
    friend class LLViewerTextureList;
    F32         adjustPartialOverlapPixelArea(F32 cos_angle_to_view_dir, F32 radius );
    bool        calcPixelArea(F32& cos_angle_to_view_dir, F32& radius) ;
public:
    static F32 calcImportanceToCamera(F32 to_view_dir, F32 dist);
    static F32 adjustPixelArea(F32 importance, F32 pixel_area) ;

public:

    LLVector3       mCenterLocal;
    LLVector3       mCenterAgent;

    LLVector2       mTexExtents[2];
    F32             mDistance;
    F32         mLastUpdateTime;
    F32         mLastSkinTime;
    F32         mLastMoveTime;
    LLMatrix4*  mTextureMatrix;
    LLMatrix4*  mSpecMapMatrix;
    LLMatrix4*  mNormalMapMatrix;
    LLDrawInfo* mDrawInfo;
    LLVOAvatar* mAvatar = nullptr;
    LLMeshSkinInfo* mSkinInfo = nullptr;

    // return mSkinInfo->mHash or 0 if mSkinInfo is null
    U64 getSkinHash();

    // true if face was recently in the main camera frustum according to LLViewerTextureList updates
    bool mInFrustum = false;
    // value of gFrameCount the last time the face was touched by LLViewerTextureList::updateImageDecodePriority
    U32 mLastTextureUpdate = 0;

private:
    LLPointer<LLVertexBuffer> mVertexBuffer;
    LLPointer<LLVertexBuffer> mVertexBufferGLTF;

    U32         mState;
    LLFacePool* mDrawPoolp;
    U32         mPoolType;
    LLColor4    mFaceColor;         // overrides material color if state |= USE_FACE_COLOR

    U16         mGeomCount;         // vertex count for this face
    U16         mGeomIndex;         // starting index into mVertexBuffer's vertex array
    U8          mTextureIndex;      // index of texture channel to use for pseudo-atlasing
    U32         mIndicesCount;
    U32         mIndicesIndex;      // index into mVertexBuffer's index array
    S32         mIndexInTex[LLRender::NUM_TEXTURE_CHANNELS];

    LLXformMatrix* mXform;

    LLPointer<LLViewerTexture> mTexture[LLRender::NUM_TEXTURE_CHANNELS];

    // mDrawablep is not supposed to be null, don't use LLPointer because
    // mDrawablep owns LLFace and LLPointer is a good way to either cause a
    // memory leak or a 'delete each other' situation if something deletes
    // drawable wrongly.
    LLDrawable* mDrawablep;
    // LLViewerObject technically owns drawable, but also it should be strictly managed
    LLPointer<LLViewerObject> mVObjp;
    S32         mTEOffset;

    S32         mReferenceIndex;
    std::vector<S32> mRiggedIndex;

    // gFrameTimeSeconds when mPixelArea was last updated
    F32         mLastPixelAreaUpdate = 0.f;

    // virtual size of face in texture area  (mPixelArea adjusted by texture repeats)
    // used to determine desired resolution of texture
    F32         mVSize;

    // pixel area face covers on screen
    F32         mPixelArea;

    //importance factor, in the range [0, 1.0].
    //1.0: the most important.
    //based on the distance from the face to the view point and the angle from the face center to the view direction.
    F32         mImportanceToCamera ;
    F32         mBoundingSphereRadius ;
    bool        mHasMedia ;
    bool        mIsMediaAllowed;

    U32 mDrawOrderIndex = 0; // see setDrawOrderIndex

protected:
    static bool sSafeRenderSelect;

public:
    struct CompareDistanceGreater
    {
        bool operator()(const LLFace* const& lhs, const LLFace* const& rhs)
        {
            return !lhs || (rhs && (lhs->mDistance > rhs->mDistance)); // farthest = first
        }
    };

    struct CompareTexture
    {
        bool operator()(const LLFace* const& lhs, const LLFace* const& rhs)
        {
            return lhs->getTexture() < rhs->getTexture();
        }
    };

    struct CompareBatchBreaker
    {
        bool operator()(const LLFace* const& lhs, const LLFace* const& rhs)
        {
            const LLTextureEntry* lte = lhs->getTextureEntry();
            const LLTextureEntry* rte = rhs->getTextureEntry();

            if(lhs->getTexture() != rhs->getTexture())
            {
                return lhs->getTexture() < rhs->getTexture();
            }
            else
            {
                return lte->getBumpShinyFullbright() < rte->getBumpShinyFullbright();
            }
        }
    };

    struct CompareTextureAndGeomCount
    {
        bool operator()(const LLFace* const& lhs, const LLFace* const& rhs)
        {
            return lhs->getTexture() == rhs->getTexture() ?
                lhs->getGeomCount() < rhs->getGeomCount() :  //smallest = first
                lhs->getTexture() > rhs->getTexture();
        }
    };

    struct CompareTextureAndLOD
    {
        bool operator()(const LLFace* const& lhs, const LLFace* const& rhs)
        {
            return lhs->getTexture() == rhs->getTexture() ?
                lhs->getLOD() < rhs->getLOD() :
                lhs->getTexture() < rhs->getTexture();
        }
    };

    struct CompareTextureAndTime
    {
        bool operator()(const LLFace* const& lhs, const LLFace* const& rhs)
        {
            return lhs->getTexture() == rhs->getTexture() ?
                lhs->mLastUpdateTime < rhs->mLastUpdateTime :
                lhs->getTexture() < rhs->getTexture();
        }
    };
};

#endif // LL_LLFACE_H