ItemSorter.cpp

Go to the documentation of this file.

/*
Copyright (C) 2003-2004 The Pentagram team

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

#include "pent_include.h"
#include "ItemSorter.h"

#include "Item.h"
#include "Shape.h"
#include "ShapeFrame.h"
#include "ShapeInfo.h"
#include "MainShapeArchive.h"
#include "RenderSurface.h"
#include "Rect.h"
#include "GameData.h"

// temp
#include "WeaponOverlay.h"
#include "MainActor.h"
#include "getObject.h"
// --

using Pentagram::Rect;

#if 0
template<class _T> class MyVector
{
public:
        typedef _T *iterator;
        typedef _T &reference;

private:
        iterator        _begin;
        iterator        _end;
        iterator        _last;

public:
        MyVector() 
        {
                _begin = 0;
                _end = 0;
                _last = 0;
        }

        iterator push_back(reference _R)
        {
                if (!_begin)
                {
                        _begin = new _T[1];
                        _end = _last = _begin + 1;
                        *_begin = _R;
                        return _begin;
                }
                
                if (_end == _last)      // At the end of the list, need to allocate more
                {
                        size_t _capacity = _last - _begin;
                        iterator _new = new _T[_capacity*2];
                        std::memcpy (_new, _begin, _capacity * sizeof(_T));
                        _end = _new + (_end - _begin);
                        delete [] _begin;
                        _begin = _new;
                        _last = _begin + (_capacity*2);
                }
                *_end = _R;
                _end++;
                return _end-1;
        }

        void clear() { _end = _begin; }

        iterator begin() { return _begin; }
        iterator end() { return _end; }
private:

        
};

#endif

// This does NOT need to be in the header

struct SortItem
{
        SortItem() : item_num(0), shape(0), order(-1), depends() { }

        uint16                                  item_num;       // Owner item number

        Shape                                   *shape;
        uint32                                  shape_num;
        uint32                                  frame;
        uint32                                  flags;          // Item flags
        uint32                                  ext_flags;      // Item extended flags

        int                                             sx, sx2;        // Screenspace X coords
        int                                             sy, sy2;        // Screenspace Y coords

        /*
                                Bounding Box layout

                   1    
                 /   \      
           /       \     1 = Left  Far  Top LFT --+
         2           3   2 = Left  Near Top LNT -++
         | \       / |   3 = Right Far  Top RFT +-+
         |   \   /   |   4 = Right Near Top RNT +++
         |     4     |   5 = Left  Near Bot LNB -+-
         |     |     |   6 = Right Far  Bot RFB +--
         5     |     6   7 = Right Near Bot LNB ++- 
           \   |   /     8 = Left  Far  Bot LFB --- (not shown)
                 \ | /    
                   7    

        */

        sint32  x, xleft;       // Worldspace bounding box x (xright = x)
        sint32  y, yfar;        // Worldspace bounding box y (ynear = y)
        sint32  z, ztop;        // Worldspace bounding box z (ztop = z)

        sint32  sxleft;         // Screenspace bounding box left extent    (LNT x coord)
        sint32  sxright;        // Screenspace bounding box right extent   (RFT x coord)

        sint32  sxtop;          // Screenspace bounding box top x coord    (LFT x coord)
        sint32  sytop;          // Screenspace bounding box top extent     (LFT y coord)

        sint32  sxbot;          // Screenspace bounding box bottom x coord (RNB x coord) ss origin
        sint32  sybot;          // Screenspace bounding box bottom extent  (RNB y coord) ss origin

        bool    f32x32 : 1;                     // Needs 1 bit  0
        bool    flat : 1;                       // Needs 1 bit  1
        bool    occl : 1;                       // Needs 1 bit  2
        bool    solid : 1;                      // Needs 1 bit  3
        bool    draw : 1;                       // Needs 1 bit  4
        bool    roof : 1;                       // Needs 1 bit  5
        bool    noisy : 1;                      // Needs 1 bit  6
        bool    anim : 1;                       // Needs 1 bit  7
        bool    trans : 1;                      // Needs 1 bit  8
        bool    fixed : 1;
        bool    land : 1;

        bool    occluded : 1;           // Set true if occluded

        sint16  clipped;                        // Clipped to RenderSurface

        sint32  order;          // Rendering order. -1 is not yet drawn

        std::vector<SortItem *> depends;        // All this Items dependencies (i.e. all objects behind)
//      MyVector<SortItem *>    depends;        // All this Items dependencies (i.e. all objects behind)

        // Functions

        // Check to see if we overlap si2
        inline bool overlap(const SortItem &si2) const;

        // Check to see if we occlude si2
        inline bool occludes(const SortItem &si2) const;

        // Operator less than
        inline bool operator<(const SortItem& si2) const;

        // Operator left shift (ok, what this does it output the comparisons)
        inline bool operator<<(const SortItem& si2) const;

};

typedef std::vector<SortItem *> SortItemVector;
//typedef MyVector<SortItem *> SortItemVector;

// Check to see if we overlap si2
inline bool SortItem::overlap(const SortItem &si2) const
{
        const int point_top_diff[2] = { sxtop - si2.sxbot, sytop - si2.sybot };
        const int point_bot_diff[2] = { sxbot - si2.sxtop, sybot - si2.sytop };

        // This function is a bit of a hack. It uses dot products between
        // points and the lines. Nothing is normalized since that isn't 
        // important

        // 'normal' of top  left line ( 2,-1) of the bounding box
        const sint32 dot_top_left = point_top_diff[0] + point_top_diff[1] * 2;

        // 'normal' of top right line ( 2, 1) of the bounding box
        const sint32 dot_top_right = -point_top_diff[0] + point_top_diff[1] * 2;

        // 'normal' of bot  left line (-2,-1) of the bounding box
        const sint32 dot_bot_left =  point_bot_diff[0] - point_bot_diff[1] * 2;

        // 'normal' of bot right line (-2, 1) of the bounding box
        const sint32 dot_bot_right = -point_bot_diff[0] - point_bot_diff[1] * 2;

        const bool right_clear = sxright <= si2.sxleft;
        const bool left_clear = sxleft >= si2.sxright;
        const bool top_left_clear = dot_top_left >= 0;
        const bool top_right_clear = dot_top_right >= 0;
        const bool bot_left_clear = dot_bot_left >= 0;
        const bool bot_right_clear = dot_bot_right >= 0;

        const bool clear = right_clear | left_clear | 
                bot_right_clear | bot_left_clear |
                top_right_clear | top_left_clear;

        return !clear;
}

// Check to see if we occlude si2
inline bool SortItem::occludes(const SortItem &si2) const
{
        const int point_top_diff[2] = { sxtop - si2.sxtop, sytop - si2.sytop };
        const int point_bot_diff[2] = { sxbot - si2.sxbot, sybot - si2.sybot };

        // This function is a bit of a hack. It uses dot products between
        // points and the lines. Nothing is normalized since that isn't 
        // important

        // 'normal' of top left line ( 2, -1) of the bounding box
        const sint32 dot_top_left = point_top_diff[0] + point_top_diff[1] * 2;

        // 'normal' of top right line ( 2, 1) of the bounding box
        const sint32 dot_top_right = -point_top_diff[0] + point_top_diff[1] * 2;

        // 'normal' of bot  left line (-2,-1) of the bounding box
        const sint32 dot_bot_left =  point_bot_diff[0] - point_bot_diff[1] * 2;

        // 'normal' of bot right line (-2, 1) of the bounding box
        const sint32 dot_bot_right = -point_bot_diff[0] - point_bot_diff[1] * 2;


        const bool right_res = sxright >= si2.sxright;
        const bool left_res = sxleft <= si2.sxleft;
        const bool top_left_res = dot_top_left <= 0;
        const bool top_right_res = dot_top_right <= 0;
        const bool bot_left_res = dot_bot_left <= 0;
        const bool bot_right_res = dot_bot_right <= 0;

        const bool occluded = right_res & left_res & 
                bot_right_res & bot_left_res &
                top_right_res & top_left_res;

        return occluded;
}

inline bool SortItem::operator<(const SortItem& si2) const
{
        const SortItem& si1 = *this;
        
        // Specialist z flat handling
        if (si1.flat && si2.flat)
        {
                // Differing z is easy for flats
                if (si1.ztop != si2.ztop) return si1.ztop < si2.ztop;

                // Equal z

                // Animated always gets drawn after
                if (si1.anim != si2.anim) return si1.anim < si2.anim;

                // Trans always gets drawn after
                if (si1.trans != si2.trans) return si1.trans < si2.trans;

                // Draw always gets drawn first
                if (si1.draw != si2.draw) return si1.draw > si2.draw;

                // Solid always gets drawn first
                if (si1.solid != si2.solid) return si1.solid > si2.solid;

                // Occludes always get drawn first
                if (si1.occl != si2.occl) return si1.occl > si2.occl;

                // 32x32 flats get drawn first
                if (si1.f32x32 != si2.f32x32) return si1.f32x32 > si2.f32x32;
        }
        // Mixed, or non flat
        else {

                // Clearly X, Y and Z (useful?)
                //if (si1.x <= si2.xleft && si1.y <= si2.yfar && si1.ztop <= si2.z) return true;
                //else if (si1.xleft >= si2.x && si1.yfar >= si2.y && si1.z >= si2.ztop) return false;

                //int front1 = si1.x + si1.y;
                //int rear1 = si1.xleft + si1.yfar;
                //int front2 = si2.x + si2.y;
                //int rear2 = si2.xleft + si2.yfar;

                // Rear of object is infront of other's front
                //if (front1 <= rear2) return true;
                //else if (rear1 >= front2) return false;

                // Clearly in z
                if (si1.ztop <= si2.z) return true;
                else if (si1.z >= si2.ztop) return false;

                // Partial in z
                //if (si1.ztop != si2.ztop) return si1.ztop < si2.ztop;
        }

        // Clearly in x and y? (useful?)
        //if (si1.x <= si2.xleft && si1.y <= si2.yfar) return true;
        //else if (si1.xleft >= si2.x && si1.yfar >= si2.y) return false;

        // Clearly in x?
        if (si1.x <= si2.xleft) return true;
        else if (si1.xleft >= si2.x) return false;

        // Clearly in y?
        if (si1.y <= si2.yfar) return true;
        else if (si1.yfar >= si2.y) return false;

        // Are overlapping in all 3 dimentions if we come here

        // ZTops?
        if (si1.ztop < si2.ztop) return true;
        else if (si1.ztop > si2.ztop) return false;

        // Biased Clearly in z
        if ((si1.ztop+si1.z)/2 <= si2.z) return true;
        else if (si1.z >= (si2.ztop+si2.z)/2) return false;

        // Biased Clearly X
        if ((si1.x+si1.xleft)/2 <= si2.xleft) return true;
        else if (si1.xleft >= (si2.x+si2.xleft)/2) return false;

        // Biased Clearly Y
        if ((si1.y+si1.yfar)/2 <= si2.yfar) return true;
        else if (si1.yfar >= (si2.y+si2.yfar)/2) return false;

        // Partial in X + Y front
        if (si1.x + si1.y != si1.x + si2.y) return (si1.x + si1.y < si2.x + si2.y);

        // Partial in X + Y back
        if (si1.xleft + si1.yfar != si1.xleft + si2.yfar) return (si1.xleft + si1.yfar < si2.xleft + si2.yfar);

        // Partial in x?
        if (si1.x != si2.x) return si1.x < si2.x;

        // Partial in y?
        if (si1.y != si2.y) return si1.y < si2.y;

        // Just sort by shape number - not a number any more (is a pointer)
        if (si1.shape_num != si2.shape_num) return si1.shape_num < si2.shape_num;

        // And then by frame
        return si1.frame < si2.frame;
}

#define COMPARISON_RETURN(val,op,tab)                                                           \
                pout << tab"if (si1."#val" != si2."#val") -> ("                         \
                                << si1.val << " != " << si2.val << ") -> "                      \
                                << (si1.val != si2.val) << std::endl;                           \
                pout << tab"{" << std::endl;                                                            \
                if (si1.val != si2.val)                                                                         \
                {                                                                                                                       \
                        pout << tab"\treturn si1."#val" "#op" si2."#val"; -> (" \
                                                << si1.val << " "#op" " << si2.val << ") -> "\
                                                << (si1.val op si2.val) << std::endl;           \
                        return si1.val op si2.val;                                                              \
                }                                                                                                                       \
                pout << tab"}" << std::endl;

#define COMPARISON_RETURN_EX(val1,op,val2,tab)                                          \
                pout << tab"if ("#val1" != "#val2") -> ("                                       \
                                << val1 << " != " << val2 << ") -> "                            \
                                << (val1 != val2) << std::endl;                                         \
                pout << tab"{" << std::endl;                                                            \
                if (val1 != val2)                                                                                       \
                {                                                                                                                       \
                        pout << tab"\treturn "#val1" "#op" "#val2"; -> ("               \
                                                << val1 << " "#op" " << val2 << ") -> "         \
                                                << (val1 op val2) << std::endl;                         \
                        return val1 op val2;                                                                    \
                }                                                                                                                       \
                pout << tab"}" << std::endl;

#define COMPARISON_RETURN_TF(val1,op,val2,tf,tab)                                       \
        pout << tab "if ("#val1" "#op" "#val2") -> ("                                   \
                                << val1 << " "#op" " << val2 << ") -> "                         \
                                << (val1 op val2) << std::endl;                                         \
                pout << tab"{" << std::endl;                                                            \
                if (val1 op val2)                                                                                       \
                {                                                                                                                       \
                        pout << tab"\treturn " << tf << std::endl;                              \
                        return tf;                                                                                              \
                }                                                                                                                       \
                pout << tab"}" << std::endl;

inline bool SortItem::operator<<(const SortItem& si2) const
{
        const SortItem& si1 = *this;
        
        if (si2.overlap(si1)) pout << "Overlaping" << std::endl;
        else 
        {
                 pout << "Not Overlaping" << std::endl;
                 return false;
        }

        // Specialist z flat handling
        pout << "if (si1.flat && si2.flat) -> if (" 
                        << si1.flat << " && " << si2.flat << ") -> " 
                        << (si1.flat && si2.flat) << std::endl;
        pout << "{" << std::endl;

        if (si1.flat && si2.flat)
        {
                // Differing z is easy for flats
                //if (si1.ztop != si2.ztop) return si1.ztop < si2.ztop;
                COMPARISON_RETURN(ztop,<,"\t");

                // Equal z

                // Animated always gets drawn after
                //if (si1.anim != si2.anim) return si1.anim < si2.anim;
                COMPARISON_RETURN(anim,<,"\t");

                // Trans always gets drawn after
                //if (si1.trans != si2.trans) return si1.trans < si2.trans;
                COMPARISON_RETURN(trans,<,"\t");

                // Draw always gets drawn first
                //if (si1.draw != si2.draw) return si1.draw > si2.draw;
                COMPARISON_RETURN(draw,>,"\t");

                // Solid always gets drawn first
                //if (si1.solid != si2.solid) return si1.solid > si2.solid;
                COMPARISON_RETURN(solid,>,"\t");

                // Occludes always get drawn first
                //if (si1.occl != si2.occl) return si1.occl > si2.occl;
                COMPARISON_RETURN(occl,>,"\t");

                // 32x32 flats get drawn first
                //if (si1.f32x32 != si2.f32x32) return si1.f32x32 > si2.f32x32;
                COMPARISON_RETURN(f32x32,>,"\t");
        }
        // Mixed, or non flat
        else {
                pout << "}" << std::endl;
                pout << "else" << std::endl;
                pout << "{" << std::endl;

                // Clearly X, Y and Z  (useful?)
                //if (si1.x <= si2.xleft && si1.y <= si2.yfar && si1.ztop <= si2.z) return true;
                //else if (si1.xleft >= si2.x && si1.yfar >= si2.y && si1.z >= si2.ztop) return false;

                //int front1 = si1.x + si1.y;
                //int rear1 = si1.xleft + si1.yfar;
                //int front2 = si2.x + si2.y;
                //int rear2 = si2.xleft + si2.yfar;

                // Rear of object is infront of other's front
                //if (front1 <= rear2) return true;
                //else if (rear1 >= front2) return false;
                //COMPARISON_RETURN_TF(front1,<=,rear2,true,"\t");
                //COMPARISON_RETURN_TF(rear1,>=,front2,false,"\t");

                // Clearly in z
                //if (si1.ztop <= si2.z) return true;
                //else if (si1.z >= si2.ztop) return false;
                COMPARISON_RETURN_TF(si1.ztop,<=,si2.z,true,"\t");
                COMPARISON_RETURN_TF(si1.z,>=,si2.ztop,false,"\t");

                // Partial in z
                //if (si1.ztop != si2.ztop) return si1.ztop < si2.ztop;
        }
        pout << "}" << std::endl;

        // Clearly in x and y? (useful?)
        //if (si1.x <= si2.xleft && si1.y <= si2.yfar) return true;
        //else if (si1.xleft >= si2.x && si1.yfar >= si2.y) return false;

        // Clearly X
        //if (si1.x <= si2.xleft) return true;
        //else if (si1.xleft >= si2.x) return false;
        COMPARISON_RETURN_TF(si1.x,<=,si2.xleft,true,"\t");
        COMPARISON_RETURN_TF(si1.xleft,>=,si2.x,false,"\t");

        // Clearly Y
        //if (si1.y <= si2.yfar) return true;
        //else if (si1.yfar >= si2.y) return false;
        COMPARISON_RETURN_TF(si1.y,<=,si2.yfar,true,"\t");
        COMPARISON_RETURN_TF(si1.yfar,>=,si2.y,false,"\t");

        // ZTops?
        COMPARISON_RETURN_TF(si1.ztop,<,si2.z,true,"");
        COMPARISON_RETURN_TF(si1.ztop,>,si2.ztop,false,"");

        // Biased Clearly in z
        //if ((si1.ztop+si1.z)/2 <= si2.z) return true;
        //else if (si1.z >= (si2.ztop+si2.z)/2) return false;
        COMPARISON_RETURN_TF((si1.ztop+si1.z)/2,<=,si2.z,true,"");
        COMPARISON_RETURN_TF(si1.z,>=,(si2.ztop+si2.z)/2,false,"");

        // Biased Clearly X
        //if ((si1.x+si1.xleft)/2 <= si2.xleft) return true;
        //else if (si1.xleft >= (si2.x+si2.xleft)/2) return false;
        COMPARISON_RETURN_TF((si1.x+si1.xleft)/2,<=,si2.xleft,true,"");
        COMPARISON_RETURN_TF(si1.xleft,>=,(si2.x+si2.xleft)/2,false,"");

        // Biased Clearly Y
        //if ((si1.y+si1.yfar)/2 <= si2.yfar) return true;
        //else if (si1.yfar >= (si2.y+si2.yfar)/2) return false;
        COMPARISON_RETURN_TF((si1.y+si1.yfar)/2,<=,si2.yfar,true,"");
        COMPARISON_RETURN_TF(si1.yfar,>=,(si2.y+si2.yfar)/2,false,"");

        // Partial in X + Y front
        //if (si1.x + si1.y != si1.x + si2.y) return (si1.x + si1.y < si2.x + si2.y);
        COMPARISON_RETURN_EX(si1.x + si1.y,<,si1.x + si2.y,"");

        // Partial in X + Y back
        //if (si1.xleft + si1.yfar != si1.xleft + si2.yfar) return (si1.xleft + si1.yfar < si2.xleft + si2.yfar);
        COMPARISON_RETURN_EX(si1.xleft + si1.yfar,<,si1.xleft + si2.yfar,"");

        // Partial in x?
        //if (si1.x != si2.x) return si1.x < si2.x;
        COMPARISON_RETURN(x,<,"");

        // Partial in y?
        //if (si1.y != si2.y) return si1.y < si2.y;
        COMPARISON_RETURN(y,<,"");

        // Just sort by shape number
//      if (si1.shape_num != si2.shape_num) return si1.shape_num < si2.shape_num;
        COMPARISON_RETURN(shape_num,<,"");

        // And then by frame
        //return si1.frame < si2.frame;
        COMPARISON_RETURN(frame,<,"");
        return 0;
}

// 
// ItemSorter
//

ItemSorter::ItemSorter(int Max_Items) : 
                shapes(0), surf(0), max_items(Max_Items), num_items(0), num_extra(0), sort_limit(0)
{
        if (max_items <= 0) max_items = Max_Items = 2048;
        items = new SortItem [max_items];
}

ItemSorter::~ItemSorter()
{
        delete [] items;
}

void ItemSorter::BeginDisplayList(RenderSurface *rs,
                                                                  sint32 camx, sint32 camy, sint32 camz)
{
        // Get the shapes, if required
        if (!shapes) shapes = GameData::get_instance()->getMainShapes();

        // Need to resize
        if (num_extra)
        {
                delete [] items;
                max_items += num_extra*2;
                items = new SortItem [max_items];
        }
        // Set the RenderSurface, and reset the item list
        surf = rs;
        num_items = 0;
        order_counter = 0;
        num_extra = 0;

        // Screenspace bounding box bottom x coord (RNB x coord)
        cam_sx = (camx - camy)/4;
        // Screenspace bounding box bottom extent  (RNB y coord)
        cam_sy = (camx + camy)/8 - camz;
}

void ItemSorter::AddItem(sint32 x, sint32 y, sint32 z, uint32 shape_num, uint32 frame_num, uint32 flags, uint32 ext_flags, uint16 item_num)
{
        //if (z > skip_lift) return;
        //if (Application::tgwds && shape == 538) return;

        // First thing, get a SortItem to use
        
        if (num_items >= max_items)
        {
                num_extra++;
                return;
        }

        SortItem *si = items+num_items;

        si->item_num = item_num;
        si->shape = shapes->getShape(shape_num);
        si->shape_num = shape_num;
        si->frame = frame_num;
        ShapeFrame *frame = si->shape->getFrame(si->frame);
        if (!frame) {
                perr << "Invalid shape: " << si->shape_num << "," << si->frame
                         << std::endl;
                return;
        }

        ShapeInfo *info = shapes->getShapeInfo(shape_num);

        //if (info->is_editor && !show_editor_items) return;
        //if (info->z > shape_max_height) return;

        // Dimensions
        sint32 xd, yd, zd;
        si->flags = flags;
        si->ext_flags = ext_flags;

        // X and Y are flipped
        if (si->flags & Item::FLG_FLIPPED) 
        {
                xd = info->y * 32;      // Multiply by 32 to get actual world size
                yd = info->x * 32;      // Multiply by 32 to get actual world size
        }
        else
        {
                xd = info->x * 32;      // Multiply by 32 to get actual world size
                yd = info->y * 32;      // Multiply by 32 to get actual world size
        }

        zd = info->z * 8;       // Multiply by 8 to get actual world size

        // Worldspace bounding box
        si->x = x; si->y = y; si->z = z;
        si->xleft = si->x - xd;
        si->yfar = si->y - yd;
        si->ztop = si->z + zd;

        // Screenspace bounding box left extent    (LNT x coord)
        si->sxleft = (si->xleft - si->y)/4 - cam_sx;
        // Screenspace bounding box right extent   (RFT x coord)
        si->sxright= (si->x - si->yfar)/4 - cam_sx;

        // Screenspace bounding box top x coord    (LFT x coord)
        si->sxtop = (si->xleft - si->yfar)/4 - cam_sx;
        // Screenspace bounding box top extent     (LFT y coord)
        si->sytop = (si->xleft + si->yfar)/8 - si->ztop - cam_sy;

        // Screenspace bounding box bottom x coord (RNB x coord)
        si->sxbot = (si->x - si->y)/4 - cam_sx;
        // Screenspace bounding box bottom extent  (RNB y coord)
        si->sybot = (si->x + si->y)/8 - si->z - cam_sy;

//      si->sxleft += swo2;
//      si->sxright += swo2;
//      si->sxbot += swo2;
//      si->sxtop += swo2;

//      si->sytop += sho2;
//      si->sybot += sho2;

        // Real Screenspace coords
        si->sx = si->sxbot - frame->xoff;       // Left
        si->sy = si->sybot - frame->yoff;       // Top
        si->sx2 = si->sx + frame->width;        // Right
        si->sy2 = si->sy + frame->height;       // Bottom

        // Do Clipping here
        si->clipped = surf->CheckClipped(Rect (si->sx,si->sy, frame->width, frame->height));
        if (si->clipped < 0) return;

        // These help out with sorting. We calc them now, so it will be faster
        si->f32x32 = xd==128 && yd==128;
        si->flat = zd == 0;

        /*
        if (Application::tgwds) {
                si->draw = false;
                si->solid = false;
                si->occl = false;
                si->roof = false;
                si->noisy = false;
                si->anim = false;
                si->trans = false;
        }
        else
        */
        {
                si->draw = info->is_draw();
                si->solid = info->is_solid();
                si->occl = info->is_occl() && !(si->ext_flags & Item::FLG_INVISIBLE);
                si->roof = info->is_roof();
                si->noisy = info->is_noisy();
                si->anim = info->animtype != 0;
                si->trans = info->is_translucent();
                si->fixed = info->is_fixed();
                si->land = info->is_land();
        }

        si->occluded = false;
        si->order = -1;

        // We will clear all the vector memory
        // Stictly speaking the vector will sort of leak memory, since they
        // are never deleted
        //si->depends.clear();
        si->depends.erase(si->depends.begin(), si->depends.end());      // MSVC.Netism

        // Iterate the list and compare shapes

        // Ok, 
        for (SortItem * si2 = items; si2 != si; ++si2)
        {
                // Doesn't overlap
                if (si2->occluded || !si->overlap(*si2)) continue;

                // Attempt to find which is infront
                if (*si < *si2)
                {
                        // si2 occludes si (us)
                        if (si2->occl && si2->occludes(*si))
                        {
                                // No need to do any more checks, this isn't visible
                                si->occluded = true;
                                break;
                        }

                        // si1 is behind si2, so add it to si2's dependency list
                        si2->depends.push_back(si);
                }
                else
                {
                        // ss occludes si2. Sadly, we can't remove it from the list.
                        if (si->occl && si->occludes(*si2)) si2->occluded = true;
                        // si2 is behind si1, so add it to si1's dependency list
                        else si->depends.push_back(si2);
                }
        }

        // Incrementing num_items adds the Item to the list
        num_items ++;
}

void ItemSorter::AddItem(Item *add)
{
#if 0

        sint32 x, y, z;
        add->getLerped(x, y, z);
        AddItem(x,y,z,add->getShape(), add->getFrame(), add->getFlags(), add->getObjId());

#else

        //if (add->iz > skip_lift) return;
        //if (Application::tgwds && shape == 538) return;

        // First thing, get a SortItem to use
        
        if (num_items >= max_items)
        {
                num_extra++;
                return;
        }

        SortItem *si = items+num_items;

        si->item_num = add->getObjId();
        si->shape = add->getShapeObject();
        si->shape_num = add->getShape();
        si->frame = add->getFrame();
        ShapeFrame *frame = si->shape->getFrame(si->frame);
        if (!frame) {
                perr << "Invalid shape: " << si->shape_num << "," << si->frame
                         << std::endl;
                return;
        }

        ShapeInfo *info = add->getShapeInfo();

        //if (info->is_editor && !show_editor_items) return;
        //if (info->z > shape_max_height) return;

        // Dimensions
        sint32 xd, yd, zd;
        si->flags = add->getFlags();
        si->ext_flags = add->getExtFlags();

        // X and Y are flipped
        if (si->flags & Item::FLG_FLIPPED) 
        {
                xd = info->y * 32;      // Multiply by 32 to get actual world size
                yd = info->x * 32;      // Multiply by 32 to get actual world size
        }
        else
        {
                xd = info->x * 32;      // Multiply by 32 to get actual world size
                yd = info->y * 32;      // Multiply by 32 to get actual world size
        }

        zd = info->z * 8;       // Multiply by 8 to get actual world size

        // Worldspace bounding box
        add->getLerped(si->x, si->y, si->z);
        si->xleft = si->x - xd;
        si->yfar = si->y - yd;
        si->ztop = si->z + zd;

        // Screenspace bounding box left extent    (LNT x coord)
        si->sxleft = (si->xleft - si->y)/4 - cam_sx;
        // Screenspace bounding box right extent   (RFT x coord)
        si->sxright= (si->x - si->yfar)/4 - cam_sx;

        // Screenspace bounding box top x coord    (LFT x coord)
        si->sxtop = (si->xleft - si->yfar)/4 - cam_sx;
        // Screenspace bounding box top extent     (LFT y coord)
        si->sytop = (si->xleft + si->yfar)/8 - si->ztop - cam_sy;

        // Screenspace bounding box bottom x coord (RNB x coord)
        si->sxbot = (si->x - si->y)/4 - cam_sx;
        // Screenspace bounding box bottom extent  (RNB y coord)
        si->sybot = (si->x + si->y)/8 - si->z - cam_sy;

//      si->sxleft += swo2;
//      si->sxright += swo2;
//      si->sxbot += swo2;
//      si->sxtop += swo2;

//      si->sytop += sho2;
//      si->sybot += sho2;

        // Real Screenspace coords
        si->sx = si->sxbot - frame->xoff;       // Left
        si->sy = si->sybot - frame->yoff;       // Top
        si->sx2 = si->sx + frame->width;        // Right
        si->sy2 = si->sy + frame->height;       // Bottom

        // Do Clipping here
        si->clipped = surf->CheckClipped(Rect (si->sx,si->sy, frame->width, frame->height));
        if (si->clipped < 0) return;

        // Thes