//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// 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.
//
// DESCRIPTION:
//	Preparation of data for rendering,
//	generation of lookups, caching, retrieval by name.
//

#include "essence/include.h"

#include "i_swap.h"
#include "i_system.h"
#include "z_zone.h"


#include "w_wad.h"

#include "doomdef.h"
#include "m_misc.h"
#include "r_local.h"
#include "p_local.h"

#include "doomstat.h"
#include "r_sky.h"


#include "r_data.h"

//
// Graphics.
// DOOM graphics for walls and sprites
// is stored in vertical runs of opaque pixels (posts).
// A column is composed of zero or more posts,
// a patch or sprite is composed of zero or more columns.
// 

//
// Texture definition.
// Each texture is composed of one or more patches,
// with patches being lumps stored in the WAD.
// The lumps are referenced by number, and patched
// into the rectangular texture space using origin
// and possibly other attributes.
//
typedef struct
{
    short	originx;
    short	originy;
    short	patch;
    short	stepdir;
    short	colormap;
} PACKEDATTR mappatch_t;


//
// Texture definition.
// A DOOM wall texture is a list of patches
// which are to be combined in a predefined order.
//
typedef struct
{
    char		name[8];
    int			masked;	
    short		width;
    short		height;
    int         obsolete;
    short		patchcount;
    mappatch_t	patches[1];
} PACKEDATTR maptexture_t;


// A single patch from a texture definition,
//  basically a rectangular area within
//  the texture rectangle.
typedef struct
{
    // Block origin (allways UL),
    // which has allready accounted
    // for the internal origin of the patch.
    short	originx;	
    short	originy;
    int		patch;
} texpatch_t;


// A maptexturedef_t describes a rectangular texture,
//  which is composed of one or more mappatch_t structures
//  that arrange graphic patches.

typedef struct texture_s texture_t;

struct texture_s
{
    // Keep name for switch changing, etc.
    char	name[8];		
    short	width;
    short	height;

    // Index in textures list

    int         index;

    // Next in hash table chain

    texture_t  *next;
    
    // All the patches[patchcount]
    //  are drawn back to front into the cached texture.
    short	patchcount;
    texpatch_t	patches[1];		
};

int firstflat;
int lastflat;
int numflats;

int firstpatch;
int lastpatch;
int numpatches;

int	firstspritelump;
int	lastspritelump;
int	numspritelumps;

size_t numtextures = 0;
texture_t**	textures;
texture_t** textures_hashtable;


int*			texturewidthmask;
// needed for texture pegging
fixed_t*		textureheight;		
int*			texturecompositesize;
short**			texturecolumnlump;
unsigned short**	texturecolumnofs;
byte**			texturecomposite;

// for global animation
int* flattranslation;
int* texturetranslation;

// needed for pre rendering
fixed_t* spritewidth;	
fixed_t* spriteoffset;
fixed_t* spritetopoffset;

lighttable_t *colormaps;

//
// MAPTEXTURE_T CACHING
// When a texture is first needed,
//  it counts the number of composite columns
//  required in the texture and allocates space
//  for a column directory and any new columns.
// The directory will simply point inside other patches
//  if there is only one patch in a given column,
//  but any columns with multiple patches
//  will have new column_ts generated.
//

//
// R_DrawColumnInCache
// Clip and draw a column
//  from a patch into a cached post.
//
void
R_DrawColumnInCache
( column_t*	patch,
  byte*		cache,
  int		originy,
  int		cacheheight )
{
    int		count;
    int		position;
    byte*	source;

    while (patch->topdelta != 0xff)
    {
	source = (byte *)patch + 3;
	count = patch->length;
	position = originy + patch->topdelta;

	if (position < 0)
	{
	    count += position;
	    position = 0;
	}

	if (position + count > cacheheight)
	    count = cacheheight - position;

	if (count > 0)
	    ES_memcpy (cache + position, source, count);
		
	patch = (column_t *)(  (byte *)patch + patch->length + 4); 
    }
}

//
// R_GenerateComposite
// Using the texture definition,
//  the composite texture is created from the patches,
//  and each column is cached.
//
void R_GenerateComposite (int texnum)
{
    byte*		block;
    texture_t*		texture;
    texpatch_t*		patch;	
    patch_t*		realpatch;
    int			x;
    int			x1;
    int			x2;
    int			i;
    column_t*		patchcol;
    short*		collump;
    unsigned short*	colofs;
	
    texture = textures[texnum];

    block = Z_Malloc (texturecompositesize[texnum],
		      PU_STATIC, 
		      &texturecomposite[texnum]);	

    collump = texturecolumnlump[texnum];
    colofs = texturecolumnofs[texnum];
    
    // Composite the columns together.
    patch = texture->patches;
		
    for (i=0 , patch = texture->patches;
	 i<texture->patchcount;
	 i++, patch++)
    {
	realpatch = W_CacheLumpNum (patch->patch, PU_CACHE);
	x1 = patch->originx;
	x2 = x1 + SHORT(realpatch->width);

	if (x1<0)
	    x = 0;
	else
	    x = x1;
	
	if (x2 > texture->width)
	    x2 = texture->width;

	for ( ; x<x2 ; x++)
	{
	    // Column does not have multiple patches?
	    if (collump[x] >= 0)
		continue;
	    
	    patchcol = (column_t *)((byte *)realpatch
				    + LONG(realpatch->columnofs[x-x1]));
	    R_DrawColumnInCache (patchcol,
				 block + colofs[x],
				 patch->originy,
				 texture->height);
	}
						
    }

    // Now that the texture has been built in column cache,
    //  it is purgable from zone memory.
    Z_ChangeTag (block, PU_CACHE);
}

//
// R_GenerateLookup
//
void R_GenerateLookup (int texnum)
{
    texture_t*		texture;
    byte*		patchcount;	// patchcount[texture->width]
    texpatch_t*		patch;	
    patch_t*		realpatch;
    int			x;
    int			x1;
    int			x2;
    int			i;
    short*		collump;
    unsigned short*	colofs;
	
    texture = textures[texnum];

    // Composited texture not created yet.
    texturecomposite[texnum] = 0;
    
    texturecompositesize[texnum] = 0;
    collump = texturecolumnlump[texnum];
    colofs = texturecolumnofs[texnum];
    
    // Now count the number of columns
    //  that are covered by more than one patch.
    // Fill in the lump / offset, so columns
    //  with only a single patch are all done.
    patchcount = (byte *) Z_Malloc(texture->width, PU_STATIC, &patchcount);
    ES_memset (patchcount, 0, texture->width);
    patch = texture->patches;

    for (i=0, patch = texture->patches; i<texture->patchcount; i++, patch++)
    {
        realpatch = W_CacheLumpNum(patch->patch, PU_CACHE);
        x1 = patch->originx;
        x2 = x1 + SHORT(realpatch->width);
        
        if (x1 < 0)
            x = 0;
        else
            x = x1;

        if (x2 > texture->width)
            x2 = texture->width;

        for ( ; x<x2 ; x++)
        {
            patchcount[x]++;
            collump[x] = patch->patch;
            colofs[x] = LONG(realpatch->columnofs[x-x1])+3;
        }
    }

    for (x=0; x < texture->width; x++)
    {
        if (!patchcount[x])
        {
            ES_debugf("R_GenerateLookup: column without a patch (%s)\n",
                texture->name);
            return;
        }

        if (patchcount[x] > 1)
        {
            // Use the cached block.
            collump[x] = -1;	
            colofs[x] = texturecompositesize[texnum];
            
            if (texturecompositesize[texnum] > 0x10000-texture->height)
            {
            I_Error ("R_GenerateLookup: texture %i is >64k",
                texnum);
            }
            
            texturecompositesize[texnum] += texture->height;
        }
    }

    Z_Free(patchcount);
}

//
// R_GetColumn
//
byte*
R_GetColumn(int tex, int col) {
    int lump;
    int ofs;
	
    col &= texturewidthmask[tex];
    lump = texturecolumnlump[tex][col];
    ofs = texturecolumnofs[tex][col];
    
    if (lump > 0)
	return (byte *)W_CacheLumpNum(lump,PU_CACHE)+ofs;

    if (!texturecomposite[tex])
	R_GenerateComposite (tex);

    return texturecomposite[tex] + ofs;
}


static void GenerateTextureHashTable(void)
{
    texture_t **rover;
    int i;
    int key;

    textures_hashtable 
            = Z_Malloc(sizeof(texture_t *) * numtextures, PU_STATIC, 0);

    ES_memset(textures_hashtable, 0, sizeof(texture_t *) * numtextures);

    // Add all textures to hash table

    for (i=0; i<numtextures; ++i)
    {
        // Store index

        textures[i]->index = i;

        // Vanilla Doom does a linear search of the texures array
        // and stops at the first entry it finds.  If there are two
        // entries with the same name, the first one in the array
        // wins. The new entry must therefore be added at the end
        // of the hash chain, so that earlier entries win.

        key = W_LumpNameHash(textures[i]->name) % numtextures;

        rover = &textures_hashtable[key];

        while (*rover != NULL)
        {
            rover = &(*rover)->next;
        }

        // Hook into hash table

        textures[i]->next = NULL;
        *rover = textures[i];
    }
}

//
// R_InitTextures
// Initializes the texture list
//  with the textures from the world map.
//
void R_InitTextures (void)
{
    maptexture_t*	mtexture;
    texture_t*		texture;
    mappatch_t*		mpatch;
    texpatch_t*		patch;

    int			i;
    int			j;

    int*		maptex;
    int*		maptex2;
    int*		maptex1;
    
    char		name[9];
    char*		names;
    char*		name_p;
    
    int*		patchlookup;
    
    int			totalwidth;
    size_t		nummappatches;
    int			offset;
    int			maxoff;
    int			maxoff2;
    int			numtextures1;
    int			numtextures2;

    int*		directory;
    
    int			temp1;
    int			temp2;
    int			temp3;

    // Load the patch names from pnames.lmp.
    name[8] = 0;
    names = W_CacheLumpName("PNAMES", PU_STATIC);
    nummappatches = *(uint32_t*)names;
    name_p = names + 4;
    patchlookup = Z_Malloc(nummappatches * sizeof(*patchlookup), PU_STATIC, NULL);

    for (i = 0; i < nummappatches; i++)
    {
        M_StringCopy(name, name_p + i * 8, sizeof(name));
        patchlookup[i] = W_CheckNumForName(name);

        if (patchlookup[i] == -1)
        {
            ES_warnf("R_InitTextures: Name not found %.9s\n", name);
        }
    }
    W_ReleaseLumpName("PNAMES");

    // Load the map texture definitions from textures.lmp.
    // The data is contained in one or two lumps,
    //  TEXTURE1 for shareware, plus TEXTURE2 for commercial.
    maptex = maptex1 = W_CacheLumpName ("TEXTURE1", PU_STATIC);
    numtextures1 = *maptex;
    maxoff = W_LumpLength (W_GetNumForName ("TEXTURE1"));
    directory = maptex+1;

    if (W_CheckNumForName ("TEXTURE2") != -1)
    {
        maptex2 = W_CacheLumpName ("TEXTURE2", PU_STATIC);
        numtextures2 = *maptex2;
        maxoff2 = W_LumpLength (W_GetNumForName ("TEXTURE2"));
    }
    else
    {
        maptex2 = NULL;
        numtextures2 = 0;
        maxoff2 = 0;
    }

    numtextures = numtextures1 + numtextures2;
	
    textures = Z_Malloc (numtextures * sizeof(*textures), PU_STATIC, 0);
    texturecolumnlump = Z_Malloc (numtextures * sizeof(*texturecolumnlump), PU_STATIC, 0);
    texturecolumnofs = Z_Malloc (numtextures * sizeof(*texturecolumnofs), PU_STATIC, 0);
    texturecomposite = Z_Malloc (numtextures * sizeof(*texturecomposite), PU_STATIC, 0);
    texturecompositesize = Z_Malloc (numtextures * sizeof(*texturecompositesize), PU_STATIC, 0);
    texturewidthmask = Z_Malloc (numtextures * sizeof(*texturewidthmask), PU_STATIC, 0);
    textureheight = Z_Malloc (numtextures * sizeof(*textureheight), PU_STATIC, 0);

    totalwidth = 0;

    //	Really complex printing shit...
    temp1 = W_GetNumForName ("S_START");  // P_???????
    temp2 = W_GetNumForName ("S_END") - 1;
    temp3 = ((temp2-temp1+63)/64) + ((numtextures+63)/64);

    for (i=0; i < numtextures; i++, directory++)
    {
        if (i == numtextures1)
        {
            // Start looking in second texture file.
            maptex = maptex2;
            maxoff = maxoff2;
            directory = maptex+1;
        }

        offset = *directory;

        if (offset > maxoff)
            I_Error ("R_InitTextures: bad texture directory");

        mtexture = (maptexture_t *) ( (byte *)maptex + offset);

        texture = textures[i] =
            Z_Malloc (sizeof(texture_t)
                + sizeof(texpatch_t)*(mtexture->patchcount-1),
                PU_STATIC, 0);

        texture->width = mtexture->width;
        texture->height = mtexture->height;
        texture->patchcount = mtexture->patchcount;

        ES_memcpy (texture->name, mtexture->name, sizeof(texture->name));
        mpatch = &mtexture->patches[0];
        patch = &texture->patches[0];

        for (j=0; j < texture->patchcount; j++, mpatch++, patch++)
        {
            if (mpatch->patch >= nummappatches) {
                I_Error (
                    "R_InitTexture: Out of bounds patch in texture %.8s (max_patches=%d)", 
                    texture->name, 
                    texture->patchcount
                );
            }

            patch->originx = mpatch->originx;
            patch->originy = mpatch->originy;
            patch->patch = patchlookup[mpatch->patch];

            if (patch->patch == -1 || patch->patch > numlumps)
            {
                I_Error ("R_InitTextures: Invalid patch in texture %.8s", texture->name);
            }
        }

        texturecolumnlump[i] = Z_Malloc (texture->width*sizeof(**texturecolumnlump), PU_STATIC,0);
        texturecolumnofs[i] = Z_Malloc (texture->width*sizeof(**texturecolumnofs), PU_STATIC,0);

        j = 1;
        while (j*2 <= texture->width) j<<=1;

        texturewidthmask[i] = j-1;
        textureheight[i] = texture->height<<FRACBITS;

        totalwidth += texture->width;
    }

    Z_Free(patchlookup);

    W_ReleaseLumpName("TEXTURE1");
    if (maptex2)
        W_ReleaseLumpName("TEXTURE2");

    // Precalculate whatever possible.	
    for (i=0 ; i<numtextures; i++) R_GenerateLookup(i);

    // Create translation table for global animation.
    texturetranslation = Z_Malloc ((numtextures+1)*sizeof(*texturetranslation), PU_STATIC, 0);

    for (i=0 ; i<numtextures ; i++) texturetranslation[i] = i;

    GenerateTextureHashTable();
}

//
// R_InitFlats
//
void R_InitFlats (void)
{
    int		i;
	
    firstflat = W_GetNumForName ("F_START") + 1;
    lastflat = W_GetNumForName ("F_END") - 1;
    numflats = lastflat - firstflat + 1;
	
    // Create translation table for global animation.
    flattranslation = Z_Malloc ((numflats+1)*sizeof(*flattranslation), PU_STATIC, 0);
    
    for (i=0 ; i<numflats ; i++)
	flattranslation[i] = i;
}

//
// R_InitSpriteLumps
// Finds the width and hoffset of all sprites in the wad,
//  so the sprite does not need to be cached completely
//  just for having the header info ready during rendering.
//
void R_InitSpriteLumps (void)
{
    int		i;
    patch_t	*patch;

    firstspritelump = W_GetNumForName ("S_START") + 1;
    lastspritelump = W_GetNumForName ("S_END") - 1;

    numspritelumps = lastspritelump - firstspritelump + 1;
    spritewidth = Z_Malloc (numspritelumps*sizeof(*spritewidth), PU_STATIC, 0);
    spriteoffset = Z_Malloc (numspritelumps*sizeof(*spriteoffset), PU_STATIC, 0);
    spritetopoffset = Z_Malloc (numspritelumps*sizeof(*spritetopoffset), PU_STATIC, 0);

    for (i=0; i< numspritelumps; i++)
    {
        patch = W_CacheLumpNum (firstspritelump+i, PU_CACHE);
        spritewidth[i] = SHORT(patch->width)<<FRACBITS;
        spriteoffset[i] = SHORT(patch->leftoffset)<<FRACBITS;
        spritetopoffset[i] = SHORT(patch->topoffset)<<FRACBITS;
    }
}

//
// R_InitColormaps
//
void R_InitColormaps (void)
{
    int	lump;

    // Load in the light tables, 
    //  256 byte align tables.
    lump = W_GetNumForName("COLORMAP");
    colormaps = W_CacheLumpNum(lump, PU_STATIC);
}

//
// R_InitData
// Locates all the lumps
//  that will be used by all views
// Must be called after W_Init.
//
void R_InitData (void)
{
    ES_debugf("R_InitData: Texture\n");
    R_InitTextures ();
    ES_debugf("R_InitData: Flags\n");
    R_InitFlats ();
    ES_debugf("R_InitData: Sprite Lumps\n");
    R_InitSpriteLumps ();
    ES_debugf("R_InitData: Colormaps\n");
    R_InitColormaps ();
}

//
// R_FlatNumForName
// Retrieval, get a flat number for a flat name.
//
int R_FlatNumForName (char* name)
{
    int		i;
    char	namet[9];

    i = W_CheckNumForName (name);

    if (i == -1)
    {
	namet[8] = 0;
	ES_memcpy (namet, name,8);
	I_Error ("R_FlatNumForName: %s not found",namet);
    }
    return i - firstflat;
}

//
// R_CheckTextureNumForName
// Check whether texture is available.
// Filter out NoTexture indicator.
//
int	R_CheckTextureNumForName (char *name)
{
    texture_t *texture;
    int key;

    // "NoTexture" marker.
    if (name[0] == '-')		
	return 0;
		
    key = W_LumpNameHash(name) % numtextures;

    texture=textures_hashtable[key]; 
    
    while (texture != NULL)
    {
	if (!ES_strncasecmp (texture->name, name, 8) )
	    return texture->index;

        texture = texture->next;
    }
    
    return -1;
}

//
// R_TextureNumForName
// Calls R_CheckTextureNumForName,
//  aborts with error message.
//
int	R_TextureNumForName (char* name)
{
    int		i;
	
    i = R_CheckTextureNumForName (name);

    if (i==-1)
    {
	I_Error ("R_TextureNumForName: %s not found",
		 name);
    }
    return i;
}

//
// R_PrecacheLevel
// Preloads all relevant graphics for the level.
//
int flatmemory;
int texturememory;
int spritememory;

void R_PrecacheLevel (void)
{
    char* flatpresent;
    char* texturepresent;
    char* spritepresent;

    int i;
    int j;
    int k;
    int lump;
    
    texture_t* texture;
    thinker_t* th;
    spriteframe_t* sf;

    if (demoplayback) return;
    
    // Precache flats.
    flatpresent = Z_Malloc(numflats, PU_STATIC, NULL);
    ES_memset (flatpresent,0,numflats);	

    for (i=0 ; i<numsectors ; i++)
    {
        flatpresent[sectors[i].floorpic] = 1;
        flatpresent[sectors[i].ceilingpic] = 1;
    }
	
    flatmemory = 0;

    for (i=0 ; i<numflats ; i++)
    {
        if (flatpresent[i])
        {
            lump = firstflat + i;
            flatmemory += lumpinfo[lump].size;
            W_CacheLumpNum(lump, PU_CACHE);
        }
    }

    Z_Free(flatpresent);
    
    // Precache textures.
    texturepresent = Z_Malloc(numtextures, PU_STATIC, NULL);
    ES_memset (texturepresent,0, numtextures);

    for (i=0 ; i<numsides ; i++)
    {
        texturepresent[sides[i].toptexture] = 1;
        texturepresent[sides[i].midtexture] = 1;
        texturepresent[sides[i].bottomtexture] = 1;
    }

    // Sky texture is always present.
    // Note that F_SKY1 is the name used to
    //  indicate a sky floor/ceiling as a flat,
    //  while the sky texture is stored like
    //  a wall texture, with an episode dependend
    //  name.
    texturepresent[skytexture] = 1;

    texturememory = 0;
    for (i=0; i<numtextures; i++)
    {
        if (!texturepresent[i])
            continue;

        texture = textures[i];

        for (j=0; j<texture->patchcount; j++)
        {
            lump = texture->patches[j].patch;
            texturememory += lumpinfo[lump].size;
            W_CacheLumpNum(lump , PU_CACHE);
        }
    }

    Z_Free(texturepresent);
    
    // Precache sprites.
    spritepresent = Z_Malloc(numsprites, PU_STATIC, NULL);
    ES_memset (spritepresent,0, numsprites);

    for (th = thinkercap.next ; th != &thinkercap ; th=th->next)
    {
        if (th->function.acp1 == (actionf_p1)P_MobjThinker)
            spritepresent[((mobj_t *)th)->sprite] = 1;
    }

    spritememory = 0;
    for (i=0 ; i<numsprites ; i++)
    {
        if (!spritepresent[i])
            continue;

        for (j=0 ;j<sprites[i].numframes; j++)
        {
            sf = &sprites[i].spriteframes[j];
            for (k=0 ; k<8 ; k++)
            {
            lump = firstspritelump + sf->lump[k];
            spritememory += lumpinfo[lump].size;
            W_CacheLumpNum(lump , PU_CACHE);
            }
        }
    }

    Z_Free(spritepresent);
}