#include "quakedef.h"

int		image_width;
int		image_height;

/*
=================================================================

  PCX Loading

=================================================================
*/

typedef struct
{
    char	manufacturer;
    char	version;
    char	encoding;
    char	bits_per_pixel;
    unsigned short	xmin,ymin,xmax,ymax;
    unsigned short	hres,vres;
    unsigned char	palette[48];
    char	reserved;
    char	color_planes;
    unsigned short	bytes_per_line;
    unsigned short	palette_type;
    char	filler[58];
    unsigned 	data;			// unbounded
} pcx_t;

/*
============
LoadPCX
============
*/
byte* LoadPCX (FILE *f, int matchwidth, int matchheight)
{
	pcx_t	*pcx, pcxbuf;
	byte	palette[768];
	byte	*pix, *image_rgba;
	int		x, y;
	int		dataByte, runLength;
	int		count;

//
// parse the PCX file
//
	fread (&pcxbuf, 1, sizeof(pcxbuf), f);

	pcx = &pcxbuf;

	if (pcx->manufacturer != 0x0a
		|| pcx->version != 5
		|| pcx->encoding != 1
		|| pcx->bits_per_pixel != 8
		|| pcx->xmax >= 320
		|| pcx->ymax >= 256)
	{
		Con_Printf ("Bad pcx file\n");
		return NULL;
	}

	if (matchwidth && (pcx->xmax+1) != matchwidth)
		return NULL;
	if (matchheight && (pcx->ymax+1) != matchheight)
		return NULL;

	// seek to palette
	fseek (f, -768, SEEK_END);
	fread (palette, 1, 768, f);

	fseek (f, sizeof(pcxbuf) - 4, SEEK_SET);

	count = (pcx->xmax+1) * (pcx->ymax+1);
	image_rgba = malloc( count * 4);

	for (y=0 ; y<=pcx->ymax ; y++)
	{
		pix = image_rgba + 4*y*(pcx->xmax+1);
		for (x=0 ; x<=pcx->xmax ; )
		{
			dataByte = fgetc(f);

			if((dataByte & 0xC0) == 0xC0)
			{
				runLength = dataByte & 0x3F;
				dataByte = fgetc(f);
			}
			else
				runLength = 1;

			while(runLength-- > 0)
			{
				pix[0] = palette[dataByte*3];
				pix[1] = palette[dataByte*3+1];
				pix[2] = palette[dataByte*3+2];
				pix[3] = 255;
				pix += 4;
				x++;
			}
		}
	}
	image_width = pcx->xmax+1;
	image_height = pcx->ymax+1;
	return image_rgba;
}

/*
=========================================================

TARGA LOADING

=========================================================
*/

typedef struct _TargaHeader {
	unsigned char 	id_length, colormap_type, image_type;
	unsigned short	colormap_index, colormap_length;
	unsigned char	colormap_size;
	unsigned short	x_origin, y_origin, width, height;
	unsigned char	pixel_size, attributes;
} TargaHeader;


TargaHeader		targa_header;

int fgetLittleShort (FILE *f)
{
	byte	b1, b2;

	b1 = fgetc(f);
	b2 = fgetc(f);

	return (short)(b1 + b2*256);
}

int fgetLittleLong (FILE *f)
{
	byte	b1, b2, b3, b4;

	b1 = fgetc(f);
	b2 = fgetc(f);
	b3 = fgetc(f);
	b4 = fgetc(f);

	return b1 + (b2<<8) + (b3<<16) + (b4<<24);
}


/*
=============
LoadTGA
=============
*/
byte* LoadTGA (FILE *fin, int matchwidth, int matchheight)
{
	int				columns, rows, numPixels;
	byte			*pixbuf;
	int				row, column;
	byte			*image_rgba;

	targa_header.id_length = fgetc(fin);
	targa_header.colormap_type = fgetc(fin);
	targa_header.image_type = fgetc(fin);
	
	targa_header.colormap_index = fgetLittleShort(fin);
	targa_header.colormap_length = fgetLittleShort(fin);
	targa_header.colormap_size = fgetc(fin);
	targa_header.x_origin = fgetLittleShort(fin);
	targa_header.y_origin = fgetLittleShort(fin);
	targa_header.width = fgetLittleShort(fin);
	targa_header.height = fgetLittleShort(fin);
	if (matchwidth && targa_header.width != matchwidth)
		return NULL;
	if (matchheight && targa_header.height != matchheight)
		return NULL;
	targa_header.pixel_size = fgetc(fin);
	targa_header.attributes = fgetc(fin);

	if (targa_header.image_type!=2 
		&& targa_header.image_type!=10) 
		Sys_Error ("LoadTGA: Only type 2 and 10 targa RGB images supported\n");

	if (targa_header.colormap_type !=0 
		|| (targa_header.pixel_size!=32 && targa_header.pixel_size!=24))
		Sys_Error ("Texture_LoadTGA: Only 32 or 24 bit images supported (no colormaps)\n");

	columns = targa_header.width;
	rows = targa_header.height;
	numPixels = columns * rows;

	image_rgba = malloc (numPixels*4);
	
	if (targa_header.id_length != 0)
		fseek(fin, targa_header.id_length, SEEK_CUR);  // skip TARGA image comment
	
	if (targa_header.image_type==2) {  // Uncompressed, RGB images
		for(row=rows-1; row>=0; row--) {
			pixbuf = image_rgba + row*columns*4;
			for(column=0; column<columns; column++) {
				unsigned char red,green,blue,alphabyte;
				switch (targa_header.pixel_size) {
					case 24:
							
							blue = getc(fin);
							green = getc(fin);
							red = getc(fin);
							*pixbuf++ = red;
							*pixbuf++ = green;
							*pixbuf++ = blue;
							*pixbuf++ = 255;
							break;
					case 32:
							blue = getc(fin);
							green = getc(fin);
							red = getc(fin);
							alphabyte = getc(fin);
							*pixbuf++ = red;
							*pixbuf++ = green;
							*pixbuf++ = blue;
							*pixbuf++ = alphabyte;
							break;
				}
			}
		}
	}
	else if (targa_header.image_type==10) {   // Runlength encoded RGB images
		unsigned char red,green,blue,alphabyte,packetHeader,packetSize,j;
		for(row=rows-1; row>=0; row--) {
			pixbuf = image_rgba + row*columns*4;
			for(column=0; column<columns; ) {
				packetHeader=getc(fin);
				packetSize = 1 + (packetHeader & 0x7f);
				if (packetHeader & 0x80) {        // run-length packet
					switch (targa_header.pixel_size) {
						case 24:
								blue = getc(fin);
								green = getc(fin);
								red = getc(fin);
								alphabyte = 255;
								break;
						case 32:
								blue = getc(fin);
								green = getc(fin);
								red = getc(fin);
								alphabyte = getc(fin);
								break;
					}
	
					for(j=0;j<packetSize;j++) {
						*pixbuf++=red;
						*pixbuf++=green;
						*pixbuf++=blue;
						*pixbuf++=alphabyte;
						column++;
						if (column==columns) { // run spans across rows
							column=0;
							if (row>0)
								row--;
							else
								goto breakOut;
							pixbuf = image_rgba + row*columns*4;
						}
					}
				}
				else {                            // non run-length packet
					for(j=0;j<packetSize;j++) {
						switch (targa_header.pixel_size) {
							case 24:
									blue = getc(fin);
									green = getc(fin);
									red = getc(fin);
									*pixbuf++ = red;
									*pixbuf++ = green;
									*pixbuf++ = blue;
									*pixbuf++ = 255;
									break;
							case 32:
									blue = getc(fin);
									green = getc(fin);
									red = getc(fin);
									alphabyte = getc(fin);
									*pixbuf++ = red;
									*pixbuf++ = green;
									*pixbuf++ = blue;
									*pixbuf++ = alphabyte;
									break;
						}
						column++;
						if (column==columns) { // pixel packet run spans across rows
							column=0;
							if (row>0)
								row--;
							else
								goto breakOut;
							pixbuf = image_rgba + row*columns*4;
						}						
					}
				}
			}
			breakOut:;
		}
	}
	
	fclose(fin);
	image_width = columns;
	image_height = rows;
	return image_rgba;
}

byte* loadimagepixels (char* filename, qboolean complain, int matchwidth, int matchheight)
{
	FILE	*f;
	char	basename[128], name[128];
	byte	*image_rgba;
	COM_StripExtension(filename, basename); // strip the extension to allow TGA skins on Q2 models despite the .pcx in the skin name
	sprintf (name, "textures/%s.tga", basename);
	COM_FOpenFile (name, &f, true);
	if (f)
		return LoadTGA (f, matchwidth, matchheight);
	sprintf (name, "textures/%s.pcx", basename);
	COM_FOpenFile (name, &f, true);
	if (f)
		return LoadPCX (f, matchwidth, matchheight);
	sprintf (name, "%s.tga", basename);
	COM_FOpenFile (name, &f, true);
	if (f)
		return LoadTGA (f, matchwidth, matchheight);
	sprintf (name, "%s.pcx", basename);
	COM_FOpenFile (name, &f, true);
	if (f)
		return LoadPCX (f, matchwidth, matchheight);
	if (image_rgba = W_GetTexture(basename, matchwidth, matchheight))
		return image_rgba;
	if (complain)
		Con_Printf ("Couldn't load %s.tga or .pcx\n", filename);
	return NULL;
}

int loadtextureimage (int texnum, char* filename, qboolean complain, int matchwidth, int matchheight)
{
	byte *data;
	if (!(data = loadimagepixels (filename, complain, matchwidth, matchheight)))
		return 0;
	if (texnum >= 0) // specific texnum, not cached
	{
		glBindTexture(GL_TEXTURE_2D, texnum);
		GL_Upload32 (data, image_width, image_height, true, true);
		free(data);
		return texnum;
	}
	else // any texnum, cached
	{
		texnum = GL_LoadTexture (filename, image_width, image_height, data, true, true, 4);
		free(data);
		return texnum;
	}
}