/* GdkPixbuf library - Windows Icon/Cursor image loader
 *
 * Copyright (C) 1999 The Free Software Foundation
 *
 * Authors: Arjan van de Ven <arjan@fenrus.demon.nl>
 *          Federico Mena-Quintero <federico@gimp.org>
 *
 * Based on io-bmp.c
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#undef DUMPBIH
/*

Icons are just like BMP's, except for the header.

Known bugs:
	* bi-tonal files aren't tested

*/

#include <config.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include "gdk-pixbuf-private.h"
#include "gdk-pixbuf-io.h"



/*

These structures are actually dummies. These are according to
the "Windows API reference guide volume II" as written by
Borland International, but GCC fiddles with the alignment of
the internal members.

*/

struct BitmapFileHeader {
	gushort bfType;
	guint bfSize;
	guint reserverd;
	guint bfOffbits;
};

struct BitmapInfoHeader {
	guint biSize;
	guint biWidth;
	guint biHeight;
	gushort biPlanes;
	gushort biBitCount;
	guint biCompression;
	guint biSizeImage;
	guint biXPelsPerMeter;
	guint biYPelsPerMeter;
	guint biClrUsed;
	guint biClrImportant;
};

#ifdef DUMPBIH
/*

DumpBIH printf's the values in a BitmapInfoHeader to the screen, for
debugging purposes.

*/
static void
DumpBIH (unsigned char *BIH)
{
	printf("biSize      = %i \n",
	       (int)(BIH[3] << 24) + (BIH[2] << 16) + (BIH[1] << 8) + (BIH[0]));
	printf("biWidth     = %i \n",
	       (int)(BIH[7] << 24) + (BIH[6] << 16) + (BIH[5] << 8) + (BIH[4]));
	printf("biHeight    = %i \n",
	       (int)(BIH[11] << 24) + (BIH[10] << 16) + (BIH[9] << 8) +
	       (BIH[8]));
	printf("biPlanes    = %i \n", (int)(BIH[13] << 8) + (BIH[12]));
	printf("biBitCount  = %i \n", (int)(BIH[15] << 8) + (BIH[14]));
	printf("biCompress  = %i \n",
	       (int)(BIH[19] << 24) + (BIH[18] << 16) + (BIH[17] << 8) +
	       (BIH[16]));
	printf("biSizeImage = %i \n",
	       (int)(BIH[23] << 24) + (BIH[22] << 16) + (BIH[21] << 8) +
	       (BIH[20]));
	printf("biXPels     = %i \n",
	       (int)(BIH[27] << 24) + (BIH[26] << 16) + (BIH[25] << 8) +
	       (BIH[24]));
	printf("biYPels     = %i \n",
	       (int)(BIH[31] << 24) + (BIH[30] << 16) + (BIH[29] << 8) +
	       (BIH[28]));
	printf("biClrUsed   = %i \n",
	       (int)(BIH[35] << 24) + (BIH[34] << 16) + (BIH[33] << 8) +
	       (BIH[32]));
	printf("biClrImprtnt= %i \n",
	       (int)(BIH[39] << 24) + (BIH[38] << 16) + (BIH[37] << 8) +
	       (BIH[36]));
}
#endif

/* Progressive loading */
struct headerpair {
	guint width;
	guint height;
	guint depth;
	guint Negative;		/* Negative = 1 -> top down BMP,
				   Negative = 0 -> bottom up BMP */
};

struct ico_progressive_state {
	ModulePreparedNotifyFunc prepared_func;
	ModuleUpdatedNotifyFunc updated_func;
	gpointer user_data;

	gint HeaderSize;	/* The size of the header-part (incl colormap) */
	guchar *HeaderBuf;	/* The buffer for the header (incl colormap) */
	gint BytesInHeaderBuf;  /* The size of the allocated HeaderBuf */
	gint HeaderDone;	/* The nr of bytes actually in HeaderBuf */

	gint LineWidth;		/* The width of a line in bytes */
	guchar *LineBuf;	/* Buffer for 1 line */
	gint LineDone;		/* # of bytes in LineBuf */
	gint Lines;		/* # of finished lines */

	gint Type;		/*
				   32 = RGB + alpha
				   24 = RGB
				   8 = 8 bit colormapped
				   4  = 4 bpp colormapped
				   1  = 1 bit bitonal
				 */


	struct headerpair Header;	/* Decoded (BE->CPU) header */

	gint			DIBoffset;
	gint			ImageScore;


	GdkPixbuf *pixbuf;	/* Our "target" */
};

gpointer gdk_pixbuf__ico_image_begin_load (ModulePreparedNotifyFunc prepared_func,
					   ModuleUpdatedNotifyFunc updated_func,
					   ModuleFrameDoneNotifyFunc frame_done_func,
					   ModuleAnimationDoneNotifyFunc anim_done_func,
					   gpointer user_data);
void gdk_pixbuf__ico_image_stop_load(gpointer data);
gboolean gdk_pixbuf__ico_image_load_increment(gpointer data, guchar * buf, guint size);



/* Shared library entry point --> Can go when generic_image_load
   enters gdk-pixbuf-io */
GdkPixbuf *
gdk_pixbuf__ico_image_load (FILE *f)
{
	guchar *membuf;
	size_t length;
	struct ico_progressive_state *State;

	GdkPixbuf *pb;

	State = gdk_pixbuf__ico_image_begin_load(NULL, NULL, NULL, NULL, NULL);
	membuf = g_malloc(4096);

	g_assert(membuf != NULL);

	while (feof(f) == 0) {
		length = fread(membuf, 1, 4096, f);
		if (length > 0)
			gdk_pixbuf__ico_image_load_increment(State, membuf, length);

	}
	g_free(membuf);
	if (State->pixbuf != NULL)
		gdk_pixbuf_ref(State->pixbuf);

	pb = State->pixbuf;

	gdk_pixbuf__ico_image_stop_load(State);
	return pb;
}

static void
DecodeHeader (guchar *Data, gint Bytes, struct ico_progressive_state *State)
{
/* For ICO's we have to be very clever. There are multiple images possible
   in an .ICO. For now, we select (in order of priority):
     1) The one with the highest number of colors
     2) The largest one
 */

	gint IconCount = 0; /* The number of icon-versions in the file */
	guchar *BIH; /* The DIB for the used icon */
 	guchar *Ptr;
 	gint I;

 	/* Step 1: The ICO header */

 	IconCount = (Data[5] << 8) + (Data[4]);

 	State->HeaderSize = 6 + IconCount*16;

 	if (State->HeaderSize>State->BytesInHeaderBuf) {
 		State->HeaderBuf=g_realloc(State->HeaderBuf,State->HeaderSize);
 		State->BytesInHeaderBuf = State->HeaderSize;
 	}
 	if (Bytes < State->HeaderSize)
 		return;

 	/* We now have all the "short-specs" of the versions
 	   So we iterate through them and select the best one */

 	State->ImageScore = 0;
 	State->DIBoffset  = 0;
 	Ptr = Data + 6;
	for (I=0;I<IconCount;I++) {
		int ThisWidth, ThisHeight,ThisColors;
		int ThisScore;

		ThisWidth = Ptr[0];
		ThisHeight = Ptr[1];
		ThisColors = (Ptr[2]);
		if (ThisColors==0)
			ThisColors=256; /* Yes, this is in the spec, ugh */

		ThisScore = ThisColors*1024+ThisWidth*ThisHeight;

		if (ThisScore>State->ImageScore) {
			State->ImageScore = ThisScore;
			State->DIBoffset = (Ptr[15]<<24)+(Ptr[14]<<16)+
					   (Ptr[13]<<8) + (Ptr[12]);

		}


		Ptr += 16;
	}

	/* We now have a winner, pointed to in State->DIBoffset,
	   so we know how many bytes are in the "header" part. */

	State->HeaderSize = State->DIBoffset + 40; /* 40 = sizeof(InfoHeader) */

 	if (State->HeaderSize>State->BytesInHeaderBuf) {
 		State->HeaderBuf=g_realloc(State->HeaderBuf,State->HeaderSize);
 		State->BytesInHeaderBuf = State->HeaderSize;
 	}
	if (Bytes<State->HeaderSize)
		return;

	BIH = Data+State->DIBoffset;

#ifdef DUMPBIH
	DumpBIH(BIH);
#endif

	/* Add the palette to the headersize */

	State->Header.width =
	    (int)(BIH[7] << 24) + (BIH[6] << 16) + (BIH[5] << 8) + (BIH[4]);
	State->Header.height =
	    (int)(BIH[11] << 24) + (BIH[10] << 16) + (BIH[9] << 8) + (BIH[8])/2;
	    /* /2 because the BIH height includes the transparency mask */
	State->Header.depth = (BIH[15] << 8) + (BIH[14]);;

	State->Type = State->Header.depth;
	if (State->Lines>=State->Header.height)
		State->Type = 1; /* The transparency mask is 1 bpp */



	/* Determine the  palette size. If the header indicates 0, it
	   is actually the maximum for the bpp. You have to love the
	   guys who made the spec. */
	I = (int)(BIH[35] << 24) + (BIH[34] << 16) + (BIH[33] << 8) + (BIH[32]);
	I = I*4;
	if ((I==0)&&(State->Type==1))
		I = 2*4;
	if ((I==0)&&(State->Type==4))
		I = 16*4;
	if ((I==0)&&(State->Type==8))
		I = 256*4;

	State->HeaderSize+=I;

 	if (State->HeaderSize>State->BytesInHeaderBuf) {
 		State->HeaderBuf=g_realloc(State->HeaderBuf,State->HeaderSize);
 		State->BytesInHeaderBuf = State->HeaderSize;
 	}
 	if (Bytes < State->HeaderSize)
 		return;

	if ((BIH[16] != 0) || (BIH[17] != 0) || (BIH[18] != 0)
	    || (BIH[19] != 0)) {
		g_assert(0); /* Compressed icons aren't allowed */
	}

	/* Negative heights mean top-down pixel-order */
	if (State->Header.height < 0) {
		State->Header.height = -State->Header.height;
		State->Header.Negative = 1;
	}
	if (State->Header.width < 0) {
		State->Header.width = -State->Header.width;
	}

	if (State->Type == 32)
		State->LineWidth = State->Header.width * 4;
	else if (State->Type == 24)
		State->LineWidth = State->Header.width * 3;
	else if (State->Type == 16)
		State->LineWidth = State->Header.height * 2;
	else if (State->Type == 8)
		State->LineWidth = State->Header.width * 1;
	else if (State->Type == 4)
		State->LineWidth = (State->Header.width+1)/2;
	else if (State->Type == 1) {
		State->LineWidth = State->Header.width / 8;
		if ((State->Header.width & 7) != 0)
			State->LineWidth++;
	} else {
		/* FIXME: Unsupported type; report it upstream */
		g_error ("DecodeHeader(): Unsupported ICO type");
		return;
	}

	/* Pad to a 32 bit boundary */
	if (((State->LineWidth % 4) > 0))
		State->LineWidth = (State->LineWidth / 4) * 4 + 4;


	if (State->LineBuf == NULL)
		State->LineBuf = g_malloc(State->LineWidth);

	g_assert(State->LineBuf != NULL);

	if (State->pixbuf == NULL) {
		/* ICOs always have an alpha channel, which will be set in a
		 * second pass after the main pixel data has been read.
		 */
		State->pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB, TRUE, 8,
						(gint) State->Header.width,
						(gint) State->Header.height);
		/* FIXME: gdk_pixbuf_new() could return NULL and we are not
		 * dealing with it!
		 */

		if (State->prepared_func != NULL)
			/* Notify the client that we are ready to go */
			(*State->prepared_func) (State->pixbuf,
						 State->user_data);

	}

}

/*
 * func - called when we have pixmap created (but no image data)
 * user_data - passed as arg 1 to func
 * return context (opaque to user)
 */

gpointer
gdk_pixbuf__ico_image_begin_load (ModulePreparedNotifyFunc prepared_func,
				  ModuleUpdatedNotifyFunc updated_func,
				  ModuleFrameDoneNotifyFunc frame_done_func,
				  ModuleAnimationDoneNotifyFunc anim_done_func,
				  gpointer user_data)
{
	struct ico_progressive_state *context;

	context = g_new0(struct ico_progressive_state, 1);
	context->prepared_func = prepared_func;
	context->updated_func = updated_func;
	context->user_data = user_data;

	context->HeaderSize = 54;
	context->HeaderBuf = g_malloc(14 + 40 + 4*256 + 512);
	/* 4*256 for the colormap */
	context->BytesInHeaderBuf = 14 + 40 + 4*256 + 512 ;
	context->HeaderDone = 0;

	context->LineWidth = 0;
	context->LineBuf = NULL;
	context->LineDone = 0;
	context->Lines = 0;

	context->Type = 0;

	memset(&context->Header, 0, sizeof(struct headerpair));


	context->pixbuf = NULL;


	return (gpointer) context;
}

/*
 * context - returned from image_begin_load
 *
 * free context, unref gdk_pixbuf
 */
void
gdk_pixbuf__ico_image_stop_load (gpointer data)
{
	struct ico_progressive_state *context =
	    (struct ico_progressive_state *) data;


	g_return_if_fail(context != NULL);

	if (context->LineBuf != NULL)
		g_free(context->LineBuf);
	context->LineBuf = NULL;
	if (context->HeaderBuf != NULL)
		g_free(context->HeaderBuf);

	if (context->pixbuf)
		gdk_pixbuf_unref(context->pixbuf);

	g_free(context);
}


static void
OneLine32 (struct ico_progressive_state *context)
{
	gint X;
	guchar *Pixels;

	X = 0;
	if (context->Header.Negative == 0)
		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  (context->Header.height - context->Lines - 1));
	else
		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  context->Lines);
	while (X < context->Header.width) {
		Pixels[X * 4 + 0] = context->LineBuf[X * 4 + 2];
		Pixels[X * 4 + 1] = context->LineBuf[X * 4 + 1];
		Pixels[X * 4 + 2] = context->LineBuf[X * 4 + 0];
		Pixels[X * 4 + 3] = context->LineBuf[X * 4 + 3];
		X++;
	}

}

static void
OneLine24 (struct ico_progressive_state *context)
{
	gint X;
	guchar *Pixels;

	X = 0;
	if (context->Header.Negative == 0)
		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  (context->Header.height - context->Lines - 1));
	else
		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  context->Lines);
	while (X < context->Header.width) {
		Pixels[X * 4 + 0] = context->LineBuf[X * 3 + 2];
		Pixels[X * 4 + 1] = context->LineBuf[X * 3 + 1];
		Pixels[X * 4 + 2] = context->LineBuf[X * 3 + 0];
		X++;
	}

}

static void
OneLine16 (struct ico_progressive_state *context)
{
	int i;
	guchar *pixels;
	guchar *src;

	if (context->Header.Negative == 0)
		pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride * (context->Header.height - context->Lines - 1));
	else
		pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride * context->Lines);

	src = context->LineBuf;

	for (i = 0; i < context->Header.width; i++) {
		int v, r, g, b;

		v = (int) src[0] | ((int) src[1] << 8);
		src += 2;

		/* Extract 5-bit RGB values */

		r = (v >> 10) & 0x1f;
		g = (v >> 5) & 0x1f;
		b = v & 0x1f;

		/* Fill the rightmost bits to form 8-bit values */

		*pixels++ = (r << 3) | (r >> 2);
		*pixels++ = (g << 3) | (g >> 2);
		*pixels++ = (b << 3) | (b >> 2);
		pixels++; /* skip alpha channel */
	}
}

static void
OneLine8 (struct ico_progressive_state *context)
{
	gint X;
	guchar *Pixels;

	X = 0;
	if (context->Header.Negative == 0)
		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  (context->Header.height - context->Lines - 1));
	else
		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  context->Lines);
	while (X < context->Header.width) {
		/* The joys of having a BGR byteorder */
		Pixels[X * 4 + 0] =
		    context->HeaderBuf[4 * context->LineBuf[X] + 42+context->DIBoffset];
		Pixels[X * 4 + 1] =
		    context->HeaderBuf[4 * context->LineBuf[X] + 41+context->DIBoffset];
		Pixels[X * 4 + 2] =
		    context->HeaderBuf[4 * context->LineBuf[X] + 40+context->DIBoffset];
		X++;
	}
}

static void
OneLine4 (struct ico_progressive_state *context)
{
	gint X;
	guchar *Pixels;

	X = 0;
	if (context->Header.Negative == 0)
		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  (context->Header.height - context->Lines - 1));
	else
		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  context->Lines);

	while (X < context->Header.width) {
		guchar Pix;

		Pix = context->LineBuf[X/2];

		Pixels[X * 4 + 0] =
		    context->HeaderBuf[4 * (Pix>>4) + 42+context->DIBoffset];
		Pixels[X * 4 + 1] =
		    context->HeaderBuf[4 * (Pix>>4) + 41+context->DIBoffset];
		Pixels[X * 4 + 2] =
		    context->HeaderBuf[4 * (Pix>>4) + 40+context->DIBoffset];
		X++;
		if (X<context->Header.width) {
			/* Handle the other 4 bit pixel only when there is one */
			Pixels[X * 4 + 0] =
			    context->HeaderBuf[4 * (Pix&15) + 42+context->DIBoffset];
			Pixels[X * 4 + 1] =
			    context->HeaderBuf[4 * (Pix&15) + 41+context->DIBoffset];
			Pixels[X * 4 + 2] =
			    context->HeaderBuf[4 * (Pix&15) + 40+context->DIBoffset];
			X++;
		}
	}

}

static void
OneLine1 (struct ico_progressive_state *context)
{
	gint X;
	guchar *Pixels;

	X = 0;
	if (context->Header.Negative == 0)
		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  (context->Header.height - context->Lines - 1));
	else
		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  context->Lines);
	while (X < context->Header.width) {
		int Bit;

		Bit = (context->LineBuf[X / 8]) >> (7 - (X & 7));
		Bit = Bit & 1;
		/* The joys of having a BGR byteorder */
		Pixels[X * 4 + 0] = Bit*255;
		Pixels[X * 4 + 1] = Bit*255;
		Pixels[X * 4 + 2] = Bit*255;
		X++;
	}
}

static void
OneLineTransp (struct ico_progressive_state *context)
{
	gint X;
	guchar *Pixels;

	X = 0;
	if (context->Header.Negative == 0)
		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  (2*context->Header.height - context->Lines - 1));
	else
		Pixels = (context->pixbuf->pixels +
			  context->pixbuf->rowstride *
			  (context->Lines-context->Header.height));
	while (X < context->Header.width) {
		int Bit;

		Bit = (context->LineBuf[X / 8]) >> (7 - (X & 7));
		Bit = Bit & 1;
		/* The joys of having a BGR byteorder */
		Pixels[X * 4 + 3] = 255-Bit*255;
#if 0
		if (Bit){
		  Pixels[X*4+0] = 255;
		  Pixels[X*4+1] = 255;
		} else {
		  Pixels[X*4+0] = 0;
		  Pixels[X*4+1] = 0;
		}
#endif
		X++;
	}
}


static void
OneLine (struct ico_progressive_state *context)
{
	context->LineDone = 0;

	if (context->Lines >= context->Header.height*2) {
		return;
	}

	if (context->Lines < context->Header.height) {
		if (context->Type == 32)
			OneLine32 (context);
		else if (context->Type == 24)
			OneLine24 (context);
		else if (context->Type == 16)
			OneLine16 (context);
		else if (context->Type == 8)
			OneLine8 (context);
		else if (context->Type == 4)
			OneLine4 (context);
		else if (context->Type == 1)
			OneLine1 (context);
		else
			g_assert_not_reached ();
	} else
		OneLineTransp(context);

	context->Lines++;
	if (context->Lines>=context->Header.height) {
	 	context->Type = 1;
		context->LineWidth = context->Header.width / 8;
		if ((context->Header.width & 7) != 0)
			context->LineWidth++;
		/* Pad to a 32 bit boundary */
		if (((context->LineWidth % 4) > 0))
			context->LineWidth = (context->LineWidth / 4) * 4 + 4;

	}


	if (context->updated_func != NULL) {
		(*context->updated_func) (context->pixbuf,
					  0,
					  context->Lines,
					  context->Header.width,
					  context->Header.height,
					  context->user_data);

	}
}

/*
 * context - from image_begin_load
 * buf - new image data
 * size - length of new image data
 *
 * append image data onto inrecrementally built output image
 */
gboolean
gdk_pixbuf__ico_image_load_increment (gpointer data, guchar * buf, guint size)
{
	struct ico_progressive_state *context =
	    (struct ico_progressive_state *) data;

	gint BytesToCopy;

	while (size > 0) {
		g_assert(context->LineDone >= 0);
		if (context->HeaderDone < context->HeaderSize) {	/* We still
									   have headerbytes to do */
			BytesToCopy =
			    context->HeaderSize - context->HeaderDone;
			if (BytesToCopy > size)
				BytesToCopy = size;

			memmove(context->HeaderBuf + context->HeaderDone,
			       buf, BytesToCopy);

			size -= BytesToCopy;
			buf += BytesToCopy;
			context->HeaderDone += BytesToCopy;

		}  else
		{
			BytesToCopy =
			    context->LineWidth - context->LineDone;
			if (BytesToCopy > size)
				BytesToCopy = size;

			if (BytesToCopy > 0) {
				memmove(context->LineBuf +
				       context->LineDone, buf,
				       BytesToCopy);

				size -= BytesToCopy;
				buf += BytesToCopy;
				context->LineDone += BytesToCopy;
			}
			if ((context->LineDone >= context->LineWidth) &&
			    (context->LineWidth > 0))
				OneLine(context);


		}

		if (context->HeaderDone >= 6)
			DecodeHeader(context->HeaderBuf,
				     context->HeaderDone, context);


	}

	return TRUE;
}
