/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
 *  Copyright (C) 2011-2014 - Daniel De Matteis
 *
 *  RetroArch 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 Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  RetroArch 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 RetroArch.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

#include "softfilter.h"
#include <stdlib.h>

#ifdef RARCH_INTERNAL
#define softfilter_get_implementation epx_get_implementation
#define softfilter_thread_data epx_softfilter_thread_data
#define filter_data epx_filter_data
#endif

#define EPX_SCALE 2

struct softfilter_thread_data
{
   void *out_data;
   const void *in_data;
   size_t out_pitch;
   size_t in_pitch;
   unsigned colfmt;
   unsigned width;
   unsigned height;
   int first;
   int last;
};

struct filter_data
{
   unsigned threads;
   struct softfilter_thread_data *workers;
   unsigned in_fmt;
};

static unsigned epx_generic_input_fmts(void)
{
   return SOFTFILTER_FMT_RGB565;
}

static unsigned epx_generic_output_fmts(unsigned input_fmts)
{
   return input_fmts;
}

static unsigned epx_generic_threads(void *data)
{
   struct filter_data *filt = (struct filter_data*)data;
   return filt->threads;
}

static void *epx_generic_create(const struct softfilter_config *config,
      unsigned in_fmt, unsigned out_fmt,
      unsigned max_width, unsigned max_height,
      unsigned threads, softfilter_simd_mask_t simd, void *userdata)
{
   (void)simd;
   (void)config;
   (void)userdata;

   struct filter_data *filt = (struct filter_data*)calloc(1, sizeof(*filt));
   if (!filt)
      return NULL;
   filt->workers = (struct softfilter_thread_data*)
      calloc(threads, sizeof(struct softfilter_thread_data));
   filt->threads = threads;
   filt->in_fmt  = in_fmt;
   if (!filt->workers)
   {
      free(filt);
      return NULL;
   }
   return filt;
}

static void epx_generic_output(void *data,
      unsigned *out_width, unsigned *out_height,
      unsigned width, unsigned height)
{
   *out_width = width * EPX_SCALE;
   *out_height = height * EPX_SCALE;
}

static void epx_generic_destroy(void *data)
{
   struct filter_data *filt = (struct filter_data*)data;

   if (!filt)
      return;

   free(filt->workers);
   free(filt);
}

static void EPX_16 (int width, int height,
      int first, int last,
      uint16_t *src, int src_stride, uint16_t *dst, int dst_stride)
{
	uint16_t	colorX, colorA, colorB, colorC, colorD;
	uint16_t	*sP, *uP, *lP;
	uint32_t	*dP1, *dP2;
	int		w, prevline;

   prevline = (first) ? 0 : src_stride;

	height -= 2;

	/*   D
	 * A X C
	 *   B
    */

	/* top edge */

	sP  = (uint16_t *)(src - prevline);
	lP  = (uint16_t *) (src + src_stride);
	dP1 = (uint32_t *) dst;
	dP2 = (uint32_t *) (dst + dst_stride);

	// left edge

	colorX = *sP;
	colorC = *++sP;
	colorB = *lP++;

	if ((colorX != colorC) && (colorB != colorX))
	{
	#ifdef MSB_FIRST
		*dP1 = (colorX << 16) + colorX;
		*dP2 = (colorX << 16) + ((colorB == colorC) ? colorB : colorX);
	#else
		*dP1 = colorX + (colorX << 16);
		*dP2 = colorX + (((colorB == colorC) ? colorB : colorX) << 16);
	#endif
	}
	else
		*dP1 = *dP2 = (colorX << 16) + colorX;

	dP1++;
	dP2++;

	//

	for (w = width - 2; w; w--)
	{
		colorA = colorX;
		colorX = colorC;
		colorC = *++sP;
		colorB = *lP++;

		if ((colorA != colorC) && (colorB != colorX))
		{
		#ifdef MSB_FIRST
			*dP1 = (colorX << 16) + colorX;
			*dP2 = (((colorA == colorB) ? colorA : colorX) << 16) + 
            ((colorB == colorC) ? colorB : colorX);
		#else
			*dP1 = colorX + (colorX << 16);
			*dP2 = ((colorA == colorB) ? colorA : colorX) + 
            (((colorB == colorC) ? colorB : colorX) << 16);
		#endif
		}
		else
			*dP1 = *dP2 = (colorX << 16) + colorX;

		dP1++;
		dP2++;
	}

	/* right edge */

	colorA = colorX;
	colorX = colorC;
	colorB = *lP;

	if ((colorA != colorX) && (colorB != colorX))
	{
	#ifdef MSB_FIRST
		*dP1 = (colorX << 16) + colorX;
		*dP2 = (((colorA == colorB) ? colorA : colorX) << 16) + colorX;
	#else
		*dP1 = colorX + (colorX << 16);
		*dP2 = ((colorA == colorB) ? colorA : colorX) + (colorX << 16);
	#endif
	}
	else
		*dP1 = *dP2 = (colorX << 16) + colorX;

	src += src_stride;
	dst += dst_stride << 1;

	for (; height; height--)
	{
		sP  = (uint16_t *) src;
		uP  = (uint16_t *) (src - src_stride);
		lP  = (uint16_t *) (src + src_stride);
		dP1 = (uint32_t *) dst;
		dP2 = (uint32_t *) (dst + dst_stride);

		/* left edge */

		colorX = *sP;
		colorC = *++sP;
		colorB = *lP++;
		colorD = *uP++;

		if ((colorX != colorC) && (colorB != colorD))
		{
		#ifdef MSB_FIRST
			*dP1 = (colorX << 16) + ((colorC == colorD) ? colorC : colorX);
			*dP2 = (colorX << 16) + ((colorB == colorC) ? colorB : colorX);
		#else
			*dP1 = colorX + (((colorC == colorD) ? colorC : colorX) << 16);
			*dP2 = colorX + (((colorB == colorC) ? colorB : colorX) << 16);
		#endif
		}
		else
			*dP1 = *dP2 = (colorX << 16) + colorX;

		dP1++;
		dP2++;

		for (w = width - 2; w; w--)
		{
			colorA = colorX;
			colorX = colorC;
			colorC = *++sP;
			colorB = *lP++;
			colorD = *uP++;

			if ((colorA != colorC) && (colorB != colorD))
			{
			#ifdef MSB_FIRST
				*dP1 = (((colorD == colorA) ? colorD : colorX) << 16) + 
               ((colorC == colorD) ? colorC : colorX);
				*dP2 = (((colorA == colorB) ? colorA : colorX) << 16) + 
               ((colorB == colorC) ? colorB : colorX);
			#else
				*dP1 = ((colorD == colorA) ? colorD : colorX) + 
               (((colorC == colorD) ? colorC : colorX) << 16);
				*dP2 = ((colorA == colorB) ? colorA : colorX) + 
               (((colorB == colorC) ? colorB : colorX) << 16);
			#endif
			}
			else
				*dP1 = *dP2 = (colorX << 16) + colorX;

			dP1++;
			dP2++;
		}

		/* right edge */

		colorA = colorX;
		colorX = colorC;
		colorB = *lP;
		colorD = *uP;

		if ((colorA != colorX) && (colorB != colorD))
		{
		#ifdef MSB_FIRST
			*dP1 = (((colorD == colorA) ? colorD : colorX) << 16) + colorX;
			*dP2 = (((colorA == colorB) ? colorA : colorX) << 16) + colorX;
		#else
			*dP1 = ((colorD == colorA) ? colorD : colorX) + (colorX << 16);
			*dP2 = ((colorA == colorB) ? colorA : colorX) + (colorX << 16);
		#endif
		}
		else
			*dP1 = *dP2 = (colorX << 16) + colorX;

		src += src_stride;
		dst += dst_stride << 1;
	}

	/* bottom edge */

	sP  = (uint16_t *) src;
	uP  = (uint16_t *) (src - src_stride);
	dP1 = (uint32_t *) dst;
	dP2 = (uint32_t *) (dst + dst_stride);

	/* left edge */

	colorX = *sP;
	colorC = *++sP;
	colorD = *uP++;

	if ((colorX != colorC) && (colorX != colorD))
	{
	#ifdef MSB_FIRST
		*dP1 = (colorX << 16) + ((colorC == colorD) ? colorC : colorX);
		*dP2 = (colorX << 16) + colorX;
	#else
		*dP1 = colorX + (((colorC == colorD) ? colorC : colorX) << 16);
		*dP2 = colorX + (colorX << 16);
	#endif
	}
	else
		*dP1 = *dP2 = (colorX << 16) + colorX;

	dP1++;
	dP2++;

	for (w = width - 2; w; w--)
	{
		colorA = colorX;
		colorX = colorC;
		colorC = *++sP;
		colorD = *uP++;

		if ((colorA != colorC) && (colorX != colorD))
		{
		#ifdef MSB_FIRST
			*dP1 = (((colorD == colorA) ? colorD : colorX) << 16) + 
            ((colorC == colorD) ? colorC : colorX);
			*dP2 = (colorX << 16) + colorX;
		#else
			*dP1 = ((colorD == colorA) ? colorD : colorX) + 
            (((colorC == colorD) ? colorC : colorX) << 16);
			*dP2 = colorX + (colorX << 16);
		#endif
		}
		else
			*dP1 = *dP2 = (colorX << 16) + colorX;

		dP1++;
		dP2++;
	}

	/* right edge */

	colorA = colorX;
	colorX = colorC;
	colorD = *uP;

	if ((colorA != colorX) && (colorX != colorD))
	{
	#ifdef MSB_FIRST
		*dP1 = (((colorD == colorA) ? colorD : colorX) << 16) + colorX;
		*dP2 = (colorX << 16) + colorX;
	#else
		*dP1 = ((colorD == colorA) ? colorD : colorX) + (colorX << 16);
		*dP2 = colorX + (colorX << 16);
	#endif
	}
	else
		*dP1 = *dP2 = (colorX << 16) + colorX;
}

static void epx_generic_rgb565(unsigned width, unsigned height,
      int first, int last, uint16_t *src, 
      unsigned src_stride, uint16_t *dst, unsigned dst_stride)
{
   EPX_16(width, height,
         first, last,
         src, src_stride,
         dst, dst_stride);

}

static void epx_work_cb_rgb565(void *data, void *thread_data)
{
   struct softfilter_thread_data *thr = 
      (struct softfilter_thread_data*)thread_data;
   uint16_t *input = (uint16_t*)thr->in_data;
   uint16_t *output = (uint16_t*)thr->out_data;
   unsigned width = thr->width;
   unsigned height = thr->height;

   epx_generic_rgb565(width, height,
         thr->first, thr->last, input,
         thr->in_pitch / SOFTFILTER_BPP_RGB565,
         output,
         thr->out_pitch / SOFTFILTER_BPP_RGB565);
}


static void epx_generic_packets(void *data,
      struct softfilter_work_packet *packets,
      void *output, size_t output_stride,
      const void *input, unsigned width, unsigned height, size_t input_stride)
{
   struct filter_data *filt = (struct filter_data*)data;
   unsigned i;
   for (i = 0; i < filt->threads; i++)
   {
      struct softfilter_thread_data *thr = 
         (struct softfilter_thread_data*)&filt->workers[i];

      unsigned y_start = (height * i) / filt->threads;
      unsigned y_end = (height * (i + 1)) / filt->threads;
      thr->out_data = (uint8_t*)output + y_start * EPX_SCALE * output_stride;
      thr->in_data = (const uint8_t*)input + y_start * input_stride;
      thr->out_pitch = output_stride;
      thr->in_pitch = input_stride;
      thr->width = width;
      thr->height = y_end - y_start;

      /* Workers need to know if they can 
       * access pixels outside their given buffer. */
      thr->first = y_start;
      thr->last = y_end == height;

      if (filt->in_fmt == SOFTFILTER_FMT_RGB565)
         packets[i].work = epx_work_cb_rgb565;
      packets[i].thread_data = thr;
   }
}

static const struct softfilter_implementation epx_generic = {
   epx_generic_input_fmts,
   epx_generic_output_fmts,

   epx_generic_create,
   epx_generic_destroy,

   epx_generic_threads,
   epx_generic_output,
   epx_generic_packets,
   SOFTFILTER_API_VERSION,
   "EPX",
   "epx",
};

const struct softfilter_implementation *softfilter_get_implementation(
      softfilter_simd_mask_t simd)
{
   (void)simd;
   return &epx_generic;
}

#ifdef RARCH_INTERNAL
#undef softfilter_get_implementation
#undef softfilter_thread_data
#undef filter_data
#endif