/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
 * 
 *  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 "scaler.h"
#include "scaler_int.h"
#include "filter.h"
#include "pixconv.h"
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <math.h>
#include "../../libretro.h"
#include "../../performance.h"

// In case aligned allocs are needed later ...
void *scaler_alloc(size_t elem_size, size_t size)
{
   return calloc(elem_size, size);
}

void scaler_free(void *ptr)
{
   free(ptr);
}

static bool allocate_frames(struct scaler_ctx *ctx)
{
   ctx->scaled.stride = ((ctx->out_width + 7) & ~7) * sizeof(uint64_t);
   ctx->scaled.width  = ctx->out_width;
   ctx->scaled.height = ctx->in_height;
   ctx->scaled.frame  = (uint64_t*)scaler_alloc(sizeof(uint64_t), (ctx->scaled.stride * ctx->scaled.height) >> 3);
   if (!ctx->scaled.frame)
      return false;

   if (ctx->in_fmt != SCALER_FMT_ARGB8888)
   {
      ctx->input.stride = ((ctx->in_width + 7) & ~7) * sizeof(uint32_t);
      ctx->input.frame = (uint32_t*)scaler_alloc(sizeof(uint32_t), (ctx->input.stride * ctx->in_height) >> 2);
      if (!ctx->input.frame)
         return false;
   }

   if (ctx->out_fmt != SCALER_FMT_ARGB8888)
   {
      ctx->output.stride = ((ctx->out_width + 7) & ~7) * sizeof(uint32_t);
      ctx->output.frame  = (uint32_t*)scaler_alloc(sizeof(uint32_t), (ctx->output.stride * ctx->out_height) >> 2);
      if (!ctx->output.frame)
         return false;
   }

   return true;
}

static bool set_direct_pix_conv(struct scaler_ctx *ctx)
{
   if (ctx->in_fmt == ctx->out_fmt)
      ctx->direct_pixconv = conv_copy;
   else if (ctx->in_fmt == SCALER_FMT_0RGB1555 && ctx->out_fmt == SCALER_FMT_ARGB8888)
      ctx->direct_pixconv = conv_0rgb1555_argb8888;
   else if (ctx->in_fmt == SCALER_FMT_RGB565 && ctx->out_fmt == SCALER_FMT_ARGB8888)
      ctx->direct_pixconv = conv_rgb565_argb8888;
   else if (ctx->in_fmt == SCALER_FMT_RGB565 && ctx->out_fmt == SCALER_FMT_BGR24)
      ctx->direct_pixconv = conv_rgb565_bgr24;
   else if (ctx->in_fmt == SCALER_FMT_0RGB1555 && ctx->out_fmt == SCALER_FMT_RGB565)
      ctx->direct_pixconv = conv_0rgb1555_rgb565;
   else if (ctx->in_fmt == SCALER_FMT_RGB565 && ctx->out_fmt == SCALER_FMT_0RGB1555)
      ctx->direct_pixconv = conv_rgb565_0rgb1555;
   else if (ctx->in_fmt == SCALER_FMT_BGR24 && ctx->out_fmt == SCALER_FMT_ARGB8888)
      ctx->direct_pixconv = conv_bgr24_argb8888;
   else if (ctx->in_fmt == SCALER_FMT_ARGB8888 && ctx->out_fmt == SCALER_FMT_0RGB1555)
      ctx->direct_pixconv = conv_argb8888_0rgb1555;
   else if (ctx->in_fmt == SCALER_FMT_ARGB8888 && ctx->out_fmt == SCALER_FMT_BGR24)
      ctx->direct_pixconv = conv_argb8888_bgr24;
   else if (ctx->in_fmt == SCALER_FMT_0RGB1555 && ctx->out_fmt == SCALER_FMT_BGR24)
      ctx->direct_pixconv = conv_0rgb1555_bgr24;
   else if (ctx->in_fmt == SCALER_FMT_ARGB8888 && ctx->out_fmt == SCALER_FMT_ABGR8888)
      ctx->direct_pixconv = conv_argb8888_abgr8888;
   else if (ctx->in_fmt == SCALER_FMT_YUYV && ctx->out_fmt == SCALER_FMT_ARGB8888)
      ctx->direct_pixconv = conv_yuyv_argb8888;
   else
      return false;

   return true;
}

static bool set_pix_conv(struct scaler_ctx *ctx)
{
   switch (ctx->in_fmt)
   {
      case SCALER_FMT_ARGB8888:
         // No need to convert :D
         break;

      case SCALER_FMT_0RGB1555:
         ctx->in_pixconv = conv_0rgb1555_argb8888;
         break;

      case SCALER_FMT_RGB565:
         ctx->in_pixconv = conv_rgb565_argb8888;
         break;

      case SCALER_FMT_BGR24:
         ctx->in_pixconv = conv_bgr24_argb8888;
         break;

      default:
         return false;
   }

   switch (ctx->out_fmt)
   {
      case SCALER_FMT_ARGB8888:
         // No need to convert :D
         break;

      case SCALER_FMT_0RGB1555:
         ctx->out_pixconv = conv_argb8888_0rgb1555;
         break;

      case SCALER_FMT_BGR24:
         ctx->out_pixconv = conv_argb8888_bgr24;
         break;

      default:
         return false;
   }

   return true;
}

bool scaler_ctx_gen_filter(struct scaler_ctx *ctx)
{
   scaler_ctx_gen_reset(ctx);

   if (ctx->in_width == ctx->out_width && ctx->in_height == ctx->out_height)
      ctx->unscaled = true; // Only pixel format conversion ...
   else
   {
      ctx->scaler_horiz = scaler_argb8888_horiz;
      ctx->scaler_vert  = scaler_argb8888_vert;
      ctx->unscaled     = false;
   }

   ctx->scaler_special = NULL;

   if (!allocate_frames(ctx))
      return false;

   if (ctx->unscaled)
   {
      if (!set_direct_pix_conv(ctx))
         return false;
   }
   else
   {
      if (!set_pix_conv(ctx))
         return false;
   }

   if (!ctx->unscaled && !scaler_gen_filter(ctx))
      return false;

   return true;
}

void scaler_ctx_gen_reset(struct scaler_ctx *ctx)
{
   scaler_free(ctx->horiz.filter);
   scaler_free(ctx->horiz.filter_pos);
   scaler_free(ctx->vert.filter);
   scaler_free(ctx->vert.filter_pos);
   scaler_free(ctx->scaled.frame);
   scaler_free(ctx->input.frame);
   scaler_free(ctx->output.frame);

   memset(&ctx->horiz, 0, sizeof(ctx->horiz));
   memset(&ctx->vert, 0, sizeof(ctx->vert));
   memset(&ctx->scaled, 0, sizeof(ctx->scaled));
   memset(&ctx->input, 0, sizeof(ctx->input));
   memset(&ctx->output, 0, sizeof(ctx->output));
}

void scaler_ctx_scale(struct scaler_ctx *ctx,
      void *output, const void *input)
{
   if (ctx->unscaled) // Just perform straight pixel conversion.
   {
      ctx->direct_pixconv(output, input,
            ctx->out_width, ctx->out_height,
            ctx->out_stride, ctx->in_stride);
   }
   else if (ctx->scaler_special) // Take some special, and (hopefully) more optimized path.
   {
      const void *inp = input;
      int in_stride   = ctx->in_stride;

      if (ctx->in_fmt != SCALER_FMT_ARGB8888)
      {
         ctx->in_pixconv(ctx->input.frame, input,
               ctx->in_width, ctx->in_height,
               ctx->input.stride, ctx->in_stride);

         inp       = ctx->input.frame;
         in_stride = ctx->input.stride;
      }

      bool conv_out  = ctx->out_fmt != SCALER_FMT_ARGB8888;
      void *outp     = output;
      int out_stride = ctx->out_stride;

      if (conv_out)
      {
         outp       = ctx->output.frame;
         out_stride = ctx->output.stride;
      }

      ctx->scaler_special(ctx, outp, inp,
            ctx->out_width, ctx->out_height,
            ctx->in_width, ctx->in_height,
            out_stride, in_stride);

      if (conv_out)
      {
         ctx->out_pixconv(output, ctx->output.frame,
               ctx->out_width, ctx->out_height,
               ctx->out_stride, ctx->output.stride);
      }
   }
   else // Take generic filter path.
   {
      if (ctx->in_fmt != SCALER_FMT_ARGB8888)
      {
         ctx->in_pixconv(ctx->input.frame, input,
               ctx->in_width, ctx->in_height,
               ctx->input.stride, ctx->in_stride);

         ctx->scaler_horiz(ctx, ctx->input.frame, ctx->input.stride);
      }
      else
         ctx->scaler_horiz(ctx, input, ctx->in_stride);

      if (ctx->out_fmt != SCALER_FMT_ARGB8888)
      {
         ctx->scaler_vert(ctx, ctx->output.frame, ctx->output.stride);

         ctx->out_pixconv(output, ctx->output.frame,
               ctx->out_width, ctx->out_height,
               ctx->out_stride, ctx->output.stride);
      }
      else
         ctx->scaler_vert(ctx, output, ctx->out_stride);
   }
}