/* This file is an image processing operation for GEGL

 *

 * GEGL is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 3 of the License, or (at your option) any later version.

 *

 * GEGL 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with GEGL; if not, see <http://www.gnu.org/licenses/>.

 *

 * Copyright 2006 Øyvind Kolås <pippin@gimp.org>

 */

#include "config.h"

#include <glib/gi18n-lib.h>

#include <math.h>

#ifdef GEGL_CHANT_PROPERTIES

gegl_chant_int_ui (size_x, _("Block Width"),  1, 123456, 16, 1, 2048, 1.5,

   _("Width of blocks in pixels"))

gegl_chant_int_ui (size_y, _("Block Height"), 1, 123456, 16, 1, 2048, 1.5,

   _("Height of blocks in pixels"))

#else

#define GEGL_CHANT_TYPE_AREA_FILTER

#define GEGL_CHANT_C_FILE       "pixelize.c"

#include "gegl-chant.h"

#define CELL_X(px, cell_width)  ((px) / (cell_width))

#define CELL_Y(py, cell_height)  ((py) / (cell_height))

static void prepare (GeglOperation *operation)

{

  GeglChantO              *o;

  GeglOperationAreaFilter *op_area;

  op_area = GEGL_OPERATION_AREA_FILTER (operation);

  o       = GEGL_CHANT_PROPERTIES (operation);

  op_area->left   =

  op_area->right  = o->size_x;

  op_area->top    =

  op_area->bottom = o->size_y;

  gegl_operation_set_format (operation, "input",

                             babl_format ("RaGaBaA float"));

  gegl_operation_set_format (operation, "output",

                             babl_format ("RaGaBaA float"));

}

static void

calc_block_colors (gfloat* block_colors,

                   const gfloat* input,

                   const GeglRectangle* roi,

                   gint size_x,

                   gint size_y)

{

  gint cx0 = CELL_X(roi->x, size_x);

  gint cy0 = CELL_Y(roi->y, size_y);

  gint cx1 = CELL_X(roi->x + roi->width - 1, size_x);

  gint cy1 = CELL_Y(roi->y + roi->height - 1, size_y);

  gint cx;

  gint cy;

  gfloat weight = 1.0f / (size_x * size_y);

  gint line_width = roi->width + 2*size_x;

  /* loop over the blocks within the region of interest */

  for (cy=cy0; cy<=cy1; ++cy)

    {

      for (cx=cx0; cx<=cx1; ++cx)

        {

          gint px = (cx * size_x) - roi->x + size_x;

          gint py = (cy * size_y) - roi->y + size_y;

          /* calculate the average color for this block */

          gint j,i,c;

          gfloat col[4] = {0.0f, 0.0f, 0.0f, 0.0f};

          for (j=py; j

            {

              for (i=px; i

                {

                  for (c=0; c<4; ++c)

                    col[c] += input[(j*line_width + i)*4 + c];

                }

            }

          for (c=0; c<4; ++c)

            block_colors[c] = weight * col[c];

          block_colors += 4;

        }

    }

}

static void

pixelize (gfloat* buf,

          const GeglRectangle* roi,

          gint size_x,

          gint size_y)

{

  gint cx0 = CELL_X(roi->x, size_x);

  gint cy0 = CELL_Y(roi->y, size_y);

  gint block_count_x = CELL_X(roi->x + roi->width - 1, size_x) - cx0 + 1;

  gint block_count_y = CELL_Y(roi->y + roi->height - 1, size_y) - cy0 + 1;

  gfloat* block_colors = g_new0 (gfloat, block_count_x * block_count_y * 4);

  gint x;

  gint y;

  gint c;

  /* calculate the average color of all the blocks */

  calc_block_colors(block_colors, buf, roi, size_x, size_y);

  /* set each pixel to the average color of the block it belongs to */

  for (y=0; y<roi->height; ++y)

    {

      gint cy = CELL_Y(y + roi->y, size_y) - cy0;

      for (x=0; x<roi->width; ++x)

        {

          gint cx = CELL_X(x + roi->x, size_x) - cx0;

          for (c=0; c<4; ++c)

            *buf++ = block_colors[(cy*block_count_x + cx)*4 + c];

        }

    }

  g_free (block_colors);

}

#include "opencl/gegl-cl.h"

#include "buffer/gegl-buffer-cl-iterator.h"

static const char* kernel_source =

"__kernel void calc_block_color(__global float4 *in,                   \n"

"                             __global float4 *out,                    \n"

"                             int xsize,                               \n"

"                             int ysize,                               \n"

"                             int roi_x,                               \n"

"                             int roi_y,                               \n"

"                             int line_width,                          \n"

"                             int block_count_x )                      \n"

"{                                                                     \n"

"    int gidx = get_global_id(0);                                      \n"

"    int gidy = get_global_id(1);                                      \n"

"    int cx = roi_x / xsize + gidx;                                    \n"

"    int cy = roi_y / ysize + gidy;                                    \n"

"                                                                      \n"

"    float weight   = 1.0f / (xsize * ysize);                          \n"

"                                                                      \n"

"    int px = cx * xsize + xsize - roi_x;                              \n"

"    int py = cy * ysize + ysize - roi_y;                              \n"

"                                                                      \n"

"    int i,j;                                                          \n"

"    float4 col = 0.0f;                                                \n"

"    for (j = py;j < py + ysize; ++j)                                  \n"

"    {                                                                 \n"

"        for (i = px;i < px + xsize; ++i)                              \n"

"        {                                                             \n"

"            col += in[j * line_width + i];                            \n"

"        }                                                             \n"

"    }                                                                 \n"

"    out[gidy * block_count_x + gidx] = col * weight;                  \n"

"                                                                      \n"

"}                                                                     \n"

"                                                                      \n"

"__kernel void kernel_pixelise (__global float4 *in,                   \n"

"                             __global float4 *out,                    \n"

"                             int xsize,                               \n"

"                             int ysize,                               \n"

"                             int roi_x,                               \n"

"                             int roi_y,                               \n"

"                             int block_count_x)                       \n"

"{                                                                     \n"

"    int gidx = get_global_id(0);                                      \n"

"    int gidy = get_global_id(1);                                      \n"

"                                                                      \n"

"    int src_width  = get_global_size(0);                              \n"

"    int cx = (gidx + roi_x) / xsize - roi_x / xsize;                  \n"

"    int cy = (gidy + roi_y) / ysize - roi_y / ysize;                  \n"

"    out[gidx + gidy * src_width] = in[cx + cy * block_count_x];       \n"

"}                                                                     \n";

static gegl_cl_run_data *cl_data = NULL;

static cl_int

cl_pixelise (cl_mem                in_tex,

             cl_mem                aux_tex,

             cl_mem                out_tex,

             const GeglRectangle  *src_rect,

             const GeglRectangle  *roi,

             gint                  xsize,

             gint                  ysize)

{

  cl_int cl_err = 0;

  const size_t gbl_size[2]= {roi->width, roi->height};

  gint cx0 = CELL_X(roi->x ,xsize);

  gint cy0 = CELL_Y(roi->y ,ysize);

  gint block_count_x = CELL_X(roi->x+roi->width - 1, xsize)-cx0 + 1;

  gint block_count_y = CELL_Y(roi->y+roi->height - 1, ysize)-cy0 + 1;

  cl_int line_width = roi->width + 2 * xsize;

  size_t gbl_size_tmp[2]={block_count_x,block_count_y};

  if (!cl_data)

  {

    const char *kernel_name[] = {"calc_block_color", "kernel_pixelise", NULL};

    cl_data = gegl_cl_compile_and_build (kernel_source, kernel_name);

  }

  if (!cl_data) return 1;

  cl_err |= gegl_clSetKernelArg(cl_data->kernel[0], 0, sizeof(cl_mem),   (void*)&in_tex);

  cl_err |= gegl_clSetKernelArg(cl_data->kernel[0], 1, sizeof(cl_mem),   (void*)&aux_tex);

  cl_err |= gegl_clSetKernelArg(cl_data->kernel[0], 2, sizeof(cl_int),   (void*)&xsize);

  cl_err |= gegl_clSetKernelArg(cl_data->kernel[0], 3, sizeof(cl_int),   (void*)&ysize);

  cl_err |= gegl_clSetKernelArg(cl_data->kernel[0], 4, sizeof(cl_int),   (void*)&roi->x);

  cl_err |= gegl_clSetKernelArg(cl_data->kernel[0], 5, sizeof(cl_int),   (void*)&roi->y);

  cl_err |= gegl_clSetKernelArg(cl_data->kernel[0], 6, sizeof(cl_int),   (void*)&line_width);

  cl_err |= gegl_clSetKernelArg(cl_data->kernel[0], 7, sizeof(cl_int),   (void*)&block_count_x);

  if (cl_err != CL_SUCCESS) return cl_err;

  cl_err = gegl_clEnqueueNDRangeKernel(gegl_cl_get_command_queue (),

                                        cl_data->kernel[0], 2,

                                        NULL, gbl_size_tmp, NULL,

                                        0, NULL, NULL);

  if (cl_err != CL_SUCCESS) return cl_err;

  cl_err |= gegl_clSetKernelArg(cl_data->kernel[1], 0, sizeof(cl_mem),   (void*)&aux_tex);

  cl_err |= gegl_clSetKernelArg(cl_data->kernel[1], 1, sizeof(cl_mem),   (void*)&out_tex);

  cl_err |= gegl_clSetKernelArg(cl_data->kernel[1], 2, sizeof(cl_int),   (void*)&xsize);

  cl_err |= gegl_clSetKernelArg(cl_data->kernel[1], 3, sizeof(cl_int),   (void*)&ysize);

  cl_err |= gegl_clSetKernelArg(cl_data->kernel[1], 4, sizeof(cl_int),   (void*)&roi->x);

  cl_err |= gegl_clSetKernelArg(cl_data->kernel[1], 5, sizeof(cl_int),   (void*)&roi->y);

  cl_err |= gegl_clSetKernelArg(cl_data->kernel[1], 6, sizeof(cl_int),   (void*)&block_count_x);

  if (cl_err != CL_SUCCESS) return cl_err;

  cl_err = gegl_clEnqueueNDRangeKernel(gegl_cl_get_command_queue (),

                                        cl_data->kernel[1], 2,

                                        NULL, gbl_size, NULL,

                                        0, NULL, NULL);

  if (cl_err != CL_SUCCESS) return cl_err;

  return cl_err;

}

static gboolean

cl_process (GeglOperation       *operation,

            GeglBuffer          *input,

            GeglBuffer          *output,

            const GeglRectangle *roi)

{

  const Babl *in_format  = gegl_operation_get_format (operation, "input");

  const Babl *out_format = gegl_operation_get_format (operation, "output");

  gint err;

  gint j;

  cl_int cl_err;

  GeglOperationAreaFilter *op_area = GEGL_OPERATION_AREA_FILTER (operation);

  GeglChantO *o = GEGL_CHANT_PROPERTIES (operation);

  GeglBufferClIterator *i = gegl_buffer_cl_iterator_new   (output,   roi, out_format, GEGL_CL_BUFFER_WRITE, GEGL_ABYSS_NONE);

                gint read = gegl_buffer_cl_iterator_add_2 (i, input, roi, in_format,  GEGL_CL_BUFFER_READ, op_area->left, op_area->right, op_area->top, op_area->bottom, GEGL_ABYSS_NONE);

                gint aux  = gegl_buffer_cl_iterator_add_2 (i, NULL,  roi, in_format,  GEGL_CL_BUFFER_AUX,  op_area->left, op_area->right, op_area->top, op_area->bottom, GEGL_ABYSS_NONE);

  while (gegl_buffer_cl_iterator_next (i, &err))

  {

    if (err) return FALSE;

    for (j=0; j < i->n; j++)

    {

      cl_err = cl_pixelise(i->tex[read][j], i->tex[aux][j], i->tex[0][j],&i->roi[read][j], &i->roi[0][j], o->size_x,o->size_y);

      if (cl_err != CL_SUCCESS)

      {

        g_warning("[OpenCL] Error in gegl:pixelise: %s", gegl_cl_errstring(cl_err));

        return FALSE;

      }

    }

  }

  return TRUE;

}

static gboolean

process (GeglOperation       *operation,

         GeglBuffer          *input,

         GeglBuffer          *output,

         const GeglRectangle *roi,

         gint                 level)

{

  GeglRectangle src_rect;

  GeglChantO *o = GEGL_CHANT_PROPERTIES (operation);

  GeglOperationAreaFilter *op_area;

  gfloat* buf;

  op_area = GEGL_OPERATION_AREA_FILTER (operation);

  src_rect = *roi;

  src_rect.x -= op_area->left;

  src_rect.y -= op_area->top;

  src_rect.width += op_area->left + op_area->right;

  src_rect.height += op_area->top + op_area->bottom;

  if (gegl_cl_is_accelerated ())

    if (cl_process (operation, input, output, roi))

      return TRUE;

  buf = g_new0 (gfloat, src_rect.width * src_rect.height * 4);

  gegl_buffer_get (input, &src_rect, 1.0, babl_format ("RaGaBaA float"), buf, GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);

  pixelize(buf, roi, o->size_x, o->size_y);

  gegl_buffer_set (output, roi, 0, babl_format ("RaGaBaA float"), buf, GEGL_AUTO_ROWSTRIDE);

  g_free (buf);

  return  TRUE;

}

static void

gegl_chant_class_init (GeglChantClass *klass)

{

  GeglOperationClass       *operation_class;

  GeglOperationFilterClass *filter_class;

  operation_class = GEGL_OPERATION_CLASS (klass);

  filter_class    = GEGL_OPERATION_FILTER_CLASS (klass);

  filter_class->process    = process;

  operation_class->prepare = prepare;

  operation_class->opencl_support = TRUE;

  gegl_operation_class_set_keys (operation_class,

    "categories" , "blur",

    "name"       , "gegl:pixelize",

    "description",

         _("Simplify image into an array of solid-colored squares"),

    NULL);

}

#endif