gimpink.c 20.2 KB
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/* The GIMP -- an image manipulation program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 * This program 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 Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */
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#include "config.h"

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#include <string.h>
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#include <glib-object.h>
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#include "paint-types.h"
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#include "base/pixel-region.h"
#include "base/temp-buf.h"
#include "base/tile.h"
#include "base/tile-manager.h"

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#include "paint-funcs/paint-funcs.h"

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#include "core/gimpdrawable.h"
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#include "core/gimpimage.h"
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#include "gimpinkoptions.h"
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#include "gimpink.h"
#include "gimpink-blob.h"
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#include "gimpink-undo.h"
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#include "gimp-intl.h"
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#define SUBSAMPLE 8
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/*  local function prototypes  */
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static void      gimp_ink_finalize       (GObject          *object);

static void      gimp_ink_paint          (GimpPaintCore    *paint_core,
                                          GimpDrawable     *drawable,
                                          GimpPaintOptions *paint_options,
                                          GimpPaintState    paint_state,
                                          guint32           time);
static TempBuf * gimp_ink_get_paint_area (GimpPaintCore    *paint_core,
                                          GimpDrawable     *drawable,
                                          GimpPaintOptions *paint_options);

static void      gimp_ink_motion         (GimpPaintCore    *paint_core,
                                          GimpDrawable     *drawable,
                                          GimpPaintOptions *paint_options,
                                          guint32           time);

static Blob    * ink_pen_ellipse         (GimpInkOptions   *options,
                                          gdouble           x_center,
                                          gdouble           y_center,
                                          gdouble           pressure,
                                          gdouble           xtilt,
                                          gdouble           ytilt,
                                          gdouble           velocity);

static void      time_smoother_add       (GimpInk          *ink,
                                          guint32           value);
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static guint32   time_smoother_result    (GimpInk          *ink);
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static void      time_smoother_init      (GimpInk          *ink,
                                          guint32           initval);
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static void      dist_smoother_add       (GimpInk          *ink,
                                          gdouble           value);
static gdouble   dist_smoother_result    (GimpInk          *ink);
static void      dist_smoother_init      (GimpInk          *ink,
                                          gdouble           initval);

static void      render_blob             (Blob             *blob,
                                          PixelRegion      *dest);
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G_DEFINE_TYPE (GimpInk, gimp_ink, GIMP_TYPE_PAINT_CORE);

#define parent_class gimp_ink_parent_class
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void
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gimp_ink_register (Gimp                      *gimp,
                   GimpPaintRegisterCallback  callback)
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{
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  (* callback) (gimp,
                GIMP_TYPE_INK,
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                GIMP_TYPE_INK_OPTIONS,
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                _("Ink"));
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}

static void
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gimp_ink_class_init (GimpInkClass *klass)
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{
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  GObjectClass       *object_class     = G_OBJECT_CLASS (klass);
  GimpPaintCoreClass *paint_core_class = GIMP_PAINT_CORE_CLASS (klass);
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  object_class->finalize           = gimp_ink_finalize;
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  paint_core_class->paint          = gimp_ink_paint;
  paint_core_class->get_paint_area = gimp_ink_get_paint_area;
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  paint_core_class->push_undo      = gimp_ink_push_undo;
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}

static void
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gimp_ink_init (GimpInk *ink)
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{
}

static void
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gimp_ink_finalize (GObject *object)
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{
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  GimpInk *ink = GIMP_INK (object);
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  if (ink->start_blob)
    {
      g_free (ink->start_blob);
      ink->start_blob = NULL;
    }

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  if (ink->last_blob)
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    {
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      g_free (ink->last_blob);
      ink->last_blob = NULL;
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    }
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  G_OBJECT_CLASS (parent_class)->finalize (object);
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}

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static void
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gimp_ink_paint (GimpPaintCore    *paint_core,
                GimpDrawable     *drawable,
                GimpPaintOptions *paint_options,
                GimpPaintState    paint_state,
                guint32           time)
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{
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  GimpInk *ink = GIMP_INK (paint_core);
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  switch (paint_state)
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    {
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    case GIMP_PAINT_STATE_INIT:
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      if (paint_core->cur_coords.x == paint_core->last_coords.x &&
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          paint_core->cur_coords.y == paint_core->last_coords.y)
        {
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          /*  start with new blobs if we're not interpolating  */

          if (ink->start_blob)
            {
              g_free (ink->start_blob);
              ink->start_blob = NULL;
            }

          if (ink->last_blob)
            {
              g_free (ink->last_blob);
              ink->last_blob = NULL;
            }
        }
      else if (ink->last_blob)
        {
          /*  save the start blob of the line for undo otherwise  */

          if (ink->start_blob)
            g_free (ink->start_blob);

          ink->start_blob = blob_duplicate (ink->last_blob);
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        }
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      break;
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    case GIMP_PAINT_STATE_MOTION:
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      gimp_ink_motion (paint_core, drawable, paint_options, time);
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      break;
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    case GIMP_PAINT_STATE_FINISH:
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      break;
    }
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}
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static TempBuf *
gimp_ink_get_paint_area (GimpPaintCore    *paint_core,
                         GimpDrawable     *drawable,
                         GimpPaintOptions *paint_options)
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{
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  GimpInk *ink  = GIMP_INK (paint_core);
  gint     x, y;
  gint     width, height;
  gint     dwidth, dheight;
  gint     x1, y1, x2, y2;
  gint     bytes;
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  bytes = gimp_drawable_bytes_with_alpha (drawable);
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  blob_bounds (ink->cur_blob, &x, &y, &width, &height);
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  dwidth  = gimp_item_width  (GIMP_ITEM (drawable));
  dheight = gimp_item_height (GIMP_ITEM (drawable));
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  x1 = CLAMP (x / SUBSAMPLE - 1,            0, dwidth);
  y1 = CLAMP (y / SUBSAMPLE - 1,            0, dheight);
  x2 = CLAMP ((x + width)  / SUBSAMPLE + 2, 0, dwidth);
  y2 = CLAMP ((y + height) / SUBSAMPLE + 2, 0, dheight);
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  /*  configure the canvas buffer  */
  if ((x2 - x1) && (y2 - y1))
    paint_core->canvas_buf = temp_buf_resize (paint_core->canvas_buf, bytes,
                                              x1, y1,
                                              (x2 - x1), (y2 - y1));
  else
    return NULL;
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  return paint_core->canvas_buf;
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}
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static void
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gimp_ink_motion (GimpPaintCore    *paint_core,
                 GimpDrawable     *drawable,
                 GimpPaintOptions *paint_options,
                 guint32           time)
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{
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  GimpInk        *ink     = GIMP_INK (paint_core);
  GimpInkOptions *options = GIMP_INK_OPTIONS (paint_options);
  GimpContext    *context = GIMP_CONTEXT (paint_options);
  GimpImage      *gimage;
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  Blob           *blob_union = NULL;
  Blob           *blob_to_render;
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  TempBuf        *area;
  guchar          col[MAX_CHANNELS];
  PixelRegion     blob_maskPR;
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  gimage = gimp_item_get_image (GIMP_ITEM (drawable));
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  if (! ink->last_blob)
    {
      ink->last_blob = ink_pen_ellipse (options,
                                        paint_core->cur_coords.x,
                                        paint_core->cur_coords.y,
                                        paint_core->cur_coords.pressure,
                                        paint_core->cur_coords.xtilt,
                                        paint_core->cur_coords.ytilt,
                                        10.0);
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      if (ink->start_blob)
        g_free (ink->start_blob);

      ink->start_blob = blob_duplicate (ink->last_blob);

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      time_smoother_init (ink, time);
      ink->last_time = time;
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      dist_smoother_init (ink, 0.0);
      ink->init_velocity = TRUE;
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      blob_to_render = ink->last_blob;
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    }
  else
    {
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      Blob    *blob;
      gdouble  dist;
      gdouble  velocity;
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      guint32  lasttime = ink->last_time;
      guint32  thistime;
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      time_smoother_add (ink, time);
      thistime = ink->last_time = time_smoother_result (ink);

      /* The time resolution on X-based GDK motion events is bloody
       * awful, hence the use of the smoothing function.  Sadly this
       * also means that there is always the chance of having an
       * indeterminite velocity since this event and the previous
       * several may still appear to issue at the same
       * instant. -ADM
       */
      if (thistime == lasttime)
        thistime = lasttime + 1;

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      dist = sqrt ((paint_core->last_coords.x - paint_core->cur_coords.x) *
                   (paint_core->last_coords.x - paint_core->cur_coords.x) +
                   (paint_core->last_coords.y - paint_core->cur_coords.y) *
                   (paint_core->last_coords.y - paint_core->cur_coords.y));
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      if (ink->init_velocity)
        {
          dist_smoother_init (ink, dist);
          ink->init_velocity = FALSE;
        }
      else
        {
          dist_smoother_add (ink, dist);
          dist = dist_smoother_result (ink);
        }

      velocity = 10.0 * sqrt ((dist) / (gdouble) (thistime - lasttime));

      blob = ink_pen_ellipse (options,
                              paint_core->cur_coords.x,
                              paint_core->cur_coords.y,
                              paint_core->cur_coords.pressure,
                              paint_core->cur_coords.xtilt,
                              paint_core->cur_coords.ytilt,
                              velocity);

      blob_union = blob_convex_union (ink->last_blob, blob);
      g_free (ink->last_blob);
      ink->last_blob = blob;
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      blob_to_render = blob_union;
    }
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  /* Get the the buffer */
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  ink->cur_blob = blob_to_render;
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  area = gimp_paint_core_get_paint_area (paint_core, drawable, paint_options);
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  ink->cur_blob = NULL;

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  if (! area)
    return;
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  gimp_image_get_foreground (gimage, drawable, context, col);
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  /*  set the alpha channel  */
  col[paint_core->canvas_buf->bytes - 1] = OPAQUE_OPACITY;
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  /*  color the pixels  */
  color_pixels (temp_buf_data (paint_core->canvas_buf), col,
                area->width * area->height, area->bytes);

  gimp_paint_core_validate_canvas_tiles (paint_core,
                                         paint_core->canvas_buf->x,
                                         paint_core->canvas_buf->y,
                                         paint_core->canvas_buf->width,
                                         paint_core->canvas_buf->height);

  /*  draw the blob directly to the canvas_tiles  */
  pixel_region_init (&blob_maskPR, paint_core->canvas_tiles,
                     paint_core->canvas_buf->x,
                     paint_core->canvas_buf->y,
                     paint_core->canvas_buf->width,
                     paint_core->canvas_buf->height,
                     TRUE);

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  render_blob (blob_to_render, &blob_maskPR);
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  /*  draw the canvas_buf using the just rendered canvas_tiles as mask */
  pixel_region_init (&blob_maskPR, paint_core->canvas_tiles,
                     paint_core->canvas_buf->x,
                     paint_core->canvas_buf->y,
                     paint_core->canvas_buf->width,
                     paint_core->canvas_buf->height,
                     FALSE);

  gimp_paint_core_paste (paint_core, &blob_maskPR, drawable,
                         GIMP_OPACITY_OPAQUE,
                         gimp_context_get_opacity (context),
                         gimp_context_get_paint_mode (context),
                         GIMP_PAINT_CONSTANT);
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  if (blob_union)
    g_free (blob_union);
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}

static Blob *
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ink_pen_ellipse (GimpInkOptions *options,
                 gdouble         x_center,
		 gdouble         y_center,
		 gdouble         pressure,
		 gdouble         xtilt,
		 gdouble         ytilt,
		 gdouble         velocity)
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{
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  BlobFunc blob_function;
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  gdouble  size;
  gdouble  tsin, tcos;
  gdouble  aspect, radmin;
  gdouble  x,y;
  gdouble  tscale;
  gdouble  tscale_c;
  gdouble  tscale_s;
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  /* Adjust the size depending on pressure. */

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  size = options->size * (1.0 + options->size_sensitivity *
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                          (2.0 * pressure - 1.0));
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  /* Adjust the size further depending on pointer velocity and
   * velocity-sensitivity.  These 'magic constants' are 'feels
   * natural' tigert-approved. --ADM
   */
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  if (velocity < 3.0)
    velocity = 3.0;

#ifdef VERBOSE
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  g_printerr ("%g (%g) -> ", size, velocity);
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#endif
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  size = (options->vel_sensitivity *
          ((4.5 * size) / (1.0 + options->vel_sensitivity * (2.0 * velocity)))
          + (1.0 - options->vel_sensitivity) * size);
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#ifdef VERBOSE
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  g_printerr ("%g\n", (gfloat) size);
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#endif

  /* Clamp resulting size to sane limits */

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  if (size > options->size * (1.0 + options->size_sensitivity))
    size = options->size * (1.0 + options->size_sensitivity);
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  if (size * SUBSAMPLE < 1.0)
    size = 1.0 / SUBSAMPLE;
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  /* Add brush angle/aspect to tilt vectorially */
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  /* I'm not happy with the way the brush widget info is combined with
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   * tilt info from the brush. My personal feeling is that
   * representing both as affine transforms would make the most
   * sense. -RLL
   */
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  tscale   = options->tilt_sensitivity * 10.0;
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  tscale_c = tscale * cos (gimp_deg_to_rad (options->tilt_angle));
  tscale_s = tscale * sin (gimp_deg_to_rad (options->tilt_angle));

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  x = (options->blob_aspect * cos (options->blob_angle) +
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       xtilt * tscale_c - ytilt * tscale_s);
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  y = (options->blob_aspect * sin (options->blob_angle) +
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       ytilt * tscale_c + xtilt * tscale_s);

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#ifdef VERBOSE
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  g_printerr ("angle %g aspect %g; %g %g; %g %g\n",
              options->blob_angle, options->blob_aspect,
              tscale_c, tscale_s, x, y);
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#endif
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  aspect = sqrt (x * x + y * y);
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  if (aspect != 0)
    {
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      tcos = x / aspect;
      tsin = y / aspect;
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    }
  else
    {
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      tsin = sin (options->blob_angle);
      tcos = cos (options->blob_angle);
    }

  aspect = CLAMP (aspect, 1.0, 10.0);

  radmin = MAX (1.0, SUBSAMPLE * size / aspect);

  switch (options->blob_type)
    {
    case GIMP_INK_BLOB_TYPE_ELLIPSE:
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      blob_function = blob_ellipse;
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      break;

    case GIMP_INK_BLOB_TYPE_SQUARE:
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      blob_function = blob_square;
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      break;

    case GIMP_INK_BLOB_TYPE_DIAMOND:
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      blob_function = blob_diamond;
      break;

    default:
      g_return_val_if_reached (NULL);
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      break;
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    }
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  return (* blob_function) (x_center * SUBSAMPLE,
                            y_center * SUBSAMPLE,
                            radmin * aspect * tcos,
                            radmin * aspect * tsin,
                            -radmin * tsin,
                            radmin * tcos);
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}

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static void
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time_smoother_init (GimpInk *ink,
                    guint32  initval)
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{
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  gint i;
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  ink->ts_index = 0;
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  for (i = 0; i < TIME_SMOOTHER_BUFFER; i++)
    ink->ts_buffer[i] = initval;
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}
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static guint32
time_smoother_result (GimpInk *ink)
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{
  gint    i;
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  guint64 result = 0;
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  for (i = 0; i < TIME_SMOOTHER_BUFFER; i++)
    result += ink->ts_buffer[i];
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  return (result / (guint64) TIME_SMOOTHER_BUFFER);
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}

static void
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time_smoother_add (GimpInk *ink,
                   guint32  value)
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{
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  guint64 long_value = (guint64) value;
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  /*  handle wrap-around of time values  */
  if (long_value < ink->ts_buffer[ink->ts_index])
    long_value += (guint64) + G_MAXUINT32;

  ink->ts_buffer[ink->ts_index++] = long_value;

  ink->ts_buffer[ink->ts_index++] = value;

  if (ink->ts_index == TIME_SMOOTHER_BUFFER)
    ink->ts_index = 0;
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}
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static void
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dist_smoother_init (GimpInk *ink,
                    gdouble  initval)
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{
  gint i;
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  ink->dt_index = 0;
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  for (i = 0; i < DIST_SMOOTHER_BUFFER; i++)
    ink->dt_buffer[i] = initval;
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}

static gdouble
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dist_smoother_result (GimpInk *ink)
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{
  gint    i;
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  gdouble result = 0.0;
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  for (i = 0; i < DIST_SMOOTHER_BUFFER; i++)
    result += ink->dt_buffer[i];
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  return (result / (gdouble) DIST_SMOOTHER_BUFFER);
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}
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static void
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dist_smoother_add (GimpInk *ink,
                   gdouble  value)
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{
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  ink->dt_buffer[ink->dt_index++] = value;
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  if (ink->dt_index == DIST_SMOOTHER_BUFFER)
    ink->dt_index = 0;
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}


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/*********************************/
/*  Rendering functions          */
/*********************************/
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/* Some of this stuff should probably be combined with the
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 * code it was copied from in paint_core.c; but I wanted
 * to learn this stuff, so I've kept it simple.
 *
 * The following only supports CONSTANT mode. Incremental
 * would, I think, interact strangely with the way we
 * do things. But it wouldn't be hard to implement at all.
 */

enum { ROW_START, ROW_STOP };

/* The insertion sort here, for SUBSAMPLE = 8, tends to beat out
 * qsort() by 4x with CFLAGS=-O2, 2x with CFLAGS=-g
 */
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static void
insert_sort (gint *data,
	     gint  n)
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{
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  gint i, j, k;
  gint tmp1, tmp2;
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  for (i = 2; i < 2 * n; i += 2)
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    {
      tmp1 = data[i];
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      tmp2 = data[i + 1];
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      j = 0;
      while (data[j] < tmp1)
	j += 2;

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      for (k = i; k > j; k -= 2)
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	{
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	  data[k]     = data[k - 2];
	  data[k + 1] = data[k - 1];
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	}

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      data[j]     = tmp1;
      data[j + 1] = tmp2;
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    }
}

static void
fill_run (guchar *dest,
	  guchar  alpha,
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	  gint    w)
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{
  if (alpha == 255)
    {
      memset (dest, 255, w);
    }
  else
    {
      while (w--)
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        {
          *dest = MAX (*dest, alpha);
          dest++;
        }
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    }
}

static void
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render_blob_line (Blob   *blob,
		  guchar *dest,
		  gint    x,
		  gint    y,
		  gint    width)
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{
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  gint  buf[4 * SUBSAMPLE];
  gint *data    = buf;
  gint  n       = 0;
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  gint  i, j;
  gint  current = 0;  /* number of filled rows at this point
		       * in the scan line
		       */
  gint last_x;
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  /* Sort start and ends for all lines */
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  j = y * SUBSAMPLE - blob->y;
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  for (i = 0; i < SUBSAMPLE; i++)
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    {
      if (j >= blob->height)
	break;
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      if ((j > 0) && (blob->data[j].left <= blob->data[j].right))
	{
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	  data[2 * n]                     = blob->data[j].left;
	  data[2 * n + 1]                 = ROW_START;
	  data[2 * SUBSAMPLE + 2 * n]     = blob->data[j].right;
	  data[2 * SUBSAMPLE + 2 * n + 1] = ROW_STOP;
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	  n++;
	}
      j++;
    }

  /*   If we have less than SUBSAMPLE rows, compress */
  if (n < SUBSAMPLE)
    {
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      for (i = 0; i < 2 * n; i++)
	data[2 * n + i] = data[2 * SUBSAMPLE + i];
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    }

  /*   Now count start and end separately */
  n *= 2;

  insert_sort (data, n);

  /* Discard portions outside of tile */

  while ((n > 0) && (data[0] < SUBSAMPLE*x))
    {
      if (data[1] == ROW_START)
	current++;
      else
	current--;
      data += 2;
      n--;
    }

  while ((n > 0) && (data[2*(n-1)] >= SUBSAMPLE*(x+width)))
    n--;
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  /* Render the row */

  last_x = 0;
698
  for (i = 0; i < n;)
699
    {
700
      gint cur_x = data[2 * i] / SUBSAMPLE - x;
701
      gint pixel;
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      /* Fill in portion leading up to this pixel */
      if (current && cur_x != last_x)
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	fill_run (dest + last_x, (255 * current) / SUBSAMPLE, cur_x - last_x);
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      /* Compute the value for this pixel */
708
      pixel = current * SUBSAMPLE;
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      while (i<n)
	{
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	  gint tmp_x = data[2 * i] / SUBSAMPLE;

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	  if (tmp_x - x != cur_x)
	    break;

717
	  if (data[2 * i + 1] == ROW_START)
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	    {
	      current++;
720
	      pixel += ((tmp_x + 1) * SUBSAMPLE) - data[2 * i];
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	    }
	  else
	    {
	      current--;
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	      pixel -= ((tmp_x + 1) * SUBSAMPLE) - data[2 * i];
726
	    }
727

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	  i++;
	}

731
      dest[cur_x] = MAX (dest[cur_x], (pixel * 255) / (SUBSAMPLE * SUBSAMPLE));
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      last_x = cur_x + 1;
    }

  if (current != 0)
737
    fill_run (dest + last_x, (255 * current)/ SUBSAMPLE, width - last_x);
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}

static void
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render_blob (Blob        *blob,
             PixelRegion *dest)
743
{
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  gint      i;
  gint      h;
  guchar   *s;
  gpointer  pr;
748

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  for (pr = pixel_regions_register (1, dest);
       pr != NULL;
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       pr = pixel_regions_process (pr))
    {
      h = dest->h;
      s = dest->data;

      for (i=0; i<h; i++)
	{
	  render_blob_line (blob, s,
			    dest->x, dest->y + i, dest->w);
	  s += dest->rowstride;
	}
    }
}