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gimp/app/tools/gimpiscissorstool.c

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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.
*/
/* This tool is based on a paper from SIGGRAPH '95:
* "Intelligent Scissors for Image Composition", Eric N. Mortensen and
* William A. Barrett, Brigham Young University.
*
* thanks to Professor D. Forsyth for prompting us to implement this tool. */
/* Personal note: Dr. Barrett, one of the authors of the paper written above
* is not only one of the most brilliant people I have ever met, he is an
* incredible professor who genuinely cares about his students and wants them
* to learn as much as they can about the topic.
*
* I didn't even notice I was taking a class from the person who wrote the
* paper until halfway through the semester.
* -- Rockwalrus
*/
/* The history of this implementation is lonog and varied. It was
* orignally done by Spencer and Peter, and worked fine in the 0.54
* (motif only) release of the gimp. Later revisions (0.99.something
* until about 1.1.4) completely changed the algorithm used, until it
* bore little resemblance to the one described in the paper above.
* The 0.54 version of the algorithm was then forwards ported to 1.1.4
* by Austin Donnelly.
*/
/* Livewire boundary implementation done by Laramie Leavitt */
#include "config.h"
#include <stdlib.h>
#include <gtk/gtk.h>
#include <gdk/gdkkeysyms.h>
#include "libgimpmath/gimpmath.h"
#include "libgimpwidgets/gimpwidgets.h"
#include "tools-types.h"
#include "base/pixel-region.h"
#include "base/temp-buf.h"
#include "base/tile-manager.h"
#include "base/tile.h"
#include "paint-funcs/paint-funcs.h"
#include "core/gimpchannel.h"
#include "core/gimpchannel-select.h"
#include "core/gimpimage.h"
#include "core/gimpimage-projection.h"
#include "core/gimpscanconvert.h"
#include "core/gimptoolinfo.h"
#include "widgets/gimphelp-ids.h"
#include "display/gimpdisplay.h"
#include "gimpiscissorstool.h"
#include "gimpeditselectiontool.h"
#include "gimpselectionoptions.h"
#include "gimptoolcontrol.h"
#include "gimp-intl.h"
/* Other defines... */
#define MAX_GRADIENT 179.606 /* == sqrt (127^2 + 127^2) */
#define GRADIENT_SEARCH 32 /* how far to look when snapping to an edge */
#define TARGET_HEIGHT 25
#define TARGET_WIDTH 25
#define POINT_WIDTH 8 /* size (in pixels) of seed handles */
#define POINT_HALFWIDTH (POINT_WIDTH / 2)
#define EXTEND_BY 0.2 /* proportion to expand cost map by */
#define FIXED 5 /* additional fixed size to expand cost map */
#define MIN_GRADIENT 63 /* gradients < this are directionless */
#define MAX_POINTS 2048
#define COST_WIDTH 2 /* number of bytes for each pixel in cost map */
#define BLOCK_WIDTH 64
#define BLOCK_HEIGHT 64
#define CONV_WIDTH (BLOCK_WIDTH + 2)
#define CONV_HEIGHT (BLOCK_HEIGHT + 2)
/* weight to give between gradient (_G) and direction (_D) */
#define OMEGA_D 0.2
#define OMEGA_G 0.8
/* sentinel to mark seed point in ?cost? map */
#define SEED_POINT 9
/* Functional defines */
#define PIXEL_COST(x) (x >> 8)
#define PIXEL_DIR(x) (x & 0x000000ff)
struct _ICurve
{
gint x1, y1;
gint x2, y2;
GPtrArray *points;
};
/* local function prototypes */
static void gimp_iscissors_tool_class_init (GimpIscissorsToolClass *klass);
static void gimp_iscissors_tool_init (GimpIscissorsTool *iscissors);
static void gimp_iscissors_tool_finalize (GObject *object);
static void gimp_iscissors_tool_control (GimpTool *tool,
GimpToolAction action,
GimpDisplay *gdisp);
static void gimp_iscissors_tool_button_press (GimpTool *tool,
GimpCoords *coords,
guint32 time,
GdkModifierType state,
GimpDisplay *gdisp);
static void gimp_iscissors_tool_button_release (GimpTool *tool,
GimpCoords *coords,
guint32 time,
GdkModifierType state,
GimpDisplay *gdisp);
static void gimp_iscissors_tool_motion (GimpTool *tool,
GimpCoords *coords,
guint32 time,
GdkModifierType state,
GimpDisplay *gdisp);
static void gimp_iscissors_tool_oper_update (GimpTool *tool,
GimpCoords *coords,
GdkModifierType state,
GimpDisplay *gdisp);
static void gimp_iscissors_tool_cursor_update (GimpTool *tool,
GimpCoords *coords,
GdkModifierType state,
GimpDisplay *gdisp);
static void gimp_iscissors_tool_reset (GimpIscissorsTool *iscissors);
static void gimp_iscissors_tool_draw (GimpDrawTool *draw_tool);
static void iscissors_convert (GimpIscissorsTool *iscissors,
GimpDisplay *gdisp);
static TileManager * gradient_map_new (GimpImage *gimage);
static void find_optimal_path (TileManager *gradient_map,
TempBuf *dp_buf,
gint x1,
gint y1,
gint x2,
gint y2,
gint xs,
gint ys);
static void find_max_gradient (GimpIscissorsTool *iscissors,
GimpImage *gimage,
gint *x,
gint *y);
static void calculate_curve (GimpTool *tool,
ICurve *curve);
static void iscissors_draw_curve (GimpDrawTool *draw_tool,
ICurve *curve);
static void iscissors_free_icurves (GSList *list);
static void iscissors_free_buffers (GimpIscissorsTool *iscissors);
static gint mouse_over_vertex (GimpIscissorsTool *iscissors,
gdouble x,
gdouble y);
static gboolean clicked_on_vertex (GimpTool *tool);
static GSList * mouse_over_curve (GimpIscissorsTool *iscissors,
gdouble x,
gdouble y);
static gboolean clicked_on_curve (GimpTool *tool);
static void precalculate_arrays (void);
static GPtrArray * plot_pixels (GimpIscissorsTool *iscissors,
TempBuf *dp_buf,
gint x1,
gint y1,
gint xs,
gint ys,
gint xe,
gint ye);
/* static variables */
/* where to move on a given link direction */
static gint move[8][2] =
{
{ 1, 0 },
{ 0, 1 },
{ -1, 1 },
{ 1, 1 },
{ -1, 0 },
{ 0, -1 },
{ 1, -1 },
{ -1, -1 },
};
/* IE:
* '---+---+---`
* | 7 | 5 | 6 |
* +---+---+---+
* | 4 | | 0 |
* +---+---+---+
* | 2 | 1 | 3 |
* `---+---+---'
*/
/* temporary convolution buffers -- */
static guchar maxgrad_conv0[TILE_WIDTH * TILE_HEIGHT * 4] = "";
static guchar maxgrad_conv1[TILE_WIDTH * TILE_HEIGHT * 4] = "";
static guchar maxgrad_conv2[TILE_WIDTH * TILE_HEIGHT * 4] = "";
static gint horz_deriv[9] =
{
1, 0, -1,
2, 0, -2,
1, 0, -1,
};
static gint vert_deriv[9] =
{
1, 2, 1,
0, 0, 0,
-1, -2, -1,
};
static gint blur_32[9] =
{
1, 1, 1,
1, 24, 1,
1, 1, 1,
};
static gfloat distance_weights[GRADIENT_SEARCH * GRADIENT_SEARCH];
static gint diagonal_weight[256];
static gint direction_value[256][4];
static gboolean initialized = FALSE;
static Tile *cur_tile = NULL;
static GimpSelectionToolClass *parent_class = NULL;
void
gimp_iscissors_tool_register (GimpToolRegisterCallback callback,
gpointer data)
{
(* callback) (GIMP_TYPE_ISCISSORS_TOOL,
GIMP_TYPE_SELECTION_OPTIONS,
gimp_selection_options_gui,
0,
"gimp-iscissors-tool",
_("Scissors"),
_("Select shapes from image"),
N_("/Tools/Selection Tools/_Intelligent Scissors"),
"I",
NULL, GIMP_HELP_TOOL_ISCISSORS,
GIMP_STOCK_TOOL_ISCISSORS,
data);
}
GType
gimp_iscissors_tool_get_type (void)
{
static GType tool_type = 0;
if (! tool_type)
{
static const GTypeInfo tool_info =
{
sizeof (GimpIscissorsToolClass),
(GBaseInitFunc) NULL,
(GBaseFinalizeFunc) NULL,
(GClassInitFunc) gimp_iscissors_tool_class_init,
NULL, /* class_finalize */
NULL, /* class_data */
sizeof (GimpIscissorsTool),
0, /* n_preallocs */
(GInstanceInitFunc) gimp_iscissors_tool_init,
};
tool_type = g_type_register_static (GIMP_TYPE_SELECTION_TOOL,
"GimpIscissorsTool",
&tool_info, 0);
}
return tool_type;
}
static void
gimp_iscissors_tool_class_init (GimpIscissorsToolClass *klass)
{
GObjectClass *object_class;
GimpToolClass *tool_class;
GimpDrawToolClass *draw_tool_class;
object_class = G_OBJECT_CLASS (klass);
tool_class = GIMP_TOOL_CLASS (klass);
draw_tool_class = GIMP_DRAW_TOOL_CLASS (klass);
parent_class = g_type_class_peek_parent (klass);
object_class->finalize = gimp_iscissors_tool_finalize;
tool_class->control = gimp_iscissors_tool_control;
tool_class->button_press = gimp_iscissors_tool_button_press;
tool_class->button_release = gimp_iscissors_tool_button_release;
tool_class->motion = gimp_iscissors_tool_motion;
tool_class->oper_update = gimp_iscissors_tool_oper_update;
tool_class->cursor_update = gimp_iscissors_tool_cursor_update;
draw_tool_class->draw = gimp_iscissors_tool_draw;
}
static void
gimp_iscissors_tool_init (GimpIscissorsTool *iscissors)
{
GimpTool *tool;
tool = GIMP_TOOL (iscissors);
iscissors->op = ISCISSORS_OP_NONE;
iscissors->dp_buf = NULL;
iscissors->curves = NULL;
iscissors->draw = DRAW_NOTHING;
iscissors->state = NO_ACTION;
iscissors->mask = NULL;
iscissors->gradient_map = NULL;
iscissors->livewire = NULL;
gimp_tool_control_set_scroll_lock (tool->control, TRUE);
gimp_tool_control_set_snap_to (tool->control, FALSE);
gimp_tool_control_set_preserve (tool->control, FALSE);
gimp_tool_control_set_tool_cursor (tool->control, GIMP_SCISSORS_TOOL_CURSOR);
gimp_iscissors_tool_reset (iscissors);
}
static void
gimp_iscissors_tool_finalize (GObject *object)
{
GimpIscissorsTool *iscissors = GIMP_ISCISSORS_TOOL (object);
gimp_iscissors_tool_reset (iscissors);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static void
gimp_iscissors_tool_control (GimpTool *tool,
GimpToolAction action,
GimpDisplay *gdisp)
{
GimpIscissorsTool *iscissors;
IscissorsDraw draw;
iscissors = GIMP_ISCISSORS_TOOL (tool);
switch (iscissors->state)
{
case SEED_PLACEMENT:
draw = DRAW_CURVE | DRAW_CURRENT_SEED;
break;
case SEED_ADJUSTMENT:
draw = DRAW_CURVE | DRAW_ACTIVE_CURVE;
break;
default:
draw = DRAW_CURVE;
break;
}
iscissors->draw = draw;
GIMP_TOOL_CLASS (parent_class)->control (tool, action, gdisp);
switch (action)
{
case PAUSE:
break;
case RESUME:
break;
case HALT:
gimp_iscissors_tool_reset (iscissors);
break;
default:
break;
}
}
static void
gimp_iscissors_tool_button_press (GimpTool *tool,
GimpCoords *coords,
guint32 time,
GdkModifierType state,
GimpDisplay *gdisp)
{
GimpIscissorsTool *iscissors;
GimpSelectionOptions *options;
iscissors = GIMP_ISCISSORS_TOOL (tool);
options = GIMP_SELECTION_OPTIONS (tool->tool_info->tool_options);
iscissors->x = coords->x;
iscissors->y = coords->y;
/* If the tool was being used in another image...reset it */
if (gimp_tool_control_is_active (tool->control) && gdisp != tool->gdisp)
{
gimp_draw_tool_stop (GIMP_DRAW_TOOL (tool));
gimp_iscissors_tool_reset (iscissors);
}
gimp_tool_control_activate (tool->control);
tool->gdisp = gdisp;
switch (iscissors->state)
{
case NO_ACTION:
iscissors->state = SEED_PLACEMENT;
iscissors->draw = DRAW_CURRENT_SEED;
if (! (state & GDK_SHIFT_MASK))
find_max_gradient (iscissors,
gdisp->gimage,
&iscissors->x,
&iscissors->y);
iscissors->x = CLAMP (iscissors->x, 0, gdisp->gimage->width - 1);
iscissors->y = CLAMP (iscissors->y, 0, gdisp->gimage->height - 1);
iscissors->ix = iscissors->x;
iscissors->iy = iscissors->y;
/* Initialize the selection core only on starting the tool */
gimp_draw_tool_start (GIMP_DRAW_TOOL (tool), gdisp);
break;
default:
/* Check if the mouse click occured on a vertex or the curve itself */
if (clicked_on_vertex (tool))
{
iscissors->nx = iscissors->x;
iscissors->ny = iscissors->y;
iscissors->state = SEED_ADJUSTMENT;
iscissors->draw = DRAW_CURVE | DRAW_ACTIVE_CURVE;
gimp_draw_tool_resume (GIMP_DRAW_TOOL (tool));
}
/* If the iscissors is connected, check if the click was inside */
else if (iscissors->connected && iscissors->mask &&
gimp_channel_value (iscissors->mask,
iscissors->x,
iscissors->y))
{
/* Undraw the curve */
gimp_tool_control_halt (tool->control);
iscissors->draw = DRAW_CURVE;
gimp_draw_tool_stop (GIMP_DRAW_TOOL (tool));
gimp_channel_select_channel (gimp_image_get_mask (gdisp->gimage),
tool->tool_info->blurb,
iscissors->mask,
0, 0,
GIMP_SELECTION_TOOL (tool)->op,
options->feather,
options->feather_radius,
options->feather_radius);
gimp_iscissors_tool_reset (iscissors);
gimp_image_flush (gdisp->gimage);
}
else if (! iscissors->connected)
{
/* if we're not connected, we're adding a new point */
/* pause the tool, but undraw nothing */
iscissors->draw = DRAW_NOTHING;
gimp_draw_tool_pause (GIMP_DRAW_TOOL (tool));
iscissors->state = SEED_PLACEMENT;
iscissors->draw = DRAW_CURRENT_SEED;
if (options->interactive)
iscissors->draw |= DRAW_LIVEWIRE;
gimp_draw_tool_resume (GIMP_DRAW_TOOL (tool));
}
break;
}
}
static void
iscissors_convert (GimpIscissorsTool *iscissors,
GimpDisplay *gdisp)
{
GimpSelectionOptions *options;
GimpScanConvert *sc;
GimpVector2 *points;
guint n_points;
GSList *list;
ICurve *icurve;
guint packed;
gint i;
gint index;
options =
GIMP_SELECTION_OPTIONS (GIMP_TOOL (iscissors)->tool_info->tool_options);
sc = gimp_scan_convert_new ();
/* go over the curves in reverse order, adding the points we have */
list = iscissors->curves;
index = g_slist_length (list);
while (index)
{
index--;
icurve = (ICurve *) g_slist_nth_data (list, index);
n_points = icurve->points->len;
points = g_new (GimpVector2, n_points);
for (i = 0; i < n_points; i ++)
{
packed = GPOINTER_TO_INT (g_ptr_array_index (icurve->points, i));
points[i].x = packed & 0x0000ffff;
points[i].y = packed >> 16;
}
gimp_scan_convert_add_points (sc, n_points, points, FALSE);
g_free (points);
}
if (iscissors->mask)
g_object_unref (iscissors->mask);
iscissors->mask = gimp_channel_new_mask (gdisp->gimage,
gdisp->gimage->width,
gdisp->gimage->height);
gimp_scan_convert_render (sc, GIMP_DRAWABLE (iscissors->mask)->tiles,
0, 0, options->antialias);
gimp_scan_convert_free (sc);
}
static void
gimp_iscissors_tool_button_release (GimpTool *tool,
GimpCoords *coords,
guint32 time,
GdkModifierType state,
GimpDisplay *gdisp)
{
GimpIscissorsTool *iscissors;
GimpSelectionOptions *options;
ICurve *curve;
iscissors = GIMP_ISCISSORS_TOOL (tool);
options = GIMP_SELECTION_OPTIONS (tool->tool_info->tool_options);
/* Make sure X didn't skip the button release event -- as it's known
* to do
*/
if (iscissors->state == WAITING)
return;
/* Undraw everything */
switch (iscissors->state)
{
case SEED_PLACEMENT:
iscissors->draw = DRAW_CURVE | DRAW_CURRENT_SEED;
if (options->interactive)
iscissors->draw |= DRAW_LIVEWIRE;
break;
case SEED_ADJUSTMENT:
iscissors->draw = DRAW_CURVE | DRAW_ACTIVE_CURVE;
break;
default:
break;
}
gimp_draw_tool_pause (GIMP_DRAW_TOOL (tool));
/* First take care of the case where the user "cancels" the action */
if (! (state & GDK_BUTTON3_MASK))
{
/* Progress to the next stage of intelligent selection */
switch (iscissors->state)
{
case SEED_PLACEMENT:
/* Add a new icurve */
if (!iscissors->first_point)
{
/* Determine if we're connecting to the first point */
if (iscissors->curves)
{
curve = (ICurve *) iscissors->curves->data;
if (abs (iscissors->x - curve->x1) < POINT_HALFWIDTH &&
abs (iscissors->y - curve->y1) < POINT_HALFWIDTH)
{
iscissors->x = curve->x1;
iscissors->y = curve->y1;
iscissors->connected = TRUE;
}
}
/* Create the new curve segment */
if (iscissors->ix != iscissors->x ||
iscissors->iy != iscissors->y)
{
curve = g_new (ICurve, 1);
curve->x1 = iscissors->ix;
curve->y1 = iscissors->iy;
iscissors->ix = curve->x2 = iscissors->x;
iscissors->iy = curve->y2 = iscissors->y;
curve->points = NULL;
iscissors->curves = g_slist_append (iscissors->curves, curve);
calculate_curve (tool, curve);
}
}
else /* this was our first point */
{
iscissors->first_point = FALSE;
}
break;
case SEED_ADJUSTMENT:
/* recalculate both curves */
if (iscissors->curve1)
{
iscissors->curve1->x1 = iscissors->nx;
iscissors->curve1->y1 = iscissors->ny;
calculate_curve (tool, iscissors->curve1);
}
if (iscissors->curve2)
{
iscissors->curve2->x2 = iscissors->nx;
iscissors->curve2->y2 = iscissors->ny;
calculate_curve (tool, iscissors->curve2);
}
break;
default:
break;
}
}
iscissors->state = WAITING;
/* Draw only the boundary */
iscissors->draw = DRAW_CURVE;
gimp_draw_tool_resume (GIMP_DRAW_TOOL (tool));
/* convert the curves into a region */
if (iscissors->connected)
iscissors_convert (iscissors, gdisp);
}
static void
gimp_iscissors_tool_motion (GimpTool *tool,
GimpCoords *coords,
guint32 time,
GdkModifierType state,
GimpDisplay *gdisp)
{
GimpIscissorsTool *iscissors;
GimpSelectionOptions *options;
iscissors = GIMP_ISCISSORS_TOOL (tool);
options = GIMP_SELECTION_OPTIONS (tool->tool_info->tool_options);
if (iscissors->state == NO_ACTION)
return;
if (iscissors->state == SEED_PLACEMENT)
{
iscissors->draw = DRAW_CURRENT_SEED;
if (options->interactive)
iscissors->draw |= DRAW_LIVEWIRE;
}
else if (iscissors->state == SEED_ADJUSTMENT)
{
iscissors->draw = DRAW_ACTIVE_CURVE;
}
gimp_draw_tool_pause (GIMP_DRAW_TOOL (tool));
iscissors->x = coords->x;
iscissors->y = coords->y;
switch (iscissors->state)
{
case SEED_PLACEMENT:
/* Hold the shift key down to disable the auto-edge snap feature */
if (! (state & GDK_SHIFT_MASK))
find_max_gradient (iscissors, gdisp->gimage,
&iscissors->x, &iscissors->y);
iscissors->x = CLAMP (iscissors->x, 0, gdisp->gimage->width - 1);
iscissors->y = CLAMP (iscissors->y, 0, gdisp->gimage->height - 1);
if (iscissors->first_point)
{
iscissors->ix = iscissors->x;
iscissors->iy = iscissors->y;
}
break;
case SEED_ADJUSTMENT:
/* Move the current seed to the location of the cursor */
if (! (state & GDK_SHIFT_MASK))
find_max_gradient (iscissors, gdisp->gimage,
&iscissors->x, &iscissors->y);
iscissors->x = CLAMP (iscissors->x, 0, gdisp->gimage->width - 1);
iscissors->y = CLAMP (iscissors->y, 0, gdisp->gimage->height - 1);
iscissors->nx = iscissors->x;
iscissors->ny = iscissors->y;
break;
default:
break;
}
gimp_draw_tool_resume (GIMP_DRAW_TOOL (tool));
}
static void
gimp_iscissors_tool_draw (GimpDrawTool *draw_tool)
{
GimpTool *tool;
GimpIscissorsTool *iscissors;
GimpDisplay *gdisp;
ICurve *curve;
GSList *list;
tool = GIMP_TOOL (draw_tool);
iscissors = GIMP_ISCISSORS_TOOL (draw_tool);
gdisp = tool->gdisp;
/* Draw the crosshairs target if we're placing a seed */
if (iscissors->draw & DRAW_CURRENT_SEED)
{
gimp_draw_tool_draw_handle (draw_tool,
GIMP_HANDLE_CROSS,
iscissors->x,
iscissors->y,
TARGET_WIDTH,
TARGET_WIDTH,
GTK_ANCHOR_CENTER,
FALSE);
/* Draw a line boundary */
if (! iscissors->first_point && ! (iscissors->draw & DRAW_LIVEWIRE))
{
gimp_draw_tool_draw_line (draw_tool,
iscissors->ix, iscissors->iy,
iscissors->x, iscissors->y,
FALSE);
}
}
/* Draw the livewire boundary */
if ((iscissors->draw & DRAW_LIVEWIRE) && ! iscissors->first_point)
{
/* See if the mouse has moved. If so, create a new segment... */
if (! iscissors->livewire ||
(iscissors->livewire &&
(iscissors->ix != iscissors->livewire->x1 ||
iscissors->x != iscissors->livewire->x2 ||
iscissors->iy != iscissors->livewire->y1 ||
iscissors->y != iscissors->livewire->y2)))
{
curve = g_new (ICurve, 1);
curve->x1 = iscissors->ix;
curve->y1 = iscissors->iy;
curve->x2 = iscissors->x;
curve->y2 = iscissors->y;
curve->points = NULL;
if (iscissors->livewire)
{
if (iscissors->livewire->points)
g_ptr_array_free (iscissors->livewire->points, TRUE);
g_free (iscissors->livewire);
iscissors->livewire = NULL;
}
iscissors->livewire = curve;
calculate_curve (tool, curve);
curve = NULL;
}
/* plot the curve */
iscissors_draw_curve (draw_tool, iscissors->livewire);
}
if ((iscissors->draw & DRAW_CURVE) && ! iscissors->first_point)
{
/* Draw a point at the init point coordinates */
if (! iscissors->connected)
{
gimp_draw_tool_draw_handle (draw_tool,
GIMP_HANDLE_FILLED_CIRCLE,
iscissors->ix,
iscissors->iy,
POINT_WIDTH,
POINT_WIDTH,
GTK_ANCHOR_CENTER,
FALSE);
}
/* Go through the list of icurves, and render each one... */
for (list = iscissors->curves; list; list = g_slist_next (list))
{
curve = (ICurve *) list->data;
if (iscissors->draw & DRAW_ACTIVE_CURVE)
{
/* don't draw curve1 at all */
if (curve == iscissors->curve1)
continue;
}
gimp_draw_tool_draw_handle (draw_tool,
GIMP_HANDLE_FILLED_CIRCLE,
curve->x1,
curve->y1,
POINT_WIDTH,
POINT_WIDTH,
GTK_ANCHOR_CENTER,
FALSE);
if (iscissors->draw & DRAW_ACTIVE_CURVE)
{
/* draw only the start handle of curve2 */
if (curve == iscissors->curve2)
continue;
}
/* plot the curve */
iscissors_draw_curve (draw_tool, curve);
}
}
if (iscissors->draw & DRAW_ACTIVE_CURVE)
{
/* plot both curves, and the control point between them */
if (iscissors->curve1)
{
gimp_draw_tool_draw_line (draw_tool,
iscissors->curve1->x2,
iscissors->curve1->y2,
iscissors->nx,
iscissors->ny,
FALSE);
}
if (iscissors->curve2)
{
gimp_draw_tool_draw_line (draw_tool,
iscissors->curve2->x1,
iscissors->curve2->y1,
iscissors->nx,
iscissors->ny,
FALSE);
}
gimp_draw_tool_draw_handle (draw_tool,
GIMP_HANDLE_FILLED_CIRCLE,
iscissors->nx,
iscissors->ny,
POINT_WIDTH,
POINT_WIDTH,
GTK_ANCHOR_CENTER,
FALSE);
}
}
static void
iscissors_draw_curve (GimpDrawTool *draw_tool,
ICurve *curve)
{
gpointer *point;
guint len;
gint npts = 0;
guint32 coords;
guint32 coords_2;
/* Uh, this shouldn't happen, but it does. So we ignore it.
* Quality code, baby.
*/
if (! curve->points)
return;
point = curve->points->pdata + 1;
len = curve->points->len - 1;
while (len--)
{
coords = GPOINTER_TO_INT (*point);
coords_2 = GPOINTER_TO_INT (*(point - 1));
point++;
if (npts < MAX_POINTS)
{
gimp_draw_tool_draw_line (draw_tool,
(coords & 0x0000ffff),
(coords >> 16),
(coords_2 & 0x0000ffff),
(coords_2 >> 16),
FALSE);
npts++;
}
else
{
g_warning ("too many points in ICurve segment!");
return;
}
}
}
static void
gimp_iscissors_tool_oper_update (GimpTool *tool,
GimpCoords *coords,
GdkModifierType state,
GimpDisplay *gdisp)
{
GimpIscissorsTool *iscissors = GIMP_ISCISSORS_TOOL (tool);
GIMP_TOOL_CLASS (parent_class)->oper_update (tool, coords, state, gdisp);
if (mouse_over_vertex (iscissors, coords->x, coords->y))
{
iscissors->op = ISCISSORS_OP_MOVE_POINT;
}
else if (mouse_over_curve (iscissors, coords->x, coords->y))
{
iscissors->op = ISCISSORS_OP_ADD_POINT;
}
else if (iscissors->connected && iscissors->mask)
{
if (gimp_channel_value (iscissors->mask, coords->x, coords->y))
{
iscissors->op = ISCISSORS_OP_SELECT;
}
else
{
iscissors->op = ISCISSORS_OP_IMPOSSIBLE;
}
}
else
{
switch (iscissors->state)
{
case WAITING:
iscissors->op = ISCISSORS_OP_ADD_POINT;
break;
case SEED_PLACEMENT:
case SEED_ADJUSTMENT:
default:
iscissors->op = ISCISSORS_OP_NONE;
break;
}
}
}
static void
gimp_iscissors_tool_cursor_update (GimpTool *tool,
GimpCoords *coords,
GdkModifierType state,
GimpDisplay *gdisp)
{
GimpIscissorsTool *iscissors = GIMP_ISCISSORS_TOOL (tool);
GdkCursorType cursor = GIMP_MOUSE_CURSOR;
GimpCursorModifier cmodifier = GIMP_CURSOR_MODIFIER_NONE;
switch (iscissors->op)
{
case ISCISSORS_OP_SELECT:
GIMP_TOOL_CLASS (parent_class)->cursor_update (tool, coords, state, gdisp);
return;
case ISCISSORS_OP_MOVE_POINT:
cmodifier = GIMP_CURSOR_MODIFIER_MOVE;
break;
case ISCISSORS_OP_ADD_POINT:
cmodifier = GIMP_CURSOR_MODIFIER_PLUS;
break;
case ISCISSORS_OP_IMPOSSIBLE:
cursor = GIMP_BAD_CURSOR;
break;
default:
break;
}
gimp_tool_set_cursor (tool, gdisp,
cursor,
GIMP_SCISSORS_TOOL_CURSOR /* tool->tool_cursor*/,
cmodifier);
}
static void
gimp_iscissors_tool_reset (GimpIscissorsTool *iscissors)
{
/* Free and reset the curve list */
if (iscissors->curves)
{
iscissors_free_icurves (iscissors->curves);
g_slist_free (iscissors->curves);
iscissors->curves = NULL;
}
/* free mask */
if (iscissors->mask)
{
g_object_unref (iscissors->mask);
iscissors->mask = NULL;
}
/* free the gradient map */
if (iscissors->gradient_map)
{
/* release any tile we were using */
if (cur_tile)
{
tile_release (cur_tile, FALSE);
cur_tile = NULL;
}
tile_manager_unref (iscissors->gradient_map);
iscissors->gradient_map = NULL;
}
iscissors->curve1 = NULL;
iscissors->curve2 = NULL;
iscissors->first_point = TRUE;
iscissors->connected = FALSE;
iscissors->draw = DRAW_NOTHING;
iscissors->state = NO_ACTION;
/* Reset the dp buffers */
iscissors_free_buffers (iscissors);
/* If they haven't already been initialized, precalculate the diagonal
* weight and direction value arrays
*/
if (!initialized)
{
precalculate_arrays ();
initialized = TRUE;
}
}
static void
iscissors_free_icurves (GSList *list)
{
ICurve * curve;
while (list)
{
curve = (ICurve *) list->data;
if (curve->points)
g_ptr_array_free (curve->points, TRUE);
g_free (curve);
list = g_slist_next (list);
}
}
static void
iscissors_free_buffers (GimpIscissorsTool *iscissors)
{
if (iscissors->dp_buf)
temp_buf_free (iscissors->dp_buf);
iscissors->dp_buf = NULL;
}
/* XXX need some scan-conversion routines from somewhere. maybe. ? */
static gint
mouse_over_vertex (GimpIscissorsTool *iscissors,
gdouble x,
gdouble y)
{
GSList *list;
ICurve *curve;
gint curves_found = 0;
/* traverse through the list, returning non-zero if the current cursor
* position is on an existing curve vertex. Set the curve1 and curve2
* variables to the two curves containing the vertex in question
*/
iscissors->curve1 = iscissors->curve2 = NULL;
list = iscissors->curves;
while (list && curves_found < 2)
{
curve = (ICurve *) list->data;
if (gimp_draw_tool_on_handle (GIMP_DRAW_TOOL (iscissors),
GIMP_TOOL (iscissors)->gdisp,
x, y,
GIMP_HANDLE_CIRCLE,
curve->x1, curve->y1,
POINT_WIDTH, POINT_WIDTH,
GTK_ANCHOR_CENTER,
FALSE))
{
iscissors->curve1 = curve;
if (curves_found++)
return curves_found;
}
else if (gimp_draw_tool_on_handle (GIMP_DRAW_TOOL (iscissors),
GIMP_TOOL (iscissors)->gdisp,
x, y,
GIMP_HANDLE_CIRCLE,
curve->x2, curve->y2,
POINT_WIDTH, POINT_WIDTH,
GTK_ANCHOR_CENTER,
FALSE))
{
iscissors->curve2 = curve;
if (curves_found++)
return curves_found;
}
list = g_slist_next (list);
}
return curves_found;
}
static gboolean
clicked_on_vertex (GimpTool *tool)
{
GimpIscissorsTool *iscissors = GIMP_ISCISSORS_TOOL (tool);
gint curves_found = 0;
curves_found = mouse_over_vertex (iscissors, iscissors->x, iscissors->y);
if (curves_found > 1)
{
/* undraw the curve */
iscissors->draw = DRAW_CURVE;
gimp_draw_tool_pause (GIMP_DRAW_TOOL (tool));
return TRUE;
}
/* if only one curve was found, the curves are unconnected, and
* the user only wants to move either the first or last point
* disallow this for now.
*/
if (curves_found == 1)
return FALSE;
return clicked_on_curve (tool);
}
static GSList *
mouse_over_curve (GimpIscissorsTool *iscissors,
gdouble x,
gdouble y)
{
GSList *list;
gpointer *pt;
gint len;
ICurve *curve;
guint32 coords;
gint tx, ty;
/* traverse through the list, returning the curve segment's list element
* if the current cursor position is on a curve...
*/
for (list = iscissors->curves; list; list = g_slist_next (list))
{
curve = (ICurve *) list->data;
pt = curve->points->pdata;
len = curve->points->len;
while (len--)
{
coords = GPOINTER_TO_INT (*pt);
pt++;
tx = coords & 0x0000ffff;
ty = coords >> 16;
/* Is the specified point close enough to the curve? */
if (gimp_draw_tool_in_radius (GIMP_DRAW_TOOL (iscissors),
GIMP_TOOL (iscissors)->gdisp,
tx, ty,
x, y,
POINT_HALFWIDTH))
{
return list;
}
}
}
return NULL;
}
static gboolean
clicked_on_curve (GimpTool *tool)
{
GimpIscissorsTool *iscissors;
GimpSelectionOptions *options;
GSList *list, *new_link;
ICurve *curve, *new_curve;
iscissors = GIMP_ISCISSORS_TOOL (tool);
options = GIMP_SELECTION_OPTIONS (tool->tool_info->tool_options);
/* traverse through the list, getting back the curve segment's list
* element if the current cursor position is on a curve...
* If this occurs, replace the curve with two new curves,
* separated by a new vertex.
*/
list = mouse_over_curve (iscissors, iscissors->x, iscissors->y);
if (list)
{
curve = (ICurve *) list->data;
/* undraw the curve */
iscissors->draw = DRAW_CURVE;
gimp_draw_tool_pause (GIMP_DRAW_TOOL (tool));
/* Create the new curve */
new_curve = g_new (ICurve, 1);
new_curve->x2 = curve->x2;
new_curve->y2 = curve->y2;
new_curve->x1 = curve->x2 = iscissors->x;
new_curve->y1 = curve->y2 = iscissors->y;
new_curve->points = NULL;
/* Create the new link and supply the new curve as data */
new_link = g_slist_alloc ();
new_link->data = new_curve;
/* Insert the new link in the list */
new_link->next = list->next;
list->next = new_link;
iscissors->curve1 = new_curve;
iscissors->curve2 = curve;
return TRUE;
}
return FALSE;
}
static void
precalculate_arrays (void)
{
gint i;
for (i = 0; i < 256; i++)
{
/* The diagonal weight array */
diagonal_weight[i] = (int) (i * G_SQRT2);
/* The direction value array */
direction_value[i][0] = (127 - abs (127 - i)) * 2;
direction_value[i][1] = abs (127 - i) * 2;
direction_value[i][2] = abs (191 - i) * 2;
direction_value[i][3] = abs (63 - i) * 2;
}
/* set the 256th index of the direction_values to the hightest cost */
direction_value[255][0] = 255;
direction_value[255][1] = 255;
direction_value[255][2] = 255;
direction_value[255][3] = 255;
}
static void
calculate_curve (GimpTool *tool,
ICurve *curve)
{
GimpIscissorsTool *iscissors;
GimpDisplay *gdisp;
gint x, y, dir;
gint xs, ys, xe, ye;
gint x1, y1, x2, y2;
gint width, height;
gint ewidth, eheight;
/* Calculate the lowest cost path from one vertex to the next as specified
* by the parameter "curve".
* Here are the steps:
* 1) Calculate the appropriate working area for this operation
* 2) Allocate a temp buf for the dynamic programming array
* 3) Run the dynamic programming algorithm to find the optimal path
* 4) Translate the optimal path into pixels in the icurve data
* structure.
*/
iscissors = GIMP_ISCISSORS_TOOL (tool);
gdisp = tool->gdisp;
/* Get the bounding box */
xs = CLAMP (curve->x1, 0, gdisp->gimage->width - 1);
ys = CLAMP (curve->y1, 0, gdisp->gimage->height - 1);
xe = CLAMP (curve->x2, 0, gdisp->gimage->width - 1);
ye = CLAMP (curve->y2, 0, gdisp->gimage->height - 1);
x1 = MIN (xs, xe);
y1 = MIN (ys, ye);
x2 = MAX (xs, xe) + 1; /* +1 because if xe = 199 & xs = 0, x2 - x1, width = 200 */
y2 = MAX (ys, ye) + 1;
/* expand the boundaries past the ending points by
* some percentage of width and height. This serves the following purpose:
* It gives the algorithm more area to search so better solutions
* are found. This is particularly helpful in finding "bumps" which
* fall outside the bounding box represented by the start and end
* coordinates of the "curve".
*/
ewidth = (x2 - x1) * EXTEND_BY + FIXED;
eheight = (y2 - y1) * EXTEND_BY + FIXED;
if (xe >= xs)
x2 += CLAMP (ewidth, 0, gdisp->gimage->width - x2);
else
x1 -= CLAMP (ewidth, 0, x1);
if (ye >= ys)
y2 += CLAMP (eheight, 0, gdisp->gimage->height - y2);
else
y1 -= CLAMP (eheight, 0, y1);
/* blow away any previous points list we might have */
if (curve->points)
{
g_ptr_array_free (curve->points, TRUE);
curve->points = NULL;
}
/* If the bounding box has width and height... */
if ((x2 - x1) && (y2 - y1))
{
width = (x2 - x1);
height = (y2 - y1);
/* Initialise the gradient map tile manager for this image if we
* don't already have one. */
if (!iscissors->gradient_map)
iscissors->gradient_map = gradient_map_new (gdisp->gimage);
/* allocate the dynamic programming array */
iscissors->dp_buf =
temp_buf_resize (iscissors->dp_buf, 4, x1, y1, width, height);
/* find the optimal path of pixels from (x1, y1) to (x2, y2) */
find_optimal_path (iscissors->gradient_map, iscissors->dp_buf,
x1, y1, x2, y2, xs, ys);
/* get a list of the pixels in the optimal path */
curve->points = plot_pixels (iscissors, iscissors->dp_buf,
x1, y1, xs, ys, xe, ye);
}
/* If the bounding box has no width */
else if ((x2 - x1) == 0)
{
/* plot a vertical line */
y = ys;
dir = (ys > ye) ? -1 : 1;
curve->points = g_ptr_array_new ();
while (y != ye)
{
g_ptr_array_add (curve->points, GINT_TO_POINTER ((y << 16) + xs));
y += dir;
}
}
/* If the bounding box has no height */
else if ((y2 - y1) == 0)
{
/* plot a horizontal line */
x = xs;
dir = (xs > xe) ? -1 : 1;
curve->points = g_ptr_array_new ();
while (x != xe)
{
g_ptr_array_add (curve->points, GINT_TO_POINTER ((ys << 16) + x));
x += dir;
}
}
}
/* badly need to get a replacement - this is _way_ too expensive */
static gboolean
gradient_map_value (TileManager *map,
gint x,
gint y,
guint8 *grad,
guint8 *dir)
{
static gint cur_tilex;
static gint cur_tiley;
guint8 *p;
if (!cur_tile ||
x / TILE_WIDTH != cur_tilex ||
y / TILE_HEIGHT != cur_tiley)
{
if (cur_tile)
tile_release (cur_tile, FALSE);
cur_tile = tile_manager_get_tile (map, x, y, TRUE, FALSE);
if (!cur_tile)
return FALSE;
cur_tilex = x / TILE_WIDTH;
cur_tiley = y / TILE_HEIGHT;
}
p = tile_data_pointer (cur_tile, x % TILE_WIDTH, y % TILE_HEIGHT);
*grad = p[0];
*dir = p[1];
return TRUE;
}
static gint
calculate_link (TileManager *gradient_map,
gint x,
gint y,
guint32 pixel,
gint link)
{
gint value = 0;
guint8 grad1, dir1, grad2, dir2;
if (!gradient_map_value (gradient_map, x, y, &grad1, &dir1))
{
grad1 = 0;
dir1 = 255;
}
/* Convert the gradient into a cost: large gradients are good, and
* so have low cost. */
grad1 = 255 - grad1;
/* calculate the contribution of the gradient magnitude */
if (link > 1)
value += diagonal_weight[grad1] * OMEGA_G;
else
value += grad1 * OMEGA_G;
/* calculate the contribution of the gradient direction */
x += (gint8)(pixel & 0xff);
y += (gint8)((pixel & 0xff00) >> 8);
if (!gradient_map_value (gradient_map, x, y, &grad2, &dir2))
{
grad2 = 0;
dir2 = 255;
}
value += (direction_value[dir1][link] + direction_value[dir2][link]) *
OMEGA_D;
return value;
}
static GPtrArray *
plot_pixels (GimpIscissorsTool *iscissors,
TempBuf *dp_buf,
gint x1,
gint y1,
gint xs,
gint ys,
gint xe,
gint ye)
{
gint x, y;
guint32 coords;
gint link;
gint width;
guint *data;
GPtrArray *list;
width = dp_buf->width;
/* Start the data pointer at the correct location */
data = (guint *) temp_buf_data (dp_buf) + (ye - y1) * width + (xe - x1);
x = xe;
y = ye;
list = g_ptr_array_new ();
while (1)
{
coords = (y << 16) + x;
g_ptr_array_add (list, GINT_TO_POINTER (coords));
link = PIXEL_DIR (*data);
if (link == SEED_POINT)
return list;
x += move[link][0];
y += move[link][1];
data += move[link][1] * width + move[link][0];
}
/* won't get here */
return NULL;
}
#define PACK(x, y) ((((y) & 0xff) << 8) | ((x) & 0xff))
#define OFFSET(pixel) ((gint8)((pixel) & 0xff) + \
((gint8)(((pixel) & 0xff00) >> 8)) * dp_buf->width)
static void
find_optimal_path (TileManager *gradient_map,
TempBuf *dp_buf,
gint x1,
gint y1,
gint x2,
gint y2,
gint xs,
gint ys)
{
gint i, j, k;
gint x, y;
gint link;
gint linkdir;
gint dirx, diry;
gint min_cost;
gint new_cost;
gint offset;
gint cum_cost[8];
gint link_cost[8];
gint pixel_cost[8];
guint32 pixel[8];
guint32 *data;
guint32 *d;
/* initialize the dynamic programming buffer */
data = (guint32 *) temp_buf_data_clear (dp_buf);
/* what directions are we filling the array in according to? */
dirx = (xs - x1 == 0) ? 1 : -1;
diry = (ys - y1 == 0) ? 1 : -1;
linkdir = (dirx * diry);
y = ys;
for (i = 0; i < dp_buf->height; i++)
{
x = xs;
d = data + (y-y1) * dp_buf->width + (x-x1);
for (j = 0; j < dp_buf->width; j++)
{
min_cost = G_MAXINT;
/* pixel[] array encodes how to get to a neigbour, if possible.
* 0 means no connection (eg edge).
* Rest packed as bottom two bytes: y offset then x offset.
* Initially, we assume we can't get anywhere. */
for (k = 0; k < 8; k++)
pixel[k] = 0;
/* Find the valid neighboring pixels */
/* the previous pixel */
if (j)
pixel[((dirx == 1) ? 4 : 0)] = PACK (-dirx, 0);
/* the previous row of pixels */
if (i)
{
pixel[((diry == 1) ? 5 : 1)] = PACK (0, -diry);
link = (linkdir == 1) ? 3 : 2;
if (j)
pixel[((diry == 1) ? (link + 4) : link)] = PACK(-dirx, -diry);
link = (linkdir == 1) ? 2 : 3;
if (j != dp_buf->width - 1)
pixel[((diry == 1) ? (link + 4) : link)] = PACK (dirx, -diry);
}
/* find the minimum cost of going through each neighbor to reach the
* seed point...
*/
link = -1;
for (k = 0; k < 8; k ++)
if (pixel[k])
{
link_cost[k] = calculate_link (gradient_map,
xs + j*dirx, ys + i*diry,
pixel [k],
((k > 3) ? k - 4 : k));
offset = OFFSET (pixel [k]);
pixel_cost[k] = PIXEL_COST (d[offset]);
cum_cost[k] = pixel_cost[k] + link_cost[k];
if (cum_cost[k] < min_cost)
{
min_cost = cum_cost[k];
link = k;
}
}
/* If anything can be done... */
if (link >= 0)
{
/* set the cumulative cost of this pixel and the new direction */
*d = (cum_cost[link] << 8) + link;
/* possibly change the links from the other pixels to this pixel...
* these changes occur if a neighboring pixel will receive a lower
* cumulative cost by going through this pixel.
*/
for (k = 0; k < 8; k ++)
if (pixel[k] && k != link)
{
/* if the cumulative cost at the neighbor is greater than
* the cost through the link to the current pixel, change the
* neighbor's link to point to the current pixel.
*/
new_cost = link_cost[k] + cum_cost[link];
if (pixel_cost[k] > new_cost)
{
/* reverse the link direction /-----------------------\ */
offset = OFFSET (pixel[k]);
d[offset] = (new_cost << 8) + ((k > 3) ? k - 4 : k + 4);
}
}
}
/* Set the seed point */
else if (!i && !j)
*d = SEED_POINT;
/* increment the data pointer and the x counter */
d += dirx;
x += dirx;
}
/* increment the y counter */
y += diry;
}
}
/* Called to fill in a newly referenced tile in the gradient map */
static void
gradmap_tile_validate (TileManager *tm,
Tile *tile)
{
static gboolean first_gradient = TRUE;
gint x, y;
gint dw, dh;
gint sw, sh;
gint i, j;
gint b;
gfloat gradient;
guint8 *gradmap;
guint8 *tiledata;
guint8 *datah, *datav;
gint8 hmax, vmax;
Tile *srctile;
PixelRegion srcPR, destPR;
GimpImage *gimage;
gimage = (GimpImage *) tile_manager_get_user_data (tm);
if (first_gradient)
{
gint radius = GRADIENT_SEARCH >> 1;
/* compute the distance weights */
for (i = 0; i < GRADIENT_SEARCH; i++)
for (j = 0; j < GRADIENT_SEARCH; j++)
distance_weights[i * GRADIENT_SEARCH + j] =
1.0 / (1 + sqrt (SQR(i - radius) + SQR(j - radius)));
first_gradient = FALSE;
}
tile_manager_get_tile_coordinates (tm, tile, &x, &y);
dw = tile_ewidth (tile);
dh = tile_eheight (tile);
/* get corresponding tile in the gimage */
srctile = tile_manager_get_tile (gimp_image_projection (gimage),
x, y, TRUE, FALSE);
if (!srctile)
return;
sw = tile_ewidth (srctile);
sh = tile_eheight (srctile);
srcPR.w = MIN (dw, sw);
srcPR.h = MIN (dh, sh);
srcPR.bytes = gimp_image_projection_bytes (gimage);
srcPR.data = tile_data_pointer (srctile, 0, 0);
srcPR.rowstride = srcPR.w * srcPR.bytes;
/* XXX tile edges? */
/* Blur the source to get rid of noise */
destPR.rowstride = TILE_WIDTH * 4;
destPR.data = maxgrad_conv0;
convolve_region (&srcPR, &destPR, blur_32, 3, 32, GIMP_NORMAL_CONVOL);
/* Set the "src" temp buf up as the new source Pixel Region */
srcPR.rowstride = destPR.rowstride;
srcPR.data = destPR.data;
/* Get the horizontal derivative */
destPR.data = maxgrad_conv1;
convolve_region (&srcPR, &destPR, horz_deriv, 3, 1, GIMP_NEGATIVE_CONVOL);
/* Get the vertical derivative */
destPR.data = maxgrad_conv2;
convolve_region (&srcPR, &destPR, vert_deriv, 3, 1, GIMP_NEGATIVE_CONVOL);
/* calculate overall gradient */
tiledata = tile_data_pointer (tile, 0, 0);
for (i = 0; i < srcPR.h; i++)
{
datah = maxgrad_conv1 + srcPR.rowstride*i;
datav = maxgrad_conv2 + srcPR.rowstride*i;
gradmap = tiledata + tile_ewidth (tile) * COST_WIDTH * i;
for (j = 0; j < srcPR.w; j++)
{
hmax = datah[0] - 128;
vmax = datav[0] - 128;
for (b = 1; b < srcPR.bytes; b++)
{
if (abs (datah[b] - 128) > abs (hmax)) hmax = datah[b] - 128;
if (abs (datav[b] - 128) > abs (vmax)) vmax = datav[b] - 128;
}
if (i == 0 || j == 0 || i == srcPR.h-1 || j == srcPR.w-1)
{
gradmap[j*COST_WIDTH] = 0;
gradmap[j*COST_WIDTH + 1] = 255;
goto contin;
}
/* 1 byte absolute magitude first */
gradient = sqrt(SQR(hmax) + SQR(vmax));
gradmap[j*COST_WIDTH] = gradient * 255 / MAX_GRADIENT;
/* then 1 byte direction */
if (gradient > MIN_GRADIENT)
{
gfloat direction;
if (!hmax)
direction = (vmax > 0) ? G_PI_2 : -G_PI_2;
else
direction = atan ((double) vmax / (double) hmax);
/* Scale the direction from between 0 and 254,
* corresponding to -PI/2, PI/2 255 is reserved for
* directionless pixels */
gradmap[j*COST_WIDTH + 1] =
(guint8) (254 * (direction + G_PI_2) / G_PI);
}
else
gradmap[j*COST_WIDTH + 1] = 255; /* reserved for weak gradient */
contin:
datah += srcPR.bytes;
datav += srcPR.bytes;
}
}
tile_release (srctile, FALSE);
}
static TileManager *
gradient_map_new (GimpImage *gimage)
{
TileManager *tm;
tm = tile_manager_new (gimage->width, gimage->height,
sizeof (guint8) * COST_WIDTH);
tile_manager_set_user_data (tm, gimage);
tile_manager_set_validate_proc (tm, gradmap_tile_validate);
return tm;
}
static void
find_max_gradient (GimpIscissorsTool *iscissors,
GimpImage *gimage,
gint *x,
gint *y)
{
PixelRegion srcPR;
gint radius;
gint i, j;
gint endx, endy;
gint sx, sy, cx, cy;
gint x1, y1, x2, y2;
void *pr;
guint8 *gradient;
gfloat g, max_gradient;
/* Initialise the gradient map tile manager for this image if we
* don't already have one. */
if (!iscissors->gradient_map)
iscissors->gradient_map = gradient_map_new (gimage);
radius = GRADIENT_SEARCH >> 1;
/* calculate the extent of the search */
cx = CLAMP (*x, 0, gimage->width);
cy = CLAMP (*y, 0, gimage->height);
sx = cx - radius;
sy = cy - radius;
x1 = CLAMP (cx - radius, 0, gimage->width);
y1 = CLAMP (cy - radius, 0, gimage->height);
x2 = CLAMP (cx + radius, 0, gimage->width);
y2 = CLAMP (cy + radius, 0, gimage->height);
/* calculate the factor to multiply the distance from the cursor by */
max_gradient = 0;
*x = cx;
*y = cy;
/* Find the point of max gradient */
pixel_region_init (&srcPR, iscissors->gradient_map,
x1, y1, x2 - x1, y2 - y1, FALSE);
/* this iterates over 1, 2 or 4 tiles only */
for (pr = pixel_regions_register (1, &srcPR);
pr != NULL;
pr = pixel_regions_process (pr))
{
endx = srcPR.x + srcPR.w;
endy = srcPR.y + srcPR.h;
for (i = srcPR.y; i < endy; i++)
{
gradient = srcPR.data + srcPR.rowstride * (i - srcPR.y);
for (j = srcPR.x; j < endx; j++)
{
g = *gradient;
gradient += COST_WIDTH;
g *= distance_weights [(i-y1) * GRADIENT_SEARCH + (j-x1)];
if (g > max_gradient)
{
max_gradient = g;
*x = j;
*y = i;
}
}
}
}
}
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