gimp/plug-ins/pagecurl/pagecurl.c

1127 lines
32 KiB
C

/* Page Curl 0.9 --- image filter plug-in for The Gimp
* Copyright (C) 1996 Federico Mena Quintero
* Ported to Gimp 1.0 1998 by Simon Budig <Simon.Budig@unix-ag.org>
*
* You can contact me at quartic@polloux.fciencias.unam.mx
* You can contact the original The Gimp authors at gimp@xcf.berkeley.edu
*
* 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.
*
*/
/* TODO for v0.5 - in 0.9 still to do...
* As of version 0.5 alpha, the only thing that is not yet implemented
* is the "Warp curl" option. Everything else seems to be working
* just fine. Please email me if you find any bugs. I know that the
* calculation code is horrible, but you don't want to tweak it anyway ;)
*/
/*
* Ported to the 0.99.x architecture by Simon Budig, Simon.Budig@unix-ag.org
* *** Why does gimp_drawable_add_alpha cause the plugin to produce an
* ** WARNING **: received tile info did not match computed tile info
* ** WARNING **: expected tile ack and received: 0
*/
/*
* Version History
* 0.5: (1996) Version for Gimp 0.54 by Federico Mena Quintero
* 0.6: (Feb '98) First Version for Gimp 0.99.x, very buggy.
* 0.8: (Mar '98) First "stable" version
* 0.9: (May '98)
* - Added support for Gradients. It is now possible to map
* a gradient to the back of the curl.
* - This implies a changed PDB-Interface: New "mode" parameter.
* - Pagecurl now returns the ID of the new layer.
* - Exchanged the meaning of FG/BG Color, because mostly the FG
* color is darker.
*/
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <gtk/gtk.h>
#include <libgimp/gimp.h>
#include <libgimp/gimpui.h>
#include "libgimp/stdplugins-intl.h"
#include "curl0.xpm"
#include "curl1.xpm"
#include "curl2.xpm"
#include "curl3.xpm"
#include "curl4.xpm"
#include "curl5.xpm"
#include "curl6.xpm"
#include "curl7.xpm"
#define PLUG_IN_NAME "plug_in_pagecurl"
#define PLUG_IN_VERSION "May 1998, 0.9"
#define NGRADSAMPLES 256
/***** Types *****/
typedef struct
{
gint do_curl_shade;
gint do_curl_gradient;
gint do_curl_warp; /* Not yet supported... */
gdouble do_curl_opacity;
gint do_shade_under;
gint do_upper_left;
gint do_upper_right;
gint do_lower_left;
gint do_lower_right;
gint do_vertical;
gint do_horizontal;
} CurlParams;
/***** Prototypes *****/
static void query (void);
static void run (gchar *name,
gint nparams,
GimpParam *param,
gint *nreturn_vals,
GimpParam **return_vals);
static void set_default_params (void);
static void dialog_ok_callback (GtkWidget *widget,
gpointer data);
static void dialog_toggle_update (GtkWidget *widget,
gint32 value);
static void dialog_scale_update (GtkAdjustment *adjustment,
gdouble *value);
static gint do_dialog (void);
static void init_calculation (void);
static gint left_of_diagl (gdouble x, gdouble y);
static gint right_of_diagr (gdouble x, gdouble y);
static gint below_diagb (gdouble x, gdouble y);
static gint right_of_diagm (gdouble x, gdouble y);
static gint inside_circle (gdouble x, gdouble y);
static void do_curl_effect (void);
static void clear_curled_region (void);
static void page_curl (void);
static guchar *get_samples (GimpDrawable *drawable);
/***** Variables *****/
GimpPlugInInfo PLUG_IN_INFO =
{
NULL, /* init_proc */
NULL, /* quit_proc */
query, /* query_proc */
run /* run_proc */
};
static CurlParams curl;
/* Image parameters */
static gint32 image_id;
static GimpDrawable *curl_layer;
static GimpDrawable *drawable;
static GdkPixmap *gdk_curl_pixmaps[8];
static GdkBitmap *gdk_curl_masks[8];
static GtkWidget *curl_pixmap_widget;
static gint sel_x1, sel_y1, sel_x2, sel_y2;
static gint true_sel_width, true_sel_height;
static gint sel_width, sel_height;
static gint drawable_position;
static gint curl_run = FALSE;
static gint32 curl_layer_ID;
/* Center and radius of circle */
static GimpVector2 center;
static double radius;
/* Useful points to keep around */
static GimpVector2 left_tangent;
static GimpVector2 right_tangent;
/* Slopes --- these are *not* in the usual geometric sense! */
static gdouble diagl_slope;
static gdouble diagr_slope;
static gdouble diagb_slope;
static gdouble diagm_slope;
/* User-configured parameters */
static guchar fore_color[3];
static guchar back_color[3];
/***** Functions *****/
MAIN ()
static void
query (void)
{
static GimpParamDef args[] =
{
{ GIMP_PDB_INT32, "run_mode", "Interactive (0), non-interactive (1)" },
{ GIMP_PDB_IMAGE, "image", "Input image" },
{ GIMP_PDB_DRAWABLE, "drawable", "Input drawable" },
{ GIMP_PDB_INT32, "mode", "Pagecurl-mode: Use FG- and BG-Color (0), Use current gradient (1)" },
{ GIMP_PDB_INT32, "edge", "Edge to curl (1-4, clockwise, starting in the lower right edge)" },
{ GIMP_PDB_INT32, "type", "vertical (0), horizontal (1)" },
{ GIMP_PDB_INT32, "shade", "Shade the region under the curl (1) or not (0)" },
};
static gint nargs = sizeof (args) / sizeof (args[0]);
static GimpParamDef return_vals[] =
{
{ GIMP_PDB_LAYER, "Curl Layer", "The new layer with the curl." }
};
static gint nreturn_vals = sizeof (return_vals) / sizeof (return_vals[0]);
INIT_I18N();
gimp_install_procedure (PLUG_IN_NAME,
"Pagecurl effect",
"This plug-in creates a pagecurl-effect.",
"Federico Mena Quintero and Simon Budig",
"Federico Mena Quintero and Simon Budig",
PLUG_IN_VERSION,
N_("<Image>/Filters/Distorts/Pagecurl..."),
"RGBA, GRAYA",
GIMP_PLUGIN,
nargs,
nreturn_vals,
args,
return_vals);
}
static void
run (gchar *name,
gint nparams,
GimpParam *param,
gint *nreturn_vals,
GimpParam **return_vals)
{
static GimpParam values[2];
GimpRunModeType run_mode;
GimpPDBStatusType status = GIMP_PDB_SUCCESS;
run_mode = param[0].data.d_int32;
set_default_params ();
/* Possibly retrieve data */
gimp_get_data (PLUG_IN_NAME, &curl);
*nreturn_vals = 2;
*return_vals = values;
values[0].type = GIMP_PDB_STATUS;
values[0].data.d_status = status;
values[1].type = GIMP_PDB_LAYER;
values[1].data.d_layer = -1;
/* Get the specified drawable */
drawable = gimp_drawable_get (param[2].data.d_drawable);
image_id = param[1].data.d_image;
if ((gimp_drawable_is_rgb (drawable->drawable_id)
|| gimp_drawable_is_gray (drawable->drawable_id))
&& gimp_drawable_has_alpha (drawable->drawable_id))
{
switch (run_mode)
{
case GIMP_RUN_INTERACTIVE:
INIT_I18N_UI();
/* First acquire information with a dialog */
if (!do_dialog ())
return;
break;
case GIMP_RUN_NONINTERACTIVE:
INIT_I18N();
/* Make sure all the arguments are there! */
if (nparams != 7)
status = GIMP_PDB_CALLING_ERROR;
if (status == GIMP_PDB_SUCCESS)
{
curl.do_curl_shade = (param[3].data.d_int32 == 0) ? 1 : 0;
curl.do_curl_gradient = 1 - curl.do_curl_shade;
switch (param[4].data.d_int32)
{
case 1:
curl.do_upper_left = 0;
curl.do_upper_right = 0;
curl.do_lower_left = 0;
curl.do_lower_right = 1;
break;
case 2:
curl.do_upper_left = 0;
curl.do_upper_right = 0;
curl.do_lower_left = 1;
curl.do_lower_right = 0;
break;
case 3:
curl.do_upper_left = 1;
curl.do_upper_right = 0;
curl.do_lower_left = 0;
curl.do_lower_right = 0;
break;
case 4:
curl.do_upper_left = 0;
curl.do_upper_right = 1;
curl.do_lower_left = 0;
curl.do_lower_right = 0;
break;
default:
break;
}
curl.do_vertical = (param[5].data.d_int32) ? 0 : 1;
curl.do_horizontal = 1 - curl.do_vertical;
curl.do_shade_under = (param[6].data.d_int32) ? 1 : 0;
}
break;
case GIMP_RUN_WITH_LAST_VALS:
INIT_I18N();
break;
default:
break;
}
if (status == GIMP_PDB_SUCCESS)
{
page_curl ();
values[1].data.d_layer = curl_layer_ID;
if (run_mode != GIMP_RUN_NONINTERACTIVE)
gimp_displays_flush ();
if (run_mode == GIMP_RUN_INTERACTIVE)
gimp_set_data (PLUG_IN_NAME, &curl, sizeof (CurlParams));
}
}
else
/* Sorry - no indexed/noalpha images */
status = GIMP_PDB_EXECUTION_ERROR;
values[0].data.d_status = status;
}
/*****************************************************
* Functions to locate the current point in the curl.
* The following functions assume an curl in the
* lower right corner.
* diagb crosses the two tangential points from the
* circle with diagl and diagr.
*
* +------------------------------------------------+
* | __-- /|
* | __-- _/ |
* | __-- / |
* | __-- _/ |
* | __-- / |
* | __--____ _/ |
* | __----~~ \ _/ |
* | __-- | _/ |
* | diagl __-- _/| _/diagr |
* | __-- diagm_/ |/ |
* | __-- /___/ |
* +-------------------------+----------------------+
*/
static gint
left_of_diagl (gdouble x,
gdouble y)
{
return (x < (sel_width + (y - sel_height) * diagl_slope));
}
static gint
right_of_diagr (gdouble x,
gdouble y)
{
return (x > (sel_width + (y - sel_height) * diagr_slope));
}
static gint
below_diagb (gdouble x,
gdouble y)
{
return (y < (right_tangent.y + (x - right_tangent.x) * diagb_slope));
}
static gint
right_of_diagm (gdouble x,
gdouble y)
{
return (x > (sel_width + (y - sel_height) * diagm_slope));
}
static gint
inside_circle (gdouble x,
gdouble y)
{
gdouble dx, dy;
dx = x - center.x;
dy = y - center.y;
return (sqrt (dx * dx + dy * dy) <= radius);
}
static void
set_default_params (void)
{
curl.do_curl_shade = 1;
curl.do_curl_gradient = 0;
curl.do_curl_warp = 0; /* Not yet supported... */
curl.do_curl_opacity = 1.0;
curl.do_shade_under = 1;
curl.do_upper_left = 0;
curl.do_upper_right = 0;
curl.do_lower_left = 0;
curl.do_lower_right = 1;
curl.do_vertical = 1;
curl.do_horizontal = 0;
}
/********************************************************************/
/* dialog callbacks */
/********************************************************************/
static void
dialog_ok_callback (GtkWidget *widget,
gpointer data)
{
curl_run = TRUE;
gtk_widget_destroy (GTK_WIDGET (data));
}
static void
dialog_scale_update (GtkAdjustment *adjustment,
gdouble *value)
{
*value = ((double) adjustment->value) / 100.0;
}
static void
dialog_toggle_update (GtkWidget *widget,
gint32 value)
{
gint pixmapindex = 0;
switch (value)
{
case 0:
curl.do_upper_left = (GTK_TOGGLE_BUTTON (widget)->active) ? 1 : 0;
break;
case 1:
curl.do_upper_right = (GTK_TOGGLE_BUTTON (widget)->active) ? 1 : 0;
break;
case 2:
curl.do_lower_left = (GTK_TOGGLE_BUTTON (widget)->active) ? 1 : 0;
break;
case 3:
curl.do_lower_right = (GTK_TOGGLE_BUTTON (widget)->active) ? 1 : 0;
break;
case 5:
curl.do_horizontal = (GTK_TOGGLE_BUTTON (widget)->active) ? 1 : 0;
break;
case 6:
curl.do_vertical = (GTK_TOGGLE_BUTTON (widget)->active) ? 1 : 0;
break;
case 8:
curl.do_shade_under = (GTK_TOGGLE_BUTTON (widget)->active) ? 1 : 0;
return;
break;
case 9:
curl.do_curl_gradient = (GTK_TOGGLE_BUTTON (widget)->active) ? 1 : 0;
curl.do_curl_shade = (GTK_TOGGLE_BUTTON (widget)->active) ? 0 : 1;
return;
break;
default:
break;
}
if (curl.do_upper_left + curl.do_upper_right +
curl.do_lower_left + curl.do_lower_right == 1 &&
curl.do_horizontal + curl.do_vertical == 1)
{
pixmapindex = curl.do_lower_left + curl.do_upper_right * 2 +
curl.do_upper_left * 3 + curl.do_horizontal * 4;
if (pixmapindex < 0 || pixmapindex > 7)
pixmapindex = 0;
gtk_pixmap_set (GTK_PIXMAP (curl_pixmap_widget),
gdk_curl_pixmaps[pixmapindex],
gdk_curl_masks[pixmapindex]);
}
}
static gint
do_dialog (void)
{
/* Missing options: Color-dialogs? / own curl layer ? / transparency
to original drawable / Warp-curl (unsupported yet) */
GtkWidget *dialog;
GtkWidget *hbox;
GtkWidget *vbox;
GtkWidget *vbox2;
GtkWidget *table;
GtkWidget *frame;
GtkWidget *shade_button;
GtkWidget *gradient_button;
GtkWidget *button;
GtkWidget *scale;
GtkStyle *style;
GtkObject *adjustment;
gint pixmapindex;
gimp_ui_init ("pagecurl", FALSE);
dialog = gimp_dialog_new ( _("Pagecurl Effect"), "pagecurl",
gimp_standard_help_func, "filters/pagecurl.html",
GTK_WIN_POS_MOUSE,
FALSE, TRUE, FALSE,
GTK_STOCK_OK, dialog_ok_callback,
NULL, NULL, NULL, TRUE, FALSE,
GTK_STOCK_CANCEL, gtk_widget_destroy,
NULL, 1, NULL, FALSE, TRUE,
NULL);
gtk_signal_connect (GTK_OBJECT (dialog), "destroy",
GTK_SIGNAL_FUNC (gtk_main_quit),
NULL);
vbox = gtk_vbox_new (FALSE, 4);
gtk_container_set_border_width (GTK_CONTAINER (vbox), 6);
gtk_box_pack_start (GTK_BOX (GTK_DIALOG (dialog)->vbox), vbox, TRUE, TRUE, 0);
gtk_widget_show (vbox);
frame = gtk_frame_new (_("Curl Location"));
gtk_box_pack_start (GTK_BOX (vbox), frame, TRUE, TRUE, 0);
table = gtk_table_new (3, 3, FALSE);
gtk_table_set_col_spacings (GTK_TABLE (table), 2);
gtk_table_set_row_spacings (GTK_TABLE (table), 2);
gtk_container_set_border_width (GTK_CONTAINER (table), 2);
gtk_container_add (GTK_CONTAINER (frame), table);
gtk_widget_realize (dialog);
style = gtk_widget_get_style (dialog);
gdk_curl_pixmaps[0] =
gdk_pixmap_create_from_xpm_d (dialog->window,
&(gdk_curl_masks[0]),
&style->bg[GTK_STATE_NORMAL],
curl0_xpm);
gdk_curl_pixmaps[1] =
gdk_pixmap_create_from_xpm_d (dialog->window,
&(gdk_curl_masks[1]),
&style->bg[GTK_STATE_NORMAL],
curl1_xpm);
gdk_curl_pixmaps[2] =
gdk_pixmap_create_from_xpm_d (dialog->window,
&(gdk_curl_masks[2]),
&style->bg[GTK_STATE_NORMAL],
curl2_xpm);
gdk_curl_pixmaps[3] =
gdk_pixmap_create_from_xpm_d (dialog->window,
&(gdk_curl_masks[3]),
&style->bg[GTK_STATE_NORMAL],
curl3_xpm);
gdk_curl_pixmaps[4] =
gdk_pixmap_create_from_xpm_d (dialog->window,
&(gdk_curl_masks[4]),
&style->bg[GTK_STATE_NORMAL],
curl4_xpm);
gdk_curl_pixmaps[5] =
gdk_pixmap_create_from_xpm_d (dialog->window,
&(gdk_curl_masks[5]),
&style->bg[GTK_STATE_NORMAL],
curl5_xpm);
gdk_curl_pixmaps[6] =
gdk_pixmap_create_from_xpm_d (dialog->window,
&(gdk_curl_masks[6]),
&style->bg[GTK_STATE_NORMAL],
curl6_xpm);
gdk_curl_pixmaps[7] =
gdk_pixmap_create_from_xpm_d (dialog->window,
&(gdk_curl_masks[7]),
&style->bg[GTK_STATE_NORMAL],
curl7_xpm);
pixmapindex = curl.do_lower_left + curl.do_upper_right * 2 +
curl.do_upper_left * 3 + curl.do_horizontal * 4;
if (pixmapindex < 0 || pixmapindex > 7)
pixmapindex = 0;
curl_pixmap_widget = gtk_pixmap_new (gdk_curl_pixmaps[pixmapindex],
gdk_curl_masks[pixmapindex]);
gtk_table_attach (GTK_TABLE (table), curl_pixmap_widget, 1, 2, 1, 2,
GTK_SHRINK, GTK_SHRINK, 0, 0);
gtk_widget_show (curl_pixmap_widget);
{
gint i;
gchar *name[] =
{
N_("Upper Left"),
N_("Upper Right"),
N_("Lower Left"),
N_("Lower Right")
};
button = NULL;
for (i = 0; i < 4; i++)
{
button = gtk_radio_button_new_with_label
((button == NULL) ?
NULL : gtk_radio_button_group (GTK_RADIO_BUTTON (button)),
gettext(name[i]));
gtk_toggle_button_set_active
(GTK_TOGGLE_BUTTON (button),
(i == 0 ? curl.do_upper_left : i == 1 ? curl.do_upper_right :
i == 2 ? curl.do_lower_left : curl.do_lower_right));
gtk_signal_connect (GTK_OBJECT (button), "toggled",
GTK_SIGNAL_FUNC (dialog_toggle_update),
(gpointer) i);
gtk_table_attach (GTK_TABLE (table), button,
(i % 2) ? 2 : 0, (i % 2) ? 3 : 1,
(i < 2) ? 0 : 2, (i < 2) ? 1 : 3,
GTK_SHRINK, GTK_SHRINK, 0, 0);
gtk_widget_show (button);
}
}
gtk_widget_show (table);
gtk_widget_show (frame);
frame = gtk_frame_new (_("Curl Orientation"));
gtk_frame_set_shadow_type (GTK_FRAME (frame), GTK_SHADOW_ETCHED_IN);
gtk_box_pack_start (GTK_BOX (vbox), frame, FALSE, FALSE, 0);
hbox = gtk_hbox_new (FALSE, 4);
gtk_container_set_border_width (GTK_CONTAINER (hbox), 2);
gtk_container_add (GTK_CONTAINER (frame), hbox);
{
gint i;
gchar *name[] =
{
N_("Horizontal"),
N_("Vertical")
};
button = NULL;
for (i = 0; i < 2; i++)
{
button = gtk_radio_button_new_with_label
((button == NULL) ?
NULL : gtk_radio_button_group (GTK_RADIO_BUTTON (button)),
gettext(name[i]));
gtk_toggle_button_set_active
(GTK_TOGGLE_BUTTON (button),
(i == 0 ? curl.do_horizontal : curl.do_vertical));
gtk_signal_connect (GTK_OBJECT (button), "toggled",
GTK_SIGNAL_FUNC (dialog_toggle_update),
(gpointer) (i + 5));
gtk_box_pack_start (GTK_BOX (hbox), button, TRUE, TRUE, 0);
gtk_widget_show (button);
}
}
gtk_widget_show (hbox);
gtk_widget_show (frame);
shade_button = gtk_check_button_new_with_label (_("Shade under Curl"));
gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (shade_button),
curl.do_shade_under ? TRUE : FALSE);
gtk_signal_connect (GTK_OBJECT (shade_button), "toggled",
GTK_SIGNAL_FUNC (dialog_toggle_update),
(gpointer) 8);
gtk_box_pack_start (GTK_BOX (vbox), shade_button, FALSE, FALSE, 0);
gtk_widget_show (shade_button);
gradient_button =
gtk_check_button_new_with_label (_("Use Current Gradient\n"
"instead of FG/BG-Color"));
gtk_label_set_justify (GTK_LABEL (GTK_BIN (gradient_button)->child),
GTK_JUSTIFY_LEFT);
gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (gradient_button),
curl.do_curl_gradient ? TRUE : FALSE);
gtk_signal_connect (GTK_OBJECT (gradient_button), "toggled",
GTK_SIGNAL_FUNC (dialog_toggle_update),
(gpointer) 9);
gtk_box_pack_start (GTK_BOX (vbox), gradient_button, FALSE, FALSE, 0);
gtk_widget_show (gradient_button);
frame = gtk_frame_new (_("Curl Opacity"));
gtk_box_pack_start (GTK_BOX (vbox), frame, FALSE, FALSE, 0);
gtk_widget_show (frame);
vbox2 = gtk_vbox_new (FALSE, 0);
gtk_container_set_border_width (GTK_CONTAINER (vbox2), 2);
gtk_container_add (GTK_CONTAINER (frame), vbox2);
gtk_widget_show (vbox2);
adjustment = gtk_adjustment_new (curl.do_curl_opacity * 100, 0.0, 100.0,
1.0, 1.0, 0.0);
gtk_signal_connect (adjustment, "value_changed",
GTK_SIGNAL_FUNC (dialog_scale_update),
&(curl.do_curl_opacity));
scale = gtk_hscale_new (GTK_ADJUSTMENT (adjustment));
gtk_widget_set_usize (GTK_WIDGET (scale), 150, 30);
gtk_range_set_update_policy (GTK_RANGE (scale), GTK_UPDATE_DELAYED);
gtk_scale_set_digits (GTK_SCALE (scale), 0);
gtk_scale_set_draw_value (GTK_SCALE (scale), TRUE);
gtk_box_pack_start (GTK_BOX (vbox2), scale, TRUE, FALSE, 0);
gtk_widget_show (scale);
gtk_widget_show (dialog);
gtk_main ();
gdk_flush ();
return curl_run;
}
static void
init_calculation (void)
{
gdouble k;
gdouble alpha, beta;
gdouble angle;
GimpVector2 v1, v2;
gint32 *image_layers;
gint32 nlayers;
GimpRGB color;
gimp_layer_add_alpha (drawable->drawable_id);
/* Image parameters */
/* Determine Position of original Layer in the Layer stack. */
image_layers = gimp_image_get_layers (image_id, &nlayers);
drawable_position = 0;
while (drawable_position < nlayers &&
image_layers[drawable_position] != drawable->drawable_id)
drawable_position++;
if (drawable_position >= nlayers)
{
fprintf (stderr, "Fatal error: drawable not found in layer stack.\n");
drawable_position = 0;
}
/* Get the bounds of the active selection */
gimp_drawable_mask_bounds (drawable->drawable_id,
&sel_x1, &sel_y1, &sel_x2, &sel_y2);
true_sel_width = sel_x2 - sel_x1;
true_sel_height = sel_y2 - sel_y1;
if (curl.do_vertical)
{
sel_width = true_sel_width;
sel_height = true_sel_height;
}
else
{
sel_width = true_sel_height;
sel_height = true_sel_width;
}
/* Circle parameters */
alpha = atan ((double) sel_height / sel_width);
beta = alpha / 2.0;
k = sel_width / ((G_PI + alpha) * sin (beta) + cos (beta));
gimp_vector2_set (&center, k * cos (beta), k * sin (beta));
radius = center.y;
/* left_tangent */
gimp_vector2_set (&left_tangent, radius * -sin (alpha), radius * cos (alpha));
gimp_vector2_add (&left_tangent, &left_tangent, &center);
/* right_tangent */
gimp_vector2_sub (&v1, &left_tangent, &center);
gimp_vector2_set (&v2, sel_width - center.x, sel_height - center.y);
angle = -2.0 * acos (gimp_vector2_inner_product (&v1, &v2) /
(gimp_vector2_length (&v1) * gimp_vector2_length (&v2)));
gimp_vector2_set (&right_tangent,
v1.x * cos (angle) + v1.y * -sin (angle),
v1.x * sin (angle) + v1.y * cos (angle));
gimp_vector2_add (&right_tangent, &right_tangent, &center);
/* Slopes */
diagl_slope = (double) sel_width / sel_height;
diagr_slope = (sel_width - right_tangent.x) / (sel_height - right_tangent.y);
diagb_slope = (right_tangent.y - left_tangent.y) / (right_tangent.x - left_tangent.x);
diagm_slope = (sel_width - center.x) / sel_height;
/* Colors */
gimp_palette_get_foreground (&color);
gimp_rgb_get_uchar (&color, &fore_color[0], &fore_color[1], &fore_color[2]);
gimp_palette_get_background (&color);
gimp_rgb_get_uchar (&color, &back_color[0], &back_color[1], &back_color[2]);
}
static void
do_curl_effect (void)
{
gint x, y, color_image;
gint x1, y1, k;
guint alpha_pos, progress, max_progress;
gdouble intensity, alpha, beta;
GimpVector2 v, dl, dr;
gdouble dl_mag, dr_mag, angle, factor;
guchar *pp, *dest, fore_grayval, back_grayval;
guchar *gradsamp;
GimpPixelRgn dest_rgn;
gpointer pr;
guchar *grad_samples = NULL;
color_image = gimp_drawable_is_rgb (drawable->drawable_id);
curl_layer =
gimp_drawable_get (gimp_layer_new (image_id,
_("Curl Layer"),
true_sel_width,
true_sel_height,
color_image ? GIMP_RGBA_IMAGE : GIMP_GRAYA_IMAGE,
100, GIMP_NORMAL_MODE));
gimp_image_add_layer (image_id, curl_layer->drawable_id, drawable_position);
curl_layer_ID = curl_layer->drawable_id;
gimp_drawable_offsets (drawable->drawable_id, &x1, &y1);
gimp_layer_set_offsets (curl_layer->drawable_id, sel_x1 + x1, sel_y1 + y1);
gimp_tile_cache_ntiles (2 * (curl_layer->width / gimp_tile_width () + 1));
/* Clear the newly created layer */
gimp_pixel_rgn_init (&dest_rgn, curl_layer,
0, 0, true_sel_width, true_sel_height, TRUE, FALSE);
for (pr = gimp_pixel_rgns_register (1, &dest_rgn);
pr != NULL;
pr = gimp_pixel_rgns_process (pr))
{
dest = dest_rgn.data;
for (y1 = dest_rgn.y; y1 < dest_rgn.y + dest_rgn.h; y1++)
{
pp = dest;
for (x1 = dest_rgn.x; x1 < dest_rgn.x + dest_rgn.w; x1++)
{
for (k = 0; k < dest_rgn.bpp; k++)
pp[k] = 0;
pp += dest_rgn.bpp;
}
dest += dest_rgn.rowstride;
}
}
gimp_drawable_flush (curl_layer);
gimp_drawable_update (curl_layer->drawable_id,
0, 0, curl_layer->width, curl_layer->height);
gimp_pixel_rgn_init (&dest_rgn, curl_layer,
0, 0, true_sel_width, true_sel_height, TRUE, TRUE);
/* Init shade_under */
gimp_vector2_set (&dl, -sel_width, -sel_height);
dl_mag = gimp_vector2_length (&dl);
gimp_vector2_set (&dr,
-(sel_width - right_tangent.x),
-(sel_height - right_tangent.y));
dr_mag = gimp_vector2_length (&dr);
alpha = acos (gimp_vector2_inner_product (&dl, &dr) / (dl_mag * dr_mag));
beta=alpha / 2;
/* Init shade_curl */
fore_grayval = INTENSITY (fore_color[0], fore_color[1], fore_color[2]);
back_grayval = INTENSITY (back_color[0], back_color[1], back_color[2]);
/* Gradient Samples */
if (curl.do_curl_gradient)
grad_samples = get_samples (curl_layer);
max_progress = 2 * sel_width * sel_height;
progress = 0;
alpha_pos = dest_rgn.bpp - 1;
/* Main loop */
for (pr = gimp_pixel_rgns_register (1, &dest_rgn);
pr != NULL;
pr = gimp_pixel_rgns_process (pr))
{
dest = dest_rgn.data;
for (y1 = dest_rgn.y; y1 < dest_rgn.y + dest_rgn.h; y1++)
{
pp = dest;
for (x1 = dest_rgn.x; x1 < dest_rgn.x + dest_rgn.w; x1++)
{
/* Map coordinates to get the curl correct... */
if (curl.do_horizontal)
{
x = (curl.do_lower_right || curl.do_lower_left) ? y1 : sel_width - 1 - y1;
y = (curl.do_upper_left || curl.do_lower_left) ? x1 : sel_height - 1 - x1;
}
else
{
x = (curl.do_upper_right || curl.do_lower_right) ? x1 : sel_width - 1 - x1;
y = (curl.do_upper_left || curl.do_upper_right) ? y1 : sel_height - 1 - y1;
}
if (left_of_diagl (x, y))
{ /* uncurled region */
for (k = 0; k <= alpha_pos; k++)
pp[k] = 0;
}
else if (right_of_diagr (x, y) ||
(right_of_diagm (x, y) &&
below_diagb (x, y) &&
!inside_circle (x, y)))
{
/* curled region */
for (k = 0; k <= alpha_pos; k++)
pp[k] = 0;
}
else
{
v.x = -(sel_width - x);
v.y = -(sel_height - y);
angle = acos (gimp_vector2_inner_product (&v, &dl) /
(gimp_vector2_length (&v) * dl_mag));
if (inside_circle (x, y) || below_diagb (x, y))
{
/* Below the curl. */
factor = angle / alpha;
for (k = 0; k < alpha_pos; k++)
pp[k] = 0;
pp[alpha_pos] = curl.do_shade_under ? (guchar) ((float) 255 * (float) factor) : 0;
}
else
{
/* On the curl */
if (curl.do_curl_gradient)
{
/* Calculate position in Gradient (0 <= intensity <= 1) */
intensity = (angle/alpha) + sin(G_PI*2 * angle/alpha)*0.075;
/* Check boundaries */
intensity = (intensity < 0 ? 0 : (intensity > 1 ? 1 : intensity ));
gradsamp = &grad_samples[((guint) (intensity * NGRADSAMPLES)) * dest_rgn.bpp];
if (color_image)
{
pp[0] = gradsamp[0];
pp[1] = gradsamp[1];
pp[2] = gradsamp[2];
}
else
pp[0] = gradsamp[0];
pp[alpha_pos] = (guchar) ((double) gradsamp[alpha_pos] * (1 - intensity*(1-curl.do_curl_opacity)));
}
else
{
intensity = pow (sin (G_PI * angle / alpha), 1.5);
if (color_image)
{
pp[0] = (intensity * back_color[0] + (1 - intensity) * fore_color[0]);
pp[1] = (intensity * back_color[1] + (1 - intensity) * fore_color[1]);
pp[2] = (intensity * back_color[2] + (1 - intensity) * fore_color[2]);
}
else
pp[0] = (intensity * back_grayval + (1 - intensity) * fore_grayval);
pp[alpha_pos] = (guchar) ((double) 255 * (1 - intensity*(1-curl.do_curl_opacity)));
}
}
}
pp += dest_rgn.bpp;
}
dest += dest_rgn.rowstride;
}
progress += dest_rgn.w * dest_rgn.h;
gimp_progress_update ((double) progress / (double) max_progress);
}
gimp_drawable_flush (curl_layer);
gimp_drawable_merge_shadow (curl_layer->drawable_id, FALSE);
gimp_drawable_update (curl_layer->drawable_id,
0, 0, curl_layer->width, curl_layer->height);
gimp_drawable_detach (curl_layer);
if (grad_samples != NULL)
g_free (grad_samples);
}
/************************************************/
static void
clear_curled_region (void)
{
GimpPixelRgn src_rgn, dest_rgn;
gpointer pr;
gint x, y;
guint x1, y1, i;
guchar *dest, *src, *pp, *sp;
guint alpha_pos, progress, max_progress;
max_progress = 2 * sel_width * sel_height;
progress = max_progress / 2;
gimp_tile_cache_ntiles (2 * (drawable->width / gimp_tile_width () + 1));
gimp_pixel_rgn_init (&src_rgn, drawable,
sel_x1, sel_y1, true_sel_width, true_sel_height,
FALSE, FALSE);
gimp_pixel_rgn_init (&dest_rgn, drawable,
sel_x1, sel_y1, true_sel_width, true_sel_height,
TRUE, TRUE);
alpha_pos = dest_rgn.bpp - 1;
if (dest_rgn.bpp != src_rgn.bpp)
fprintf (stderr, "WARNING: src_rgn.bpp != dest_rgn.bpp!\n");
for (pr = gimp_pixel_rgns_register (2, &dest_rgn, &src_rgn);
pr != NULL;
pr = gimp_pixel_rgns_process (pr))
{
dest = dest_rgn.data;
src = src_rgn.data;
for (y1 = dest_rgn.y; y1 < dest_rgn.y + dest_rgn.h; y1++)
{
sp = src;
pp = dest;
for (x1 = dest_rgn.x; x1 < dest_rgn.x + dest_rgn.w; x1++)
{
/* Map coordinates to get the curl correct... */
if (curl.do_horizontal)
{
x = (curl.do_lower_right || curl.do_lower_left) ? y1 - sel_y1 : sel_width - 1 - (y1 - sel_y1);
y = (curl.do_upper_left || curl.do_lower_left) ? x1 - sel_x1 : sel_height - 1 - (x1 - sel_x1);
}
else
{
x = (curl.do_upper_right || curl.do_lower_right) ? x1 - sel_x1 : sel_width - 1 - (x1 - sel_x1);
y = (curl.do_upper_left || curl.do_upper_right) ? y1 - sel_y1 : sel_height - 1 - (y1 - sel_y1);
}
for (i = 0; i < alpha_pos; i++)
pp[i] = sp[i];
if (right_of_diagr (x, y) ||
(right_of_diagm (x, y) &&
below_diagb (x, y) &&
!inside_circle (x, y)))
{
/* Right of the curl */
pp[alpha_pos] = 0;
}
else
{
pp[alpha_pos] = sp[alpha_pos];
}
pp += dest_rgn.bpp;
sp += src_rgn.bpp;
}
src += src_rgn.rowstride;
dest += dest_rgn.rowstride;
}
progress += dest_rgn.w * dest_rgn.h;
gimp_progress_update ((double) progress / (double) max_progress);
}
gimp_drawable_flush (drawable);
gimp_drawable_merge_shadow (drawable->drawable_id, TRUE);
gimp_drawable_update (drawable->drawable_id,
sel_x1, sel_y1, true_sel_width, true_sel_height);
gimp_drawable_detach (drawable);
}
static void
page_curl (void)
{
gimp_undo_push_group_start (image_id);
gimp_progress_init ( _("Page Curl..."));
init_calculation ();
do_curl_effect ();
clear_curled_region ();
gimp_undo_push_group_end (image_id);
}
/*
Returns NGRADSAMPLES samples of active gradient.
Each sample has (gimp_drawable_bpp (drawable->drawable_id)) bytes.
"ripped" from gradmap.c.
*/
static guchar *
get_samples (GimpDrawable *drawable)
{
gdouble *f_samples, *f_samp; /* float samples */
guchar *b_samples, *b_samp; /* byte samples */
gint bpp, color, has_alpha, alpha;
gint i, j;
f_samples = gimp_gradients_sample_uniform (NGRADSAMPLES);
bpp = gimp_drawable_bpp (drawable->drawable_id);
color = gimp_drawable_is_rgb (drawable->drawable_id);
has_alpha = gimp_drawable_has_alpha (drawable->drawable_id);
alpha = (has_alpha ? bpp - 1 : bpp);
b_samples = g_new (guchar, NGRADSAMPLES * bpp);
for (i = 0; i < NGRADSAMPLES; i++)
{
b_samp = &b_samples[i * bpp];
f_samp = &f_samples[i * 4];
if (color)
for (j = 0; j < 3; j++)
b_samp[j] = f_samp[j] * 255;
else
b_samp[0] = INTENSITY (f_samp[0], f_samp[1], f_samp[2]) * 255;
if (has_alpha)
b_samp[alpha] = f_samp[3] * 255;
}
g_free (f_samples);
return b_samples;
}