gimp/plug-ins/pagecurl/pagecurl.c
Sven Neumann cadc2734f4 applied gimp-quinet-980414-0; adds new tips applied gimp-quinet-980414-1;
* gimp_tips.txt: applied gimp-quinet-980414-0; adds new tips
        * plug-ins/pagecurl/pagecurl.c: applied gimp-quinet-980414-1;
        defines M_PI
        * app/app_procs.c: applied gimp-quinet-980414-2; adds more
        information to the startup screen
        * app/gradient.c: applied gradient-041398-seth; fixes the
        behavior that the gradient editor would become insensitive
        forever if the color selection dialog were close
        * app/regex.c
        * plugins/script-fu/regex.c: partially applied
        gimp-jbuhler-980412-0; adds braces to nested if/else


--Sven
1998-04-14 19:24:23 +00:00

947 lines
29 KiB
C

/* Page Curl 0.8 --- 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 0.8 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
*/
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <gtk/gtk.h>
#include <gdk/gdk.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"
#include <libgimp/gimp.h>
#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif /* M_PI */
#define PLUG_IN_NAME "plug_in_pagecurl"
#define PLUG_IN_VERSION "Mar 1998, 0.8"
/***** Macros *****/
/* Convert color to Gray ala Gimp... */
#define INTENSITY(r,g,b) (r * 0.30 + g * 0.59 + b * 0.11 + 0.001)
/***** Types *****/
typedef struct {
double x, y;
} vector_t;
typedef struct {
gint do_curl_shade;
gint do_curl_warp; /* Not yet supported... */
double 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 set_default_params (void);
static void dialog_close_callback (GtkWidget *, gpointer);
static void dialog_ok_callback (GtkWidget *, gpointer);
static void dialog_cancel_callback (GtkWidget *, gpointer);
static void dialog_toggle_update (GtkWidget *, gint);
static void dialog_scale_update (GtkAdjustment *, double *);
static void query (void);
static void run (gchar * name,
gint nparams,
GParam * param,
gint * nreturn_vals,
GParam ** return_vals);
static int do_dialog (void);
static void v_set (vector_t * v, double x, double y);
static void v_add (vector_t * v, vector_t a, vector_t b);
static void v_sub (vector_t * v, vector_t a, vector_t b);
static double v_mag (vector_t v);
static double v_dot (vector_t a, vector_t b);
static void init_calculation ();
static int left_of_diagl (double x, double y);
static int right_of_diagr (double x, double y);
static int below_diagb (double x, double y);
static int right_of_diagm (double x, double y);
static int inside_circle (double x, double y);
static void do_curl_effect (void);
static void clear_curled_region (void);
static void page_curl (void);
/***** Variables *****/
GPlugInInfo PLUG_IN_INFO = {
NULL, /* init_proc */
NULL, /* quit_proc */
query, /* query_proc */
run /* run_proc */
}; /* PLUG_IN_INFO */
static CurlParams curl;
/* Image parameters */
gint32 image_id;
GDrawable *curl_layer;
GDrawable *drawable;
GDrawable *layer_mask;
typedef GdkPixmap *GdkPmP;
GdkPmP gdk_curl_pixmaps[8];
typedef GdkBitmap *GdkBmP;
GdkBmP gdk_curl_masks[8];
GtkWidget *curl_pixmap_widget;
gint sel_x1, sel_y1, sel_x2, sel_y2;
gint true_sel_width, true_sel_height;
gint sel_width, sel_height;
gint drawable_position;
static gint curl_run = FALSE;
/* Center and radius of circle */
vector_t center;
double radius;
/* Useful points to keep around */
vector_t left_tangent;
vector_t right_tangent;
/* Slopes --- these are *not* in the usual geometric sense! */
double diagl_slope;
double diagr_slope;
double diagb_slope;
double diagm_slope;
/* User-configured parameters */
guchar fore_color[3];
guchar back_color[3];
/***** Functions *****/
/****/
MAIN ()
/****/
/*************************/
/* Some Vector-functions */
static void v_set (vector_t * v, double x, double y) {
v->x = x;
v->y = y;
} /* v_set */
static void v_add (vector_t * v, vector_t a, vector_t b) {
v->x = a.x + b.x;
v->y = a.y + b.y;
} /* v_add */
static void v_sub (vector_t * v, vector_t a, vector_t b) {
v->x = a.x - b.x;
v->y = a.y - b.y;
} /* v_sub */
static double v_mag (vector_t v) {
return sqrt (v.x * v.x + v.y * v.y);
} /* v_mag */
static double v_dot (vector_t a, vector_t b) {
return a.x * b.x + a.y * b.y;
} /* v_dot */
/*****************************************************
* 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 int left_of_diagl (double x, double y) {
return (x < (sel_width + (y - sel_height) * diagl_slope));
} /* left_of_diagl */
static int right_of_diagr (double x, double y) {
return (x > (sel_width + (y - sel_height) * diagr_slope));
} /* right_of_diagr */
static int below_diagb (double x, double y) {
return (y < (right_tangent.y + (x - right_tangent.x) * diagb_slope));
} /* below_diagb */
static int right_of_diagm (double x, double y) {
return (x > (sel_width + (y - sel_height) * diagm_slope));
} /* right_of_diagm */
static int inside_circle (double x, double y) {
double dx, dy;
dx = x - center.x;
dy = y - center.y;
return (sqrt (dx * dx + dy * dy) <= radius);
} /* inside_circle */
/*****/
static void query (void) {
static GParamDef args[] = {
{PARAM_INT32, "run_mode", "Interactive (0) , non-interactive (1)"},
{PARAM_IMAGE, "image", "Input image"},
{PARAM_DRAWABLE, "drawable", "Input drawable"},
{PARAM_INT32, "edge", "Edge to curl (1-4, clockwise, starting in the lower right edge)"},
{PARAM_INT32, "type", "vertical (0), horizontal (1)"},
{PARAM_INT32, "shade", "Shade the region under the curl (1) or not (0)"},
}; /* args */
static GParamDef *return_vals = NULL;
static int nargs = sizeof (args) / sizeof (args[0]);
static int nreturn_vals = 0;
gimp_install_procedure (PLUG_IN_NAME,
"Pagecurl effect",
"This plug-in creates an pagecurl-effect.",
"Federico Mena Quintero and Simon Budig",
"Federico Mena Quintero and Simon Budig",
PLUG_IN_VERSION,
"<Image>/Filters/Distorts/Pagecurl",
"RGBA*, GRAYA*",
PROC_PLUG_IN,
nargs,
nreturn_vals,
args,
return_vals);
} /* query */
static void run (gchar * name,
gint nparams,
GParam * param,
gint * nreturn_vals,
GParam ** return_vals) {
static GParam values[1];
GRunModeType run_mode;
GStatusType status = STATUS_SUCCESS;
run_mode = param[0].data.d_int32;
set_default_params ();
/* Possibly retrieve data */
gimp_get_data (PLUG_IN_NAME, &curl);
*nreturn_vals = 1;
*return_vals = values;
values[0].type = PARAM_STATUS;
values[0].data.d_status = status;
/* Get the specified drawable */
drawable = gimp_drawable_get (param[2].data.d_drawable);
image_id = param[1].data.d_image;
if ((gimp_drawable_color (drawable->id)
|| gimp_drawable_gray (drawable->id))
&& gimp_drawable_has_alpha (drawable->id)) {
switch (run_mode) {
case RUN_INTERACTIVE:
/* First acquire information with a dialog */
if (!do_dialog ())
return;
break;
case RUN_NONINTERACTIVE:
/* Make sure all the arguments are there! */
if (nparams != 6)
status = STATUS_CALLING_ERROR;
if (status == STATUS_SUCCESS) {
switch (param[3].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[4].data.d_int32) ? 0 : 1;
curl.do_horizontal = 1 - curl.do_vertical;
curl.do_shade_under = (param[5].data.d_int32) ? 1 : 0;
}
break;
case RUN_WITH_LAST_VALS:
break;
default:
break;
}
if (status == STATUS_SUCCESS) {
page_curl ();
if (run_mode != RUN_NONINTERACTIVE)
gimp_displays_flush ();
if (run_mode == RUN_INTERACTIVE)
gimp_set_data (PLUG_IN_NAME, &curl, sizeof (CurlParams));
}
} else
/* Sorry - no indexed/noalpha images */
status = STATUS_EXECUTION_ERROR;
values[0].data.d_status = status;
} /* run */
/*****/
static void set_default_params (void) {
curl.do_curl_shade = 1;
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;
} /* set_default_params */
/********************************************************************/
/* dialog callbacks */
/********************************************************************/
static void dialog_close_callback (GtkWidget * widget, gpointer data) {
gtk_main_quit ();
}
static void dialog_ok_callback (GtkWidget * widget, gpointer data) {
curl_run = TRUE;
gtk_widget_destroy (GTK_WIDGET (data));
}
static void dialog_cancel_callback (GtkWidget * widget, gpointer data) {
gtk_widget_destroy (GTK_WIDGET (data));
}
static void dialog_scale_update (GtkAdjustment * adjustment, double *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;
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 int do_dialog (void) {
/* Missing options: Color-dialogs? / own curl layer ? / transparency
to original drawable / Warp-curl (unsupported yet) */
GtkWidget *dialog;
GtkWidget *orhbox1, *orhbox2, *vbox, *ivbox, *corner_frame, *orient_frame;
GtkWidget *shade_button, *button, *label, *scale;
GtkStyle *style;
GtkObject *adjustment;
gint pixmapindex;
gint argc;
gchar **argv;
argc = 1;
argv = g_new (gchar *, 1);
argv[0] = g_strdup ("pagecurl");
gtk_init (&argc, &argv);
gtk_rc_parse (gimp_gtkrc ());
gdk_set_use_xshm (gimp_use_xshm ());
dialog = gtk_dialog_new ();
gtk_window_set_title (GTK_WINDOW (dialog), "Pagecurl effect");
gtk_container_border_width (GTK_CONTAINER (dialog), 0);
gtk_widget_realize (dialog);
gtk_signal_connect (GTK_OBJECT (dialog), "destroy",
(GtkSignalFunc) dialog_close_callback,
NULL);
button = gtk_button_new_with_label ("OK");
GTK_WIDGET_SET_FLAGS (button, GTK_CAN_DEFAULT);
gtk_signal_connect (GTK_OBJECT (button), "clicked",
(GtkSignalFunc) dialog_ok_callback,
dialog);
gtk_box_pack_start (GTK_BOX (GTK_DIALOG (dialog)->action_area), button, TRUE, TRUE, 0);
gtk_widget_grab_default (button);
gtk_widget_show (button);
button = gtk_button_new_with_label ("Cancel");
GTK_WIDGET_SET_FLAGS (button, GTK_CAN_DEFAULT);
gtk_signal_connect (GTK_OBJECT (button), "clicked",
(GtkSignalFunc) dialog_cancel_callback,
dialog);
gtk_box_pack_start (GTK_BOX (GTK_DIALOG (dialog)->action_area), button, TRUE, TRUE, 0);
gtk_widget_show (button);
vbox = gtk_vbox_new (FALSE, 5);
gtk_container_border_width (GTK_CONTAINER (vbox), 5);
gtk_box_pack_start (GTK_BOX (GTK_DIALOG (dialog)->vbox),
vbox, FALSE, FALSE, 0);
/*****/
orhbox1 = gtk_hbox_new (FALSE, 5);
gtk_container_border_width (GTK_CONTAINER (orhbox1), 0);
gtk_container_add (GTK_CONTAINER (vbox), orhbox1);
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_box_pack_start (GTK_BOX (orhbox1),
curl_pixmap_widget, TRUE, TRUE, 0);
gtk_widget_show (curl_pixmap_widget);
corner_frame = gtk_frame_new ("Curl location");
gtk_frame_set_shadow_type (GTK_FRAME (corner_frame), GTK_SHADOW_ETCHED_IN);
gtk_box_pack_start (GTK_BOX (orhbox1),
corner_frame, TRUE, TRUE, 0);
ivbox = gtk_vbox_new (FALSE, 0);
gtk_container_border_width (GTK_CONTAINER (ivbox), 5);
gtk_container_add (GTK_CONTAINER (corner_frame), ivbox);
{
int i;
char *name[4] =
{"Upper left", "Upper right", "Lower left", "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)),
name[i]);
gtk_toggle_button_set_state (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",
(GtkSignalFunc) dialog_toggle_update,
(gpointer) i);
gtk_box_pack_start (GTK_BOX (ivbox), button, FALSE, FALSE, 0);
gtk_widget_show (button);
}
}
gtk_widget_show (ivbox);
gtk_widget_show (corner_frame);
gtk_widget_show (orhbox1);
/*****/
orient_frame = gtk_frame_new ("Curl orientation");
gtk_frame_set_shadow_type (GTK_FRAME (orient_frame), GTK_SHADOW_ETCHED_IN);
gtk_box_pack_start (GTK_BOX (vbox),
orient_frame, FALSE, FALSE, 0);
orhbox2 = gtk_hbox_new (FALSE, 5);
gtk_container_border_width (GTK_CONTAINER (orhbox2), 5);
gtk_container_add (GTK_CONTAINER (orient_frame), orhbox2);
{
int i;
char *name[2] =
{"horizontal", "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)),
name[i]);
gtk_toggle_button_set_state (GTK_TOGGLE_BUTTON (button),
(i == 0 ? curl.do_horizontal : curl.do_vertical));
gtk_signal_connect (GTK_OBJECT (button), "toggled",
(GtkSignalFunc) dialog_toggle_update,
(gpointer) (i + 5));
gtk_box_pack_start (GTK_BOX (orhbox2), button, TRUE, FALSE, 0);
gtk_widget_show (button);
}
}
gtk_widget_show (orhbox2);
gtk_widget_show (orient_frame);
shade_button = gtk_toggle_button_new_with_label ("Shade under curl");
gtk_toggle_button_set_state (GTK_TOGGLE_BUTTON (shade_button),
curl.do_shade_under ? TRUE : FALSE);
gtk_signal_connect (GTK_OBJECT (shade_button), "toggled",
(GtkSignalFunc) dialog_toggle_update, (gpointer) 8);
gtk_box_pack_start (GTK_BOX (vbox), shade_button, TRUE, FALSE, 0);
gtk_widget_show (shade_button);
label = gtk_label_new ("Curl opacity");
gtk_misc_set_alignment (GTK_MISC (label), 0.0, 0.5);
gtk_box_pack_start (GTK_BOX (vbox), label, TRUE, FALSE, 0);
gtk_widget_show (label);
adjustment = gtk_adjustment_new (curl.do_curl_opacity * 100, 0.0, 100.0,
1.0, 1.0, 1.0);
gtk_signal_connect (adjustment, "value_changed",
(GtkSignalFunc) 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 (vbox), scale, TRUE, FALSE, 0);
gtk_widget_show (scale);
/*****/
gtk_widget_show (vbox);
gtk_widget_show (dialog);
gtk_main ();
gdk_flush ();
return curl_run;
} /* do_dialog */
/*****/
static void init_calculation () {
double k;
double alpha, beta;
double angle;
vector_t v1, v2;
gint32 *image_layers, nlayers;
gimp_layer_add_alpha (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->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->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;
} /* else */
/* Circle parameters */
alpha = atan ((double) sel_height / sel_width);
beta = alpha / 2.0;
k = sel_width / ((M_PI + alpha) * sin (beta) + cos (beta));
v_set (&center, k * cos (beta), k * sin (beta));
radius = center.y;
/* left_tangent */
v_set (&left_tangent, radius * -sin (alpha), radius * cos (alpha));
v_add (&left_tangent, left_tangent, center);
/* right_tangent */
v_sub (&v1, left_tangent, center);
v_set (&v2, sel_width - center.x, sel_height - center.y);
angle = -2.0 * acos (v_dot (v1, v2) / (v_mag (v1) * v_mag (v2)));
v_set (&right_tangent,
v1.x * cos (angle) + v1.y * -sin (angle),
v1.x * sin (angle) + v1.y * cos (angle));
v_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 (&fore_color[0], &fore_color[1], &fore_color[2]);
gimp_palette_get_background (&back_color[0], &back_color[1], &back_color[2]);
} /* init_calculation */
/*****/
static void do_curl_effect (void) {
gint x, y, color_image;
gint x1, y1, k;
guint alpha_pos, progress, max_progress;
gdouble intensity, alpha;
vector_t v, dl, dr;
gdouble dl_mag, dr_mag, angle, factor;
guchar *pp, *dest, fore_grayval, back_grayval;
GPixelRgn dest_rgn;
gpointer pr;
color_image = gimp_drawable_color (drawable->id);
curl_layer =
gimp_drawable_get (gimp_layer_new (image_id,
"Curl layer",
true_sel_width,
true_sel_height,
color_image ? RGBA_IMAGE : GRAYA_IMAGE,
100, NORMAL_MODE));
gimp_image_add_layer (image_id, curl_layer->id, drawable_position);
gimp_drawable_offsets (drawable->id, &x1, &y1);
gimp_layer_set_offsets (curl_layer->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->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 */
v_set (&dl, -sel_width, -sel_height);
dl_mag = v_mag (dl);
v_set (&dr, -(sel_width - right_tangent.x), -(sel_height - right_tangent.y));
dr_mag = v_mag (dr);
alpha = acos (v_dot (dl, dr) / (dl_mag * dr_mag));
/* 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]);
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 (v_dot (v, dl) / (v_mag (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 */
intensity = pow (sin (M_PI * angle / alpha), 1.5);
if (color_image) {
pp[0] = (intensity * fore_color[0] + (1 - intensity) * back_color[0]);
pp[1] = (intensity * fore_color[1] + (1 - intensity) * back_color[1]);
pp[2] = (intensity * fore_color[2] + (1 - intensity) * back_color[2]);
} else
pp[0] = (intensity * fore_grayval + (1 - intensity) * back_grayval);
pp[alpha_pos] = (guchar) ((double) 255 * (1 - intensity*(1-curl.do_curl_opacity)));
}
}
pp += dest_rgn.bpp;
} /* for y1 */
dest += dest_rgn.rowstride;
} /* for x1 */
progress += dest_rgn.w * dest_rgn.h;
gimp_progress_update ((double) progress / (double) max_progress);
} /* Pixel Regions loop end */
gimp_drawable_flush (curl_layer);
gimp_drawable_merge_shadow (curl_layer->id, FALSE);
gimp_drawable_update (curl_layer->id, 0, 0, curl_layer->width, curl_layer->height);
gimp_drawable_detach (curl_layer);
}
/************************************************/
static void clear_curled_region () {
GPixelRgn 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->id, TRUE);
gimp_drawable_update (drawable->id, sel_x1, sel_y1, true_sel_width, true_sel_height);
gimp_drawable_detach (drawable);
}
/*****/
static void page_curl () {
int nreturn_vals;
gimp_run_procedure ("gimp_undo_push_group_start", &nreturn_vals,
PARAM_IMAGE, image_id,
PARAM_END);
gimp_progress_init ("Page Curl");
init_calculation ();
do_curl_effect ();
clear_curled_region ();
gimp_run_procedure ("gimp_undo_push_group_end", &nreturn_vals,
PARAM_IMAGE, image_id,
PARAM_END);
} /* page_curl */