/*
#
# File : curve_editor2d.cpp
# ( C++ source file )
#
# Description : A simple user interface to construct 2D spline curves.
# This file is a part of the CImg Library project.
# ( http://cimg.sourceforge.net )
#
# Copyright : David Tschumperle
# ( http://tschumperle.users.greyc.fr/ )
# Antonio Albiol Colomer
# ( http://personales.upv.es/~aalbiol/index-english.html )
#
# License : CeCILL v2.0
# ( http://www.cecill.info/licences/Licence_CeCILL_V2-en.html )
#
# This software is governed by the CeCILL license under French law and
# abiding by the rules of distribution of free software. You can use,
# modify and/ or redistribute the software under the terms of the CeCILL
# license as circulated by CEA, CNRS and INRIA at the following URL
# "http://www.cecill.info".
#
# As a counterpart to the access to the source code and rights to copy,
# modify and redistribute granted by the license, users are provided only
# with a limited warranty and the software's author, the holder of the
# economic rights, and the successive licensors have only limited
# liability.
#
# In this respect, the user's attention is drawn to the risks associated
# with loading, using, modifying and/or developing or reproducing the
# software by the user in light of its specific status of free software,
# that may mean that it is complicated to manipulate, and that also
# therefore means that it is reserved for developers and experienced
# professionals having in-depth computer knowledge. Users are therefore
# encouraged to load and test the software's suitability as regards their
# requirements in conditions enabling the security of their systems and/or
# data to be ensured and, more generally, to use and operate it in the
# same conditions as regards security.
#
# The fact that you are presently reading this means that you have had
# knowledge of the CeCILL license and that you accept its terms.
#
*/
#include "CImg.h"
using namespace cimg_library;
#undef min
#undef max
// Compute distance from a point to a segment.
//---------------------------------------------
float dist_segment(const float x, const float y, const float x1, const float y1, const float x2, const float y2) {
const float
dx = x2 - x1,
dy = y2 - y1,
long_segment = (float)std::sqrt(dx*dx + dy*dy);
if (long_segment==0) { const float ddx = x - x1, ddy = y - y1; return (float)std::sqrt(ddx*ddx + ddy*ddy); }
const float
unitx = dx/long_segment,
unity = dy/long_segment,
vx = x - x1,
vy = y - y1,
long_proy = vx*unitx + vy*unity,
proyx = x1 + long_proy*unitx,
proyy = y1 + long_proy*unity;
if (long_proy>long_segment) { const float ddx = x - x2, ddy = y - y2; return std::sqrt(ddx*ddx+ddy*ddy); }
else if (long_proy<0) { const float ddx = x - x1, ddy = y - y1; return std::sqrt(ddx*ddx+ddy*ddy); }
const float ddx = x - proyx, ddy = y - proyy;
return std::sqrt(ddx*ddx+ddy*ddy);
}
// Main procedure
//---------------
int main(int argc, char **argv) {
// Read command line parameters
//-----------------------------
cimg_usage("2D Spline Curve Editor");
const char *file_i = cimg_option("-i",(char*)0,"Input image");
const float contrast = cimg_option("-contrast",0.6f,"Image contrast");
const char *file_ip = cimg_option("-ip",(char*)0,"Input control points");
const char *file_oc = cimg_option("-oc",(char*)0,"Output curve points");
const char *file_op = cimg_option("-op",(char*)0,"Output control points");
const char *file_od = cimg_option("-od",(char*)0,"Output distance function");
bool interp = cimg_option("-poly",true,"Use polynomial interpolation");
bool closed = cimg_option("-closed",true,"Closed curve");
bool show_tangents = cimg_option("-tangents",false,"Show tangents");
bool show_points = cimg_option("-points",true,"Show control points");
bool show_outline = cimg_option("-outline",true,"Show polygon outline");
bool show_indices = cimg_option("-indices",true,"Show points indices");
bool show_coordinates = cimg_option("-coords",false,"Show points coordinates");
const float precision = cimg_option("-prec",0.05f,"Precision of curve discretization");
// Init image data
//-----------------
const unsigned char yellow[] = { 255,255,0 }, white[] = { 255,255,255 }, green[] = { 0,255,0 },
blue[] = { 120,200,255 }, purple[] = { 255,100,255 }, black[] = { 0,0,0 };
CImg<unsigned char> img0, img, help_img;
if (file_i) {
std::fprintf(stderr,"\n - Load input image '%s' : ",cimg::basename(file_i));
img0 = CImg<>(file_i).normalize(0,255.0f*contrast);
std::fprintf(stderr,"Size = %dx%dx%dx%d \n",img0.width(),img0.height(),img0.depth(),img0.spectrum());
img0.resize(-100,-100,1,3);
}
else {
std::fprintf(stderr,"\n - No input image specified, use default 512x512 image.\n");
img0.assign(512,512,1,3,0).draw_grid(32,32,0,0,false,false,green,0.4f,0xCCCCCCCC,0xCCCCCCCC);
}
help_img.assign(220,210,1,3,0).
draw_text(5,5,
"------------------------------------------\n"
"2D Curve Editor\n"
"------------------------------------------\n"
"Left button : Create or move control point\n"
"Right button : Delete control point\n"
"Spacebar : Switch interpolation\n"
"Key 'C' : Switch open/closed mode\n"
"Key 'T' : Show/hide tangents\n"
"Key 'P' : Show/hide control points\n"
"Key 'O' : Show/hide polygon outline\n"
"Key 'N' : Show/hide points indices\n"
"Key 'X' : Show/hide points coordinates\n"
"Key 'H' : Show/hide this help\n"
"Key 'S' : Save control points\n"
"Key 'R' : Reset curve\n",
green);
CImgDisplay disp(img0,"2D Curve Editor",0);
CImgList<float> points, curve;
bool moving = false, help = !file_i;
if (file_ip) {
std::fprintf(stderr," - Load input control points '%s' : ",cimg::basename(file_ip));
points = CImg<>(file_ip).transpose()<'x';
std::fprintf(stderr," %u points\n",points.size());
}
// Enter interactive loop
//------------------------
while (!disp.is_closed() && !disp.is_keyESC() && !disp.is_keyQ()) {
// Handle mouse manipulation
//---------------------------
const unsigned int button = disp.button();
const float
x = disp.mouse_x()*(float)img0.width()/disp.width(),
y = disp.mouse_y()*(float)img0.height()/disp.height();
if (points && button && x>=0 && y>=0) {
// Find nearest point and nearest segment
float dmin_pt = cimg::type<float>::max(), dmin_seg = dmin_pt;
unsigned int p_pt = 0, p_seg = 0;
cimglist_for(points,p) {
const unsigned int
pnext = closed?(p+1)%points.size():(p+1<(int)points.size()?p+1:p);
const float
xp = points(p,0),
yp = points(p,1);
const float
d_pt = (xp-x)*(xp-x) + (yp-y)*(yp-y),
d_seg = dist_segment(x,y,xp,yp,points(pnext,0),points(pnext,1));
if (d_pt<dmin_pt) { dmin_pt = d_pt; p_pt = p; }
if (d_seg<dmin_seg) { dmin_seg = d_seg; p_seg = p; }
}
// Handle button
if (button&1) {
if (dmin_pt<100 || moving) { points(p_pt,0) = x; points(p_pt,1) = y; }
else points.insert(CImg<>::vector(x,y),p_seg+1);
moving = true;
}
if (button&2 && dmin_pt<100) {
if (points.size()>3) points.remove(p_pt);
disp.set_button();
}
}
if (!button) moving = false;
if (disp.key()) {
switch (disp.key()) {
case cimg::keySPACE : interp = !interp; break;
case cimg::keyC : closed = !closed; break;
case cimg::keyT : show_tangents = !show_tangents; break;
case cimg::keyP : show_points = !show_points; break;
case cimg::keyO : show_outline = !show_outline; break;
case cimg::keyN : show_indices = !show_indices; break;
case cimg::keyX : show_coordinates = !show_coordinates; break;
case cimg::keyR : points.assign(); break;
case cimg::keyH : help = !help; break;
case cimg::keyS : {
const char *filename = file_op?file_op:"curve_points.dlm";
std::fprintf(stderr," - Save control points in '%s'\n",filename);
(points>'x').transpose().save(filename);
} break;
}
disp.set_key();
}
// Init list of points if empty
//------------------------------
if (!points) {
const float
x0 = img0.width()/4.0f,
y0 = img0.height()/4.0f,
x1 = img0.width() - x0,
y1 = img0.height() - y0;
points.insert(CImg<>::vector(x0,y0)).
insert(CImg<>::vector(x1,y0)).
insert(CImg<>::vector(x1,y1)).
insert(CImg<>::vector(x0,y1));
}
// Estimate curve tangents
//-------------------------
CImg<> tangents(points.size(),2);
cimglist_for(points,p) {
const unsigned int
p0 = closed?(p+points.size()-1)%points.size():(p?p-1:0),
p1 = closed?(p+1)%points.size():(p+1<(int)points.size()?p+1:p);
const float
x = points(p,0),
y = points(p,1),
x0 = points(p0,0),
y0 = points(p0,1),
x1 = points(p1,0),
y1 = points(p1,1),
u0 = x-x0,
v0 = y-y0,
n0 = 1e-8f + (float)std::sqrt(u0*u0 + v0*v0),
u1 = x1-x,
v1 = y1-y,
n1 = 1e-8f + (float)std::sqrt(u1*u1 + v1*v1),
u = u0/n0 + u1/n1,
v = v0/n0 + v1/n1,
n = 1e-8f + (float)std::sqrt(u*u + v*v),
fact = 0.5f*(n0 + n1);
tangents(p,0) = fact*u/n;
tangents(p,1) = fact*v/n;
}
// Estimate 3th-order polynomial interpolation
//---------------------------------------------
curve.assign();
const unsigned int pmax = points.size()-(closed?0:1);
for (unsigned int p0 = 0; p0<pmax; p0++) {
const unsigned int
p1 = closed?(p0+1)%points.size():(p0+1<points.size()?p0+1:p0);
const float
x0 = points(p0,0),
y0 = points(p0,1),
x1 = points(p1,0),
y1 = points(p1,1);
float ax = 0, bx = 0, cx = 0, dx = 0, ay = 0, by = 0, cy = 0, dy = 0;
if (interp) {
const float
u0 = tangents(p0,0),
v0 = tangents(p0,1),
u1 = tangents(p1,0),
v1 = tangents(p1,1);
ax = 2*(x0 - x1) + u0 + u1;
bx = 3*(x1 - x0) - 2*u0 - u1;
cx = u0;
dx = x0;
ay = 2*(y0 - y1) + v0 + v1;
by = 3*(y1 - y0) - 2*v0 - v1;
cy = v0;
dy = y0;
} else {
ax = ay = bx = by = 0;
dx = x0;
dy = y0;
cx = x1 - x0;
cy = y1 - y0;
}
const float tmax = 1 + precision;
for (float t = 0; t<tmax; t+=precision) {
const float
xt = ax*t*t*t + bx*t*t + cx*t + dx,
yt = ay*t*t*t + by*t*t + cy*t + dy;
curve.insert(CImg<>::vector(xt,yt));
}
}
// Draw curve and display image
//-------------------------------
const float
factx = (float)disp.width()/img0.width(),
facty = (float)disp.height()/img0.height();
img = img0.get_resize(disp.width(),disp.height());
if (help) img.draw_image(help_img,0.6f);
if (interp && show_outline) {
CImg<> npoints = points>'x';
npoints.get_shared_row(0)*=factx;
npoints.get_shared_row(1)*=facty;
img.draw_polygon(npoints,blue,0.4f);
if (closed) img.draw_polygon(npoints,yellow,0.8f,0x11111111);
else img.draw_line(npoints,yellow,0.8f,0x11111111);
}
CImg<> ncurve = curve>'x';
ncurve.get_shared_row(0)*=factx;
ncurve.get_shared_row(1)*=facty;
if (closed) img.draw_polygon(ncurve,white,1.0f,~0U);
else img.draw_line(ncurve,white);
if (show_points) cimglist_for(points,p) {
const float
x = points(p,0)*factx,
y = points(p,1)*facty;
if (show_tangents) {
const float
u = tangents(p,0),
v = tangents(p,1),
n = 1e-8f + (float)std::sqrt(u*u + v*v),
nu = u/n,
nv = v/n;
img.draw_arrow((int)(x - 15*nu),(int)(y - 15*nv),(int)(x + 15*nu),(int)(y + 15*nv),green);
}
if (show_indices) img.draw_text((int)x,(int)(y-16),"%d",purple,black,1,13,p);
if (show_coordinates) img.draw_text((int)(x-24),(int)(y+8),"(%d,%d)",yellow,black,0.5f,13,(int)points(p,0),(int)points(p,1));
img.draw_circle((int)x,(int)y,3,blue,0.7f);
}
img.display(disp);
disp.wait();
if (disp.is_resized()) disp.resize(false);
}
// Save output result and exit
//-----------------------------
if (file_op) {
std::fprintf(stderr," - Save control points in '%s'\n",cimg::basename(file_op));
(points>'x').transpose().save(file_op);
}
if (file_oc) {
std::fprintf(stderr," - Save curve points in '%s'\n",cimg::basename(file_oc));
(curve>'x').transpose().save(file_oc);
}
if (file_od) {
std::fprintf(stderr," - Computing distance function, please wait...."); std::fflush(stderr);
CImg<> ncurve = (closed?(+curve).insert(curve[0]):curve)>'x';
const float zero = 0.0f, one = 1.0f;
CImg<> distance =
CImg<>(img0.width(),img0.height(),1,1,-1.0f).draw_line(ncurve,&zero).draw_fill(0,0,&one).
distance(0);
std::fprintf(stderr,"\n - Save distance function in '%s'\n",cimg::basename(file_od));
distance.save(file_od);
}
std::fprintf(stderr," - Exit.\n");
std::exit(0);
return 0;
}