// Copyright (C) 2008 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#ifndef DLIB_DRAW_IMAGe_
#define DLIB_DRAW_IMAGe_
#include "draw_abstract.h"
#include "../algs.h"
#include "../pixel.h"
#include "../matrix.h"
#include <cmath>
namespace dlib
{
// ----------------------------------------------------------------------------------------
template <
typename image_type,
typename pixel_type
>
void draw_line (
long x1,
long y1,
long x2,
long y2,
image_type& c_,
const pixel_type& val
)
{
image_view<image_type> c(c_);
if (x1 == x2)
{
// make sure y1 comes before y2
if (y1 > y2)
swap(y1,y2);
if (x1 < 0 || x1 >= c.nc())
return;
// this is a vertical line
for (long y = y1; y <= y2; ++y)
{
if (y < 0 || y >= c.nr())
continue;
assign_pixel(c[y][x1], val);
}
}
else if (y1 == y2)
{
// make sure x1 comes before x2
if (x1 > x2)
swap(x1,x2);
if (y1 < 0 || y1 >= c.nr())
return;
// this is a horizontal line
for (long x = x1; x <= x2; ++x)
{
if (x < 0 || x >= c.nc())
continue;
assign_pixel(c[y1][x] , val);
}
}
else
{
// This part is a little more complicated because we are going to perform alpha
// blending so the diagonal lines look nice.
const rectangle valid_area = get_rect(c);
rgb_alpha_pixel alpha_pixel;
assign_pixel(alpha_pixel, val);
const unsigned char max_alpha = alpha_pixel.alpha;
const long rise = (((long)y2) - ((long)y1));
const long run = (((long)x2) - ((long)x1));
if (std::abs(rise) < std::abs(run))
{
const double slope = ((double)rise)/run;
double first, last;
if (x1 > x2)
{
first = std::max(x2,valid_area.left());
last = std::min(x1,valid_area.right());
}
else
{
first = std::max(x1,valid_area.left());
last = std::min(x2,valid_area.right());
}
long y;
long x;
const double x1f = x1;
const double y1f = y1;
for (double i = first; i <= last; ++i)
{
const double dy = slope*(i-x1f) + y1f;
const double dx = i;
y = static_cast<long>(dy);
x = static_cast<long>(dx);
if (y >= valid_area.top() && y <= valid_area.bottom())
{
alpha_pixel.alpha = static_cast<unsigned char>((1.0-(dy-y))*max_alpha);
assign_pixel(c[y][x], alpha_pixel);
}
if (y+1 >= valid_area.top() && y+1 <= valid_area.bottom())
{
alpha_pixel.alpha = static_cast<unsigned char>((dy-y)*max_alpha);
assign_pixel(c[y+1][x], alpha_pixel);
}
}
}
else
{
const double slope = ((double)run)/rise;
double first, last;
if (y1 > y2)
{
first = std::max(y2,valid_area.top());
last = std::min(y1,valid_area.bottom());
}
else
{
first = std::max(y1,valid_area.top());
last = std::min(y2,valid_area.bottom());
}
long x;
long y;
const double x1f = x1;
const double y1f = y1;
for (double i = first; i <= last; ++i)
{
const double dx = slope*(i-y1f) + x1f;
const double dy = i;
y = static_cast<long>(dy);
x = static_cast<long>(dx);
if (x >= valid_area.left() && x <= valid_area.right())
{
alpha_pixel.alpha = static_cast<unsigned char>((1.0-(dx-x))*max_alpha);
assign_pixel(c[y][x], alpha_pixel);
}
if (x+1 >= valid_area.left() && x+1 <= valid_area.right())
{
alpha_pixel.alpha = static_cast<unsigned char>((dx-x)*max_alpha);
assign_pixel(c[y][x+1], alpha_pixel);
}
}
}
}
}
// ----------------------------------------------------------------------------------------
template <
typename image_type,
typename pixel_type
>
void draw_line (
image_type& c,
const point& p1,
const point& p2,
const pixel_type& val
)
{
draw_line(p1.x(),p1.y(),p2.x(),p2.y(),c,val);
}
// ----------------------------------------------------------------------------------------
template <
typename image_type,
typename pixel_type
>
void draw_rectangle (
image_type& c,
const rectangle& rect,
const pixel_type& val
)
{
draw_line(c, rect.tl_corner(), rect.tr_corner(), val);
draw_line(c, rect.bl_corner(), rect.br_corner(), val);
draw_line(c, rect.tl_corner(), rect.bl_corner(), val);
draw_line(c, rect.tr_corner(), rect.br_corner(), val);
}
// ----------------------------------------------------------------------------------------
template <
typename image_type,
typename pixel_type
>
void draw_rectangle (
image_type& c,
const rectangle& rect,
const pixel_type& val,
unsigned int thickness
)
{
for (unsigned int i = 0; i < thickness; ++i)
{
if ((i%2)==0)
draw_rectangle(c,shrink_rect(rect,(i+1)/2),val);
else
draw_rectangle(c,grow_rect(rect,(i+1)/2),val);
}
}
// ----------------------------------------------------------------------------------------
template <
typename image_type,
typename pixel_type
>
void fill_rect (
image_type& img_,
const rectangle& rect,
const pixel_type& pixel
)
{
image_view<image_type> img(img_);
rectangle area = rect.intersect(get_rect(img));
for (long r = area.top(); r <= area.bottom(); ++r)
{
for (long c = area.left(); c <= area.right(); ++c)
{
assign_pixel(img[r][c], pixel);
}
}
}
// ----------------------------------------------------------------------------------------
template <
typename image_array_type
>
matrix<typename image_traits<typename image_array_type::value_type>::pixel_type> tile_images (
const image_array_type& images
)
{
typedef typename image_traits<typename image_array_type::value_type>::pixel_type T;
if (images.size() == 0)
return matrix<T>();
const unsigned long size_nc = square_root(images.size());
const unsigned long size_nr = (size_nc*(size_nc-1)>=images.size())? size_nc-1 : size_nc;
// Figure out the size we have to use for each chip in the big main image. We will
// use the largest dimensions seen across all the chips.
long nr = 0;
long nc = 0;
for (unsigned long i = 0; i < images.size(); ++i)
{
nr = std::max(num_rows(images[i]), nr);
nc = std::max(num_columns(images[i]), nc);
}
matrix<T> temp(size_nr*nr, size_nc*nc);
T background_color;
assign_pixel(background_color, 0);
temp = background_color;
unsigned long idx = 0;
for (unsigned long r = 0; r < size_nr; ++r)
{
for (unsigned long c = 0; c < size_nc; ++c)
{
if (idx < images.size())
{
set_subm(temp, r*nr, c*nc, nr, nc) = mat(images[idx]);
}
++idx;
}
}
return temp;
}
// ----------------------------------------------------------------------------------------
template <
typename image_type,
typename pixel_type
>
void draw_solid_circle (
image_type& img_,
const dpoint& center_point,
double radius,
const pixel_type& pixel
)
{
image_view<image_type> img(img_);
using std::sqrt;
const rectangle valid_area(get_rect(img));
const double x = center_point.x();
const double y = center_point.y();
const point cp(center_point);
if (radius > 1)
{
long first_x = static_cast<long>(x - radius + 0.5);
long last_x = static_cast<long>(x + radius + 0.5);
const double rs = radius*radius;
// ensure that we only loop over the part of the x dimension that this
// image contains.
if (first_x < valid_area.left())
first_x = valid_area.left();
if (last_x > valid_area.right())
last_x = valid_area.right();
long top, bottom;
top = static_cast<long>(sqrt(std::max(rs - (first_x-x-0.5)*(first_x-x-0.5),0.0))+0.5);
top += y;
long last = top;
// draw the left half of the circle
long middle = std::min(cp.x()-1,last_x);
for (long i = first_x; i <= middle; ++i)
{
double a = i - x + 0.5;
// find the top of the arc
top = static_cast<long>(sqrt(std::max(rs - a*a,0.0))+0.5);
top += y;
long temp = top;
while(top >= last)
{
bottom = y - top + y;
draw_line(img_, point(i,top),point(i,bottom),pixel);
--top;
}
last = temp;
}
middle = std::max(cp.x(),first_x);
top = static_cast<long>(sqrt(std::max(rs - (last_x-x+0.5)*(last_x-x+0.5),0.0))+0.5);
top += y;
last = top;
// draw the right half of the circle
for (long i = last_x; i >= middle; --i)
{
double a = i - x - 0.5;
// find the top of the arc
top = static_cast<long>(sqrt(std::max(rs - a*a,0.0))+0.5);
top += y;
long temp = top;
while(top >= last)
{
bottom = y - top + y;
draw_line(img_, point(i,top),point(i,bottom),pixel);
--top;
}
last = temp;
}
}
else if (valid_area.contains(cp))
{
// For circles smaller than a pixel we will just alpha blend them in proportion
// to how small they are.
rgb_alpha_pixel temp;
assign_pixel(temp, pixel);
temp.alpha = static_cast<unsigned char>(255*radius + 0.5);
assign_pixel(img[cp.y()][cp.x()], temp);
}
}
// ----------------------------------------------------------------------------------------
}
#endif // DLIB_DRAW_IMAGe_