// 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 <cmath> namespace dlib { // ---------------------------------------------------------------------------------------- template < typename image_type > void draw_line ( long x1, long y1, long x2, long y2, image_type& c, typename image_type::type val ) { if (x1 == x2) { // make sure y1 comes before y2 if (y1 > y2) swap(y1,y2); // this is a vertical line for (long y = y1; y <= y2; ++y) { if (y < 0 || y >= c.nr()) continue; c[y][x1] = val; } } else if (y1 == y2) { // make sure x1 comes before x2 if (x1 > x2) swap(x1,x2); // this is a horizontal line for (long x = x1; x <= x2; ++x) { if (x < 0 || x >= c.nc()) continue; c[y1][x] = val; } } else { 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 = x2; last = x1; } else { first = x1; last = x2; } long y; long x; const double x1f = x1; const double y1f = y1; for (double i = first; i <= last; ++i) { y = static_cast<long>(slope*(i-x1f) + y1f); x = static_cast<long>(i); if (y < 0 || y >= c.nr()) continue; if (x < 0 || x >= c.nc()) continue; c[y][x] = val; } } else { const double slope = ((double)run)/rise; double first, last; if (y1 > y2) { first = y2; last = y1; } else { first = y1; last = y2; } long x; long y; const double x1f = x1; const double y1f = y1; for (double i = first; i <= last; ++i) { x = static_cast<long>(slope*(i-y1f) + x1f); y = static_cast<long>(i); if (x < 0 || x >= c.nc()) continue; if (y < 0 || y >= c.nr()) continue; c[y][x] = val; } } } } // ---------------------------------------------------------------------------------------- } #endif // DLIB_DRAW_IMAGe_