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Templated blur implementation + specializations for color_rgb(a)

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This commit is contained in:
Nikita Lisitsa 2020-09-23 20:19:27 +03:00
parent f193ddf41d
commit 80e8c59a1e
2 changed files with 69 additions and 38 deletions
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44
libs/pcg/include/psemek/pcg/blur.hpp
View file

@ -3,9 +3,51 @@
#include <psemek/gfx/pixmap.hpp>
#include <psemek/pcg/seamless.hpp>
#include <vector>
namespace psemek::pcg
{
gfx::basic_pixmap<float> blur(gfx::basic_pixmap<float> const & p, int size, float sigma, seamless_tag);
namespace detail
{
std::vector<float> gauss_coeffs(int size, float sigma);
}
template <typename T>
gfx::basic_pixmap<T> blur(gfx::basic_pixmap<T> const & p, int size, float sigma, seamless_tag)
{
gfx::basic_pixmap<T> res({p.width(), p.height()}, T{});
auto c = detail::gauss_coeffs(size, sigma);
for (std::size_t y = 0; y < p.height(); ++y)
{
for (std::size_t x = 0; x < p.width(); ++x)
{
for (int j = - size; j <= size; ++j)
{
for (int i = - size; i <= size; ++i)
{
int ix = (x + i);
while (ix < 0) ix += p.width();
if (static_cast<std::size_t>(ix) >= p.width()) ix = ix % p.width();
int iy = (y + j);
while (iy < 0) iy += p.height();
if (static_cast<std::size_t>(iy) >= p.height()) iy = iy % p.height();
res(x, y) += p(ix, iy) * c[i + size] * c[j + size];
}
}
}
}
return res;
}
gfx::pixmap_rgb blur(gfx::pixmap_rgb const & p, int size, float sigma, seamless_tag);
gfx::pixmap_rgba blur(gfx::pixmap_rgba const & p, int size, float sigma, seamless_tag);
}

63
libs/pcg/source/blur.cpp
View file

@ -1,4 +1,5 @@
#include <psemek/pcg/blur.hpp>
#include <psemek/gfx/color.hpp>
#include <cmath>
#include <vector>
@ -6,50 +7,38 @@
namespace psemek::pcg
{
static std::vector<float> gauss_coeffs(int size, float sigma)
namespace detail
{
std::vector<float> res(2 * size + 1);
float sum = 0.f;
for (int i = -size; i <= size; ++i)
std::vector<float> gauss_coeffs(int size, float sigma)
{
float x = (i / sigma);
res[i + size] = std::exp(- x * x);
sum += res[i + size];
std::vector<float> res(2 * size + 1);
float sum = 0.f;
for (int i = -size; i <= size; ++i)
{
float x = (i / sigma);
res[i + size] = std::exp(- x * x);
sum += res[i + size];
}
for (auto & c : res)
c /= sum;
return res;
}
for (auto & c : res)
c /= sum;
return res;
}
gfx::basic_pixmap<float> blur(gfx::basic_pixmap<float> const & p, int size, float sigma, seamless_tag)
gfx::pixmap_rgb blur(gfx::pixmap_rgb const & p, int size, float sigma, seamless_tag)
{
gfx::basic_pixmap<float> res({p.width(), p.height()}, 0.f);
auto converted = util::map([](gfx::color_rgb const & c){ return gfx::to_colorf(c); }, p);
converted = blur(converted, size, sigma, seamless);
return util::map([](geom::vector<float, 3> const & c){ return gfx::to_coloru8(c); }, converted);
}
auto c = gauss_coeffs(size, sigma);
for (std::size_t y = 0; y < p.height(); ++y)
{
for (std::size_t x = 0; x < p.width(); ++x)
{
for (int j = - size; j <= size; ++j)
{
for (int i = - size; i <= size; ++i)
{
int ix = (x + i);
while (ix < 0) ix += p.width();
if (static_cast<std::size_t>(ix) >= p.width()) ix = ix % p.width();
int iy = (y + j);
while (iy < 0) iy += p.height();
if (static_cast<std::size_t>(iy) >= p.height()) iy = iy % p.height();
res(x, y) += p(ix, iy) * c[i + size] * c[j + size];
}
}
}
}
return res;
gfx::pixmap_rgba blur(gfx::pixmap_rgba const & p, int size, float sigma, seamless_tag)
{
auto converted = util::map([](gfx::color_rgba const & c){ return gfx::to_colorf(c); }, p);
converted = blur(converted, size, sigma, seamless);
return util::map([](geom::vector<float, 4> const & c){ return gfx::to_coloru8(c); }, converted);
}
}