archive-gh-me/mapnik
1
0
Fork 0
mirror of https://github.com/mapnik/mapnik.git synced 2025-12-08 20:13:09 +00:00
Code Issues Projects Releases Wiki Activity

image-filters: apply image-filters in demultiplied colour space

Browse Source
This commit is contained in:
artemp 2014-06-19 13:26:40 +01:00
parent c605ce81aa
commit 2fb3069825
2 changed files with 5 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
include/mapnik/image_filter.hpp
View File

@ -142,26 +142,6 @@ boost::gil::rgba8_view_t rgba8_view(Image & img)
img.width() * sizeof(rgba8_pixel_t));
}
namespace detail {
template <typename T>
inline void premultiply_alpha( T & dst)
{
auto alpha = dst[3];
if (alpha < 255)
{
if (alpha == 0)
{
dst[0] = dst[1] = dst[2] = 0;
}
dst[0] = (dst[0] * alpha + 255) >> 8;
dst[1] = (dst[1] * alpha + 255) >> 8;
dst[2] = (dst[2] * alpha + 255) >> 8;
}
}
}
template <typename Image>
struct double_buffer
{
@ -274,7 +254,7 @@ void apply_convolution_3x3(Src const& src_view, Dst & dst_view, Filter const& fi
// top row
for (int x = 0 ; x < src_view.width(); ++x)
{
*dst_it = src_loc[loc11];
(*dst_it)[3] = src_loc[loc11][3]; // Dst.a = Src.a
for (int i = 0; i < 3; ++i)
{
bits32f p[9];
@ -310,7 +290,6 @@ void apply_convolution_3x3(Src const& src_view, Dst & dst_view, Filter const& fi
process_channel(p, (*dst_it)[i], filter);
}
detail::premultiply_alpha(*dst_it);
++src_loc.x();
++dst_it;
}
@ -322,7 +301,7 @@ void apply_convolution_3x3(Src const& src_view, Dst & dst_view, Filter const& fi
{
for (int x = 0; x < src_view.width(); ++x)
{
*dst_it = src_loc[loc11];
(*dst_it)[3] = src_loc[loc11][3]; // Dst.a = Src.a
for (int i = 0; i < 3; ++i)
{
bits32f p[9];
@ -358,8 +337,6 @@ void apply_convolution_3x3(Src const& src_view, Dst & dst_view, Filter const& fi
}
process_channel(p, (*dst_it)[i], filter);
}
detail::premultiply_alpha(*dst_it);
++dst_it;
++src_loc.x();
}
@ -371,7 +348,7 @@ void apply_convolution_3x3(Src const& src_view, Dst & dst_view, Filter const& fi
//src_loc = src_view.xy_at(0,src_view.height()-1);
for (int x = 0 ; x < src_view.width(); ++x)
{
*dst_it = src_loc[loc11];
(*dst_it)[3] = src_loc[loc11][3]; // Dst.a = Src.a
for (int i = 0; i < 3; ++i)
{
bits32f p[9];
@ -407,7 +384,6 @@ void apply_convolution_3x3(Src const& src_view, Dst & dst_view, Filter const& fi
p[8] = p[2];
process_channel(p, (*dst_it)[i], filter);
}
detail::premultiply_alpha(*dst_it);
++src_loc.x();
++dst_it;
}

2
src/agg/agg_renderer.cpp
View File

@ -275,10 +275,12 @@ void agg_renderer<T0,T1>::end_style_processing(feature_type_style const& st)
{
blend_from = true;
mapnik::filter::filter_visitor<image_32> visitor(*current_buffer_);
current_buffer_->demultiply(); // apply image-filters in de-multiplied color space
for (mapnik::filter::filter_type const& filter_tag : st.image_filters())
{
boost::apply_visitor(visitor, filter_tag);
}
current_buffer_->premultiply(); // back to pre-multiplied color space
}
if (st.comp_op())
{