RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-07-26 12:47:45 +00:00
Code Issues Activity Actions

LibGfx: Handle signed distance field edges better

Browse source 
Small change to treat pixels outside the signed distance field bitmap
as outside the shape.
This commit is contained in:
MacDue 2023-03-23 22:48:12 +00:00 • committed by Linus Groh
parent fcaa535dec
commit 98040c508f
1 changed files with 11 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

17
Userland/Libraries/LibGfx/Painter.cpp
View file

@ -2583,6 +2583,13 @@ void Painter::draw_signed_distance_field(IntRect const& dst_rect, Color color, G
return x * x * (3 - 2 * x);
};
auto pixel_at = [&](unsigned x, unsigned y) -> u8 {
// Returning 255 means this pixel is outside the shape.
if (x >= sdf.width() || y >= sdf.height())
return 255;
return sdf.pixel_at(x, y);
};
for (int i = 0; i < clipped_rect.height(); ++i) {
for (int j = 0; j < clipped_rect.width(); ++j) {
auto point = IntPoint { j, i };
@ -2592,12 +2599,10 @@ void Painter::draw_signed_distance_field(IntRect const& dst_rect, Color color, G
auto target_fraction_x = (x_ratio * sample_point.x()) - target_x;
auto target_fraction_y = (y_ratio * sample_point.y()) - target_y;
auto x2 = min(target_x + 1, sdf.width() - 1);
auto y2 = min(target_y + 1, sdf.height() - 1);
auto a = sdf.pixel_at(target_x, target_y);
auto b = sdf.pixel_at(x2, target_y);
auto c = sdf.pixel_at(target_x, y2);
auto d = sdf.pixel_at(x2, y2);
auto a = pixel_at(target_x, target_y);
auto b = pixel_at(target_x + 1, target_y);
auto c = pixel_at(target_x, target_y + 1);
auto d = pixel_at(target_x + 1, target_y + 1);
float distance = (a * (1 - target_fraction_x) * (1 - target_fraction_y)
+ b * target_fraction_x * (1 - target_fraction_y)