diff options
Diffstat (limited to 'src/util.cpp')
-rw-r--r-- | src/util.cpp | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/src/util.cpp b/src/util.cpp index 19d590e..672b089 100644 --- a/src/util.cpp +++ b/src/util.cpp @@ -40,3 +40,56 @@ unique_fd::~unique_fd() close(this->fd); } } + +void rectangle::fit(unsigned long to_width, unsigned long to_height) +{ + // fit rect within (to_width x to_height) + + if (to_width <= width()) { + // scale to fit with + set_bottom(top() + (static_cast<long>(to_width) * height() / width()) - 1); + set_right(left() + to_width - 1); + } else { + // scale to fit height + set_right(left() + (static_cast<long>(to_height) * width () / height()) - 1); + set_bottom(top() + to_height - 1); + } +} + +void rectangle::center(unsigned long outer_w, unsigned long outer_h) +{ + long inner_w = width(); + long inner_h = height(); + + set_left((outer_w - inner_w) / 2); + set_right(left() + inner_w - 1); + set_top((outer_h - inner_h) / 2); + set_bottom(top() + inner_h - 1); +} + +void rectangle::set_aspect(double ratio) +{ + // aspect ratio is width:height (= width/height) + // e.g. Landscape of HD's ratio is 16:9 (= 1.777...) + // Portrait of HD's ratio is 9:16 (= 0.5625) + // + // width / height = ratio + // width * height = area + // + // width = sqrt(ratio * area) + // height = width / ratio + + long orig_w = width(); + long orig_h = height(); + + if (ratio >= 1) { + // width >= height + // try to keep width + set_right(left() + orig_w - 1); + set_bottom(top() + static_cast<long>(orig_w / ratio + 0.5) - 1); + } else { + set_bottom(top() + orig_h - 1); + set_right(left() + static_cast<long>(orig_h * ratio + 0.5) - 1); + } +} + |