add layout_align helper functions (65879199) · Commits · github_fork / Clip

common/graphics/layout.cc

+45 −0

Original line number	Diff line number	Diff line
		@@ -63,6 +63,51 @@ Rectangle layout_margin_box(
		return box;
		}

		void layout_align(
		const Rectangle& bbox,
		double tx,
		double ty,
		double* ox,
		double* oy) {
		double mx = bbox.x + bbox.w / 2;
		double my = bbox.y + bbox.h / 2;
		*ox = (tx - mx);
		*oy = (ty - my);
		}

		void layout_align(
		const Rectangle& bbox,
		double tx,
		double ty,
		HAlign align_x,
		VAlign align_y,
		double* ox,
		double* oy) {
		switch (align_x) {
		case HAlign::LEFT:
		tx += bbox.w / 2;
		break;
		case HAlign::RIGHT:
		tx -= bbox.w / 2;
		break;
		case HAlign::CENTER:
		break;
		}

		switch (align_y) {
		case VAlign::TOP:
		ty += bbox.h / 2;
		break;
		case VAlign::BOTTOM:
		ty -= bbox.h / 2;
		break;
		case VAlign::CENTER:
		break;
		}

		return layout_align(bbox, tx, ty, ox, oy);
		}

		std::ostream& operator <<(std::ostream& os, const Rectangle& r) {
		os << "Rectangle(";
		os << r.x;

+37 −1

Original line number	Diff line number	Diff line
		@@ -43,6 +43,16 @@ struct Rectangle {
		double h;
		};

		std::ostream& operator <<(std::ostream& os, const Rectangle& c);

		enum class HAlign {
		LEFT, CENTER, RIGHT
		};

		enum class VAlign {
		TOP, CENTER, BOTTOM
		};

		Rectangle layout_margin_box(
		const Rectangle& parent,
		double margin_top,
		@@ -50,7 +60,33 @@ Rectangle layout_margin_box(
		double margin_bottom,
		double margin_left);

		std::ostream& operator <<(std::ostream& os, const Rectangle& c);
		/**
		* Given a bounding box and a target point (tx, ty) and (sx, sy) == (0, 0),
		* calculate a translate offset (ox, oy) for the bounding box so that new
		* bounding box midpoint point is equal to the target point.
		*/
		void layout_align(
		const Rectangle& bbox,
		double tx,
		double ty,
		double* ox,
		double* oy);

		/**
		* Given a bounding box and a target point (tx, ty) and (sx, sy) == (0, 0),
		* calculate a translate offset (ox, oy) for the bounding box so that new
		* bounding box alignment point is equal to the target point. You can choose
		* from one of 9 alignment points using the halign and valign parameters.
		*/
		void layout_align(
		const Rectangle& bbox,
		double tx,
		double ty,
		HAlign halign,
		VAlign valign,
		double* ox,
		double* oy);


		} // namespace plotfx