MR::UI::RectAllocator Class Reference

#include <MRUIRectAllocator.h>

Inheritance diagram for MR::UI::RectAllocator:

Classes
struct	FindFreeRectResult

Public Types
using	FindPotentiallyOverlappingRects = std::function<void( Box2f target, std::function<void( const char* name, Box2f box )> overlaps )>

Public Member Functions
MRVIEWER_API	RectAllocator ()
MRVIEWER_API FindFreeRectResult	findFreeRect (Box2f preferredRect, Box2f preferredBounds, FindPotentiallyOverlappingRects findOverlaps, ImVec2 axisWeights=ImVec2(1, 1))

Static Public Member Functions
static bool	rectRectOverlap (Box2f a, Box2f b)

Detailed Description

A generic rect allocator. Given a set of rects and a target rect, finds the closest free rect next to the target (using dijkstra's algorithm). The class can be reused multiple times to avoid repeated heap allocation, it doesn't store any state other than memory pools. For optimal results you should bring your own AABB tree (see FindPotentiallyOverlappingRects) below, but in simple cases you can get away with a flat list.

Member Typedef Documentation

FindPotentiallyOverlappingRects

using MR::UI::RectAllocator::FindPotentiallyOverlappingRects = std::function<void( Box2f target, std::function<void( const char* name, Box2f box )> overlaps )>

Given an input rect, this function must find all POTENTIALLY overlapping rects ("overlapping" means according to rectRectOverlap()). name is only useful for debugging.

Constructor & Destructor Documentation

RectAllocator()

MRVIEWER_API MR::UI::RectAllocator::RectAllocator

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Member Function Documentation

findFreeRect()

MRVIEWER_API FindFreeRectResult MR::UI::RectAllocator::findFreeRect ( Box2f preferredRect, Box2f preferredBounds, FindPotentiallyOverlappingRects findOverlaps, ImVec2 axisWeights = ImVec2(1, 1) )

nodiscard

Finds a free rectangle of the specified size, as close as possible to the specified position. On failure, returns .ok == false and returns the input rect unchanged.

Parameters

preferredBounds	The outer bounds that we try to fit the rect into. The input rect doesn't need to be in bounds, but we will not move it more out of bounds than it already is.
findOverlaps	Given any rect, this must return all existing rects potentially overlapping with it.
axisWeights	This sets the preference for X and Y axes. Larger number = less likely to shift over that axis.

rectRectOverlap()

static bool MR::UI::RectAllocator::rectRectOverlap ( Box2f a, Box2f b )

inlinestaticnodiscard

Checks if two rects overlap. We can't use .intersects() here because we want .max to be exclusive, while .intersects() treats both bounds as inclusive.

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The documentation for this class was generated from the following file:

• MRUIRectAllocator.h