CODEWITHSUNDEEP
c++bitmaptexturespackingbin-packing
Wunkolo
Wunkolo

Reputation: 33

Packing bitmaps

I am trying to pack font glyph images into a single texture. The bitmaps are 1 byte per pixel monochromatic and I wish to pack them all together onto 1 texture. I am able to calculate the minimum texture size required but I am unable to manage an algorithm to packing them all together.

I currently have the bitmaps stored as char pointers and I am able to get the dimensions of each.

Upvotes: 2

Views: 1455

Answers (2)

Viktor Latypov
Viktor Latypov

Reputation: 14467

Simple packing algorithm can be found here: http://www.blackpawn.com/texts/lightmaps/

It is called "Guillotine pack" in Jukka Jylänki's paper "A Thousand Ways To Pack the Bin".

The pseudo-code at blackpawn.com is really simple.

There are also related answers for similar questions: Piece together several images into one big image

Upvotes: 1

Emile Cormier
Emile Cormier

Reputation: 29199

I'm not an expert in bin packing, but here's a simple algorithm you may try.

  1. Order glyphs from tallest to shortest. The tallest glyphs will be placed first.
  2. Let H be the height of the next tallest unplaced glyph.
  3. Expand your texture vertically by adding a level of height H.
  4. Fill the level with the remaining glyphs (tallest to shortest) until there is no room left for the next glyph.
  5. Goto #2

This is known as Next-Fit Decreasing Height (NFDH) algorithm. An interactive demo can be seen here.

Since your glyphs are more or less the same height, I think this simple algorithm should give you good results.

Check out this survey for more algorithms.

Upvotes: 3

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