From: Mike Austin <noone@...>
Date: 2006-03-11T11:33:43+09:00
Subject: Optimizing ruby constant array data

I decided it was time to do a little profiling, and am so glad that it's built 
right into Ruby.  My biggest problem seems to be array access:

  %   cumulative   self              self     total
time   seconds   seconds    calls  ms/call  ms/call  name
36.02     3.35      3.35      350     9.57    15.10  String#each_byte
10.45     4.32      0.97    27230     0.04     0.04  Array#[]
  6.73     4.95      0.63    16100     0.04     0.04  GL.Vertex

I'll eventually go to display-lists or similar in OpenGL, but I was wondering 
if I could optimize this any further?

def draw_string( string )
   size = font.height
   x = 0

   GL::Enable( GL::TEXTURE_2D )
   GL::Begin( GL::QUADS )
   string.each_byte do |char|
     offset = char - 32
     GL::TexCoord2f( @tex_coords_left[offset], @tex_coords_top[offset] );
     GL::Vertex(        x,    0 )
     GL::TexCoord2f( @tex_coords_left[offset], @tex_coords_bottom[offset] );
     GL::Vertex(        x, size )
     GL::TexCoord2f( @tex_coords_right[offset], @tex_coords_bottom[offset] );
     GL::Vertex( x + size, size )
     GL::TexCoord2f( @tex_coords_right[offset], @tex_coords_top[offset] );
     GL::Vertex( x + size,    0 )
     x += @sizes[char-32][0]
   end
   GL::End()
   GL::Disable( GL::TEXTURE_2D )
end


Thanks,
Mike