Mike Austin <noone / nowhere.com> writes:

> 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

Perhaps use #at instead of #[] ?  Using texture coord arrays might
help too.  But if that's really only 10% of the total time, I don't
think it's going to make too much difference...