Like the topic title indicates, I'm asking what is the fastest way to check if a bitmap's a solid color?
I'm trying to check and see if a 32x32 bitmap is solid magic pink.

EDIT: nm, I misunderstood the question.

The real answer: two for loops.

And getpixel I assume? I guess it's not too slow for only loading bitmap routines.

You can also use direct access. Or one of the colour depth specific access functions that don't do bounds checking.

_getpixel32()

Okee doke. Thanks

Perhaps this from exfire.c, with some little change you can adjust it to fit your need:

This article from Gamedev about digital processing can help too for implementing gaussian blur.
_

//Untested 
bool is_solid_color(BITMAP *src, int col)
{
  int x = 0, y = 0;
  int check_col = -1;
  while(y < src->h && (check_col = getpixel(src,x++,y)) == col)
    if(x == src->w) {  x = 0; y++;   }

  if(check_col != col)
    return false;
  return true;
}

Funny thing about this is the worst case scenario is when the bitmap IS the given solid color.

Onewing Phipps:

bool is_solid_color(BITMAP *src, int col)
{
  int x = 0, y = 0;
  int check_col = -1;
  while(y < src->h && (check_col = getpixel(src,x++,y)) == col)
    if(x == src->w) {  x = 0; y++;   }

  // just a minor improvement
  return check_col == col;
}