OK, you know a lot more about this than me, but the book book I have been reading uses IntersectRect(RECT rect1, RECT rect2) and that returns true if the two rects that hold the position of your two sprites are colliding.
Code:
// This code is lifted from the book, hope it is not infringing copyrights
int Collision(SPRITE sprite1, SPRITE sprite2)
{
RECT rect1;
rect1.left = sprite1.x+1;
rect1.top = sprite1.y+1;
rect1.right = sprite1.x + sprite1.width-1;
rect1.bottom = sprite1.y + sprite1.height-1;
RECT rect2;
rect2.left = sprite2.x+1;
rect2.top = sprite2.y+1;
rect2.right = sprite2.x + sprite2.width-1;
rect2.bottom = sprite2.y + sprite2.height-1;
RECT dest;
return IntersectRect(&dest, &rect1, &rect2);
}
The &dest is a dummy rect