// ============================================================
//          Triangles                                  
// ------------------------------------------------------------

@mixin triangle($color: #000, $height: 1em, $width: 1em, $angle: 0) 
  
  @if unit($height) == "" or unit($height) == "%" 
    @debug "in triangle #$height is not a compatable unit for height."
  

  @if unit($width) == "" or unit($width) == "%" 
    @debug "in triangle #$width is not a compatable unit for width."
  

  // offset 45deg to make each side start at 0
  $deg: $angle + 45
  // if units, remove units
  @if unit($deg) == deg 
    $deg: $deg / 1deg
  
  // shift to be on a scale from 0 to 90.
  @while $deg > 90 
    $deg: $deg - 90
  
  @while $deg < 0 
    $deg: $deg + 90
  
  // Get a ratio of 90 to multiply by.
  $deg: $deg / 90

  // make sure metrics are reset
  display: block
  width: 0
  height: 0
  border: 0 solid transparent

  // run through sides
  @if $angle <= 45 or $angle > 315 
    border-bottom-color: $color
    border-width: 0 ($width * abs($deg - 1)) $height ($width * $deg)
  
  @if $angle > 45 and $angle <= 135 
    border-left-color: $color
    border-width: ($height * $deg) 0 ($height * abs($deg - 1)) $width
  
  @if $angle > 135 and $angle <= 225 
    border-top-color: $color
    border-width: $height ($width * $deg) 0 ($width * abs($deg - 1))
  
  @if $angle > 225 and $angle <= 315 
    border-right-color: $color
    border-width: ($height * abs($deg - 1)) $width ($height * $deg) 0