/// _functions.scss -*- Mode: text; indent-tabs-mode: nil; basic-offset: 2 -*-

// Strip Unit - From Foundation
// Removes the unit (e.g. px, em, rem) from a value, returning the number only.
//
// @param {number} $num - Number to strip unit from.
// @return The same number, sans unit.
@function strip-unit($num) {
  @return $num / ($num * 0 + 1);
}

/// sp|dp to px
// Google's Material design specs are in 'sp' or 'dp' which are not css units
// 'dp' is 'density independant pexels' and 'sp' is 'scale-independent pixels' (same as dp, but will be scaled by the user's font size preference)
// Android gives a 160dpi  base value to 'sp' and 'dp', but Google's examples seems to use 'sp' as 'px'
// We define a scaling factor in case we need to adjust
// 'sp' is scale to 1 css-px for a rem-base-value of 16px (default)
// 'dp' is scale to 1 css-px according to scaling factor
//
// sp-to-px converts a 'sp' value  to css-pixel value. Units, if specified will be stripped
// dp-to-px converts a 'dp' value  to css-pixel value. Units, if specified will be stripped
//
// @param {number} $value - sp or dp value to convert.
//
// @return {number} in px.
//
@function dp-to-px($value)  {
  $value: strip-unit($value) * strip-unit($sg-dp-scale-factor) * 1px;
  @if ($value == 0sp) { $value: 0; } // Turn 0rem into 0
  @return $value;
}
@function sp-to-px($value)  {
  $value: strip-unit($value) * $sg-sp-value * 16px;
  @if ($value == 0sp) { $value: 0; } // Turn 0sp into 0
  @return $value;
}

/// Utility fonction to easily get any hue from any palette anyware
/// More easy to remember than variable names
@function sg-color($color, $hue) {
  @return map-get($color, $hue);
}

/// Utility fonction to easily get font size from typographic scale
/// More easy to remember than variable names.
/// @usage : provide type-size from the Material design typographic scale
/// (caption, body, button, menu, subhead, title, headline, display-1, display-2, display-3, display-4 ; ther's also shortcut aliases : d1, d2, d3, d4)
/// @return : type size
@function sg-size($size) {
  @return (map-get($typeSize, $size) * 1px);
}