//! Image and color representations.

use std::ops::{Index, IndexMut};

/// RGBA8 color.
#[derive(Clone, Debug, PartialEq)]
pub struct Color
{
   pub r: u8,
   pub g: u8,
   pub b: u8,
   pub a: u8,
}

/// Image with width and height.
pub struct Image
{
   w:      usize,
   h:      usize,
   pub cr: Vec<Color>,
}

impl Color
{
   /// Converts a R5G5B5 format color to RGBA8.
   pub fn from_r5g5b5(rgb: u16) -> Color
   {
      let r = rgb >> 10 & 0x1f;
      let g = rgb >> 5 & 0x1f;
      let b = rgb & 0x1f;
      Color{r: (r << 3 | r >> 2) as u8,
            g: (g << 3 | g >> 2) as u8,
            b: (b << 3 | b >> 2) as u8,
            a: 255}
   }
}

impl Image
{
   /// Creates a new Image structure.
   pub fn new(w: usize, h: usize) -> Image
   {
      Image{w, h, cr: Vec::with_capacity(w * h)}
   }

   pub fn w(&self) -> usize
   {
      self.w
   }

   pub fn h(&self) -> usize
   {
      self.h
   }
}

impl Index<(usize, usize)> for Image
{
   type Output = Color;

   fn index(&self, (x, y): (usize, usize)) -> &Color
   {
      &self.cr[x + y * self.w]
   }
}

impl IndexMut<(usize, usize)> for Image
{
   fn index_mut(&mut self, (x, y): (usize, usize)) -> &mut Color
   {
      &mut self.cr[x + y * self.w]
   }
}

// EOF