Add get_image function to IconState

src/dirs.rs

@@ -15,6 +15,12 @@ bitflags! {
 	}
 }
 
+impl std::fmt::Display for Dirs {
+	fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+		write!(f, "{} ({:?})", self.bits(), self)
+	}
+}
+
 /// A list of every cardinal direction.
 pub const CARDINAL_DIRS: [Dirs; 4] = [Dirs::NORTH, Dirs::SOUTH, Dirs::EAST, Dirs::WEST];
 

src/error.rs

@@ -1,26 +1,28 @@
-use std::io;
-use thiserror::Error;
-
-#[derive(Error, Debug)]
-pub enum DmiError {
-	#[error("IO error")]
-	Io(#[from] io::Error),
-	#[error("Image-processing error")]
-	Image(#[from] image::error::ImageError),
-	#[error("FromUtf8 error")]
-	FromUtf8(#[from] std::string::FromUtf8Error),
-	#[error("ParseInt error")]
-	ParseInt(#[from] std::num::ParseIntError),
-	#[error("ParseFloat error")]
-	ParseFloat(#[from] std::num::ParseFloatError),
-	#[error("Invalid chunk type (byte outside the range `A-Za-z`): {chunk_type:?}")]
-	InvalidChunkType { chunk_type: [u8; 4] },
-	#[error("CRC mismatch (stated {stated:?}, calculated {calculated:?})")]
-	CrcMismatch { stated: u32, calculated: u32 },
-	#[error("Dmi error: {0}")]
-	Generic(String),
-	#[error("Encoding error: {0}")]
-	Encoding(String),
-	#[error("Conversion error: {0}")]
-	Conversion(String),
-}
+use std::io;
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum DmiError {
+	#[error("IO error")]
+	Io(#[from] io::Error),
+	#[error("Image-processing error")]
+	Image(#[from] image::error::ImageError),
+	#[error("FromUtf8 error")]
+	FromUtf8(#[from] std::string::FromUtf8Error),
+	#[error("ParseInt error")]
+	ParseInt(#[from] std::num::ParseIntError),
+	#[error("ParseFloat error")]
+	ParseFloat(#[from] std::num::ParseFloatError),
+	#[error("Invalid chunk type (byte outside the range `A-Za-z`): {chunk_type:?}")]
+	InvalidChunkType { chunk_type: [u8; 4] },
+	#[error("CRC mismatch (stated {stated:?}, calculated {calculated:?})")]
+	CrcMismatch { stated: u32, calculated: u32 },
+	#[error("Dmi error: {0}")]
+	Generic(String),
+	#[error("Dmi IconState error: {0}")]
+	IconState(String),
+	#[error("Encoding error: {0}")]
+	Encoding(String),
+	#[error("Conversion error: {0}")]
+	Conversion(String),
+}

src/icon.rs

@@ -1,8 +1,8 @@
-use crate::dirs::Dirs;
+use crate::dirs::{Dirs, ALL_DIRS, ORDINAL_DIRS};
 use crate::{error, ztxt, RawDmi};
 use image::codecs::png;
-use image::imageops;
 use image::GenericImageView;
+use image::{imageops, DynamicImage};
 use std::collections::HashMap;
 use std::io::prelude::*;
 use std::io::Cursor;
@@ -29,6 +29,21 @@ pub const DIR_ORDERING: [Dirs; 8] = [
 	Dirs::NORTHWEST,
 ];
 
+/// Given a Dir, gives its order with a DMI file (equivalent: DIR_ORDERING.iter().position(Dir))
+pub fn dir_to_dmi_index(dir: &Dirs) -> Option<u32> {
+	match *dir {
+		Dirs::SOUTH => Some(0),
+		Dirs::NORTH => Some(1),
+		Dirs::EAST => Some(2),
+		Dirs::WEST => Some(3),
+		Dirs::SOUTHEAST => Some(4),
+		Dirs::SOUTHWEST => Some(5),
+		Dirs::NORTHEAST => Some(6),
+		Dirs::NORTHWEST => Some(7),
+		_ => None,
+	}
+}
+
 impl Icon {
 	pub fn load<R: Read>(reader: R) -> Result<Icon, error::DmiError> {
 		let raw_dmi = RawDmi::load(reader)?;
@@ -484,6 +499,49 @@ pub struct IconState {
 	pub unknown_settings: Option<HashMap<String, String>>,
 }
 
+impl IconState {
+	/// Gets a specific DynamicImage from `images`, given a dir and frame.
+	pub fn get_image(&self, dir: &Dirs, frame: u32) -> Result<&DynamicImage, error::DmiError> {
+		if self.frames < frame {
+			return Err(error::DmiError::IconState(format!(
+				"Specified frame \"{}\" is larger than the number of frames ({}) in icon_state \"{}\"",
+				frame, self.frames, self.name
+			)));
+		}
+		if (self.dirs == 1 && *dir != Dirs::SOUTH)
+			|| (self.dirs == 4 && !ORDINAL_DIRS.contains(dir))
+			|| (self.dirs == 8 && !ALL_DIRS.contains(dir))
+		{
+			return Err(error::DmiError::IconState(format!(
+				"Dir specified {} is not in the set of valid dirs ({} dirs) in icon_state \"{}\"",
+				dir, self.dirs, self.name
+			)));
+		}
+
+		let image_idx = match dir_to_dmi_index(dir) {
+			Some(idx) => (idx + 1) * frame - 1,
+			None => {
+				return Err(error::DmiError::IconState(format!(
+					"Dir specified {} is not a valid dir within DMI ordering! (icon_state: {})",
+					dir, self.name
+				)));
+			}
+		};
+
+		match self.images.get(image_idx as usize) {
+        Some(image) => {
+					Ok(image)
+				},
+        None => {
+          Err(error::DmiError::IconState(format!(
+							"Out of bounds index {} in icon_state \"{}\" (images len: {} dirs: {}, frames: {} - dir: {}, frame: {})",
+							image_idx, self.name, self.images.len(), self.dirs, self.frames, dir, frame
+					)))
+        }
+    }
+	}
+}
+
 impl Default for IconState {
 	fn default() -> Self {
 		IconState {