Add screenpacked abstraction over u8

6 files changed, 86 insertions, 82 deletions

diff --git a/gifed/src/block/extension/graphiccontrol.rs b/gifed/src/block/extension/graphiccontrol.rs
index 04086a6..5806884 100644
--- a/gifed/src/block/extension/graphiccontrol.rs
+++ b/gifed/src/block/extension/graphiccontrol.rs
@@ -25,7 +25,7 @@ impl GraphicControl {
 
 		ret.set_disposal_method(disposal_method);
 		ret.packed.set_user_input(user_input_flag);
-		ret.packed.set_transparent_color(transparency_flag);
+		ret.packed.set_transparent_flag(transparency_flag);
 
 		ret
 	}
@@ -61,7 +61,7 @@ impl GraphicControl {
 	/// Returns the index that should be replaced by a fully transparent pixel
 	/// if the transparency flag is set, or None if it's not set.
 	pub fn transparent_index(&self) -> Option<u8> {
-		if self.packed.transparent_color() {
+		if self.packed.transparent_flag() {
 			Some(self.transparency_index)
 		} else {
 			None
@@ -77,7 +77,7 @@ impl GraphicControl {
 	/// Sets the transparent index and flips the flag to indicate a transparent
 	/// index is present if `index` is `Some`.
 	pub fn set_transparent_index(&mut self, index: Option<u8>) {
-		self.packed.set_transparent_color(index.is_some());
+		self.packed.set_transparent_flag(index.is_some());
 
 		if let Some(index) = index {
 			self.transparency_index = index;
diff --git a/gifed/src/block/packed.rs b/gifed/src/block/packed.rs
index a80b807..f091fb3 100644
--- a/gifed/src/block/packed.rs
+++ b/gifed/src/block/packed.rs
@@ -9,35 +9,47 @@ impl GraphicPacked {
 	}
 
 	pub fn reserved(&self) -> u8 {
-		graphic_reserved(self.raw)
+		self.raw & 0b111_000_0_0 >> 5
 	}
 
 	pub fn set_reserved(&mut self, reserved: u8) {
-		set_graphic_reserved(&mut self.raw, reserved)
+		// We care about the three least significant bits and we want to shift
+		// them so they're at the top, five away. From 000_001_1_1 to 111_000_0_0
+		self.raw = (reserved & 0b0000_0111) << 5;
 	}
 
 	pub fn disposal_method(&self) -> u8 {
-		disposal_method(self.raw)
+		self.raw & 0b000_111_0_0 >> 2
 	}
 
 	pub fn set_disposal_method(&mut self, disposal: u8) {
-		set_disposal_method(&mut self.raw, disposal)
+		// Care about 3 least significant bits and we want them three from the top
+		// from 000_001_1_1 into 000_111_0_0
+		self.raw = (disposal & 0b0000_0111) << 2;
 	}
 
 	pub fn user_input(&self) -> bool {
-		user_input(self.raw)
+		self.raw & 0b000_000_1_0 > 0
 	}
 
 	pub fn set_user_input(&mut self, flag: bool) {
-		set_user_input(&mut self.raw, flag)
+		if flag {
+			self.raw |= 0b000_000_1_0;
+		} else {
+			self.raw &= 0b111_111_0_1;
+		}
 	}
 
-	pub fn transparent_color(&self) -> bool {
-		transparent_color(self.raw)
+	pub fn transparent_flag(&self) -> bool {
+		self.raw & 0b000_000_0_1 > 0
 	}
 
-	pub fn set_transparent_color(&mut self, flag: bool) {
-		set_transparent_flag(&mut self.raw, flag)
+	pub fn set_transparent_flag(&mut self, flag: bool) {
+		if flag {
+			self.raw |= 0b000_000_0_1;
+		} else {
+			self.raw &= 0b111_111_1_0;
+		}
 	}
 }
 
@@ -112,61 +124,56 @@ impl ImagePacked {
 		self.raw & 0b0_0_0_00_111
 	}
 
-	pub fn set_color_table_size(&mut self, reserved: u8) {
+	pub fn set_color_table_size(&mut self, size: u8) {
 		// The color table is the least significant already, don't do anything
 		// except select the bits
-		self.raw = reserved & 0b0_0_0_00_111;
+		self.raw = size & 0b0_0_0_00_111;
 	}
 }
 
-#[inline]
-fn graphic_reserved(packed: u8) -> u8 {
-	packed & 0b111_000_0_0 >> 5
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub struct ScreenPacked {
+	pub raw: u8,
 }
 
-#[inline]
-fn disposal_method(packed: u8) -> u8 {
-	packed & 0b000_111_0_0 >> 2
-}
+impl ScreenPacked {
+	pub fn color_table(&self) -> bool {
+		self.raw & 0b1_000_0_000 > 0
+	}
 
-#[inline]
-fn user_input(packed: u8) -> bool {
-	packed & 0b000_000_1_0 > 0
-}
+	pub fn set_color_table(&mut self, flag: bool) {
+		if flag {
+			self.raw |= 0b1_0_0_00_000;
+		} else {
+			self.raw &= 0b0_1_1_11_111;
+		}
+	}
 
-#[inline]
-fn transparent_color(packed: u8) -> bool {
-	packed & 0b000_000_0_1 > 0
-}
+	pub fn color_resolution(&self) -> u8 {
+		(self.raw & 0b0_111_0_000) >> 4
+	}
 
-#[inline]
-fn set_graphic_reserved(packed: &mut u8, reserved: u8) {
-	// We care about the three least significant bits and we want to shift
-	// them so they're at the top, five away. From 000_001_1_1 to 111_000_0_0
-	*packed = (reserved & 0b0000_0111) << 5;
-}
+	pub fn set_color_resolution(&mut self, resolution: u8) {
+		self.raw = (resolution & 0b0000_0111) << 4;
+	}
 
-#[inline]
-fn set_disposal_method(packed: &mut u8, disposal: u8) {
-	// Care about 3 least significant bits and we want them three from the top
-	// from 000_001_1_1 into 000_111_0_0
-	*packed = (disposal & 0b0000_0111) << 2;
-}
+	pub fn sorted(&self) -> bool {
+		self.raw & 0b0_000_1_000 > 0
+	}
 
-#[inline]
-fn set_user_input(packed: &mut u8, flag: bool) {
-	if flag {
-		*packed |= 0b000_000_1_0;
-	} else {
-		*packed &= 0b111_111_0_1;
+	pub fn set_sorted(&mut self, flag: bool) {
+		if flag {
+			self.raw |= 0b0_000_1_000;
+		} else {
+			self.raw &= 0b1_111_0_111;
+		}
+	}
+
+	pub fn color_table_size(&self) -> u8 {
+		self.raw & 0b0_0_0_00_111
 	}
-}
 
-#[inline]
-fn set_transparent_flag(packed: &mut u8, flag: bool) {
-	if flag {
-		*packed |= 0b000_000_0_1;
-	} else {
-		*packed &= 0b111_111_1_0;
+	pub fn set_color_table_size(&mut self, size: u8) {
+		self.raw = size & 0b0_0_0_00_111;
 	}
 }
diff --git a/gifed/src/block/screendescriptor.rs b/gifed/src/block/screendescriptor.rs
index dc0257d..6b318b5 100644
--- a/gifed/src/block/screendescriptor.rs
+++ b/gifed/src/block/screendescriptor.rs
@@ -1,9 +1,11 @@
 use std::convert::TryInto;
 
+use super::{packed::ScreenPacked, ColorTable};
+
 pub struct ScreenDescriptor {
 	pub width: u16,
 	pub height: u16,
-	pub packed: u8,
+	pub packed: ScreenPacked,
 	pub background_color_index: u8,
 	pub pixel_aspect_ratio: u8,
 }
@@ -13,37 +15,32 @@ impl ScreenDescriptor {
 		Self {
 			width,
 			height,
-			packed: 0,
+			packed: ScreenPacked { raw: 0 },
 			background_color_index: 0,
 			pixel_aspect_ratio: 0,
 		}
 	}
 
-	pub fn set_color_table_present(&mut self, is_present: bool) {
-		if is_present {
-			self.packed |= 0b1000_0000;
+	/// This data structure **does not** contain the color table, only a flag to
+	/// indicate if one is present and it's size.
+	pub fn set_color_table_metadata<T: AsRef<ColorTable>>(&mut self, table: Option<T>) {
+		if let Some(table) = table {
+			let table = table.as_ref();
+			self.packed.set_color_table(true);
+			self.packed.set_color_table_size(table.packed_len());
 		} else {
-			self.packed &= 0b0111_1111;
+			self.packed.set_color_table(false);
+			// This is not strictly needed, but we'll clear it anyway
+			self.packed.set_color_table_size(0);
 		}
 	}
 
-	pub fn set_color_table_size(&mut self, size: u8) {
-		println!("scts: {}", size);
-		// GCT size is calulated by raising two to this number plus one,
-		// so we have to work backwards.
-		let size = (size as f32).log2().ceil() - 1f32;
-		self.packed |= size as u8;
-	}
-
-	//TODO: Setter for sort flag in packed field
-	//TODO: Setter for color resolution in packed field
-
-	pub fn color_table_present(&self) -> bool {
-		self.packed & 0b1000_0000 != 0
+	pub fn has_color_table(&self) -> bool {
+		self.packed.color_table()
 	}
 
 	pub fn color_table_len(&self) -> usize {
-		crate::packed_to_color_table_length(self.packed & 0b0000_0111)
+		crate::packed_to_color_table_length(self.packed.color_table_size())
 	}
 }
 
@@ -52,7 +49,7 @@ impl From<&ScreenDescriptor> for Box<[u8]> {
 		let mut vec = vec![];
 		vec.extend_from_slice(&lsd.width.to_le_bytes());
 		vec.extend_from_slice(&lsd.height.to_le_bytes());
-		vec.push(lsd.packed);
+		vec.push(lsd.packed.raw);
 		vec.push(lsd.background_color_index);
 		vec.push(lsd.pixel_aspect_ratio);
 
@@ -71,7 +68,7 @@ impl From<[u8; 7]> for ScreenDescriptor {
 		Self {
 			width,
 			height,
-			packed,
+			packed: ScreenPacked { raw: packed },
 			background_color_index,
 			pixel_aspect_ratio,
 		}
diff --git a/gifed/src/reader/mod.rs b/gifed/src/reader/mod.rs
index 68e15c4..e852d26 100644
--- a/gifed/src/reader/mod.rs
+++ b/gifed/src/reader/mod.rs
@@ -30,7 +30,7 @@ impl GifReader {
 
 		let mut gif = Self::read_required(&mut reader)?;
 
-		if gif.screen_descriptor.color_table_present() {
+		if gif.screen_descriptor.has_color_table() {
 			let gct_size = gif.screen_descriptor.color_table_len() * 3;
 			gif.global_color_table = Some(Self::read_color_table(&mut reader, gct_size)?);
 		}
diff --git a/gifed/src/writer/gifbuilder.rs b/gifed/src/writer/gifbuilder.rs
index 337e404..2141fc7 100644
--- a/gifed/src/writer/gifbuilder.rs
+++ b/gifed/src/writer/gifbuilder.rs
@@ -1,5 +1,6 @@
 use std::convert::TryInto;
 
+use crate::block::packed::ScreenPacked;
 use crate::block::{Block, ColorTable, LoopCount, ScreenDescriptor, Version};
 use crate::writer::ImageBuilder;
 use crate::{EncodingError, Gif};
@@ -84,15 +85,14 @@ impl GifBuilder {
 		let mut lsd = ScreenDescriptor {
 			width: self.width,
 			height: self.height,
-			packed: 0, // Set later
+			packed: ScreenPacked { raw: 0 }, // Set later
 			background_color_index: self.background_color_index,
 			pixel_aspect_ratio: 0, //TODO: Allow configuring
 		};
 
 		if let Some(gct) = &self.global_color_table {
 			println!("build {}", gct.len());
-			lsd.set_color_table_present(true);
-			lsd.set_color_table_size((gct.len() - 1) as u8);
+			lsd.set_color_table_metadata(Some(gct));
 		}
 
 		Ok(Gif {
diff --git a/gifprobe/src/main.rs b/gifprobe/src/main.rs
index c6bc0f8..241c421 100644
--- a/gifprobe/src/main.rs
+++ b/gifprobe/src/main.rs
@@ -24,7 +24,7 @@ fn main() {
 		gif.screen_descriptor.height.yellow()
 	);
 
-	if gif.screen_descriptor.color_table_present() {
+	if gif.screen_descriptor.has_color_table() {
 		println!(
 			"\tGlobal Color Table Present {}\n\tGlobal Color Table Size {}",
 			"Yes".green(),