1 files changed, 83 insertions, 0 deletions
diff --git a/gifed/src/block/packed.rs b/gifed/src/block/packed.rs
new file mode 100644
index 0000000..4eaa5b8
--- /dev/null
+++ b/gifed/src/block/packed.rs
@@ -0,0 +1,83 @@
+struct InnerPacked<T> {
+	raw: T,
+}
+
+impl InnerPacked<&u8> {
+	#[inline]
+	fn color_table(&self) -> bool {
+		self.raw & 0b1000_0000 > 0
+	}
+
+	#[inline]
+	fn color_resolution(&self) -> u8 {
+		(self.raw & 0b0111_0000) >> 4
+	}
+
+	#[inline]
+	fn logical_sort(&self) -> bool {
+		self.raw & 0b0000_1000 > 0
+	}
+
+	#[inline]
+	fn image_sort(&self) -> bool {
+		self.raw & 0b0010_0000 > 0
+	}
+
+	#[inline]
+	fn color_table_size(&self) -> u8 {
+		self.raw & 0b0000_0111
+	}
+
+	#[inline]
+	fn interlace(&self) -> bool {
+		self.raw & 0b0100_0000 > 0
+	}
+}
+
+impl InnerPacked<&mut u8> {
+	#[inline]
+	fn set_color_table(&mut self, flag: bool) {
+		if flag {
+			*self.raw |= 0b1000_0000;
+		} else {
+			*self.raw &= 0b0111_1111;
+		}
+	}
+
+	#[inline]
+	fn set_color_resolution(&mut self, resolution: u8) {
+		*self.raw |= (resolution & 0b0111_0000) << 4;
+	}
+
+	#[inline]
+	fn set_logical_sort(&mut self, flag: bool) {
+		if flag {
+			*self.raw |= 0b0000_1000;
+		} else {
+			*self.raw &= 0b1111_0111;
+		}
+	}
+
+	#[inline]
+	fn set_image_sort(&mut self, flag: bool) {
+		if flag {
+			*self.raw |= 0b0010_0000;
+		} else {
+			*self.raw &= 0b1101_1111;
+		}
+	}
+
+	#[inline]
+	fn set_color_table_size(&mut self, size: u8) {
+		*self.raw |= size & 0b0000_0111;
+	}
+
+	#[inline]
+	fn set_interlace(&mut self, flag: bool) {
+		if flag {
+			*self.raw |= 0b0100_0000;
+		} else {
+			*self.raw &= 0b1011_1111;
+		}
+	}
+}