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|
use crate::{
block::{
extension::{DisposalMethod, GraphicControl},
ColorTable, ImageDescriptor, IndexedImage, Version,
},
EncodingError,
};
pub struct ImageBuilder {
left_offset: u16,
top_offset: u16,
width: u16,
height: u16,
color_table: Option<ColorTable>,
delay: u16,
disposal_method: DisposalMethod,
transparent_index: Option<u8>,
indicies: Vec<u8>,
}
impl ImageBuilder {
pub fn new(width: u16, height: u16) -> Self {
Self {
left_offset: 0,
top_offset: 0,
width,
height,
color_table: None,
delay: 0,
disposal_method: DisposalMethod::NoAction,
transparent_index: None,
indicies: vec![],
}
}
pub fn offset(mut self, left: u16, top: u16) -> Self {
self.left_offset = left;
self.top_offset = top;
self
}
pub fn palette(mut self, table: ColorTable) -> Self {
self.color_table = Some(table);
self
}
/// Time to wait, in hundreths of a second, before this image is drawn
pub fn delay(mut self, hundreths: u16) -> Self {
self.delay = hundreths;
self
}
pub fn disposal_method(mut self, method: DisposalMethod) -> Self {
self.disposal_method = method;
self
}
pub fn transparent_index(mut self, index: Option<u8>) -> Self {
self.transparent_index = index;
self
}
pub fn required_version(&self) -> Version {
if self.delay > 0
|| self.disposal_method != DisposalMethod::NoAction
|| self.transparent_index.is_some()
{
Version::Gif89a
} else {
Version::Gif87a
}
}
pub fn get_graphic_control(&self) -> Option<GraphicControl> {
if self.required_version() == Version::Gif89a {
if let Some(transindex) = self.transparent_index {
Some(GraphicControl::new(
self.disposal_method,
false,
true,
self.delay,
transindex,
))
} else {
Some(GraphicControl::new(
self.disposal_method,
false,
false,
self.delay,
0,
))
}
} else {
None
}
}
pub fn indicies(mut self, indicies: Vec<u8>) -> Self {
self.indicies = indicies;
self
}
pub fn build(self) -> Result<IndexedImage, EncodingError> {
let expected_len = self.width as usize * self.height as usize;
if self.indicies.len() != expected_len {
return Err(EncodingError::IndicieSizeMismatch {
expected: expected_len,
got: self.indicies.len(),
});
}
let mut imgdesc = ImageDescriptor {
left: self.left_offset,
top: self.top_offset,
width: self.width,
height: self.height,
packed: 0, // Set later
};
if let Some(lct) = &self.color_table {
imgdesc.set_color_table_present(true);
imgdesc.set_color_table_size(lct.packed_len());
}
Ok(IndexedImage {
image_descriptor: imgdesc,
local_color_table: self.color_table,
indicies: self.indicies,
})
}
}
|
