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use core::{
convert::TryFrom,
fmt::{self, Display, Formatter},
};
use crate::{InvalidConversionError, Value};
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
#[repr(C)]
pub enum PixelFormat {
RGB = 0,
BGR = 1,
GrayScale = 2,
}
impl From<PixelFormat> for i32 {
fn from(p: PixelFormat) -> i32 { p as i32 }
}
impl From<PixelFormat> for u32 {
fn from(p: PixelFormat) -> u32 { p as u32 }
}
impl From<PixelFormat> for Value {
fn from(p: PixelFormat) -> Value { Value::Integer(p.into()) }
}
impl TryFrom<i32> for PixelFormat {
type Error = PixelFormatConversionError;
fn try_from(i: i32) -> Result<PixelFormat, Self::Error> {
match i {
0 => Ok(PixelFormat::RGB),
1 => Ok(PixelFormat::BGR),
2 => Ok(PixelFormat::GrayScale),
_ => Err(PixelFormatConversionError::InvalidConstant { value: i }),
}
}
}
impl TryFrom<Value> for PixelFormat {
type Error = PixelFormatConversionError;
fn try_from(value: Value) -> Result<PixelFormat, Self::Error> {
let integer = i32::try_from(value)?;
PixelFormat::try_from(integer)
}
}
#[derive(Debug, Copy, Clone, PartialEq)]
pub enum PixelFormatConversionError {
InvalidConstant { value: i32 },
Value(InvalidConversionError),
}
impl From<InvalidConversionError> for PixelFormatConversionError {
fn from(e: InvalidConversionError) -> Self {
PixelFormatConversionError::Value(e)
}
}
impl Display for PixelFormatConversionError {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
match self {
PixelFormatConversionError::InvalidConstant { value } => {
write!(f, "{} isn't a valid pixel format", value)
},
PixelFormatConversionError::Value(_) => {
write!(f, "Unable to convert from a Value")
},
}
}
}
#[cfg(feature = "std")]
impl std::error::Error for PixelFormatConversionError {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
match self {
PixelFormatConversionError::InvalidConstant { .. } => None,
PixelFormatConversionError::Value(e) => Some(e),
}
}
}