Better choice for the pixel format

This commit is contained in:
Pierre Krieger 2015-07-25 15:57:03 +02:00
parent f6b7088011
commit 2d4c382f0b

View file

@ -68,6 +68,7 @@ pub use window::{AvailableMonitorsIter, MonitorID, get_available_monitors, get_p
pub use native_monitor::NativeMonitorId;
use std::io;
use std::cmp::Ordering;
mod api;
mod platform;
@ -426,56 +427,100 @@ impl<'a> BuilderAttribs<'a> {
fn choose_pixel_format<T, I>(&self, iter: I) -> Result<(T, PixelFormat), CreationError>
where I: IntoIterator<Item=(T, PixelFormat)>, T: Clone
{
let mut current_result = None;
let mut current_software_result = None;
// TODO: do this more properly
for (id, format) in iter {
// filtering formats that don't match the requirements
let iter = iter.into_iter().filter(|&(_, ref format)| {
if format.color_bits < self.color_bits.unwrap_or(0) {
continue;
return false;
}
if format.alpha_bits < self.alpha_bits.unwrap_or(0) {
continue;
return false;
}
if format.depth_bits < self.depth_bits.unwrap_or(0) {
continue;
return false;
}
if format.stencil_bits < self.stencil_bits.unwrap_or(0) {
continue;
return false;
}
if !format.stereoscopy && self.stereoscopy {
continue;
return false;
}
if let Some(req_ms) = self.multisampling {
match format.multisampling {
Some(val) if val >= req_ms => (),
_ => continue
_ => return false
}
} else {
if format.multisampling.is_some() {
continue;
return false;
}
}
if let Some(srgb) = self.srgb {
if srgb != format.srgb {
continue;
return false;
}
}
current_software_result = Some((id.clone(), format.clone()));
if format.hardware_accelerated {
current_result = Some((id, format));
}
}
true
});
current_result.or(current_software_result)
.ok_or(CreationError::NoAvailablePixelFormat)
// sorting so that the preferred format comes first
let mut formats = iter.collect::<Vec<_>>();
formats.sort_by(|&(_, ref left), &(_, ref right)| {
// prefer hardware-accelerated formats
if left.hardware_accelerated && !right.hardware_accelerated {
return Ordering::Less;
} else if right.hardware_accelerated && !left.hardware_accelerated {
return Ordering::Greater;
}
// prefer sRGB formats
if left.srgb && !right.srgb {
return Ordering::Less;
} else if right.srgb && !left.srgb {
return Ordering::Greater;
}
// prefer formats with the highest color+alpha bits
if left.color_bits + left.alpha_bits != right.color_bits + right.alpha_bits {
return (right.color_bits + right.alpha_bits)
.cmp(&(left.color_bits + left.alpha_bits));
}
// prefer double-buffering formats
if left.double_buffer && !right.double_buffer {
return Ordering::Less;
} else if right.double_buffer && !left.double_buffer {
return Ordering::Greater;
}
// prefer formats with the highest depth bits
if left.depth_bits != right.depth_bits {
return (right.depth_bits).cmp(&left.depth_bits);
}
// prefer formats with the highest stencil bits
if left.stencil_bits != right.stencil_bits {
return (right.stencil_bits).cmp(&left.stencil_bits);
}
// prefer formats with multisampling
if left.multisampling.is_some() && right.multisampling.is_none() {
return Ordering::Less;
} else if right.multisampling.is_some() && left.multisampling.is_none() {
return Ordering::Greater;
}
// default
return Ordering::Equal;
});
formats.into_iter().next().ok_or(CreationError::NoAvailablePixelFormat)
}
}