slint/internal/backends/linuxkms/display/swdisplay/dumbbuffer.rs
2025-07-28 10:19:28 +02:00

222 lines
8.5 KiB
Rust

// Copyright © SixtyFPS GmbH <info@slint.dev>
// SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
use std::cell::RefCell;
use std::sync::Arc;
use crate::drmoutput::DrmOutput;
use drm::control::Device;
use i_slint_core::platform::PlatformError;
pub struct DumbBufferDisplay {
drm_output: DrmOutput,
/// Currently displayed buffer
front_buffer: RefCell<DumbBuffer>,
/// Buffer next to be rendered into
back_buffer: RefCell<DumbBuffer>,
/// Buffer currently on the way to the display, to become front_buffer
in_flight_buffer: RefCell<DumbBuffer>,
}
impl DumbBufferDisplay {
pub fn new(
device_opener: &crate::DeviceOpener,
renderer_formats: &[drm::buffer::DrmFourcc],
) -> Result<Arc<dyn super::SoftwareBufferDisplay>, PlatformError> {
let drm_output = DrmOutput::new(device_opener)?;
let available_formats = drm_output.get_supported_formats()?;
let format = super::negotiate_format(renderer_formats, &available_formats)
.ok_or_else(|| PlatformError::Other(
format!("No compatible format found for DumbBuffer. Renderer supports: {:?}, FB supports: {:?}",
renderer_formats, available_formats).into()))?;
let (depth, bpp) = pixel_format_params(format)
.ok_or_else(|| format!("Cannot get depth and bpp for pixel format: {format:?}"))?;
let front_buffer: RefCell<DumbBuffer> =
DumbBuffer::allocate(&drm_output.drm_device, drm_output.size(), format, depth, bpp)
.map_err(|err| format!("Could not allocate drm dumb buffer: {err}"))?
.into();
let back_buffer = DumbBuffer::allocate(
&drm_output.drm_device,
drm_output.size(),
front_buffer.borrow().format,
front_buffer.borrow().depth,
front_buffer.borrow().bpp,
)?
.into();
let in_flight_buffer = DumbBuffer::allocate(
&drm_output.drm_device,
drm_output.size(),
front_buffer.borrow().format,
front_buffer.borrow().depth,
front_buffer.borrow().bpp,
)?
.into();
Ok(Arc::new(Self { drm_output, front_buffer, back_buffer, in_flight_buffer }))
}
}
impl super::SoftwareBufferDisplay for DumbBufferDisplay {
fn size(&self) -> (u32, u32) {
self.drm_output.size()
}
fn map_back_buffer(
&self,
callback: &mut dyn FnMut(
&'_ mut [u8],
u8,
drm::buffer::DrmFourcc,
) -> Result<(), PlatformError>,
) -> Result<(), PlatformError> {
let mut back_buffer = self.back_buffer.borrow_mut();
let age = back_buffer.age;
let format = back_buffer.format;
self.drm_output
.drm_device
.map_dumb_buffer(&mut back_buffer.buffer_handle)
.map_err(|e| PlatformError::Other(format!("Error mapping dumb buffer: {e}").into()))
.and_then(|mut buffer| callback(buffer.as_mut(), age, format))
}
fn as_presenter(self: Arc<Self>) -> Arc<dyn crate::display::Presenter> {
self
}
}
impl crate::display::Presenter for DumbBufferDisplay {
fn present(&self) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
self.drm_output.wait_for_page_flip();
self.back_buffer.swap(&self.front_buffer);
self.front_buffer.swap(&self.in_flight_buffer);
self.in_flight_buffer.borrow_mut().age = 1;
for buffer in [&self.back_buffer, &self.front_buffer] {
let mut buffer_borrow = buffer.borrow_mut();
if buffer_borrow.age != 0 {
buffer_borrow.age += 1;
}
}
// TODO: dirty framebuffer
self.drm_output.present(
self.in_flight_buffer.borrow().buffer_handle,
self.in_flight_buffer.borrow().fb_handle,
)?;
Ok(())
}
}
struct DumbBuffer {
fb_handle: drm::control::framebuffer::Handle,
buffer_handle: drm::control::dumbbuffer::DumbBuffer,
age: u8,
format: drm::buffer::DrmFourcc,
depth: u32,
bpp: u32,
}
/// Returns the pixel depth and bits-per-pixel values for a given DRM pixel format.
fn pixel_format_params(format: drm::buffer::DrmFourcc) -> Option<(u32, u32)> {
match format {
// 32-bit RGB formats
drm::buffer::DrmFourcc::Xrgb8888 => Some((24, 32)),
drm::buffer::DrmFourcc::Argb8888 => Some((32, 32)),
drm::buffer::DrmFourcc::Xbgr8888 => Some((24, 32)),
drm::buffer::DrmFourcc::Abgr8888 => Some((32, 32)),
drm::buffer::DrmFourcc::Rgbx8888 => Some((24, 32)),
drm::buffer::DrmFourcc::Rgba8888 => Some((32, 32)),
drm::buffer::DrmFourcc::Bgrx8888 => Some((24, 32)),
drm::buffer::DrmFourcc::Bgra8888 => Some((32, 32)),
// 30-bit RGB formats (10 bits per channel)
drm::buffer::DrmFourcc::Xrgb2101010 => Some((30, 32)),
drm::buffer::DrmFourcc::Argb2101010 => Some((32, 32)),
drm::buffer::DrmFourcc::Xbgr2101010 => Some((30, 32)),
drm::buffer::DrmFourcc::Abgr2101010 => Some((32, 32)),
drm::buffer::DrmFourcc::Rgbx1010102 => Some((30, 32)),
drm::buffer::DrmFourcc::Rgba1010102 => Some((32, 32)),
drm::buffer::DrmFourcc::Bgrx1010102 => Some((30, 32)),
drm::buffer::DrmFourcc::Bgra1010102 => Some((32, 32)),
// 24-bit RGB formats
drm::buffer::DrmFourcc::Rgb888 => Some((24, 24)),
drm::buffer::DrmFourcc::Bgr888 => Some((24, 24)),
// 16-bit RGB formats
drm::buffer::DrmFourcc::Rgb565 => Some((16, 16)),
drm::buffer::DrmFourcc::Bgr565 => Some((16, 16)),
drm::buffer::DrmFourcc::Xrgb1555 => Some((15, 16)),
drm::buffer::DrmFourcc::Argb1555 => Some((16, 16)),
drm::buffer::DrmFourcc::Xbgr1555 => Some((15, 16)),
drm::buffer::DrmFourcc::Abgr1555 => Some((16, 16)),
drm::buffer::DrmFourcc::Rgbx5551 => Some((15, 16)),
drm::buffer::DrmFourcc::Rgba5551 => Some((16, 16)),
drm::buffer::DrmFourcc::Bgrx5551 => Some((15, 16)),
drm::buffer::DrmFourcc::Bgra5551 => Some((16, 16)),
drm::buffer::DrmFourcc::Xrgb4444 => Some((12, 16)),
drm::buffer::DrmFourcc::Argb4444 => Some((16, 16)),
drm::buffer::DrmFourcc::Xbgr4444 => Some((12, 16)),
drm::buffer::DrmFourcc::Abgr4444 => Some((16, 16)),
drm::buffer::DrmFourcc::Rgbx4444 => Some((12, 16)),
drm::buffer::DrmFourcc::Rgba4444 => Some((16, 16)),
drm::buffer::DrmFourcc::Bgrx4444 => Some((12, 16)),
drm::buffer::DrmFourcc::Bgra4444 => Some((16, 16)),
// 8-bit indexed formats
drm::buffer::DrmFourcc::C8 => Some((8, 8)),
// YUV packed formats
drm::buffer::DrmFourcc::Yuyv => Some((16, 16)),
drm::buffer::DrmFourcc::Yvyu => Some((16, 16)),
drm::buffer::DrmFourcc::Uyvy => Some((16, 16)),
drm::buffer::DrmFourcc::Vyuy => Some((16, 16)),
// YUV planar formats
drm::buffer::DrmFourcc::Yuv420 => Some((12, 12)), // 4:2:0 = 8 + 2 + 2 = 12 bpp
drm::buffer::DrmFourcc::Yvu420 => Some((12, 12)),
drm::buffer::DrmFourcc::Yuv422 => Some((16, 16)), // 4:2:2 = 8 + 4 + 4 = 16 bpp
drm::buffer::DrmFourcc::Yvu422 => Some((16, 16)),
drm::buffer::DrmFourcc::Yuv444 => Some((24, 24)), // 4:4:4 = 8 + 8 + 8 = 24 bpp
drm::buffer::DrmFourcc::Yvu444 => Some((24, 24)),
// NV formats (semi-planar YUV)
drm::buffer::DrmFourcc::Nv12 => Some((12, 12)),
drm::buffer::DrmFourcc::Nv21 => Some((12, 12)),
drm::buffer::DrmFourcc::Nv16 => Some((16, 16)),
drm::buffer::DrmFourcc::Nv61 => Some((16, 16)),
drm::buffer::DrmFourcc::Nv24 => Some((24, 24)),
drm::buffer::DrmFourcc::Nv42 => Some((24, 24)),
_ => None,
}
}
impl DumbBuffer {
fn allocate(
device: &impl drm::control::Device,
(width, height): (u32, u32),
format: drm::buffer::DrmFourcc,
depth: u32,
bpp: u32,
) -> Result<Self, PlatformError> {
let buffer_handle =
device.create_dumb_buffer((width, height), format, bpp).map_err(|e| {
format!(
"Error creating dumb buffer ({}/{}): {} for format {format}",
width, height, e
)
})?;
let fb_handle = device.add_framebuffer(&buffer_handle, depth, bpp).map_err(|e| {
format!("Error creating framebuffer for dumb buffer for format {format}: {e}")
})?;
Ok(Self { fb_handle, buffer_handle, age: 0, format, depth, bpp })
}
}