dtourolle
6f33517b35
The merge weighted every overlap pixel by its distance from each frame's edge, a 200 px linear cross-fade. Anything the frames disagreed on — parallax in the near foreground, grass in the wind, a walker — came out twice at half strength: a soft double edge at 1:1. dr_pano::seam picks, per output texel at proxy resolution, which frame a pixel comes from. Where a new frame overlaps the composite the cost is the gain-corrected difference plus local detail plus nearness to either frame's edge, taken as the worst over a small window, and the cut is a dynamic-programming path across the overlap. merge.wgsl weights each frame by its tent-filtered share of that map, a 64 px blend that follows the seam, with the edge feather kept as the fallback. The page's preview uses the same map, and examples/merge.rs takes --feather-only for comparison.
660 lines
25 KiB
Rust
660 lines
25 KiB
Rust
//! TRACES: FR-MRG-10 | FR-MRG-11
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//! The merge: source frames warped into an output surface, chunk by chunk.
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//!
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//! The per-pixel half of a panorama (FR-MRG-10), on the GPU: the warp of a
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//! source tile into an output chunk, the weighted accumulation across
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//! frames, and the resolve to sixteen-bit samples. The geometry it is
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//! given — rotations, focal length, projection — is `dr-pano`'s, solved on
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//! proxies before any full-resolution pixel exists (panorama.md §5), and
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//! that is what makes this simple: every output pixel's source coordinates
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//! are a closed-form function, so a chunk can be produced from the source
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//! tiles that project into it and nothing else.
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//!
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//! # The loop
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//!
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//! ```text
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//! for each band of rows of the output:
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//! for each chunk across the band:
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//! zero the accumulator
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//! for each frame whose footprint meets the chunk:
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//! the source rectangle the chunk needs, from the geometry
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//! render it camera-linear through the pipeline (the tile)
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//! warp the tile into the chunk, accumulate ← GPU
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//! resolve the chunk to u16 ← GPU
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//! copy it into the band
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//! hand the band to the writer (one DNG strip)
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//! ```
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//!
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//! No stage holds the composite (FR-MRG-11): the working set is one
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//! chunk's accumulator, one tile, one band of u16 rows. The frame textures
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//! are the caller's to provide and cache — `source` is asked for frame `k`
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//! as it is needed, and a caller short of memory may demosaic on demand.
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//!
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//! # The blend
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//!
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//! With a seam map (`dr_pano::seam`), a frame's weight at a pixel is its
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//! share of the map about that pixel — whole on its own side of a seam,
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//! nothing on the other, and a ramp across a window `seam_blend` pixels
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//! wide that follows the seam. Without one, or where the map has nothing
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//! to say, the weight is the distance to the frame's edge over `feather`,
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//! which hides exposure steps and does not hide parallax: the average draws
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//! anything the frames disagree on twice.
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//!
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//! # What is not here yet
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//!
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//! A Laplacian pyramid, which would let the seam's blend be narrow for
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//! detail and wide for exposure at once. Gain is a scalar per frame the
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//! caller supplies.
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use std::sync::Arc;
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use dr_pano::bundle::Cameras;
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use dr_pano::projection::{Bounds, Projection};
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use dr_pano::seam::SeamMap;
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use wgpu::util::DeviceExt;
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use crate::readback::await_mapping;
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use crate::{AdjustPass, DemosaicedImage, GpuContext, GpuError};
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/// One frame's part in the merge.
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pub struct MergeFrame {
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/// The frame's edit, for its lens corrections — the only part of an
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/// edit the camera-space tap uses (FR-MRG-2).
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pub graph: Arc<dr_pipeline::EditGraph>,
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/// Multiplies the frame's samples, to bring its exposure to the
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/// reference frame's. 1.0 for no correction.
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pub gain: f32,
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}
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/// The output the merge produces.
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#[derive(Debug, Clone, PartialEq)]
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pub struct MergeOutput {
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pub projection: Projection,
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/// The projection's scale in output pixels: the cylinder's radius, the
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/// plane's distance. The source focal length at full resolution gives
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/// output pixels the size of source pixels at the centre.
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pub scale: f64,
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/// The rectangle of the projection to produce, centred coordinates.
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pub bounds: Bounds,
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/// Pixels over which a frame's weight ramps up from its edge.
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pub feather: f32,
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/// Which frame each part of the output is taken from, laid out at the
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/// proxies' scale; `None` for the feathered average everywhere.
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pub seams: Option<Arc<SeamMap>>,
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/// The width, in output pixels, of the blend across a seam.
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pub seam_blend: f32,
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/// Chunk size: the unit of GPU work and of memory.
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pub chunk: (u32, u32),
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/// Multiplies a normalised sample (1.0 = white) to the sensor's scale.
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pub sample_scale: f32,
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/// The white balance the composite will be developed with — the
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/// inverse of its `AsShotNeutral` — so that a blown sample can be
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/// written as the camera value that balance calls grey.
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pub balance: [f32; 3],
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}
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impl MergeOutput {
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pub fn width(&self) -> u32 {
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self.bounds.width().ceil().max(1.0) as u32
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}
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pub fn height(&self) -> u32 {
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self.bounds.height().ceil().max(1.0) as u32
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}
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}
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/// A band of finished rows: `rows × width × 3` RGB `u16`, plus a coverage
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/// mask (`true` where any frame reached the pixel).
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pub struct Band<'a> {
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pub first_row: u32,
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pub rows: u32,
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pub rgb: &'a [u16],
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pub covered: &'a [bool],
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}
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#[repr(C)]
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#[derive(Clone, Copy, bytemuck::Pod, bytemuck::Zeroable)]
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struct WarpParams {
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chunk_origin: [f32; 2],
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chunk_size: [u32; 2],
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projection: u32,
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proj_scale: f32,
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focal: f32,
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gain: f32,
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r0: [f32; 4],
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r1: [f32; 4],
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r2: [f32; 4],
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frame_size: [f32; 2],
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tile_origin: [f32; 2],
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tile_size: [u32; 2],
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feather: f32,
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clip_onset: f32,
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balance: [f32; 4],
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seam_origin: [f32; 2],
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seam_size: [u32; 2],
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seam_px: f32,
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seam_radius: f32,
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frame_index: u32,
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seam_on: u32,
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}
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#[repr(C)]
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#[derive(Clone, Copy, bytemuck::Pod, bytemuck::Zeroable)]
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struct ResolveParams {
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chunk_size: [u32; 2],
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scale: f32,
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_pad: f32,
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}
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/// The two pipelines and the chunk buffers.
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pub struct MergePass {
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ctx: GpuContext,
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warp: wgpu::ComputePipeline,
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warp_layout: wgpu::BindGroupLayout,
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resolve: wgpu::ComputePipeline,
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resolve_layout: wgpu::BindGroupLayout,
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/// Accumulator and packed output for the current chunk size.
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buffers: Option<(wgpu::Buffer, wgpu::Buffer, wgpu::Buffer, (u32, u32))>,
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}
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impl MergePass {
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pub fn new(ctx: &GpuContext) -> Result<Self, GpuError> {
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let module = ctx
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.device
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.create_shader_module(wgpu::ShaderModuleDescriptor {
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label: Some("merge"),
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source: wgpu::ShaderSource::Wgsl(include_str!("shaders/merge.wgsl").into()),
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});
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let uniform = |binding| wgpu::BindGroupLayoutEntry {
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binding,
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visibility: wgpu::ShaderStages::COMPUTE,
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ty: wgpu::BindingType::Buffer {
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ty: wgpu::BufferBindingType::Uniform,
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has_dynamic_offset: false,
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min_binding_size: None,
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},
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count: None,
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};
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let storage = |binding, read_only| wgpu::BindGroupLayoutEntry {
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binding,
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visibility: wgpu::ShaderStages::COMPUTE,
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ty: wgpu::BindingType::Buffer {
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ty: wgpu::BufferBindingType::Storage { read_only },
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has_dynamic_offset: false,
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min_binding_size: None,
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},
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count: None,
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};
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let warp_layout = ctx
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.device
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.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
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label: Some("merge-warp-bgl"),
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entries: &[
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uniform(0),
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wgpu::BindGroupLayoutEntry {
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binding: 1,
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visibility: wgpu::ShaderStages::COMPUTE,
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ty: wgpu::BindingType::Texture {
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// Unfilterable: rgba32float, loaded by hand.
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sample_type: wgpu::TextureSampleType::Float { filterable: false },
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view_dimension: wgpu::TextureViewDimension::D2,
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multisampled: false,
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},
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count: None,
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},
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storage(2, false),
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wgpu::BindGroupLayoutEntry {
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binding: 3,
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visibility: wgpu::ShaderStages::COMPUTE,
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ty: wgpu::BindingType::Texture {
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sample_type: wgpu::TextureSampleType::Uint,
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view_dimension: wgpu::TextureViewDimension::D2,
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multisampled: false,
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},
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count: None,
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},
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],
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});
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let resolve_layout =
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ctx.device
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.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
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label: Some("merge-resolve-bgl"),
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entries: &[uniform(0), storage(1, true), storage(2, false)],
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});
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let pipeline = |name: &str, layout: &wgpu::BindGroupLayout| {
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let pl = ctx
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.device
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.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
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label: Some(name),
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bind_group_layouts: &[Some(layout)],
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immediate_size: 0,
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});
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ctx.device
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.create_compute_pipeline(&wgpu::ComputePipelineDescriptor {
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label: Some(name),
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layout: Some(&pl),
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module: &module,
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entry_point: Some(name),
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compilation_options: Default::default(),
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cache: None,
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})
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};
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Ok(MergePass {
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ctx: ctx.clone(),
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warp: pipeline("warp", &warp_layout),
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warp_layout,
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resolve: pipeline("resolve", &resolve_layout),
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resolve_layout,
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buffers: None,
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})
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}
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/// Allocate the chunk buffers for this size if the last ones differ.
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fn ensure_buffers(&mut self, chunk: (u32, u32)) {
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if self.buffers.as_ref().is_none_or(|b| b.3 != chunk) {
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let n = u64::from(chunk.0) * u64::from(chunk.1);
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let acc = self.ctx.device.create_buffer(&wgpu::BufferDescriptor {
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label: Some("merge-acc"),
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size: n * 16,
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usage: wgpu::BufferUsages::STORAGE | wgpu::BufferUsages::COPY_DST,
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mapped_at_creation: false,
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});
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let out = self.ctx.device.create_buffer(&wgpu::BufferDescriptor {
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label: Some("merge-out"),
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size: n * 8,
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usage: wgpu::BufferUsages::STORAGE | wgpu::BufferUsages::COPY_SRC,
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mapped_at_creation: false,
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});
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let read = self.ctx.device.create_buffer(&wgpu::BufferDescriptor {
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label: Some("merge-read"),
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size: n * 8,
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usage: wgpu::BufferUsages::COPY_DST | wgpu::BufferUsages::MAP_READ,
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mapped_at_creation: false,
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});
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self.buffers = Some((acc, out, read, chunk));
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}
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}
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fn chunk_buffers(&self) -> (&wgpu::Buffer, &wgpu::Buffer, &wgpu::Buffer) {
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let b = self.buffers.as_ref().expect("ensured by the caller");
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(&b.0, &b.1, &b.2)
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}
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/// Produce the whole output, band by band, handing each finished band
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/// to `sink`.
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///
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/// `cameras` are in **full-resolution source pixels** (`frame_size`),
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/// with frame `k` corresponding to `frames[k]` and `source(k)`. `source`
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/// supplies the demosaiced frame on demand and may cache as it sees fit.
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#[allow(clippy::too_many_arguments)]
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pub fn merge<S, F>(
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&mut self,
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adjust: &mut AdjustPass,
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frames: &[MergeFrame],
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cameras: &Cameras,
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frame_size: (u32, u32),
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output: &MergeOutput,
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mut source: S,
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mut sink: F,
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mut cancelled: impl FnMut() -> bool,
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) -> Result<(), GpuError>
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where
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S: FnMut(usize) -> Result<Arc<DemosaicedImage>, GpuError>,
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F: FnMut(Band<'_>) -> Result<(), GpuError>,
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{
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let (out_w, out_h) = (output.width(), output.height());
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let (cw, ch) = (output.chunk.0.max(8), output.chunk.1.max(8));
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let (fw, fh) = (frame_size.0 as f64, frame_size.1 as f64);
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let mut band_rgb = vec![0u16; (out_w * ch * 3) as usize];
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let mut band_cov = vec![false; (out_w * ch) as usize];
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let mut chunk_px: Vec<u32> = Vec::new();
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// The seam map, once for the whole output, and where it sits in
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// this output's coordinates. A one-texel stand-in when there is
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// none, because the binding is not optional.
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let (seam_tex, seam_origin, seam_px, seam_radius, seam_size) = match &output.seams {
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Some(m) => {
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let ((ou, ov), px) = m.at_scale(output.scale);
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let radius = m.blend_radius(output.scale, f64::from(output.seam_blend));
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(
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self.label_texture(m.width as u32, m.height as u32, &m.labels),
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[ou as f32, ov as f32],
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px as f32,
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radius as f32,
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[m.width as u32, m.height as u32],
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)
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}
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None => (
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self.label_texture(1, 1, &[dr_pano::seam::NONE]),
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[0.0; 2],
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1.0,
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1.0,
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[1, 1],
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),
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};
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let seam_view = seam_tex.create_view(&Default::default());
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let seam_on = u32::from(output.seams.is_some());
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let mut y = 0u32;
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while y < out_h {
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let rows = ch.min(out_h - y);
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band_rgb.iter_mut().for_each(|v| *v = 0);
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band_cov.iter_mut().for_each(|v| *v = false);
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let mut x = 0u32;
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while x < out_w {
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if cancelled() {
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return Err(GpuError::Readback("merge cancelled".into()));
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}
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let cols = cw.min(out_w - x);
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let origin = (
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output.bounds.min_u + f64::from(x),
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output.bounds.min_v + f64::from(y),
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);
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self.zero_accumulator((cols, rows));
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for (k, frame) in frames.iter().enumerate() {
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let Some(rect) = source_rect(
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output.projection,
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output.scale,
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cameras,
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k,
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origin,
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(cols, rows),
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(fw, fh),
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) else {
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continue;
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};
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let image = source(k)?;
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// The tile: that rectangle of the frame, camera-linear,
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// at 1:1.
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let view = dr_pipeline::CropRect {
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x: (rect.0 as f32) / fw as f32,
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y: (rect.1 as f32) / fh as f32,
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width: (rect.2 as f32) / fw as f32,
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height: (rect.3 as f32) / fh as f32,
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};
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let shader = frame.graph.compose_camera_linear(view);
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let tile = adjust.render_camera_linear(&image, &shader, rect.2, rect.3)?;
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let r = cameras.rotations[k].transpose();
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let params = WarpParams {
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chunk_origin: [origin.0 as f32, origin.1 as f32],
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chunk_size: [cols, rows],
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projection: match output.projection {
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Projection::Perspective => 0,
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Projection::Cylindrical => 1,
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Projection::Spherical => 2,
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},
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proj_scale: output.scale as f32,
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focal: cameras.focal as f32,
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gain: frame.gain,
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r0: [r.0[0][0] as f32, r.0[0][1] as f32, r.0[0][2] as f32, 0.0],
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r1: [r.0[1][0] as f32, r.0[1][1] as f32, r.0[1][2] as f32, 0.0],
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r2: [r.0[2][0] as f32, r.0[2][1] as f32, r.0[2][2] as f32, 0.0],
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frame_size: [fw as f32, fh as f32],
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tile_origin: [rect.0 as f32, rect.1 as f32],
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tile_size: [rect.2, rect.3],
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feather: output.feather,
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clip_onset: dr_pipeline::CLIP_ONSET,
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balance: [
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output.balance[0].max(1e-3),
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output.balance[1].max(1e-3),
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output.balance[2].max(1e-3),
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0.0,
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],
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seam_origin,
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seam_size,
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seam_px,
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seam_radius,
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frame_index: k as u32,
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seam_on,
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};
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self.accumulate(¶ms, tile, &seam_view);
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}
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self.resolve_chunk((cols, rows), output.sample_scale, &mut chunk_px)?;
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// Into the band.
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for row in 0..rows as usize {
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for col in 0..cols as usize {
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let px = chunk_px[(row * cols as usize + col) * 2..][..2].to_vec();
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let i = row * out_w as usize + (x as usize + col);
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band_rgb[i * 3] = (px[0] & 0xFFFF) as u16;
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band_rgb[i * 3 + 1] = (px[0] >> 16) as u16;
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band_rgb[i * 3 + 2] = (px[1] & 0xFFFF) as u16;
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band_cov[i] = (px[1] >> 16) != 0;
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}
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}
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x += cols;
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}
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sink(Band {
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first_row: y,
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rows,
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rgb: &band_rgb[..(out_w * rows * 3) as usize],
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covered: &band_cov[..(out_w * rows) as usize],
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})?;
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y += rows;
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}
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Ok(())
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}
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fn zero_accumulator(&mut self, chunk: (u32, u32)) {
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self.ensure_buffers(chunk);
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let (acc, _, _) = self.chunk_buffers();
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let n = u64::from(chunk.0) * u64::from(chunk.1) * 16;
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let mut enc = self.ctx.device.create_command_encoder(&Default::default());
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enc.clear_buffer(acc, 0, Some(n));
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self.ctx.queue.submit(Some(enc.finish()));
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}
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/// The seam map's labels as an `r8uint` texture.
|
||
fn label_texture(&self, width: u32, height: u32, labels: &[u8]) -> wgpu::Texture {
|
||
let size = wgpu::Extent3d {
|
||
width,
|
||
height,
|
||
depth_or_array_layers: 1,
|
||
};
|
||
let tex = self.ctx.device.create_texture(&wgpu::TextureDescriptor {
|
||
label: Some("merge-seams"),
|
||
size,
|
||
mip_level_count: 1,
|
||
sample_count: 1,
|
||
dimension: wgpu::TextureDimension::D2,
|
||
format: wgpu::TextureFormat::R8Uint,
|
||
usage: wgpu::TextureUsages::TEXTURE_BINDING | wgpu::TextureUsages::COPY_DST,
|
||
view_formats: &[],
|
||
});
|
||
self.ctx.queue.write_texture(
|
||
wgpu::TexelCopyTextureInfo {
|
||
texture: &tex,
|
||
mip_level: 0,
|
||
origin: wgpu::Origin3d::ZERO,
|
||
aspect: wgpu::TextureAspect::All,
|
||
},
|
||
labels,
|
||
wgpu::TexelCopyBufferLayout {
|
||
offset: 0,
|
||
bytes_per_row: Some(width),
|
||
rows_per_image: Some(height),
|
||
},
|
||
size,
|
||
);
|
||
tex
|
||
}
|
||
|
||
fn accumulate(&mut self, params: &WarpParams, tile: &wgpu::Texture, seams: &wgpu::TextureView) {
|
||
let chunk = (params.chunk_size[0], params.chunk_size[1]);
|
||
let uniforms = self
|
||
.ctx
|
||
.device
|
||
.create_buffer_init(&wgpu::util::BufferInitDescriptor {
|
||
label: Some("merge-warp-params"),
|
||
contents: bytemuck::bytes_of(params),
|
||
usage: wgpu::BufferUsages::UNIFORM,
|
||
});
|
||
let view = tile.create_view(&Default::default());
|
||
self.ensure_buffers(chunk);
|
||
let (acc, _, _) = self.chunk_buffers();
|
||
let bind = self
|
||
.ctx
|
||
.device
|
||
.create_bind_group(&wgpu::BindGroupDescriptor {
|
||
label: Some("merge-warp-bg"),
|
||
layout: &self.warp_layout,
|
||
entries: &[
|
||
wgpu::BindGroupEntry {
|
||
binding: 0,
|
||
resource: uniforms.as_entire_binding(),
|
||
},
|
||
wgpu::BindGroupEntry {
|
||
binding: 1,
|
||
resource: wgpu::BindingResource::TextureView(&view),
|
||
},
|
||
wgpu::BindGroupEntry {
|
||
binding: 2,
|
||
resource: acc.as_entire_binding(),
|
||
},
|
||
wgpu::BindGroupEntry {
|
||
binding: 3,
|
||
resource: wgpu::BindingResource::TextureView(seams),
|
||
},
|
||
],
|
||
});
|
||
let mut enc = self.ctx.device.create_command_encoder(&Default::default());
|
||
{
|
||
let mut pass = enc.begin_compute_pass(&Default::default());
|
||
pass.set_pipeline(&self.warp);
|
||
pass.set_bind_group(0, &bind, &[]);
|
||
pass.dispatch_workgroups(chunk.0.div_ceil(8), chunk.1.div_ceil(8), 1);
|
||
}
|
||
self.ctx.queue.submit(Some(enc.finish()));
|
||
}
|
||
|
||
fn resolve_chunk(
|
||
&mut self,
|
||
chunk: (u32, u32),
|
||
scale: f32,
|
||
out: &mut Vec<u32>,
|
||
) -> Result<(), GpuError> {
|
||
let params = ResolveParams {
|
||
chunk_size: [chunk.0, chunk.1],
|
||
scale,
|
||
_pad: 0.0,
|
||
};
|
||
let uniforms = self
|
||
.ctx
|
||
.device
|
||
.create_buffer_init(&wgpu::util::BufferInitDescriptor {
|
||
label: Some("merge-resolve-params"),
|
||
contents: bytemuck::bytes_of(¶ms),
|
||
usage: wgpu::BufferUsages::UNIFORM,
|
||
});
|
||
let n = u64::from(chunk.0) * u64::from(chunk.1);
|
||
self.ensure_buffers(chunk);
|
||
let (acc, packed, read) = self.chunk_buffers();
|
||
let bind = self
|
||
.ctx
|
||
.device
|
||
.create_bind_group(&wgpu::BindGroupDescriptor {
|
||
label: Some("merge-resolve-bg"),
|
||
layout: &self.resolve_layout,
|
||
entries: &[
|
||
wgpu::BindGroupEntry {
|
||
binding: 0,
|
||
resource: uniforms.as_entire_binding(),
|
||
},
|
||
wgpu::BindGroupEntry {
|
||
binding: 1,
|
||
resource: acc.as_entire_binding(),
|
||
},
|
||
wgpu::BindGroupEntry {
|
||
binding: 2,
|
||
resource: packed.as_entire_binding(),
|
||
},
|
||
],
|
||
});
|
||
let mut enc = self.ctx.device.create_command_encoder(&Default::default());
|
||
{
|
||
let mut pass = enc.begin_compute_pass(&Default::default());
|
||
pass.set_pipeline(&self.resolve);
|
||
pass.set_bind_group(0, &bind, &[]);
|
||
pass.dispatch_workgroups(chunk.0.div_ceil(8), chunk.1.div_ceil(8), 1);
|
||
}
|
||
enc.copy_buffer_to_buffer(packed, 0, read, 0, n * 8);
|
||
self.ctx.queue.submit(Some(enc.finish()));
|
||
|
||
let slice = read.slice(..n * 8);
|
||
let (tx, rx) = std::sync::mpsc::channel();
|
||
slice.map_async(wgpu::MapMode::Read, move |r| {
|
||
let _ = tx.send(r);
|
||
});
|
||
await_mapping(&self.ctx, &rx)?;
|
||
{
|
||
let data = slice.get_mapped_range();
|
||
out.clear();
|
||
out.extend_from_slice(bytemuck::cast_slice::<u8, u32>(&data));
|
||
}
|
||
read.unmap();
|
||
Ok(())
|
||
}
|
||
}
|
||
|
||
/// The rectangle of frame `k` (x, y, w, h in source pixels) a chunk reads,
|
||
/// or `None` if the chunk sees nothing of the frame.
|
||
///
|
||
/// Walks the chunk's border, projects each point into the frame, and takes
|
||
/// the bounding box with a two-pixel margin for the bilinear fetch. The
|
||
/// border rather than the corners because under a cylinder or sphere the
|
||
/// extreme of a footprint is not at a corner.
|
||
fn source_rect(
|
||
projection: Projection,
|
||
scale: f64,
|
||
cameras: &Cameras,
|
||
k: usize,
|
||
origin: (f64, f64),
|
||
size: (u32, u32),
|
||
frame: (f64, f64),
|
||
) -> Option<(u32, u32, u32, u32)> {
|
||
let (w, h) = (f64::from(size.0), f64::from(size.1));
|
||
let steps = 16;
|
||
let mut min = (f64::MAX, f64::MAX);
|
||
let mut max = (f64::MIN, f64::MIN);
|
||
let mut any = false;
|
||
let mut visit = |u: f64, v: f64| {
|
||
let d = projection.to_direction(scale, u, v);
|
||
if let Some((x, y)) = cameras.project(k, d) {
|
||
let (x, y) = (x + frame.0 / 2.0, y + frame.1 / 2.0);
|
||
min = (min.0.min(x), min.1.min(y));
|
||
max = (max.0.max(x), max.1.max(y));
|
||
any = true;
|
||
}
|
||
};
|
||
for s in 0..=steps {
|
||
let t = f64::from(s) / f64::from(steps);
|
||
visit(origin.0 + w * t, origin.1);
|
||
visit(origin.0 + w * t, origin.1 + h);
|
||
visit(origin.0, origin.1 + h * t);
|
||
visit(origin.0 + w, origin.1 + h * t);
|
||
}
|
||
// The interior too, coarsely: a chunk can contain a frame entirely.
|
||
for i in 1..4 {
|
||
for j in 1..4 {
|
||
visit(
|
||
origin.0 + w * f64::from(i) / 4.0,
|
||
origin.1 + h * f64::from(j) / 4.0,
|
||
);
|
||
}
|
||
}
|
||
if !any {
|
||
return None;
|
||
}
|
||
let x0 = (min.0.floor() - 2.0).max(0.0);
|
||
let y0 = (min.1.floor() - 2.0).max(0.0);
|
||
let x1 = (max.0.ceil() + 2.0).min(frame.0);
|
||
let y1 = (max.1.ceil() + 2.0).min(frame.1);
|
||
if x1 <= x0 || y1 <= y0 {
|
||
return None;
|
||
}
|
||
Some((x0 as u32, y0 as u32, (x1 - x0) as u32, (y1 - y0) as u32))
|
||
}
|