plane_region.rs 13.2 KB
Newer Older
Romain Vimont's avatar
Romain Vimont committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89
// Copyright (c) 2019, The rav1e contributors. All rights reserved
//
// This source code is subject to the terms of the BSD 2 Clause License and
// the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
// was not distributed with this source code in the LICENSE file, you can
// obtain it at www.aomedia.org/license/software. If the Alliance for Open
// Media Patent License 1.0 was not distributed with this source code in the
// PATENTS file, you can obtain it at www.aomedia.org/license/patent.

use crate::context::*;
use crate::plane::*;
use crate::util::*;

use std::marker::PhantomData;
use std::ops::{Index, IndexMut};
use std::slice;

/// Rectangle of a plane region, in pixels
#[derive(Debug, Clone, Copy)]
pub struct Rect {
  // coordinates relative to the plane origin (xorigin, yorigin)
  pub x: isize,
  pub y: isize,
  pub width: usize,
  pub height: usize,
}

impl Rect {
  #[inline(always)]
  pub fn decimated(&self, xdec: usize, ydec: usize) -> Self {
    Self {
      x: self.x >> xdec,
      y: self.y >> ydec,
      width: self.width >> xdec,
      height: self.height >> ydec,
    }
  }
}

/// Structure to describe a rectangle area in several ways
///
/// To retrieve a subregion from a region, we need to provide the subregion
/// bounds, relative to its parent region. The subregion must always be included
/// in its parent region.
///
/// For that purpose, we could just use a rectangle (x, y, width, height), but
/// this would be too cumbersome to use in practice. For example, we often need
/// to pass a subregion from an offset, using the same bottom-right corner as
/// its parent, or to pass a subregion expressed in block offset instead of
/// pixel offset.
///
/// Area provides a flexible way to describe a subregion.
#[derive(Debug, Clone, Copy)]
pub enum Area {
  /// A well-defined rectangle
  Rect { x: isize, y: isize, width: usize, height: usize },
  /// A rectangle starting at offset (x, y) and ending at the bottom-right
  /// corner of the parent
  StartingAt { x: isize, y: isize },
  /// A well-defined rectangle with offset expressed in blocks
  BlockRect { bo: BlockOffset, width: usize, height: usize },
  /// a rectangle starting at given block offset until the bottom-right corner
  /// of the parent
  BlockStartingAt { bo: BlockOffset },
}

impl Area {
  #[inline(always)]
  pub fn to_rect(
    &self,
    xdec: usize,
    ydec: usize,
    parent_width: usize,
    parent_height: usize,
  ) -> Rect {
    match *self {
      Area::Rect { x, y, width, height } => Rect { x, y, width, height },
      Area::StartingAt { x, y } => Rect {
        x,
        y,
        width: (parent_width as isize - x) as usize,
        height: (parent_height as isize - y) as usize,
      },
      Area::BlockRect { bo, width, height } => Rect {
        x: (bo.x >> xdec << BLOCK_TO_PLANE_SHIFT) as isize,
        y: (bo.y >> ydec << BLOCK_TO_PLANE_SHIFT) as isize,
        width,
        height,
      },
90 91 92 93 94 95 96 97 98 99
      Area::BlockStartingAt { bo } => {
        let x = (bo.x >> xdec << BLOCK_TO_PLANE_SHIFT) as isize;
        let y = (bo.y >> ydec << BLOCK_TO_PLANE_SHIFT) as isize;
        Rect {
          x,
          y,
          width: (parent_width as isize - x) as usize,
          height: (parent_height as isize - y) as usize,
        }
      },
Romain Vimont's avatar
Romain Vimont committed
100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224
    }
  }
}

/// Bounded region of a plane
///
/// This allows to give access to a rectangular area of a plane without
/// giving access to the whole plane.
#[derive(Debug)]
pub struct PlaneRegion<'a, T: Pixel> {
  data: *const T, // points to (plane_cfg.x, plane_cfg.y)
  pub plane_cfg: &'a PlaneConfig,
  // private to guarantee borrowing rules
  rect: Rect,
  phantom: PhantomData<&'a T>,
}

/// Mutable bounded region of a plane
///
/// This allows to give mutable access to a rectangular area of the plane
/// without giving access to the whole plane.
#[derive(Debug)]
pub struct PlaneRegionMut<'a, T: Pixel> {
  data: *mut T, // points to (plane_cfg.x, plane_cfg.y)
  pub plane_cfg: &'a PlaneConfig,
  rect: Rect,
  phantom: PhantomData<&'a mut T>,
}

// common impl for PlaneRegion and PlaneRegionMut
macro_rules! plane_region_common {
  // $name: PlaneRegion or PlaneRegionMut
  // $as_ptr: as_ptr or as_mut_ptr
  // $opt_mut: nothing or mut
  ($name:ident, $as_ptr:ident $(,$opt_mut:tt)?) => {
    impl<'a, T: Pixel> $name<'a, T> {

      #[inline(always)]
      pub fn new(plane: &'a $($opt_mut)? Plane<T>, rect: Rect) -> Self {
        assert!(rect.x >= -(plane.cfg.xorigin as isize));
        assert!(rect.y >= -(plane.cfg.yorigin as isize));
        assert!(plane.cfg.xorigin as isize + rect.x + rect.width as isize <= plane.cfg.stride as isize);
        assert!(plane.cfg.yorigin as isize + rect.y + rect.height as isize <= plane.cfg.alloc_height as isize);
        let origin = (plane.cfg.yorigin as isize + rect.y) * plane.cfg.stride as isize
                    + plane.cfg.xorigin as isize + rect.x;
        Self {
          data: unsafe { plane.data.$as_ptr().offset(origin) },
          plane_cfg: &plane.cfg,
          rect,
          phantom: PhantomData,
        }
      }

      #[inline(always)]
      pub fn data_ptr(&self) -> *const T {
        self.data
      }

      #[inline(always)]
      pub fn rect(&self) -> &Rect {
        &self.rect
      }

      #[inline(always)]
      pub fn rows_iter(&self) -> RowsIter<'_, T> {
        RowsIter {
          data: self.data,
          stride: self.plane_cfg.stride,
          width: self.rect.width,
          remaining: self.rect.height,
          phantom: PhantomData,
        }
      }

      /// Return a view to a subregion of the plane
      ///
      /// The subregion must be included in (i.e. must not exceed) this region.
      ///
      /// It is described by an `Area`, relative to this region.
      ///
      /// # Example
      ///
      /// ```
      /// # use rav1e::tiling::*;
      /// # fn f(region: &PlaneRegion<'_, u16>) {
      /// // a subregion from (10, 8) to the end of the region
      /// let subregion = region.subregion(Area::StartingAt { x: 10, y: 8 });
      /// # }
      /// ```
      ///
      /// ```
      /// # use rav1e::context::*;
      /// # use rav1e::tiling::*;
      /// # fn f(region: &PlaneRegion<'_, u16>) {
      /// // a subregion from the top-left of block (2, 3) having size (64, 64)
      /// let bo = BlockOffset { x: 2, y: 3 };
      /// let subregion = region.subregion(Area::BlockRect { bo, width: 64, height: 64 });
      /// # }
      /// ```
      #[inline(always)]
      pub fn subregion(&self, area: Area) -> PlaneRegion<'_, T> {
        let rect = area.to_rect(
          self.plane_cfg.xdec,
          self.plane_cfg.ydec,
          self.rect.width,
          self.rect.height,
        );
        assert!(rect.x >= 0 && rect.x as usize <= self.rect.width);
        assert!(rect.y >= 0 && rect.y as usize <= self.rect.height);
        let data = unsafe {
          self.data.add(rect.y as usize * self.plane_cfg.stride + rect.x as usize)
        };
        let absolute_rect = Rect {
          x: self.rect.x + rect.x,
          y: self.rect.y + rect.y,
          width: rect.width,
          height: rect.height,
        };
        PlaneRegion {
          data,
          plane_cfg: &self.plane_cfg,
          rect: absolute_rect,
          phantom: PhantomData,
        }
      }
225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267

      #[inline(always)]
      pub fn to_frame_plane_offset(&self, tile_po: PlaneOffset) -> PlaneOffset {
        PlaneOffset {
          x: self.rect.x + tile_po.x,
          y: self.rect.y + tile_po.y,
        }
      }

      #[inline(always)]
      pub fn to_frame_block_offset(&self, tile_bo: BlockOffset) -> BlockOffset {
        debug_assert!(self.rect.x >= 0);
        debug_assert!(self.rect.y >= 0);
        let PlaneConfig { xdec, ydec, .. } = self.plane_cfg;
        debug_assert!(self.rect.x as usize % (MI_SIZE >> xdec) == 0);
        debug_assert!(self.rect.y as usize % (MI_SIZE >> ydec) == 0);
        let bx = self.rect.x as usize >> MI_SIZE_LOG2 - xdec;
        let by = self.rect.y as usize >> MI_SIZE_LOG2 - ydec;
        BlockOffset {
          x: bx + tile_bo.x,
          y: by + tile_bo.y,
        }
      }

      #[inline(always)]
      pub fn to_frame_super_block_offset(
        &self,
        tile_sbo: SuperBlockOffset,
        sb_size_log2: usize
      ) -> SuperBlockOffset {
        debug_assert!(sb_size_log2 == 6 || sb_size_log2 == 7);
        debug_assert!(self.rect.x >= 0);
        debug_assert!(self.rect.y >= 0);
        let PlaneConfig { xdec, ydec, .. } = self.plane_cfg;
        debug_assert!(self.rect.x as usize % (1 << sb_size_log2 - xdec) == 0);
        debug_assert!(self.rect.y as usize % (1 << sb_size_log2 - ydec) == 0);
        let sbx = self.rect.x as usize >> sb_size_log2 - xdec;
        let sby = self.rect.y as usize >> sb_size_log2 - ydec;
        SuperBlockOffset {
          x: sbx + tile_sbo.x,
          y: sby + tile_sbo.y,
        }
      }
Romain Vimont's avatar
Romain Vimont committed
268 269 270 271 272
    }

    unsafe impl<T: Pixel> Send for $name<'_, T> {}
    unsafe impl<T: Pixel> Sync for $name<'_, T> {}

273
    impl<T: Pixel> Index<usize> for $name<'_, T> {
Romain Vimont's avatar
Romain Vimont committed
274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370
      type Output = [T];

      #[inline(always)]
      fn index(&self, index: usize) -> &Self::Output {
        assert!(index < self.rect.height);
        unsafe {
          let ptr = self.data.add(index * self.plane_cfg.stride);
          slice::from_raw_parts(ptr, self.rect.width)
        }
      }
    }
  }
}

plane_region_common!(PlaneRegion, as_ptr);
plane_region_common!(PlaneRegionMut, as_mut_ptr, mut);

impl<'a, T: Pixel> PlaneRegionMut<'a, T> {
  #[inline(always)]
  pub fn data_ptr_mut(&mut self) -> *mut T {
    self.data
  }

  #[inline(always)]
  pub fn rows_iter_mut(&mut self) -> RowsIterMut<'_, T> {
    RowsIterMut {
      data: self.data,
      stride: self.plane_cfg.stride,
      width: self.rect.width,
      remaining: self.rect.height,
      phantom: PhantomData,
    }
  }

  /// Return a mutable view to a subregion of the plane
  ///
  /// The subregion must be included in (i.e. must not exceed) this region.
  ///
  /// It is described by an `Area`, relative to this region.
  ///
  /// # Example
  ///
  /// ```
  /// # use rav1e::tiling::*;
  /// # fn f(region: &mut PlaneRegionMut<'_, u16>) {
  /// // a mutable subregion from (10, 8) having size (32, 32)
  /// let subregion = region.subregion_mut(Area::Rect { x: 10, y: 8, width: 32, height: 32 });
  /// # }
  /// ```
  ///
  /// ```
  /// # use rav1e::context::*;
  /// # use rav1e::tiling::*;
  /// # fn f(region: &mut PlaneRegionMut<'_, u16>) {
  /// // a mutable subregion from the top-left of block (2, 3) to the end of the region
  /// let bo = BlockOffset { x: 2, y: 3 };
  /// let subregion = region.subregion_mut(Area::BlockStartingAt { bo });
  /// # }
  /// ```
  #[inline(always)]
  pub fn subregion_mut(&mut self, area: Area) -> PlaneRegionMut<'_, T> {
    let rect = area.to_rect(
      self.plane_cfg.xdec,
      self.plane_cfg.ydec,
      self.rect.width,
      self.rect.height,
    );
    assert!(rect.x >= 0 && rect.x as usize <= self.rect.width);
    assert!(rect.y >= 0 && rect.y as usize <= self.rect.height);
    let data = unsafe {
      self.data.add(rect.y as usize * self.plane_cfg.stride + rect.x as usize)
    };
    let absolute_rect = Rect {
      x: self.rect.x + rect.x,
      y: self.rect.y + rect.y,
      width: rect.width,
      height: rect.height,
    };
    PlaneRegionMut {
      data,
      plane_cfg: &self.plane_cfg,
      rect: absolute_rect,
      phantom: PhantomData,
    }
  }

  #[inline(always)]
  pub fn as_const(&self) -> PlaneRegion<'_, T> {
    PlaneRegion {
      data: self.data,
      plane_cfg: self.plane_cfg,
      rect: self.rect,
      phantom: PhantomData,
    }
  }
}

371
impl<T: Pixel> IndexMut<usize> for PlaneRegionMut<'_, T> {
Romain Vimont's avatar
Romain Vimont committed
372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447
  #[inline(always)]
  fn index_mut(&mut self, index: usize) -> &mut Self::Output {
    assert!(index < self.rect.height);
    unsafe {
      let ptr = self.data.add(index * self.plane_cfg.stride);
      slice::from_raw_parts_mut(ptr, self.rect.width)
    }
  }
}

/// Iterator over plane region rows
pub struct RowsIter<'a, T: Pixel> {
  data: *const T,
  stride: usize,
  width: usize,
  remaining: usize,
  phantom: PhantomData<&'a T>,
}

/// Mutable iterator over plane region rows
pub struct RowsIterMut<'a, T: Pixel> {
  data: *mut T,
  stride: usize,
  width: usize,
  remaining: usize,
  phantom: PhantomData<&'a mut T>,
}

impl<'a, T: Pixel> Iterator for RowsIter<'a, T> {
  type Item = &'a [T];

  #[inline(always)]
  fn next(&mut self) -> Option<Self::Item> {
    if self.remaining > 0 {
      let row = unsafe {
        let ptr = self.data;
        self.data = self.data.add(self.stride);
        slice::from_raw_parts(ptr, self.width)
      };
      Some(row)
    } else {
      None
    }
  }

  #[inline(always)]
  fn size_hint(&self) -> (usize, Option<usize>) {
    (self.remaining, Some(self.remaining))
  }
}

impl<'a, T: Pixel> Iterator for RowsIterMut<'a, T> {
  type Item = &'a mut [T];

  #[inline(always)]
  fn next(&mut self) -> Option<Self::Item> {
    if self.remaining > 0 {
      let row = unsafe {
        let ptr = self.data;
        self.data = self.data.add(self.stride);
        slice::from_raw_parts_mut(ptr, self.width)
      };
      Some(row)
    } else {
      None
    }
  }

  #[inline(always)]
  fn size_hint(&self) -> (usize, Option<usize>) {
    (self.remaining, Some(self.remaining))
  }
}

impl<T: Pixel> ExactSizeIterator for RowsIter<'_, T> {}
impl<T: Pixel> ExactSizeIterator for RowsIterMut<'_, T> {}