vectorio/_vectorshape.py

   1 # SPDX-FileCopyrightText: 2020 Melissa LeBlanc-Williams for Adafruit Industries
   2 #
   3 # SPDX-License-Identifier: MIT
   4
   5 """
   6 `vectorio._vectorshape`
   7 ================================================================================
   8
   9 vectorio for Blinka
  10
  11 **Software and Dependencies:**
  12
  13 * Adafruit Blinka:
  14   https://github.com/adafruit/Adafruit_Blinka/releases
  15
  16 * Author(s): Melissa LeBlanc-Williams
  17
  18 """
  19
  20 import struct
  21 from typing import Union, Tuple
  22 from circuitpython_typing import WriteableBuffer
  23 from displayio._colorconverter import ColorConverter
  24 from displayio._colorspace import Colorspace
  25 from displayio._palette import Palette
  26 from displayio._area import Area
  27 from displayio._structs import null_transform, InputPixelStruct, OutputPixelStruct
  28
  29 __version__ = "0.0.0+auto.0"
  30 __repo__ = "https://github.com/adafruit/Adafruit_Blinka_displayio.git"
  31
  32
  33 class _VectorShape:
  34     def __init__(
  35         self,
  36         pixel_shader: Union[ColorConverter, Palette],
  37         x: int,
  38         y: int,
  39     ):
  40         self._x = x
  41         self._y = y
  42         self._pixel_shader = pixel_shader
  43         self._hidden = False
  44         self._current_area_dirty = True
  45         self._current_area = Area(0, 0, 0, 0)
  46         self._ephemeral_dirty_area = Area(0, 0, 0, 0)
  47         self._absolute_transform = null_transform
  48         self._get_screen_area(self._current_area)
  49
  50     @property
  51     def x(self) -> int:
  52         """X position of the center point of the circle in the parent."""
  53         return self._x
  54
  55     @x.setter
  56     def x(self, value: int) -> None:
  57         if self._x == value:
  58             return
  59         self._x = value
  60         self._shape_set_dirty()
  61
  62     @property
  63     def y(self) -> int:
  64         """Y position of the center point of the circle in the parent."""
  65         return self._y
  66
  67     @y.setter
  68     def y(self, value: int) -> None:
  69         if self._y == value:
  70             return
  71         self._y = value
  72         self._shape_set_dirty()
  73
  74     @property
  75     def hidden(self) -> bool:
  76         """Hide the circle or not."""
  77         return self._hidden
  78
  79     @hidden.setter
  80     def hidden(self, value: bool) -> None:
  81         self._hidden = value
  82         self._shape_set_dirty()
  83
  84     @property
  85     def location(self) -> Tuple[int, int]:
  86         """(X,Y) position of the center point of the circle in the parent."""
  87         return (self._x, self._y)
  88
  89     @location.setter
  90     def location(self, value: Tuple[int, int]) -> None:
  91         if len(value) != 2:
  92             raise ValueError("location must be a list or tuple with exactly 2 integers")
  93         x = value[0]
  94         y = value[1]
  95         dirty = False
  96         if self._x != x:
  97             self._x = x
  98             dirty = True
  99         if self._y != y:
 100             self._y = y
 101             dirty = True
 102         if dirty:
 103             self._shape_set_dirty()
 104
 105     @property
 106     def pixel_shader(self) -> Union[ColorConverter, Palette]:
 107         """The pixel shader of the circle."""
 108         return self._pixel_shader
 109
 110     @pixel_shader.setter
 111     def pixel_shader(self, value: Union[ColorConverter, Palette]) -> None:
 112         self._pixel_shader = value
 113
 114     def _get_area(self, _out_area: Area) -> Area:
 115         raise NotImplementedError("Subclass must implement _get_area")
 116
 117     def _get_pixel(self, _x: int, _y: int) -> int:
 118         raise NotImplementedError("Subclass must implement _get_pixel")
 119
 120     def _shape_set_dirty(self) -> None:
 121         current_area = Area()
 122         self._get_screen_area(current_area)
 123         moved = current_area != self._current_area
 124         if moved:
 125             # This will add _current_area (the old position) to dirty area
 126             self._current_area.union(
 127                 self._ephemeral_dirty_area, self._ephemeral_dirty_area
 128             )
 129             # This will add the new position to the dirty area
 130             current_area.union(self._ephemeral_dirty_area, self._ephemeral_dirty_area)
 131             # Dirty area tracks the shape's footprint between draws.  It's reset on refresh finish.
 132             current_area.copy_into(self._current_area)
 133         self._current_area_dirty = True
 134
 135     def _get_dirty_area(self, out_area: Area) -> Area:
 136         out_area.x1 = out_area.x2
 137         self._ephemeral_dirty_area.union(self._current_area, out_area)
 138         return True  # For now just always redraw.
 139
 140     def _get_screen_area(self, out_area) -> Area:
 141         self._get_area(out_area)
 142         if self._absolute_transform.transpose_xy:
 143             x = self._absolute_transform.x + self._absolute_transform.dx * self._y
 144             y = self._absolute_transform.y + self._absolute_transform.dy * self._x
 145             if self._absolute_transform.dx < 1:
 146                 out_area.y1 = out_area.y1 * -1 + 1
 147                 out_area.y2 = out_area.y2 * -1 + 1
 148             if self._absolute_transform.dy < 1:
 149                 out_area.x1 = out_area.x1 * -1 + 1
 150                 out_area.x2 = out_area.x2 * -1 + 1
 151             self._area_transpose(out_area)
 152         else:
 153             x = self._absolute_transform.x + self._absolute_transform.dx * self._x
 154             y = self._absolute_transform.y + self._absolute_transform.dy * self._y
 155             if self._absolute_transform.dx < 1:
 156                 out_area.x1 = out_area.x1 * -1 + 1
 157                 out_area.x2 = out_area.x2 * -1 + 1
 158             if self._absolute_transform.dy < 1:
 159                 out_area.y1 = out_area.y1 * -1 + 1
 160                 out_area.y2 = out_area.y2 * -1 + 1
 161         out_area.canon()
 162         out_area.shift(x, y)
 163
 164     @staticmethod
 165     def _area_transpose(to_transpose: Area) -> Area:
 166         to_transpose.x1, to_transpose.y1 = to_transpose.y1, to_transpose.x1
 167         to_transpose.x2, to_transpose.y2 = to_transpose.y2, to_transpose.x2
 168
 169     def _screen_to_shape_coordinates(self, x: int, y: int) -> Tuple[int, int]:
 170         """Get the target pixel based on the shape's coordinate space"""
 171         if self._absolute_transform.transpose_xy:
 172             out_shape_x = (
 173                 y - self._absolute_transform.y - self._absolute_transform.dy * self._x
 174             )
 175             out_shape_y = (
 176                 x - self._absolute_transform.x - self._absolute_transform.dx * self._y
 177             )
 178
 179             if self._absolute_transform.dx < 1:
 180                 out_shape_x *= -1
 181             if self._absolute_transform.dy < 1:
 182                 out_shape_y *= -1
 183         else:
 184             out_shape_x = (
 185                 x - self._absolute_transform.x - self._absolute_transform.dx * self._x
 186             )
 187             out_shape_y = (
 188                 y - self._absolute_transform.y - self._absolute_transform.dy * self._y
 189             )
 190
 191             if self._absolute_transform.dx < 1:
 192                 out_shape_x *= -1
 193             if self._absolute_transform.dy < 1:
 194                 out_shape_y *= -1
 195
 196             # It's mirrored via dx. Maybe we need to add support for also separately mirroring?
 197             # if self.absolute_transform.mirror_x:
 198             #    pixel_to_get_x = (
 199             #        (shape_area.x2 - shape_area.x1)
 200             #        - (pixel_to_get_x - shape_area.x1)
 201             #        + shape_area.x1
 202             #        - 1
 203             #    )
 204             # if self.absolute_transform.mirror_y:
 205             #    pixel_to_get_y = (
 206             #        (shape_area.y2 - shape_area.y1)
 207             #        - (pixel_to_get_y - shape_area.y1)
 208             #        + +shape_area.y1
 209             #        - 1
 210             #    )
 211
 212         return out_shape_x, out_shape_y
 213
 214     def _shape_contains(self, x: int, y: int) -> bool:
 215         shape_x, shape_y = self._screen_to_shape_coordinates(x, y)
 216         return self._get_pixel(shape_x, shape_y) != 0
 217
 218     def _fill_area(
 219         self,
 220         colorspace: Colorspace,
 221         area: Area,
 222         mask: WriteableBuffer,
 223         buffer: WriteableBuffer,
 224     ) -> bool:
 225         # pylint: disable=too-many-locals,too-many-branches,too-many-statements
 226         if self._hidden:
 227             return False
 228
 229         overlap = Area()
 230         if not area.compute_overlap(self._current_area, overlap):
 231             return False
 232
 233         full_coverage = area == overlap
 234         pixels_per_byte = 8 // colorspace.depth
 235         linestride_px = area.width()
 236         line_dirty_offset_px = (overlap.y1 - area.y1) * linestride_px
 237         column_dirty_offset_px = overlap.x1 - area.x1
 238
 239         input_pixel = InputPixelStruct()
 240         output_pixel = OutputPixelStruct()
 241
 242         shape_area = Area()
 243         self._get_area(shape_area)
 244
 245         mask_start_px = line_dirty_offset_px
 246
 247         for input_pixel.y in range(overlap.y1, overlap.y2):
 248             mask_start_px += column_dirty_offset_px
 249             for input_pixel.x in range(overlap.x1, overlap.x2):
 250                 # Check the mask first to see if the pixel has already been set.
 251                 pixel_index = mask_start_px + (input_pixel.x - overlap.x1)
 252                 mask_doubleword = mask[pixel_index // 32]
 253                 mask_bit = pixel_index % 32
 254                 if (mask_doubleword & (1 << mask_bit)) != 0:
 255                     continue
 256                 output_pixel.pixel = 0
 257
 258                 # Cast input screen coordinates to shape coordinates to pick the pixel to draw
 259                 pixel_to_get_x, pixel_to_get_y = self._screen_to_shape_coordinates(
 260                     input_pixel.x, input_pixel.y
 261                 )
 262                 input_pixel.pixel = self._get_pixel(pixel_to_get_x, pixel_to_get_y)
 263
 264                 # vectorio shapes use 0 to mean "area is not covered."
 265                 # We can skip all the rest of the work for this pixel
 266                 # if it's not currently covered by the shape.
 267                 if input_pixel.pixel == 0:
 268                     full_coverage = False
 269                 else:
 270                     # Pixel is not transparent. Let's pull the pixel value index down
 271                     # to 0-base for more error-resistant palettes.
 272                     input_pixel.pixel -= 1
 273                     output_pixel.opaque = True
 274                     if self._pixel_shader is None:
 275                         output_pixel.pixel = input_pixel.pixel
 276                     elif isinstance(self._pixel_shader, Palette):
 277                         self._pixel_shader._get_color(  # pylint: disable=protected-access
 278                             colorspace, input_pixel, output_pixel
 279                         )
 280                     elif isinstance(self._pixel_shader, ColorConverter):
 281                         self._pixel_shader._convert(  # pylint: disable=protected-access
 282                             colorspace, input_pixel, output_pixel
 283                         )
 284
 285                     if not output_pixel.opaque:
 286                         full_coverage = False
 287
 288                     mask[pixel_index // 32] |= 1 << (pixel_index % 32)
 289                     if colorspace.depth == 16:
 290                         struct.pack_into(
 291                             "H",
 292                             buffer.cast("B"),
 293                             pixel_index * 2,
 294                             output_pixel.pixel,
 295                         )
 296                     elif colorspace.depth == 32:
 297                         struct.pack_into(
 298                             "I",
 299                             buffer.cast("B"),
 300                             pixel_index * 4,
 301                             output_pixel.pixel,
 302                         )
 303                     elif colorspace.depth == 8:
 304                         buffer.cast("B")[pixel_index] = output_pixel.pixel & 0xFF
 305                     elif colorspace.depth < 8:
 306                         # Reorder the offsets to pack multiple rows into
 307                         # a byte (meaning they share a column).
 308                         if not colorspace.pixels_in_byte_share_row:
 309                             row = pixel_index // linestride_px
 310                             col = pixel_index % linestride_px
 311                             # Dividing by pixels_per_byte does truncated division
 312                             # even if we multiply it back out
 313                             pixel_index = (
 314                                 col * pixels_per_byte
 315                                 + (row // pixels_per_byte)
 316                                 * pixels_per_byte
 317                                 * linestride_px
 318                                 + (row % pixels_per_byte)
 319                             )
 320                         shift = (pixel_index % pixels_per_byte) * colorspace.depth
 321                         if colorspace.reverse_pixels_in_byte:
 322                             # Reverse the shift by subtracting it from the leftmost shift
 323                             shift = (pixels_per_byte - 1) * colorspace.depth - shift
 324                         buffer.cast("B")[pixel_index // pixels_per_byte] |= (
 325                             output_pixel.pixel << shift
 326                         )
 327             mask_start_px += linestride_px - column_dirty_offset_px
 328
 329         return full_coverage
 330
 331     def _finish_refresh(self) -> None:
 332         if self._ephemeral_dirty_area.empty() and not self._current_area_dirty:
 333             return
 334         # Reset dirty area to nothing
 335         self._ephemeral_dirty_area.x1 = self._ephemeral_dirty_area.x2
 336         self._current_area_dirty = False
 337
 338         if isinstance(self._pixel_shader, (Palette, ColorConverter)):
 339             self._pixel_shader._finish_refresh()  # pylint: disable=protected-access
 340
 341     def _get_refresh_areas(self, areas: list[Area]) -> None:
 342         if self._current_area_dirty or (
 343             isinstance(self._pixel_shader, (Palette, ColorConverter))
 344             and self._pixel_shader._needs_refresh  # pylint: disable=protected-access
 345         ):
 346             if not self._ephemeral_dirty_area.empty():
 347                 # Both are dirty, check if we should combine the areas or draw separately
 348                 # Draws as few pixels as possible both when animations move short distances
 349                 # and large distances. The display core implementation currently doesn't
 350                 # combine areas to reduce redrawing of masked areas. If it does, this could
 351                 # be simplified to just return the 2 possibly overlapping areas.
 352                 area_swap = Area()
 353                 self._ephemeral_dirty_area.compute_overlap(
 354                     self._current_area, area_swap
 355                 )
 356                 overlap_size = area_swap.size()
 357                 self._ephemeral_dirty_area.union(self._current_area, area_swap)
 358                 union_size = area_swap.size()
 359                 current_size = self._current_area.size()
 360                 dirty_size = self._ephemeral_dirty_area.size()
 361
 362                 if union_size - dirty_size - current_size + overlap_size <= min(
 363                     dirty_size, current_size
 364                 ):
 365                     # The excluded / non-overlapping area from the disjoint dirty and current
 366                     # areas is smaller than the smallest area we need to draw. Redrawing the
 367                     # overlapping area would cost more than just drawing the union disjoint
 368                     # area once.
 369                     area_swap.copy_into(self._ephemeral_dirty_area)
 370                 else:
 371                     # The excluded area between the 2 dirty areas is larger than the smallest
 372                     # dirty area. It would be more costly to combine these areas than possibly
 373                     # redraw some overlap.
 374                     areas.append(self._current_area)
 375                 areas.append(self._ephemeral_dirty_area)
 376             else:
 377                 areas.append(self._current_area)
 378         elif not self._ephemeral_dirty_area.empty():
 379             areas.append(self._ephemeral_dirty_area)
 380
 381     def _update_transform(self, group_transform) -> None:
 382         self._absolute_transform = (
 383             null_transform if group_transform is None else group_transform
 384         )
 385         self._shape_set_dirty()