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             self._current_area.union(
 126                 self._ephemeral_dirty_area, self._ephemeral_dirty_area
 127             )
 128             # Dirty area tracks the shape's footprint between draws.  It's reset on refresh finish.
 129             current_area.copy_into(self._current_area)
 130         self._current_area_dirty = True
 131
 132     def _get_dirty_area(self, out_area: Area) -> Area:
 133         out_area.x1 = out_area.x2
 134         self._ephemeral_dirty_area.union(self._current_area, out_area)
 135         return True  # For now just always redraw.
 136
 137     def _get_screen_area(self, out_area) -> Area:
 138         self._get_area(out_area)
 139         if self._absolute_transform.transpose_xy:
 140             x = self._absolute_transform.x + self._absolute_transform.dx * self._y
 141             y = self._absolute_transform.y + self._absolute_transform.dy * self._x
 142             if self._absolute_transform.dx < 1:
 143                 out_area.y1 = out_area.y1 * -1 + 1
 144                 out_area.y2 = out_area.y2 * -1 + 1
 145             if self._absolute_transform.dy < 1:
 146                 out_area.x1 = out_area.x1 * -1 + 1
 147                 out_area.x2 = out_area.x2 * -1 + 1
 148             self._area_transpose(out_area)
 149         else:
 150             x = self._absolute_transform.x + self._absolute_transform.dx * self._x
 151             y = self._absolute_transform.y + self._absolute_transform.dy * self._y
 152             if self._absolute_transform.dx < 1:
 153                 out_area.x1 = out_area.x1 * -1 + 1
 154                 out_area.x2 = out_area.x2 * -1 + 1
 155             if self._absolute_transform.dy < 1:
 156                 out_area.y1 = out_area.y1 * -1 + 1
 157                 out_area.y2 = out_area.y2 * -1 + 1
 158         out_area.canon()
 159         out_area.shift(x, y)
 160
 161     @staticmethod
 162     def _area_transpose(to_transpose: Area) -> Area:
 163         to_transpose.x1, to_transpose.y1 = to_transpose.y1, to_transpose.x1
 164         to_transpose.x2, to_transpose.y2 = to_transpose.y2, to_transpose.x2
 165
 166     def _screen_to_shape_coordinates(self, x: int, y: int) -> Tuple[int, int]:
 167         """Get the target pixel based on the shape's coordinate space"""
 168         if self._absolute_transform.transpose_xy:
 169             out_shape_x = (
 170                 y - self._absolute_transform.y - self._absolute_transform.dy * self._x
 171             )
 172             out_shape_y = (
 173                 x - self._absolute_transform.x - self._absolute_transform.dx * self._y
 174             )
 175
 176             if self._absolute_transform.dx < 1:
 177                 out_shape_x *= -1
 178             if self._absolute_transform.dy < 1:
 179                 out_shape_y *= -1
 180         else:
 181             out_shape_x = (
 182                 x - self._absolute_transform.x - self._absolute_transform.dx * self._x
 183             )
 184             out_shape_y = (
 185                 y - self._absolute_transform.y - self._absolute_transform.dy * self._y
 186             )
 187
 188             if self._absolute_transform.dx < 1:
 189                 out_shape_x *= -1
 190             if self._absolute_transform.dy < 1:
 191                 out_shape_y *= -1
 192
 193             # It's mirrored via dx. Maybe we need to add support for also separately mirroring?
 194             # if self.absolute_transform.mirror_x:
 195             #    pixel_to_get_x = (
 196             #        (shape_area.x2 - shape_area.x1)
 197             #        - (pixel_to_get_x - shape_area.x1)
 198             #        + shape_area.x1
 199             #        - 1
 200             #    )
 201             # if self.absolute_transform.mirror_y:
 202             #    pixel_to_get_y = (
 203             #        (shape_area.y2 - shape_area.y1)
 204             #        - (pixel_to_get_y - shape_area.y1)
 205             #        + +shape_area.y1
 206             #        - 1
 207             #    )
 208
 209         return out_shape_x, out_shape_y
 210
 211     def _shape_contains(self, x: int, y: int) -> bool:
 212         shape_x, shape_y = self._screen_to_shape_coordinates(x, y)
 213         return self._get_pixel(shape_x, shape_y) != 0
 214
 215     def _fill_area(
 216         self,
 217         colorspace: Colorspace,
 218         area: Area,
 219         mask: WriteableBuffer,
 220         buffer: WriteableBuffer,
 221     ) -> bool:
 222         # pylint: disable=too-many-locals,too-many-branches,too-many-statements
 223         if self._hidden:
 224             return False
 225
 226         overlap = Area()
 227         if not area.compute_overlap(self._current_area, overlap):
 228             return False
 229
 230         full_coverage = area == overlap
 231         pixels_per_byte = 8 // colorspace.depth
 232         linestride_px = area.width()
 233         line_dirty_offset_px = (overlap.y1 - area.y1) * linestride_px
 234         column_dirty_offset_px = overlap.x1 - area.x1
 235
 236         input_pixel = InputPixelStruct()
 237         output_pixel = OutputPixelStruct()
 238
 239         shape_area = Area()
 240         self._get_area(shape_area)
 241
 242         mask_start_px = line_dirty_offset_px
 243
 244         for input_pixel.y in range(overlap.y1, overlap.y2):
 245             mask_start_px += column_dirty_offset_px
 246             for input_pixel.x in range(overlap.x1, overlap.x2):
 247                 # Check the mask first to see if the pixel has already been set.
 248                 pixel_index = mask_start_px + (input_pixel.x - overlap.x1)
 249                 mask_doubleword = mask[pixel_index // 32]
 250                 mask_bit = pixel_index % 32
 251                 if (mask_doubleword & (1 << mask_bit)) != 0:
 252                     continue
 253                 output_pixel.pixel = 0
 254
 255                 # Cast input screen coordinates to shape coordinates to pick the pixel to draw
 256                 pixel_to_get_x, pixel_to_get_y = self._screen_to_shape_coordinates(
 257                     input_pixel.x, input_pixel.y
 258                 )
 259                 input_pixel.pixel = self._get_pixel(pixel_to_get_x, pixel_to_get_y)
 260
 261                 # vectorio shapes use 0 to mean "area is not covered."
 262                 # We can skip all the rest of the work for this pixel
 263                 # if it's not currently covered by the shape.
 264                 if input_pixel.pixel == 0:
 265                     full_coverage = False
 266                 else:
 267                     # Pixel is not transparent. Let's pull the pixel value index down
 268                     # to 0-base for more error-resistant palettes.
 269                     input_pixel.pixel -= 1
 270                     output_pixel.opaque = True
 271                     if self._pixel_shader is None:
 272                         output_pixel.pixel = input_pixel.pixel
 273                     elif isinstance(self._pixel_shader, Palette):
 274                         self._pixel_shader._get_color(  # pylint: disable=protected-access
 275                             colorspace, input_pixel, output_pixel
 276                         )
 277                     elif isinstance(self._pixel_shader, ColorConverter):
 278                         self._pixel_shader._convert(  # pylint: disable=protected-access
 279                             colorspace, input_pixel, output_pixel
 280                         )
 281
 282                     if not output_pixel.opaque:
 283                         full_coverage = False
 284
 285                     mask[pixel_index // 32] |= 1 << (pixel_index % 32)
 286                     if colorspace.depth == 16:
 287                         struct.pack_into(
 288                             "H",
 289                             buffer.cast("B"),
 290                             pixel_index * 2,
 291                             output_pixel.pixel,
 292                         )
 293                     elif colorspace.depth == 32:
 294                         struct.pack_into(
 295                             "I",
 296                             buffer.cast("B"),
 297                             pixel_index * 4,
 298                             output_pixel.pixel,
 299                         )
 300                     elif colorspace.depth == 8:
 301                         buffer.cast("B")[pixel_index] = output_pixel.pixel & 0xFF
 302                     elif colorspace.depth < 8:
 303                         # Reorder the offsets to pack multiple rows into
 304                         # a byte (meaning they share a column).
 305                         if not colorspace.pixels_in_byte_share_row:
 306                             row = pixel_index // linestride_px
 307                             col = pixel_index % linestride_px
 308                             # Dividing by pixels_per_byte does truncated division
 309                             # even if we multiply it back out
 310                             pixel_index = (
 311                                 col * pixels_per_byte
 312                                 + (row // pixels_per_byte)
 313                                 * pixels_per_byte
 314                                 * linestride_px
 315                                 + (row % pixels_per_byte)
 316                             )
 317                         shift = (pixel_index % pixels_per_byte) * colorspace.depth
 318                         if colorspace.reverse_pixels_in_byte:
 319                             # Reverse the shift by subtracting it from the leftmost shift
 320                             shift = (pixels_per_byte - 1) * colorspace.depth - shift
 321                         buffer.cast("B")[pixel_index // pixels_per_byte] |= (
 322                             output_pixel.pixel << shift
 323                         )
 324             mask_start_px += linestride_px - column_dirty_offset_px
 325
 326         return full_coverage
 327
 328     def _finish_refresh(self) -> None:
 329         if self._ephemeral_dirty_area.empty() and not self._current_area_dirty:
 330             return
 331         # Reset dirty area to nothing
 332         self._ephemeral_dirty_area.x1 = self._ephemeral_dirty_area.x2
 333         self._current_area_dirty = False
 334
 335         if isinstance(self._pixel_shader, (Palette, ColorConverter)):
 336             self._pixel_shader._finish_refresh()  # pylint: disable=protected-access
 337
 338     def _get_refresh_areas(self, areas: list[Area]) -> None:
 339         if self._current_area_dirty or (
 340             isinstance(self._pixel_shader, (Palette, ColorConverter))
 341             and self._pixel_shader._needs_refresh  # pylint: disable=protected-access
 342         ):
 343             if not self._ephemeral_dirty_area.empty():
 344                 # Both are dirty, check if we should combine the areas or draw separately
 345                 # Draws as few pixels as possible both when animations move short distances
 346                 # and large distances. The display core implementation currently doesn't
 347                 # combine areas to reduce redrawing of masked areas. If it does, this could
 348                 # be simplified to just return the 2 possibly overlapping areas.
 349                 area_swap = Area()
 350                 self._ephemeral_dirty_area.compute_overlap(
 351                     self._current_area, area_swap
 352                 )
 353                 overlap_size = area_swap.size()
 354                 self._ephemeral_dirty_area.union(self._current_area, area_swap)
 355                 union_size = area_swap.size()
 356                 current_size = self._current_area.size()
 357                 dirty_size = self._ephemeral_dirty_area.size()
 358
 359                 if union_size - dirty_size - current_size + overlap_size <= min(
 360                     dirty_size, current_size
 361                 ):
 362                     # The excluded / non-overlapping area from the disjoint dirty and current
 363                     # areas is smaller than the smallest area we need to draw. Redrawing the
 364                     # overlapping area would cost more than just drawing the union disjoint
 365                     # area once.
 366                     area_swap.copy_into(self._ephemeral_dirty_area)
 367                 else:
 368                     # The excluded area between the 2 dirty areas is larger than the smallest
 369                     # dirty area. It would be more costly to combine these areas than possibly
 370                     # redraw some overlap.
 371                     areas.append(self._current_area)
 372                 areas.append(self._ephemeral_dirty_area)
 373             else:
 374                 areas.append(self._current_area)
 375         elif not self._ephemeral_dirty_area.empty():
 376             areas.append(self._ephemeral_dirty_area)
 377
 378     def _update_transform(self, group_transform) -> None:
 379         self._absolute_transform = (
 380             null_transform if group_transform is None else group_transform
 381         )
 382         self._shape_set_dirty()