class RotateFlip

class RotateFlip

Defined at line 37 of file ../../src/ui/scenic/lib/types/rotate_flip.h

Covers the rotate/flip permutations supported by

`fuchsia.hardware.display.types/CoordinateTransformation`.

Enum names read in application order: rotation first, then the named

reflection ("rotate-then-flip"). Reflections flip the image across the

specified axis: e.g. `kReflectX` mirrors across a horizontal line,

swapping top and bottom rows.

Rotations do not commute with reflections, so each reflection-carrying

value also has a flip-then-rotate reading that names the OTHER axis

(e.g. `kRotateCcw90ReflectY` is equivalently REFLECT_X followed by

ROTATE_CCW_90); `From(Orientation, ImageFlip)` converts from that

flip-first form.

TODO(https://fxbug.dev/356385730): Flatland2 introduces `FlipThenRotate`, which adopts Android

conventions. These differ from current display coordinator conventions:

- Android uses flip-then-rotate, display coordinator uses rotate-then-flip

- Android uses clockwise, display coordinator uses counter-clockwise

Eventually both display coordinator and Scenic impl are expected to adopt the Android convention.

Public Methods

void RotateFlip ()

Defined at line 168 of file ../../src/ui/scenic/lib/types/rotate_flip.h

void RotateFlip (const RotateFlip & )

Defined at line 170 of file ../../src/ui/scenic/lib/types/rotate_flip.h

void RotateFlip (RotateFlip && )

Defined at line 171 of file ../../src/ui/scenic/lib/types/rotate_flip.h

RotateFlip & operator= (const RotateFlip & )

Defined at line 172 of file ../../src/ui/scenic/lib/types/rotate_flip.h

RotateFlip & operator= (RotateFlip && )

Defined at line 173 of file ../../src/ui/scenic/lib/types/rotate_flip.h

void ~RotateFlip ()

Defined at line 174 of file ../../src/ui/scenic/lib/types/rotate_flip.h

Enum enum_value ()

Used for hashing/printing/etc; not useful for general users.

Defined at line 189 of file ../../src/ui/scenic/lib/types/rotate_flip.h

RotateFlip From (const fuchsia_ui_composition::Orientation & rotation, const fuchsia_ui_composition::ImageFlip & flip)

Returns the transform that applies `flip` first, followed by

`rotation`: Flatland's convention, where the flip happens in image

space before any rotation. The equivalent rotate-then-flip enum value

often names a different reflection axis than `flip`; see the per-case

comments in the implementation.

Defined at line 198 of file ../../src/ui/scenic/lib/types/rotate_flip.h

RotateFlip From (const fuchsia_hardware_display_types::wire::CoordinateTransformation & coordinate_transform)

`RotateFlip` directly mirrors the hardware display type

`fuchsia.hardware.display.types/CoordinateTransformation`: same numeric

values, converted by cast.

Defined at line 261 of file ../../src/ui/scenic/lib/types/rotate_flip.h

RotateFlip From (const fuchsia_ui_composition::FlipThenRotate & flip_then_rotate)

static

Defined at line 268 of file ../../src/ui/scenic/lib/types/rotate_flip.h

RotateFlip kIdentity ()

Static "constructors".

Defined at line 306 of file ../../src/ui/scenic/lib/types/rotate_flip.h

RotateFlip kReflectX ()

static

Defined at line 309 of file ../../src/ui/scenic/lib/types/rotate_flip.h

RotateFlip kReflectY ()

static

Defined at line 312 of file ../../src/ui/scenic/lib/types/rotate_flip.h

RotateFlip kRotateCcw180 ()

static

Defined at line 315 of file ../../src/ui/scenic/lib/types/rotate_flip.h

RotateFlip kRotateCcw90 ()

static

Defined at line 318 of file ../../src/ui/scenic/lib/types/rotate_flip.h

RotateFlip kRotateCcw90ReflectX ()

static

Defined at line 321 of file ../../src/ui/scenic/lib/types/rotate_flip.h

RotateFlip kRotateCcw90ReflectY ()

static

Defined at line 326 of file ../../src/ui/scenic/lib/types/rotate_flip.h

RotateFlip kRotateCcw270 ()

static

Defined at line 331 of file ../../src/ui/scenic/lib/types/rotate_flip.h

void RotateFlip (RotateFlip::Enum val)

Defined at line 195 of file ../../src/ui/scenic/lib/types/rotate_flip.h

RotateFlip RotatedBy (Enum rotation)

Returns the RotateFlip equivalent to applying this transform first, then

`rotation`. `rotation` must be a pure rotation (kIdentity or one of the

kRotateCcw* values); reflections are rejected via CHECK.

Defined at line 339 of file ../../src/ui/scenic/lib/types/rotate_flip.h

RotateFlip RotatedBy (RotateFlip rotation)

Defined at line 388 of file ../../src/ui/scenic/lib/types/rotate_flip.h

fuchsia_hardware_display_types::wire::CoordinateTransformation ToDisplayCoordinateTransformation ()

Defined at line 392 of file ../../src/ui/scenic/lib/types/rotate_flip.h

Enumerations

enum class Enum : uint8_t
Name Value Comments
kIdentity 0

Image pixels are passed through without any change.
kReflectX 1

Image pixels are reflected across a line meeting the image's center, parallel to the X axis.

This enum member's numeric value has a single bit set to 1. Any
transformation whose value has this bit set involves an X reflection.

This transformation is also called an "X flip".

Example:
|a b c d| |i j k l|
|e f g h| -> |e f g h|
|i j k l| |a b c d|
kReflectY 2

Image pixels are reflected across a line meeting the image's center, parallel to the Y axis.

This enum member's numeric value has a single bit set to 1. Any
transformation whose value has this bit set involves an Y reflection.

This transformation is also called an "Y flip".

Example:
|a b c d| |d c b a|
|e f g h| -> |h g f e|
|i j k l| |l k j i|
kRotateCcw180 3

Image pixels are rotated around the image's center counter-clockwise by 180 degrees.

This is equivalent to applying the `REFLECT_X` and `REFLECT_Y`
transforms. `REFLECT_X` and `REFLECT_Y` are commutative, so their
ordering doesn't matter.

Example:
|a b c d| |l k j i|
|e f g h| -> |h g f e|
|i j k l| |d c b a|
kRotateCcw90 4

Image pixels are rotated around the image's center counter-clockwise by 90 degrees.

The image produced by this transformation has different dimensions from
the input image.

This enum member's numeric value has a single bit set to 1. Any
transformation whose value has this bit set involves a 90-degree
counter-clockwise rotation.

Example:
|a b c d| |d h l|
|e f g h| -> |c g k|
|i j k l| |b f j|
|a e i|
kRotateCcw90ReflectX 5

Image pixels are transformed using `ROTATE_CCW_90`, followed by `REFLECT_X`.

The image produced by this transformation has different dimensions from
the input image.

Example:
|a b c d| |a e i|
|e f g h| -> |b f j|
|i j k l| |c g k|
|d h l|
kRotateCcw90ReflectY 6

Image pixels are transformed using `ROTATE_CCW_90`, followed by `REFLECT_Y`.

The image produced by this transformation has different dimensions from
the input image.

Example:
|a b c d| |l h d|
|e f g h| -> |k g c|
|i j k l| |j f b|
|i e a|
kRotateCcw270 7

Image pixels are rotated around the image's center counter-clockwise by 270 degrees.

The image produced by this transformation has different dimensions from
the input image.

This is equivalent to applying the `ROTATE_CCW_90` transform, followed
by `REFLECT_X` and `REFLECT_Y`. `REFLECT_X` and `REFLECT_Y` are
commutative, so their ordering doesn't matter.

Example:
|a b c d| |i e a|
|e f g h| -> |j f b|
|i j k l| |k g c|
|l h d|

Defined at line 39 of file ../../src/ui/scenic/lib/types/rotate_flip.h

Friends

bool RotateFlip (const RotateFlip & lhs, const RotateFlip & rhs)
bool RotateFlip (const RotateFlip & lhsconst RotateFlip & rhs)