Recording

class Recording

Immutable command buffer containing recorded draw operations.

Created by Recorder::finish(). Operations can be traversed in original order via accept() or in sorted order via dispatch().

Public Functions

Recording(std::vector<CompactDrawOp> ops, DrawOpArena arena, std::vector<std::shared_ptr<Image>> images)

Construct a Recording from operations, arena, and images.

Parameters:

  • ops – Vector of compact draw operations.

  • arena – Arena holding variable-length data.

  • images – Vector of referenced images.

void accept(DrawOpVisitor &visitor) const

Traverse operations in original recording order.

Parameters:

visitor – The visitor to receive each operation.

inline const DrawOpArena &arena() const

Get the data arena.

void dispatch(DrawOpVisitor &visitor, const class DrawPass &pass) const

Dispatch operations in sorted order defined by a draw pass.

Parameters:

  • visitor – The visitor to receive each operation.

  • pass – The draw pass defining execution order.

const Image *getImage(u32 index) const

Get an image by index.

Parameters:

index – Index into the images list.

Returns:

Pointer to the Image, or nullptr if out of range.

inline const std::vector<std::shared_ptr<Image>> &images() const

Get the list of referenced images.

inline const std::vector<CompactDrawOp> &ops() const

Get the list of recorded operations.

class Recorder

Records draw operations into a compact command buffer.

Call drawing methods to accumulate operations, then finish() to produce an immutable Recording.

Public Functions

void clearClip()

Record a clear-clip operation.

void drawImage(std::shared_ptr<Image> image, f32 x, f32 y)

Record an image-drawing operation.

Parameters:

  • image – Shared pointer to the image.

  • x – X position.

  • y – Y position.

void drawLine(Point p1, Point p2, Color c, f32 width)

Record a line-drawing operation.

Parameters:

  • p1 – Start point.

  • p2 – End point.

  • c – Line color.

  • width – Line width.

void drawPolyline(const Point *pts, i32 count, Color c, f32 width)

Record a polyline-drawing operation.

Parameters:

  • pts – Array of vertices.

  • count – Number of points.

  • c – Line color.

  • width – Line width.

void drawText(Point p, std::string_view text, Color c)

Record a text-drawing operation.

Parameters:

  • p – Position of the text baseline.

  • text – UTF-8 text to draw.

  • c – Text color.

void fillRect(Rect r, Color c)

Record a fill-rectangle operation.

Parameters:

  • r – Rectangle to fill.

  • c – Fill color.

std::unique_ptr<Recording> finish()

Finish recording and produce an immutable Recording.

Returns:

Unique pointer to the completed Recording.

void reset()

Reset the recorder, discarding all accumulated operations.

void setClip(Rect r)

Record a set-clip operation.

Parameters:

r – The clipping rectangle.

void strokeRect(Rect r, Color c, f32 width)

Record a stroke-rectangle operation.

Parameters:

  • r – Rectangle to stroke.

  • c – Stroke color.

  • width – Stroke line width.

class DrawOpArena

Arena allocator for variable-length DrawOp data (strings, point arrays).

Public Functions

explicit DrawOpArena(size_t initialCapacity = 4096)

Construct an arena with the given initial capacity.

Parameters:

initialCapacity – Initial byte capacity (default 4096).

u32 allocate(size_t bytes)

Allocate raw storage.

Parameters:

bytes – Number of bytes to allocate.

Returns:

Byte offset into the arena.

const Point *getPoints(u32 offset) const

Retrieve stored points by offset.

Parameters:

offset – Byte offset returned by storePoints().

Returns:

Pointer to the first Point.

const char *getString(u32 offset) const

Retrieve a stored string by offset.

Parameters:

offset – Byte offset returned by storeString().

Returns:

Pointer to the null-terminated string.

void reset()

Reset the arena, discarding all stored data.

u32 storePoints(const Point *pts, i32 count)

Store a points array in the arena.

Parameters:

  • pts – Pointer to the points array.

  • count – Number of points.

Returns:

Byte offset to the stored points.

u32 storeString(std::string_view str)

Store a string in the arena.

Parameters:

str – The string to store.

Returns:

Byte offset to the stored string.