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 clearTransform()

Record a clear-transform 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 drawLine(Point p1, Point p2, const Paint &p)

Record a line-drawing operation using a Paint.

Parameters:

• p1 – Start point.

• p2 – End point.

• p – Paint describing style, color, blend, opacity.

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 drawPolyline(const Point *pts, i32 count, const Paint &p)

Record a polyline-drawing operation using a Paint.

Parameters:

• pts – Array of vertices.

• count – Number of points.

• p – Paint describing style, color, blend, opacity.

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 drawText(Point pos, std::string_view text, const Paint &p)

Record a text-drawing operation using a Paint.

Parameters:

• pos – Position of the text baseline.

• text – UTF-8 text to draw.

• p – Paint describing style, color, blend, opacity.

void fillCircle(f32 cx, f32 cy, f32 radius, Color c)

Record a fill-circle operation.

Parameters:

• cx – Center X.

• cy – Center Y.

• radius – Circle radius.

• c – Fill color.

void fillCircle(f32 cx, f32 cy, f32 radius, const Paint &p)

Record a fill-circle operation using a Paint.

Parameters:

• cx – Center X.

• cy – Center Y.

• radius – Circle radius.

• p – Paint describing style, color, blend, opacity.

void fillRect(Rect r, Color c)

Record a fill-rectangle operation.

Parameters:

• r – Rectangle to fill.

• c – Fill color.

void fillRect(Rect r, const Paint &p)

Record a fill-rectangle operation using a Paint.

Parameters:

• r – Rectangle to fill.

• p – Paint describing style, color, blend, opacity.

void fillRoundRect(Rect r, f32 rx, f32 ry, Color c)

Record a fill-rounded-rectangle operation.

Parameters:

• r – The rectangle.

• rx – Corner radius in X.

• ry – Corner radius in Y.

• c – Fill color.

void fillRoundRect(Rect r, f32 rx, f32 ry, const Paint &p)

Record a fill-rounded-rectangle operation using a Paint.

Parameters:

• r – The rectangle.

• rx – Corner radius in X.

• ry – Corner radius in Y.

• p – Paint describing style, color, blend, opacity.

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 setTransform(const Matrix &m)

Record a set-transform operation.

Parameters:

m – The transformation matrix.

void strokeCircle(f32 cx, f32 cy, f32 radius, Color c, f32 width)

Record a stroke-circle operation.

Parameters:

• cx – Center X.

• cy – Center Y.

• radius – Circle radius.

• c – Stroke color.

• width – Stroke line width.

void strokeCircle(f32 cx, f32 cy, f32 radius, const Paint &p)

Record a stroke-circle operation using a Paint.

Parameters:

• cx – Center X.

• cy – Center Y.

• radius – Circle radius.

• p – Paint describing style, color, blend, opacity.

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.

void strokeRect(Rect r, const Paint &p)

Record a stroke-rectangle operation using a Paint.

Parameters:

• r – Rectangle to stroke.

• p – Paint describing style, color, blend, opacity.

void strokeRoundRect(Rect r, f32 rx, f32 ry, Color c, f32 width)

Record a stroke-rounded-rectangle operation.

Parameters:

• r – The rectangle.

• rx – Corner radius in X.

• ry – Corner radius in Y.

• c – Stroke color.

• width – Stroke line width.

void strokeRoundRect(Rect r, f32 rx, f32 ry, const Paint &p)

Record a stroke-rounded-rectangle operation using a Paint.

Parameters:

• r – The rectangle.

• rx – Corner radius in X.

• ry – Corner radius in Y.

• p – Paint describing style, color, blend, opacity.

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 Matrix *getMatrix(u32 offset) const

Retrieve a stored matrix by offset.

Parameters:

offset – Byte offset returned by storeMatrix().

Returns:

Pointer to the Matrix.

const Point *getPoints(u32 offset) const

Retrieve stored points by offset.

Parameters:

offset – Byte offset returned by storePoints().

Returns:

Pointer to the first Point.

void getRoundRect(u32 offset, Rect &r, f32 &rx, f32 &ry) const

Retrieve stored rounded rectangle data.

Parameters:

• offset – Byte offset returned by storeRoundRect().

• r – Output rectangle.

• rx – Output corner radius in X.

• ry – Output corner radius in Y.

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 storeMatrix(const Matrix &m)

Store a matrix in the arena.

Parameters:

m – The matrix to store.

Returns:

Byte offset to the stored matrix.

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 storeRoundRect(Rect r, f32 rx, f32 ry)

Store rounded rectangle data (Rect + rx + ry) in the arena.

Parameters:

• r – The rectangle.

• rx – Corner radius in X.

• ry – Corner radius in Y.

Returns:

Byte offset to the stored data.

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.