Abstract implementation backend for PaintEngine. More...

#include <paintengine.h>

Collaboration diagram for PaintEngine::Impl:

[legend]

Public Member Functions
virtual	~Impl ()
	Virtual destructor.

const PixelFormat *	pixelFormat () const
	Returns the pixel format used by this implementation.

virtual bool	blit (const Point2Di32 &destTopLeft, const Image &src, const Point2Di32 &srcTopLeft, const Size2Du32 &srcSize) const
	Blits a rectangular region from a source image onto the surface.

virtual Pixel	createPixel (const uint16_t *comps, size_t compCount) const
	Creates a Pixel value from component values.

virtual size_t	drawPoints (const Pixel &pixel, const Point2Di32 *points, size_t pointCount) const
	Draws a set of points onto the surface.

virtual size_t	compositePoints (const Pixel &pixel, const Point2Di32 points, const float alphas, size_t pointCount) const
	Composites a set of points onto the surface with per-point alpha.

virtual bool	fill (const Pixel &pixel) const
	Fills the entire surface with a single pixel value.

virtual size_t	drawLines (const Pixel &pixel, const Line2Di32 *lines, size_t count) const
	Draws a set of line segments onto the surface.

virtual size_t	drawRect (const Pixel &pixel, const Rect< int32_t > &rect) const
	Draws a rectangle outline.

virtual size_t	fillRect (const Pixel &pixel, const Rect< int32_t > &rect) const
	Fills a rectangle with a solid color.

virtual size_t	drawCircle (const Pixel &pixel, const Point2Di32 &center, int radius) const
	Draws a circle outline.

virtual size_t	fillCircle (const Pixel &pixel, const Point2Di32 &center, int radius) const
	Fills a circle with a solid color.

virtual size_t	drawEllipse (const Pixel &pixel, const Point2Di32 &center, const Size2Du32 &size) const
	Draws an ellipse outline.

virtual size_t	fillEllipse (const Pixel &pixel, const Point2Di32 &center, const Size2Du32 &size) const
	Fills an ellipse with a solid color.

Protected Attributes
const PixelFormat *	_pixelFormat = nullptr
	Pixel format for this implementation.

Detailed Description

Abstract implementation backend for PaintEngine.

Subclass this to provide pixel-format-specific drawing operations. The PaintEngine facade delegates every call to the active Impl instance.

Member Function Documentation

◆ blit()

virtual bool PaintEngine::Impl::blit	(	const Point2Di32 &	destTopLeft,
		const Image &	src,
		const Point2Di32 &	srcTopLeft,
		const Size2Du32 &	srcSize
	)		const

virtual

Blits a rectangular region from a source image onto the surface.

Parameters

destTopLeft	Top-left corner on the destination surface.
src	Source image to copy from.
srcTopLeft	Top-left corner of the source region.
srcSize	Size of the source region to copy.

Returns: true on success, false on failure.

◆ compositePoints()

virtual size_t PaintEngine::Impl::compositePoints	(	const Pixel &	pixel,
		const Point2Di32 *	points,
		const float *	alphas,
		size_t	pointCount
	)		const

virtual

Composites a set of points onto the surface with per-point alpha.

The default implementation simply calls drawPoints() without compositing. Reimplement in your surface-specific subclass to support true alpha compositing.

Parameters

pixel	The pixel value to composite.
points	Array of points to composite.
alphas	Array of alpha values, one per point.
pointCount	Number of points in the arrays.

Returns: The number of points actually composited.

◆ createPixel()

virtual Pixel PaintEngine::Impl::createPixel	(	const uint16_t *	comps,
		size_t	compCount
	)		const

virtual

Creates a Pixel value from component values.

The returned Pixel is in a format specific to the underlying data layout and may contain pre-packed component values for fast drawing. Do not modify the returned Pixel unless you know the underlying packing format.

Parameters

comps	Array of component values.
compCount	Number of components in the array.

Returns: A Pixel suitable for use with this engine's draw calls.

◆ drawCircle()

virtual size_t PaintEngine::Impl::drawCircle	(	const Pixel &	pixel,
		const Point2Di32 &	center,
		int	radius
	)		const

virtual

Draws a circle outline.

Default implementation uses the midpoint circle algorithm.

Parameters

pixel	The pixel value to draw with.
center	Center of the circle.
radius	Radius in pixels.

Returns: The number of points drawn.

◆ drawEllipse()

virtual size_t PaintEngine::Impl::drawEllipse	(	const Pixel &	pixel,
		const Point2Di32 &	center,
		const Size2Du32 &	size
	)		const

virtual

Draws an ellipse outline.

Default implementation uses the midpoint ellipse algorithm.

Parameters

pixel	The pixel value to draw with.
center	Center of the ellipse.
size	Half-widths (rx, ry) of the ellipse.

Returns: The number of points drawn.

◆ drawLines()

virtual size_t PaintEngine::Impl::drawLines	(	const Pixel &	pixel,
		const Line2Di32 *	lines,
		size_t	count
	)		const

virtual

Draws a set of line segments onto the surface.

The default implementation rasterizes each line into a point list and calls drawPoints(). Reimplement for a natively faster line-drawing path.

Parameters

pixel	The pixel value to draw with.
lines	Array of line segments to draw.
count	Number of line segments in the array.

Returns: The number of points drawn.

◆ drawPoints()

virtual size_t PaintEngine::Impl::drawPoints	(	const Pixel &	pixel,
		const Point2Di32 *	points,
		size_t	pointCount
	)		const

virtual

Draws a set of points onto the surface.

Parameters

pixel	The pixel value to draw.
points	Array of points to draw.
pointCount	Number of points in the array.

Returns: The number of points actually drawn.

◆ drawRect()

virtual size_t PaintEngine::Impl::drawRect	(	const Pixel &	pixel,
		const Rect< int32_t > &	rect
	)		const

virtual

Draws a rectangle outline.

Default implementation rasterizes the outline into a point list and calls drawPoints().

Parameters

pixel	The pixel value to draw with.
rect	The rectangle to draw.

Returns: The number of points drawn.

◆ fill()

virtual bool PaintEngine::Impl::fill ( const Pixel & pixel ) const

virtual

Fills the entire surface with a single pixel value.

Parameters

pixel The pixel value to fill with.

Returns: true on success, false on failure.

◆ fillCircle()

virtual size_t PaintEngine::Impl::fillCircle	(	const Pixel &	pixel,
		const Point2Di32 &	center,
		int	radius
	)		const

virtual

Fills a circle with a solid color.

Default implementation uses the midpoint circle algorithm with horizontal scanline fill.

Parameters

pixel	The pixel value to fill with.
center	Center of the circle.
radius	Radius in pixels.

Returns: The number of points drawn.

◆ fillEllipse()

virtual size_t PaintEngine::Impl::fillEllipse	(	const Pixel &	pixel,
		const Point2Di32 &	center,
		const Size2Du32 &	size
	)		const

virtual

Fills an ellipse with a solid color.

Default implementation uses the midpoint ellipse algorithm with horizontal scanline fill.

Parameters

pixel	The pixel value to fill with.
center	Center of the ellipse.
size	Half-widths (rx, ry) of the ellipse.

Returns: The number of points drawn.

◆ fillRect()

virtual size_t PaintEngine::Impl::fillRect	(	const Pixel &	pixel,
		const Rect< int32_t > &	rect
	)		const

virtual

Fills a rectangle with a solid color.

Default implementation rasterizes all interior points.

Parameters

pixel	The pixel value to fill with.
rect	The rectangle to fill.

Returns: The number of points drawn.

◆ pixelFormat()

const PixelFormat * PaintEngine::Impl::pixelFormat ( ) const

inline

Returns the pixel format used by this implementation.

Returns: Pointer to the PixelFormat, or nullptr if unset.

The documentation for this class was generated from the following file:

include/promeki/proav/paintengine.h

Public Member Functions

Protected Attributes

Detailed Description

Member Function Documentation

◆ blit()

◆ compositePoints()

◆ createPixel()

◆ drawCircle()

◆ drawEllipse()

◆ drawLines()

◆ drawPoints()

◆ drawRect()

◆ fill()

◆ fillCircle()

◆ fillEllipse()

◆ fillRect()

◆ pixelFormat()