In-memory framebuffer for RGB565 (16 bits per pixel) color displays. More...

Public Types
using	pixel_type = rgb565
	The value type written by set_pixel.

Public Member Functions
	rgb565_framebuffer (size_t width, size_t height)
	Creates a framebuffer of the given dimensions, with all pixels black.

size_t	width () const noexcept
	Returns the width in pixels.

size_t	height () const noexcept
	Returns the height in pixels.

void	set_pixel (size_t x, size_t y, rgb565 color) noexcept
	Sets a single pixel to the given color.

rgb565	get_pixel (size_t x, size_t y) const noexcept
	Returns the color of a single pixel.

void	fill (rgb565 color) noexcept
	Sets every pixel to the given color.

void	clear () noexcept
	Sets every pixel to black (equivalent to `fill({})`).

std::span< const rgb565 >	data () const noexcept
	Returns the raw pixel data.

void	flush (panel &panel, size_t x=0, size_t y=0) const
	Draws the full framebuffer to a panel.

void	flush_rows (panel &panel, size_t y_start, size_t y_end) const
	Draws a horizontal band of the framebuffer to a panel.

void	flush_region (panel &panel, size_t x_start, size_t y_start, size_t x_end, size_t y_end) const
	Draws a rectangular region of the framebuffer to a panel.

result< void >	try_flush (panel &panel, size_t x=0, size_t y=0) const
	Draws the full framebuffer to a panel.

result< void >	try_flush_rows (panel &panel, size_t y_start, size_t y_end) const
	Draws a horizontal band of the framebuffer to a panel.

result< void >	try_flush_region (panel &panel, size_t x_start, size_t y_start, size_t x_end, size_t y_end) const
	Draws a rectangular region of the framebuffer to a panel.

Static Public Member Functions
static result< rgb565_framebuffer >	make (size_t width, size_t height)
	Creates a framebuffer of the given dimensions, with all pixels black.

Detailed Description

In-memory framebuffer for RGB565 (16 bits per pixel) color displays.

Pixels are stored row-major as rgb565 values (panel byte order), so the buffer can be passed directly to a color panel's draw_bitmap. The pixel (x, y) is at index y * width() + x.

Draw into the framebuffer with set_pixel and friends, then push it to a panel with flush. A full frame at 16 bpp is large (a 240x320 panel needs 150 KB), so the framebuffer may also be sized as a horizontal band and flushed at a destination offset, rendering the frame in slices:

idfxx::lcd::rgb565_framebuffer band(display.width(), 40);
for (size_t y = 0; y < display.height(); y += band.height()) {
    band.fill({0, 0, 0});
    // ... draw the slice covering rows [y, y + band.height()) ...
    band.flush(display, 0, y);
}

This is a plain value type: copyable, movable, and independent of any panel.

Definition at line 53 of file rgb565_framebuffer.hpp.

Member Typedef Documentation

◆ pixel_type

using idfxx::lcd::rgb565_framebuffer::pixel_type = rgb565

The value type written by set_pixel.

Definition at line 56 of file rgb565_framebuffer.hpp.

Constructor & Destructor Documentation

◆ rgb565_framebuffer()

idfxx::lcd::rgb565_framebuffer::rgb565_framebuffer	(	size_t	width,
		size_t	height
	)

inline

Creates a framebuffer of the given dimensions, with all pixels black.

Parameters

width	Width in pixels; must be non-zero.
height	Height in pixels; must be non-zero.

Note: Only available when CONFIG_COMPILER_CXX_EXCEPTIONS is enabled in menuconfig.

Exceptions

std::system_error on error (e.g. invalid dimensions).

Definition at line 68 of file rgb565_framebuffer.hpp.

Member Function Documentation

◆ clear()

void idfxx::lcd::rgb565_framebuffer::clear ( )

inlinenoexcept

Sets every pixel to black (equivalent to fill({})).

Definition at line 131 of file rgb565_framebuffer.hpp.

References fill().

◆ data()

std::span< const rgb565 > idfxx::lcd::rgb565_framebuffer::data ( ) const

inlinenoexcept

Returns the raw pixel data.

The span holds width() * height() values in the row-major layout described in the class documentation, suitable for passing directly to a color panel's draw_bitmap.

Returns: A read-only view of the pixel data.

Definition at line 142 of file rgb565_framebuffer.hpp.

◆ fill()

void idfxx::lcd::rgb565_framebuffer::fill ( rgb565 color )

inlinenoexcept

Sets every pixel to the given color.

Parameters

color The color to fill with.

Definition at line 128 of file rgb565_framebuffer.hpp.

Referenced by clear().

◆ flush()

void idfxx::lcd::rgb565_framebuffer::flush	(	panel &	panel,
		size_t	x = `0`,
		size_t	y = `0`
	)		const

inline

Draws the full framebuffer to a panel.

The framebuffer's top-left corner lands at (x, y) on the panel, so a band-sized framebuffer can render a taller frame in slices. The panel must use the RGB565 format.

Parameters

panel	The panel to draw to.
x	Destination column of the framebuffer's left edge.
y	Destination row of the framebuffer's top edge.

Note: Only available when CONFIG_COMPILER_CXX_EXCEPTIONS is enabled in menuconfig.

Exceptions

std::system_error on error.

Definition at line 158 of file rgb565_framebuffer.hpp.

References try_flush(), and idfxx::unwrap().

◆ flush_region()

void idfxx::lcd::rgb565_framebuffer::flush_region	(	panel &	panel,
		size_t	x_start,
		size_t	y_start,
		size_t	x_end,
		size_t	y_end
	)		const

inline

Draws a rectangular region of the framebuffer to a panel.

The region spans columns [x_start, x_end) and rows [y_start, y_end), and is drawn to the same coordinates on the panel. Full-width regions transfer in a single draw; narrower regions transfer one draw per row. The panel must use the RGB565 format and should match the framebuffer's dimensions.

Parameters

panel	The panel to draw to.
x_start	First column of the region, inclusive.
y_start	First row of the region, inclusive.
x_end	End column, exclusive; must satisfy `x_start < x_end <= width()`.
y_end	End row, exclusive; must satisfy `y_start < y_end <= height()`.

Note: Only available when CONFIG_COMPILER_CXX_EXCEPTIONS is enabled in menuconfig.

Exceptions

std::system_error on error (e.g. an invalid region).

Definition at line 192 of file rgb565_framebuffer.hpp.

References try_flush_region(), and idfxx::unwrap().

◆ flush_rows()

void idfxx::lcd::rgb565_framebuffer::flush_rows	(	panel &	panel,
		size_t	y_start,
		size_t	y_end
	)		const

inline

Draws a horizontal band of the framebuffer to a panel.

The band spans rows [y_start, y_end) across the full width, and is drawn to the same rows on the panel. The panel must use the RGB565 format and should match the framebuffer's dimensions.

Parameters

panel	The panel to draw to.
y_start	First row of the band, inclusive.
y_end	End row of the band, exclusive; must satisfy `y_start < y_end <= height()`.

Note: Only available when CONFIG_COMPILER_CXX_EXCEPTIONS is enabled in menuconfig.

Exceptions

std::system_error on error (e.g. an invalid row range).

Definition at line 173 of file rgb565_framebuffer.hpp.

References try_flush_rows(), and idfxx::unwrap().

◆ get_pixel()

rgb565 idfxx::lcd::rgb565_framebuffer::get_pixel	(	size_t	x,
		size_t	y
	)		const

inlinenoexcept

Returns the color of a single pixel.

Parameters

x	Column, in `[0, width())`.
y	Row, in `[0, height())`.

Returns: The pixel's color, or black if the coordinates are out of range.

Definition at line 117 of file rgb565_framebuffer.hpp.

◆ height()

size_t idfxx::lcd::rgb565_framebuffer::height ( ) const

inlinenoexcept

Returns the height in pixels.

Definition at line 92 of file rgb565_framebuffer.hpp.

Referenced by make().

◆ make()

static result< rgb565_framebuffer > idfxx::lcd::rgb565_framebuffer::make	(	size_t	width,
		size_t	height
	)

inlinestatic

Creates a framebuffer of the given dimensions, with all pixels black.

Parameters

width	Width in pixels; must be non-zero.
height	Height in pixels; must be non-zero.

Returns: The new rgb565_framebuffer, or an error.

Return values

idfxx::errc::invalid_arg if width or height is zero.

Definition at line 81 of file rgb565_framebuffer.hpp.

References idfxx::error(), height(), idfxx::invalid_arg, and width().

◆ set_pixel()

void idfxx::lcd::rgb565_framebuffer::set_pixel	(	size_t	x,
		size_t	y,
		rgb565	color
	)

inlinenoexcept

Sets a single pixel to the given color.

Out-of-range coordinates are ignored.

Parameters

x	Column, in `[0, width())`.
y	Row, in `[0, height())`.
color	The color to write.

Definition at line 103 of file rgb565_framebuffer.hpp.

◆ try_flush()

result< void > idfxx::lcd::rgb565_framebuffer::try_flush	(	panel &	panel,
		size_t	x = `0`,
		size_t	y = `0`
	)		const

inline

Draws the full framebuffer to a panel.

The framebuffer's top-left corner lands at (x, y) on the panel, so a band-sized framebuffer can render a taller frame in slices. The panel must use the RGB565 format.

Parameters

panel	The panel to draw to.
x	Destination column of the framebuffer's left edge.
y	Destination row of the framebuffer's top edge.

Returns: Success, or an error.

Definition at line 209 of file rgb565_framebuffer.hpp.

References idfxx::lcd::panel::try_draw_bitmap().

Referenced by flush().

◆ try_flush_region()

result< void > idfxx::lcd::rgb565_framebuffer::try_flush_region	(	panel &	panel,
		size_t	x_start,
		size_t	y_start,
		size_t	x_end,
		size_t	y_end
	)		const

inline

Draws a rectangular region of the framebuffer to a panel.

The region spans columns [x_start, x_end) and rows [y_start, y_end), and is drawn to the same coordinates on the panel. Full-width regions transfer in a single draw; narrower regions transfer one draw per row. The panel must use the RGB565 format and should match the framebuffer's dimensions.

Parameters

panel	The panel to draw to.
x_start	First column of the region, inclusive.
y_start	First row of the region, inclusive.
x_end	End column, exclusive; must satisfy `x_start < x_end <= width()`.
y_end	End row, exclusive; must satisfy `y_start < y_end <= height()`.

Returns: Success, or an error.

Return values

idfxx::errc::invalid_arg if the region is invalid.

Definition at line 254 of file rgb565_framebuffer.hpp.

References idfxx::error(), idfxx::invalid_arg, and idfxx::lcd::panel::try_draw_bitmap().

Referenced by flush_region(), and try_flush_rows().

◆ try_flush_rows()

result< void > idfxx::lcd::rgb565_framebuffer::try_flush_rows	(	panel &	panel,
		size_t	y_start,
		size_t	y_end
	)		const

inline

Draws a horizontal band of the framebuffer to a panel.

The band spans rows [y_start, y_end) across the full width, and is drawn to the same rows on the panel. The panel must use the RGB565 format and should match the framebuffer's dimensions.

Parameters

panel	The panel to draw to.
y_start	First row of the band, inclusive.
y_end	End row of the band, exclusive; must satisfy `y_start < y_end <= height()`.

Returns: Success, or an error.

Return values

idfxx::errc::invalid_arg if the row range is invalid.

Definition at line 232 of file rgb565_framebuffer.hpp.

References try_flush_region().

Referenced by flush_rows().

◆ width()

size_t idfxx::lcd::rgb565_framebuffer::width ( ) const

inlinenoexcept

Returns the width in pixels.

Definition at line 89 of file rgb565_framebuffer.hpp.

Referenced by make().

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

idfxx_lcd/include/idfxx/lcd/rgb565_framebuffer.hpp

Public Types

Public Member Functions

Static Public Member Functions

Detailed Description

Member Typedef Documentation

◆ pixel_type

Constructor & Destructor Documentation

◆ rgb565_framebuffer()

Member Function Documentation

◆ clear()

◆ data()

◆ fill()

◆ flush()

◆ flush_region()

◆ flush_rows()

◆ get_pixel()

◆ height()

◆ make()

◆ set_pixel()

◆ try_flush()

◆ try_flush_region()

◆ try_flush_rows()

◆ width()