Pixel Definition

Collaboration diagram for Pixel Definition:

Detailed Description

Macros
#define	BJ_PIXEL_TYPE_INDEX   0x01
	Pixel type: Indexed (palette-based).
#define	BJ_PIXEL_TYPE_BITFIELD   0x02
	Pixel type: Bitfield representation (e.g., RGB565).
#define	BJ_PIXEL_TYPE_BYTES   0x03
	Pixel type: Byte-packed representation (e.g., RGBA8888).
#define	BJ_PIXEL_ORDER_RGB   0x01
	Pixel order: Red-Green-Blue (RGB).
#define	BJ_PIXEL_ORDER_XRGB   BJ_PIXEL_ORDER_RGB
	Pixel order: Same as BJ_PIXEL_ORDER_RGB with unused alpha.
#define	BJ_PIXEL_ORDER_BGR   0x02
	Pixel order: Blue-Green-Red (BGR).
#define	BJ_PIXEL_ORDER_XBGR   BJ_PIXEL_ORDER_BGR
	Pixel order: Same as BJ_PIXEL_ORDER_BGR with unused alpha.
#define	BJ_PIXEL_ORDER_RGBX   0x03
	Pixel order: Red-Green-Blue with padding byte (RGBX).
#define	BJ_PIXEL_ORDER_BGRX   0x04
	Pixel order: Blue-Green-Red with padding byte (BGRX).
#define	BJ_PIXEL_ORDER_ARGB   0x05
	Pixel order: Alpha-Red-Green-Blue (ARGB).
#define	BJ_PIXEL_ORDER_ABGR   0x06
	Pixel order: Alpha-Blue-Green-Red (ABGR).
#define	BJ_PIXEL_ORDER_RGBA   0x07
	Pixel order: Red-Green-Blue-Alpha (RGBA).
#define	BJ_PIXEL_ORDER_BGRA   0x08
	Pixel order: Blue-Green-Red-Alpha (BGRA).
#define	BJ_PIXEL_LAYOUT_1555   0x00
	Pixel layout: 16-bit with 1-bit alpha, 5-bit red, green, and blue (1555).
#define	BJ_PIXEL_LAYOUT_8888   0x01
	Pixel layout: 32-bit with 8 bits per channel (8888).
#define	BJ_PIXEL_LAYOUT_565   0x02
	Pixel layout: 16-bit with 5 bits for red and blue, 6 bits for green (565).
#define	BJ_PIXEL_MODE_MAKE(bpp, type, layout, order)
	Creates a pixel format mode from bits-per-pixel, type, layout, and order.
#define	BJ_PIXEL_MODE_MAKE_INDEXED(bpp)
	Creates a pixel format for indexed (palette-based) pixels.
#define	BJ_PIXEL_MODE_MAKE_BITFIELD_16(layout, order)
	Creates a 16-bit bitfield pixel format.
#define	BJ_PIXEL_MODE_MAKE_BITFIELD_32(layout, order)
	Creates a 32-bit bitfield pixel format.
#define	BJ_PIXEL_MODE_MAKE_BYTES(bpp, order)
	Creates a byte-packed pixel format.
#define	BJ_PIXEL_GET_BPP(fmt)
	Extracts the bits-per-pixel from a pixel format.
#define	BJ_PIXEL_GET_TYPE(fmt)
	Extracts the pixel type from a pixel format.
#define	BJ_PIXEL_GET_LAYOUT(fmt)
	Extracts the pixel layout from a pixel format.
#define	BJ_PIXEL_GET_ORDER(fmt)
	Extracts the pixel order from a pixel format.

Enumerations
enum	bj_pixel_mode {   BJ_PIXEL_MODE_UNKNOWN = 0x00u , BJ_PIXEL_MODE_INDEXED_1 = 0x00000101u , BJ_PIXEL_MODE_INDEXED_4 = 0x00000104u , BJ_PIXEL_MODE_INDEXED_8 = 0x00000108u ,   BJ_PIXEL_MODE_XRGB1555 = 0x01000210u , BJ_PIXEL_MODE_RGB565 = 0x01020210u , BJ_PIXEL_MODE_XRGB8888 = 0x01010220u , BJ_PIXEL_MODE_BGR24 = 0x02000318u }
	Representation of a pixel encoding. More...

Functions
void	bj_pixel_rgb (bj_pixel_mode mode, uint32_t value, uint8_t *p_red, uint8_t *p_green, uint8_t *p_blue)
	Gets the RGB value of a pixel given its 32-bits representation.
uint32_t	bj_pixel_value (bj_pixel_mode mode, uint8_t red, uint8_t green, uint8_t blue)
	Returns an opaque value representing a pixel color, given its RGB composition.
int	bj_compute_pixel_mode (uint8_t bpp, uint32_t red_mask, uint32_t green_mask, uint32_t blue_mask)
	Determine the most suitable bj_pixel_mode from a set of masks.
size_t	bj_compute_bitmap_stride (size_t width, bj_pixel_mode mode)
	Returns the stride used for encoding a bitmaps in Banjo.

Macro Definition Documentation

BJ_PIXEL_GET_BPP

#define BJ_PIXEL_GET_BPP

(

fmt

)

Value:

((fmt) & 0xFF)

Parameters

fmt	Pixel format value.

BJ_PIXEL_GET_LAYOUT

#define BJ_PIXEL_GET_LAYOUT

(

fmt

)

Value:

(((fmt) >> 16) & 0xFF)

Parameters

fmt	Pixel format value.

BJ_PIXEL_GET_ORDER

#define BJ_PIXEL_GET_ORDER

(

fmt

)

Value:

(((fmt) >> 24) & 0xFF)

Parameters

fmt	Pixel format value.

BJ_PIXEL_GET_TYPE

#define BJ_PIXEL_GET_TYPE

(

fmt

)

Value:

(((fmt) >> 8) & 0xFF)

Parameters

fmt	Pixel format value.

BJ_PIXEL_MODE_MAKE

#define BJ_PIXEL_MODE_MAKE	(		bpp,
			type,
			layout,
			order )

Value:

(((order & 0xFF) << 24) | ((layout & 0xFF) << 16) | ((type & 0xFF) << 8) | (bpp & 0xFF))

Parameters

bpp	Bits-per-pixel.
type	Pixel type (e.g., indexed, bitfield, or bytes).
layout	Pixel layout (e.g., 1555, 8888, or 565).
order	Pixel order (e.g., RGB, ARGB, etc.).

BJ_PIXEL_MODE_MAKE_BITFIELD_16

#define BJ_PIXEL_MODE_MAKE_BITFIELD_16	(		layout,
			order )

Value:

BJ_PIXEL_MODE_MAKE(16, BJ_PIXEL_TYPE_BITFIELD, layout, order)

Parameters

layout	Pixel layout (e.g., 1555, 565).
order	Pixel order (e.g., RGB, ARGB).

BJ_PIXEL_MODE_MAKE_BITFIELD_32

#define BJ_PIXEL_MODE_MAKE_BITFIELD_32	(		layout,
			order )

Value:

BJ_PIXEL_MODE_MAKE(32, BJ_PIXEL_TYPE_BITFIELD, layout, order)

Parameters

layout	Pixel layout (e.g., 8888).
order	Pixel order (e.g., RGB, ARGB).

BJ_PIXEL_MODE_MAKE_BYTES

#define BJ_PIXEL_MODE_MAKE_BYTES	(		bpp,
			order )

Value:

BJ_PIXEL_MODE_MAKE(bpp, BJ_PIXEL_TYPE_BYTES, 0, order)

Parameters

bpp	Bits-per-pixel.
order	Pixel order (e.g., RGB, ARGB).

BJ_PIXEL_MODE_MAKE_INDEXED

#define BJ_PIXEL_MODE_MAKE_INDEXED

(

bpp

)

Value:

BJ_PIXEL_MODE_MAKE(bpp, BJ_PIXEL_TYPE_INDEX, 0, 0)

Parameters

bpp	Bits-per-pixel.

Enumeration Type Documentation

bj_pixel_mode

enum bj_pixel_mode

Enumerator
BJ_PIXEL_MODE_UNKNOWN	Unknown/Invalid pixel mode.
BJ_PIXEL_MODE_INDEXED_1	1bpp indexed
BJ_PIXEL_MODE_INDEXED_4	4bpp indexed
BJ_PIXEL_MODE_INDEXED_8	8bpp indexed
BJ_PIXEL_MODE_XRGB1555	16bpp 555-RGB
BJ_PIXEL_MODE_RGB565	16bpp 565-RGB
BJ_PIXEL_MODE_XRGB8888	32bpp RGB
BJ_PIXEL_MODE_BGR24	24bpp BGR

Function Documentation

bj_compute_bitmap_stride()

size_t bj_compute_bitmap_stride	(	size_t	width,
		bj_pixel_mode	mode )

In a bitmap, the stride is the actual number of bytes used to encode a single row of pixels. Hence, the total size needed for a bitmap of width x height encoded with mode is equal to bj_compute_bitmap_stride(width, mode) * height.

Banjo uses the bits-per-pixel information from mode to compute the stride and aligns the byte count to 4.

Parameters

width	The width in pixel of a row
mode	The pixel mode

Returns

The bitmap stride in bytes

bj_compute_pixel_mode()

int bj_compute_pixel_mode	(	uint8_t	bpp,
		uint32_t	red_mask,
		uint32_t	green_mask,
		uint32_t	blue_mask )

This function can be used to retrieve what Banjo consider as the pixel mode corresponding to a given depth and masks.

If not suitable pixel mode is found, BJ_PIXEL_MODE_UNKNOWN is returned.

Parameters

bpp	The number of bits used to encode a pixel.
red_mask	A bitmask for the red channel information in the bits.
green_mask	A bitmask for the green channel information in the bits.
blue_mask	A bitmask for the blue channel information in the bits.

Returns

A bj_pixel_mode value.

bj_pixel_rgb()

void bj_pixel_rgb	(	bj_pixel_mode	mode,
		uint32_t	value,
		uint8_t *	p_red,
		uint8_t *	p_green,
		uint8_t *	p_blue )

Parameters

mode	The pixel mode
value	The opaque pixel value
p_red	A location to the red component
p_green	A location to the green component
p_blue	A location to the blue component

bj_pixel_value()

uint32_t bj_pixel_value	(	bj_pixel_mode	mode,
		uint8_t	red,
		uint8_t	green,
		uint8_t	blue )

Parameters

mode	The pixel mode
red	The red component of the color
green	The green component of the color
blue	The blue component of the color

Returns

An opaque uint32_t value.