QR encoding

Encode text into a 1-bpp packed QR raster (no capability required). More...

Functions
int	host_qr_measure (const char *data, uint8_t max_version, uint8_t ecc, uint16_t *out_modules)
	Measure the QR module count for data without rendering.
int	host_qr_render_bitmap (const char *data, uint8_t max_version, uint8_t ecc, uint8_t scale, uint8_t quiet_modules, uint8_t *out, size_t out_size, uint16_t *out_stride_bytes, uint16_t *out_height_px)
	Encode data into a packed 1-bpp QR raster.

Detailed Description

Encode text into a 1-bpp packed QR raster (no capability required).

Pure compute on caller memory. The output layout matches the surface and image APIs: packed rows, MSB-first, a set bit is black. Blit the result onto a surface with host_surface_draw_bitmap or send it to a printer.

Function Documentation

host_qr_measure()

int host_qr_measure	(	const char *	data,
		uint8_t	max_version,
		uint8_t	ecc,
		uint16_t *	out_modules )

Measure the QR module count for data without rendering.

Parameters

data	NUL-terminated payload text.
max_version	Maximum QR version 1..20 (0 = 20).
ecc	ECC level 0..3 (LOW, MED, QUART, HIGH).
out_modules	Receives the side length in modules.

Returns

HOST_OK, HOST_ERR_INVALID_ARG, HOST_ERR_GENERIC (data too long).

Definition at line 16 of file host_api_qr.cpp.

References HOST_ERR_GENERIC, HOST_ERR_INVALID_ARG, HOST_OK, and cdc::ui::qr::measure().

Referenced by cdc::plugin_manager::w_host_qr_measure().

host_qr_render_bitmap()

int host_qr_render_bitmap	(	const char *	data,
		uint8_t	max_version,
		uint8_t	ecc,
		uint8_t	scale,
		uint8_t	quiet_modules,
		uint8_t *	out,
		size_t	out_size,
		uint16_t *	out_stride_bytes,
		uint16_t *	out_height_px )

Encode data into a packed 1-bpp QR raster.

Side length is (modules + 2 * quiet_modules) * scale pixels, capped at

1. The quiet zone renders white.

   Parameters

   data	NUL-terminated payload text.
   max_version	Maximum QR version 1..20 (0 = 20).
   ecc	ECC level 0..3.
   scale	Pixels per module (0 counts as 1).
   quiet_modules	Quiet-zone width in modules per edge.
   out	Caller buffer for packed rows.
   out_size	Capacity of out in bytes.
   out_stride_bytes	Receives the row stride in bytes.
   out_height_px	Receives the side length in pixels.

   Returns

   HOST_OK, HOST_ERR_INVALID_ARG (bad args or side > 1024), HOST_ERR_NO_MEMORY (out too small), HOST_ERR_GENERIC.

Definition at line 24 of file host_api_qr.cpp.

References HOST_ERR_GENERIC, HOST_ERR_INVALID_ARG, HOST_ERR_NO_MEMORY, HOST_OK, and cdc::ui::qr::render().

Referenced by cdc::plugin_manager::w_host_qr_render_bitmap().