Internals and scratch

The converters the Benchmark example measures, the flush's chunk buffers as scratch memory, and the frame size. More...

Functions
uint32_t	gfx_convertRows_ram (uint8_t *dst, uint16_t row, uint16_t rows)
	Converts framebuffer rows into the panel's format, with the converter in SRAM.
uint32_t	gfx_convertRows_flash (uint8_t *dst, uint16_t row, uint16_t rows)
	Converts framebuffer rows into the panel's format, with the converter in flash (for comparison with gfx_convertRows_ram()).
uint32_t	gfx_convertSpan_ram (uint8_t *dst, const uint8_t *src, uint32_t srcBytes)
	Converts a run of framebuffer bytes into the panel's format (the SRAM converter every flush uses).
uint8_t *	gfx_chunkScratch (void)
	1 KB of word-aligned scratch memory: the flush's chunk buffers.
uint32_t	gfx_frameBytes (void)
	Bytes the panel receives for a full frame in the current mode.

Detailed Description

The converters the Benchmark example measures, the flush's chunk buffers as scratch memory, and the frame size.

Function Documentation

gfx_convertRows_ram()

uint32_t gfx_convertRows_ram	(	uint8_t *	dst,
		uint16_t	row,
		uint16_t	rows
	)

Converts framebuffer rows into the panel's format, with the converter in SRAM.

_ram lives in SRAM, _flash lives in flash. Benchmarking both is how you measure the 3-wait-state penalty.

Parameters

dst	Where the panel-format bytes go.
row	First framebuffer row.
rows	How many rows.

Returns

Bytes written to dst.

gfx_convertRows_flash()

uint32_t gfx_convertRows_flash	(	uint8_t *	dst,
		uint16_t	row,
		uint16_t	rows
	)

Converts framebuffer rows into the panel's format, with the converter in flash (for comparison with gfx_convertRows_ram()).

Parameters

dst	Where the panel-format bytes go.
row	First framebuffer row.
rows	How many rows.

Returns

Bytes written to dst.

gfx_convertSpan_ram()

uint32_t gfx_convertSpan_ram	(	uint8_t *	dst,
		const uint8_t *	src,
		uint32_t	srcBytes
	)

Converts a run of framebuffer bytes into the panel's format (the SRAM converter every flush uses).

Parameters

dst	Where the panel-format bytes go.
src	4 bpp source bytes, two pixels each.
srcBytes	How many source bytes.

Returns

Bytes written to dst.

gfx_chunkScratch()

uint8_t * gfx_chunkScratch

(

void

)

1 KB of word-aligned scratch memory: the flush's chunk buffers.

2 * GFX_CHUNK_BYTES, idle from gfx_wait() until the next flush starts. Handy for decoding, masks, building a flash page, an SD card block - never across a flush. gfx_sprite4Rot() and gfx_textFx() use it, so it does not survive them either.

Returns

The start of the scratch.

gfx_frameBytes()

uint32_t gfx_frameBytes

(

void

)

Bytes the panel receives for a full frame in the current mode.

Returns

32768 (16 bpp), 24576 (12 bpp) or 49152 (18 bpp) at 128x128.