lv_draw_buf.h

Typedefs

typedef void *(*lv_draw_buf_malloc_cb)(size_t size, lv_color_format_t color_format)

typedef void (*lv_draw_buf_free_cb)(void *draw_buf)

typedef void *(*lv_draw_buf_align_cb)(void *buf, lv_color_format_t color_format)

typedef void (*lv_draw_buf_invalidate_cache_cb)(void *buf, uint32_t stride, lv_color_format_t color_format, const lv_area_t *area)

typedef uint32_t (*lv_draw_buf_width_to_stride_cb)(uint32_t w, lv_color_format_t color_format)

typedef void *(*lv_draw_buf_go_to_xy_cb)(const void *buf, uint32_t stride, lv_color_format_t color_format, lv_coord_t x, lv_coord_t y)

typedef void (*lv_draw_buf_clear_cb)(void *buf, uint32_t w, uint32_t h, lv_color_format_t color_format, const lv_area_t *a)

typedef void (*lv_draw_buf_copy_cb)(void *dest_buf, uint32_t dest_w, uint32_t dest_h, const lv_area_t *dest_area_to_copy, void *src_buf, uint32_t src_w, uint32_t src_h, const lv_area_t *src_area_to_copy, lv_color_format_t color_format)

Functions

void _lv_draw_buf_init_handlers(void): Called internally to initialize the draw_buf_handlers in lv_global

lv_draw_buf_handlers_t *lv_draw_buf_get_handlers(void)

Get the struct which holds the callbacks for draw buf management. Custom callback can be set on the returned value

Returns:: pointer to the struct of handlers

void *lv_draw_buf_malloc(size_t size_bytes, lv_color_format_t color_format)

Allocate a buffer with the given size. It might allocate slightly larger buffer to fulfill the alignment requirements.

Note

The returned value can be saved in draw_buf->buf

Note

lv_draw_buf_align can be sued the align the returned pointer

Parameters:

size -- the size to allocate in bytes
color_format -- the color format of the buffer to allocate

Returns:

the allocated buffer.

void lv_draw_buf_free(void *buf)

Free a buffer allocated by lv_draw_buf_malloc

Parameters:: buf -- pointer to a buffer

void *lv_draw_buf_align(void *buf, lv_color_format_t color_format)

Align the address of a buffer. The buffer needs to be large enough for the real data after alignment

Parameters:

buf -- the data to align
color_format -- the color format of the buffer

Returns:

the aligned buffer

void lv_draw_buf_invalidate_cache(void *buf, uint32_t stride, lv_color_format_t color_format, const lv_area_t *area)

Invalidate the cache of the buffer

Parameters:

buf -- a memory address to invalidate
stride -- stride of the buffer
color_format -- color format of the buffer
area -- the area to invalidate in the buffer

uint32_t lv_draw_buf_width_to_stride(uint32_t w, lv_color_format_t color_format)

Calculate the stride in bytes based on a width and color format

Parameters:

w -- the width in pixels
color_format -- the color format

Returns:

the stride in bytes

void *lv_draw_buf_go_to_xy(const void *buf, uint32_t stride, lv_color_format_t color_format, lv_coord_t x, lv_coord_t y)

Got to a pixel at X and Y coordinate in a buffer

Parameters:

buf -- pointer to a buffer
stride -- stride of the buffer
color_format -- color format of the buffer
x -- the target X coordinate
y -- the target X coordinate

Returns:

buf offset to point to the given X and Y coordinate

void lv_draw_buf_clear(void *buf, uint32_t w, uint32_t h, lv_color_format_t color_format, const lv_area_t *a)

Clear an area on the buffer

Parameters:

draw_buf -- pointer to draw buffer
w -- width of the buffer
h -- height of the buffer
color_format -- color format of the buffer
a -- the area to clear, or NULL to clear the whole buffer

void lv_draw_buf_copy(void *dest_buf, uint32_t dest_w, uint32_t dest_h, const lv_area_t *dest_area_to_copy, void *src_buf, uint32_t src_w, uint32_t src_h, const lv_area_t *src_area_to_copy, lv_color_format_t color_format)