lv_draw_private.h

API reference for lv_draw_private.h

See Also: Public APIThis is the private implementation. See the public header for the stable interface.lv_draw.h

Structs

struct

_lv_draw_task_t

Modified by NXP in 2024

Member	Type	Description
next	lv_draw_task_t *
type	lv_draw_task_type_t
area	lv_area_t	The area where to draw
_real_area	lv_area_t	The real draw area. E.g. for shadow, outline, or transformed images it's different from area
clip_area_original	lv_area_t	The original area which is updated
clip_area	lv_area_t	The clip area of the layer is saved here when the draw task is created. As the clip area of the layer can be changed as new draw tasks are added its current value needs to be saved. Therefore during drawing the layer's clip area shouldn't be used as it might be already changed for other draw tasks.
target_layer	lv_layer_t *
draw_unit	lv_draw_unit_t *
state	volatile int
draw_dsc	void *	int instead of lv_draw_task_state_t to be sure its atomic
opa	lv_opa_t	Opacity of the layer
preferred_draw_unit_id	uint8_t	The ID of the draw_unit which should take this task
preference_score	uint8_t	Set to which extent preferred_draw_unit_id is good at this task. 80: means 20% better (faster) than software rendering 100: the default value 110: means 10% worse (slower) than software rendering

struct

_lv_draw_mask_t

Member	Type	Description
user_data	void *

struct

_lv_draw_unit_t

Member	Type	Description
next	lv_draw_unit_t *
name	const char *	Name and ID of the draw unit, for debugging purposes only.
idx	int32_t
dispatch_cb	int32_t(*)(lv_draw_unit_t *draw_unit, lv_layer_t *layer)	Called to try to assign a draw task to itself. lv_draw_get_next_available_task can be used to get an independent draw task. A draw task should be assign only if the draw unit can draw it too
evaluate_cb	int32_t(*)(lv_draw_unit_t *draw_unit, lv_draw_task_t *task)
wait_for_finish_cb	int32_t(*)(lv_draw_unit_t *draw_unit)	Called to signal the unit to complete all tasks in order to return their ready status. This callback can be implemented in case of asynchronous task processing. Below is an example to show the difference between synchronous and asynchronous: Synchronous: LVGL thread DRAW thread HW task1 --> submit --> Receive task1 wait_for_finish() <– task1->state = READY <– Complete task1 task2 --> submit --> Receive task2 wait_for_finish() task2->state = READY <– Complete task2 task3 --> submit --> Receive task3 wait_for_finish() <– task3->state = READY <– Complete task3 task4 --> submit --> Receive task4 wait_for_finish() <– task4->state = READY <– Complete task4 NO MORE TASKS Asynchronous: LVGL thread DRAW thread HW is IDLE task1 --> queue task1 submit --> Receive task1 task2 --> queue task2 is BUSY (with task1) task3 --> queue task3 still BUSY (with task1) task4 --> queue task4 becomes IDLE <– task1->state = READY <– Complete task1 submit --> Receive task2, task3, task4 NO MORE TASKS wait_for_finish_cb() wait_for_finish() <– Complete task2, task3, task4 <– task2->state = READY <– <– task3->state = READY <– <– task4->state = READY <–
delete_cb	int32_t(*)(lv_draw_unit_t *draw_unit)	Called to delete draw unit.
event_cb	void(*)(lv_event_t *event)	Called when an event is sent to the draw unit.

struct

lv_draw_global_info_t

Member	Type	Description
unit_head	lv_draw_unit_t *
unit_cnt	uint32_t
used_memory_for_layers	uint32_t
sync	lv_thread_sync_t
circle_cache_mutex	lv_mutex_t
task_running	bool

Dependencies