lv_draw.h

API reference for lv_draw.h

Summary

Functions

draw/lv_draw.h:265function

lv_draw_get_available_task

If there is only one draw unit check the first draw task if it's available. If there are multiple draw units call lv_draw_get_next_available_task to find a task.

lv_draw_task_t * lv_draw_get_available_task(lv_layer_t *layer, lv_draw_task_t *t_prev, uint8_t draw_unit_id)

Name	Type	Description
`layer`	`lv_layer_t *`	the draw layer to search in
`t_prev`	`lv_draw_task_t *`	continue searching from this task
`draw_unit_id`	`uint8_t`	check the task where `preferred_draw_unit_id` equals this value or `LV_DRAW_UNIT_NONE`

Returns: lv_draw_task_t * — an available draw task or NULL if there is not any

draw/lv_draw.h:284function

lv_draw_get_next_available_task

Find and available draw task

lv_draw_task_t * lv_draw_get_next_available_task(lv_layer_t *layer, lv_draw_task_t *t_prev, uint8_t draw_unit_id)

Name	Type	Description
`layer`	`lv_layer_t *`	the draw layer to search in
`t_prev`	`lv_draw_task_t *`	continue searching from this task
`draw_unit_id`	`uint8_t`	check the task where `preferred_draw_unit_id` equals this value or `LV_DRAW_UNIT_NONE`

Returns: lv_draw_task_t * — an available draw task or NULL if there is not any

draw/lv_draw.h:294function

Tell how many draw task are waiting to be drawn on the area of t_check. It can be used to determine if a GPU shall combine many draw tasks into one or not. If a lot of tasks are waiting for the current ones it makes sense to draw them one-by-one to not block the dependent tasks' rendering

uint32_t lv_draw_get_dependent_count(lv_draw_task_t *t_check)

Name	Type	Description
`t_check`	`lv_draw_task_t *`	the task whose dependent tasks shall be counted

Returns: uint32_t — number of tasks depending on t_check

draw/lv_draw.h:358function

lv_draw_task_get_type

Get the type of a draw task

lv_draw_task_type_t lv_draw_task_get_type(const lv_draw_task_t *t)

Name	Type	Description
`t`	`const lv_draw_task_t *`	the draw task to get the type of

Returns: lv_draw_task_type_t — the draw task type

draw/lv_draw.h:365function

lv_draw_task_get_draw_dsc

Get the draw descriptor of a draw task

void * lv_draw_task_get_draw_dsc(const lv_draw_task_t *t)

Name	Type	Description
`t`	`const lv_draw_task_t *`	the draw task to get the draw descriptor of

Returns: void * — a void pointer to the draw descriptor

draw/lv_draw.h:372function

lv_draw_task_get_area

Get the draw area of a draw task

void lv_draw_task_get_area(const lv_draw_task_t *t, lv_area_t *area)

Name	Type	Description
`t`	`const lv_draw_task_t *`	the draw task to get the draw area of
`area`	`lv_area_t *`	the destination where the draw area will be stored

Enums

draw/lv_draw.h:47enum

lv_draw_task_type_t

Name	Value
`LV_DRAW_TASK_TYPE_NONE`	`0`
`LV_DRAW_TASK_TYPE_FILL`
`LV_DRAW_TASK_TYPE_BORDER`
`LV_DRAW_TASK_TYPE_BOX_SHADOW`
`LV_DRAW_TASK_TYPE_LETTER`
`LV_DRAW_TASK_TYPE_LABEL`
`LV_DRAW_TASK_TYPE_IMAGE`
`LV_DRAW_TASK_TYPE_LAYER`
`LV_DRAW_TASK_TYPE_LINE`
`LV_DRAW_TASK_TYPE_ARC`
`LV_DRAW_TASK_TYPE_TRIANGLE`
`LV_DRAW_TASK_TYPE_MASK_RECTANGLE`
`LV_DRAW_TASK_TYPE_MASK_BITMAP`
`LV_DRAW_TASK_TYPE_BLUR`
`LV_DRAW_TASK_TYPE_VECTOR`
`LV_DRAW_TASK_TYPE_3D`

Used by 1 function

lv_draw_add_task — param type

draw/lv_draw.h:70enum

lv_draw_task_state_t

Name	Description
`LV_DRAW_TASK_STATE_BLOCKED`	Waiting for an other task to be finished. For example in case of `LV_DRAW_TASK_TYPE_LAYER` (used to blend a layer) is blocked until all the draw tasks of the layer is rendered.
`LV_DRAW_TASK_STATE_WAITING`	The draw task is added to the layers list and waits to be rendered.
`LV_DRAW_TASK_STATE_QUEUED`	The draw task is added to the command queue of the draw unit. As the queued task are executed in order it's possible to queue multiple draw task (for the same draw unit) even if they are depending on each other. Therefore `lv_draw_get_available_task` and `lv_draw_get_next_available_task` can return draw task for the same draw unit even if a dependent draw task is not finished ready yet.
`LV_DRAW_TASK_STATE_IN_PROGRESS`	The draw task is being rendered. This draw task needs to be finished before `lv_draw_get_available_task` and `lv_draw_get_next_available_task` would return any depending draw tasks.
`LV_DRAW_TASK_STATE_FINISHED`	The draw task is rendered. It will be removed from the draw task list of the layer and freed automatically.

Structs

struct

_lv_layer_t

Member	Type	Description
`draw_buf`	`lv_draw_buf_t *`	Target draw buffer of the layer
`draw_task_head`	`lv_draw_task_t *`	Linked list of draw tasks
`parent`	`lv_layer_t *`	Parent layer
`next`	`lv_layer_t *`	Next layer
`user_data`	`void *`	User data
`buf_area`	`lv_area_t`	The absolute coordinates of the buffer
`phy_clip_area`	`lv_area_t`	The physical clipping area relative to the display
`_clip_area`	`lv_area_t`	NEVER USE IT DRAW UNITS. USED INTERNALLY DURING DRAW TASK CREATION. The current clip area with absolute coordinates, always the same or smaller than `buf_area` Can be set before new draw tasks are added to indicate the clip area of the draw tasks. Therefore `lv_draw_add_task()` always saves it in the new draw task to know the clip area when the draw task was added. During drawing the draw units also sees the saved clip_area and should use it during drawing. During drawing the layer's clip area shouldn't be used as it might be already changed for other draw tasks.
`partial_y_offset`	`int32_t`	Partial y offset
`recolor`	`lv_color32_t`	Recolor of the layer
`color_format`	`lv_color_format_t`	The color format of the layer. LV_COLOR_FORMAT_...
`all_tasks_added`	`bool`	Flag indicating all tasks are added
`opa`	`lv_opa_t`	Opacity of the layer

struct

lv_draw_dsc_base_t

Member	Type	Description
`obj`	`lv_obj_t *`	The widget for which draw descriptor was created
`part`	`uint32_t`	The widget part for which draw descriptor was created
`id1`	`uint32_t`	A widget type specific ID (e.g. table row index). See the docs of the given widget.
`id2`	`uint32_t`	A widget type specific ID (e.g. table column index). See the docs of the given widget.
`layer`	`lv_layer_t *`	The target layer
`drop_shadow_ofs_x`	`int16_t`	Drop shadow offset in X
`drop_shadow_ofs_y`	`int16_t`	Drop shadow offset in Y
`drop_shadow_color`	`lv_color_t`	Drop shadow color
`drop_shadow_opa`	`lv_opa_t`	Drop shadow opacity
`drop_shadow_blur_radius`	`int32_t`	Drop shadow blur radius
`drop_shadow_quality`	`lv_blur_quality_t`	Drop shadow blur quality
`dsc_size`	`size_t`	Size of the specific draw descriptor into which this base descriptor is embedded
`user_data`	`void *`	Any custom user data