lv_draw_arc.h

Functions

void lv_draw_arc_dsc_init(lv_draw_arc_dsc_t *dsc)

Initialize an arc draw descriptor.

Parameters:

dsc – pointer to a draw descriptor

lv_draw_arc_dsc_t *lv_draw_task_get_arc_dsc(lv_draw_task_t *task)

Try to get an arc draw descriptor from a draw task.

Parameters:

task – draw task

Returns:

the task's draw descriptor or NULL if the task is not of type LV_DRAW_TASK_TYPE_ARC

void lv_draw_arc(lv_layer_t *layer, const lv_draw_arc_dsc_t *dsc)

Create an arc draw task.

Parameters:

  • layer – pointer to a layer

  • dsc – pointer to an initialized draw descriptor variable

void lv_draw_arc_get_area(int32_t x, int32_t y, uint16_t radius, lv_value_precise_t start_angle, lv_value_precise_t end_angle, int32_t w, bool rounded, lv_area_t *area)

Get an area the should be invalidated when the arcs angle changed between start_angle and end_ange

Parameters:

  • x – the x coordinate of the center of the arc

  • y – the y coordinate of the center of the arc

  • radius – the radius of the arc

  • start_angle – the start angle of the arc (0 deg on the bottom, 90 deg on the right)

  • end_angle – the end angle of the arc

  • w – width of the arc

  • rounded – true: the arc is rounded

  • area – store the area to invalidate here

struct lv_draw_arc_dsc_t

Public Members

lv_draw_dsc_base_t base
lv_color_t color

The color of the arc

int32_t width

The width (thickness) of the arc

lv_value_precise_t start_angle

The start angle in 1 degree units (if LV_USE_FLOAT is enabled a float number can be also used) 0° is the 3 o'clock position, 90° is the 6 o'clock, etc.

lv_value_precise_t end_angle

The end angle, similarly to start_angle.

lv_point_t center

The center point of the arc.

uint16_t radius

The outer radius of the arc

const void *img_src

An image source to be used instead of color. NULL if unused

lv_opa_t opa

Opacity of the arc in 0...255 range. LV_OPA_TRANSP, LV_OPA_10, LV_OPA_20, .. LV_OPA_COVER can be used as well

uint8_t rounded

1: Make the arc ends rounded