lv_grad.h

Enums

enum lv_grad_dir_t

The direction of the gradient.

Values:

enumerator LV_GRAD_DIR_NONE: No gradient (the grad_color property is ignored)

enumerator LV_GRAD_DIR_VER: Simple vertical (top to bottom) gradient

enumerator LV_GRAD_DIR_HOR: Simple horizontal (left to right) gradient

enumerator LV_GRAD_DIR_LINEAR: Linear gradient defined by start and end points. Can be at any angle.

enumerator LV_GRAD_DIR_RADIAL: Radial gradient defined by start and end circles

enumerator LV_GRAD_DIR_CONICAL: Conical gradient defined by center point, start and end angles

enum lv_grad_extend_t

Gradient behavior outside the defined range.

Values:

enumerator LV_GRAD_EXTEND_PAD: Repeat the same color

enumerator LV_GRAD_EXTEND_REPEAT: Repeat the pattern

enumerator LV_GRAD_EXTEND_REFLECT: Repeat the pattern mirrored

Functions

void lv_grad_init_stops(lv_grad_dsc_t *grad, const lv_color_t colors[], const lv_opa_t opa[], const uint8_t fracs[], int num_stops)

Initialize gradient color map from a table

Parameters:

grad – pointer to a gradient descriptor
colors – color array
fracs – position array (0..255): if NULL, then colors are distributed evenly
opa – opacity array: if NULL, then LV_OPA_COVER is assumed
num_stops – number of gradient stops (1..LV_GRADIENT_MAX_STOPS)

void lv_grad_horizontal_init(lv_grad_dsc_t *dsc)

Helper function to initialize a horizontal gradient.

Parameters:: dsc – gradient descriptor

void lv_grad_vertical_init(lv_grad_dsc_t *dsc)

Helper function to initialize a vertical gradient.

Parameters:: dsc – gradient descriptor

void lv_grad_linear_init(lv_grad_dsc_t *dsc, int32_t from_x, int32_t from_y, int32_t to_x, int32_t to_y, lv_grad_extend_t extend)

Helper function to initialize linear gradient

Parameters:

dsc – gradient descriptor
from_x – start x position: can be a coordinate or an lv_pct() value predefined constants LV_GRAD_LEFT, LV_GRAD_RIGHT, LV_GRAD_TOP, LV_GRAD_BOTTOM, LV_GRAD_CENTER can be used as well
from_y – start y position
to_x – end x position
to_y – end y position
extend – one of LV_GRAD_EXTEND_PAD, LV_GRAD_EXTEND_REPEAT or LV_GRAD_EXTEND_REFLECT

void lv_grad_radial_init(lv_grad_dsc_t *dsc, int32_t center_x, int32_t center_y, int32_t to_x, int32_t to_y, lv_grad_extend_t extend)

Helper function to initialize radial gradient

Parameters:

dsc – gradient descriptor
center_x – center x position: can be a coordinate or an lv_pct() value predefined constants LV_GRAD_LEFT, LV_GRAD_RIGHT, LV_GRAD_TOP, LV_GRAD_BOTTOM, LV_GRAD_CENTER can be used as well
center_y – center y position
to_x – point on the end circle x position
to_y – point on the end circle y position
extend – one of LV_GRAD_EXTEND_PAD, LV_GRAD_EXTEND_REPEAT or LV_GRAD_EXTEND_REFLECT

void lv_grad_radial_set_focal(lv_grad_dsc_t *dsc, int32_t center_x, int32_t center_y, int32_t radius)

Set focal (starting) circle of a radial gradient

Parameters:

dsc – gradient descriptor
center_x – center x position: can be a coordinate or an lv_pct() value predefined constants LV_GRAD_LEFT, LV_GRAD_RIGHT, LV_GRAD_TOP, LV_GRAD_BOTTOM, LV_GRAD_CENTER can be used as well
center_y – center y position
radius – radius of the starting circle (NOTE: this must be a scalar number, not percentage)

void lv_grad_conical_init(lv_grad_dsc_t *dsc, int32_t center_x, int32_t center_y, int32_t start_angle, int32_t end_angle, lv_grad_extend_t extend)

Helper function to initialize conical gradient

Parameters:

dsc – gradient descriptor
center_x – center x position: can be a coordinate or an lv_pct() value predefined constants LV_GRAD_LEFT, LV_GRAD_RIGHT, LV_GRAD_TOP, LV_GRAD_BOTTOM, LV_GRAD_CENTER can be used as well
center_y – center y position
start_angle – start angle in degrees
end_angle – end angle in degrees
extend – one of LV_GRAD_EXTEND_PAD, LV_GRAD_EXTEND_REPEAT or LV_GRAD_EXTEND_REFLECT

struct lv_grad_stop_t

#include <lv_grad.h>

A gradient stop definition. This matches a color and a position in a virtual 0-255 scale.

Public Members

lv_color_t color: The stop color

lv_opa_t opa: The opacity of the color

uint8_t frac: The stop position in 1/255 unit

struct lv_grad_dsc_t

#include <lv_grad.h>

A descriptor of a gradient.

Public Members

lv_grad_stop_t stops[2]: A gradient stop array

uint8_t stops_count: The number of used stops in the array

lv_grad_dir_t dir: The gradient direction. Any of LV_GRAD_DIR_NONE, LV_GRAD_DIR_VER, LV_GRAD_DIR_HOR, LV_GRAD_TYPE_LINEAR, LV_GRAD_TYPE_RADIAL, LV_GRAD_TYPE_CONICAL

lv_grad_extend_t extend: Behaviour outside the defined range. LV_GRAD_EXTEND_NONE, LV_GRAD_EXTEND_PAD, LV_GRAD_EXTEND_REPEAT, LV_GRAD_EXTEND_REFLECT

lv_point_t start: Linear gradient vector start point

lv_point_t end

Linear gradient vector end point

Center of the ending circle in local coordinates

struct lv_grad_dsc_t::[anonymous]::[anonymous] linear

lv_point_t focal: Center of the focal (starting) circle in local coordinates

lv_point_t focal_extent: Point on the circle (can be the same as the center)

lv_point_t end_extent: Point on the circle determining the radius of the gradient

struct lv_grad_dsc_t::[anonymous]::[anonymous] radial

lv_point_t center: Conical gradient center point

int16_t start_angle: Start angle 0..3600

int16_t end_angle: End angle 0..3600

struct lv_grad_dsc_t::[anonymous]::[anonymous] conical

union lv_grad_dsc_t::[anonymous] params

void *state