lv_draw_sw_gradient.h
Functions
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void lv_gradient_color_calculate(const lv_grad_dsc_t *dsc, int32_t range, int32_t frac, lv_grad_color_t *color_out, lv_opa_t *opa_out)
Compute the color in the given gradient and fraction Gradient are specified in a virtual [0-255] range, so this function scales the virtual range to the given range
- Parameters:
dsc -- The gradient descriptor to use
range -- The range to use in computation.
frac -- The current part used in the range. frac is in [0; range]
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lv_grad_t *lv_gradient_get(const lv_grad_dsc_t *gradient, int32_t w, int32_t h)
Get a gradient cache from the given parameters
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void lv_gradient_cleanup(lv_grad_t *grad)
Clean up the gradient item after it was get with
lv_grad_get_from_cache.- Parameters:
grad -- pointer to a gradient
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void lv_gradient_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)
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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
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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
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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)
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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
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void lv_gradient_linear_setup(lv_grad_dsc_t *dsc, const lv_area_t *coords)
Calculate constants from the given parameters that are used during rendering
- Parameters:
dsc -- gradient descriptor
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void lv_gradient_linear_cleanup(lv_grad_dsc_t *dsc)
Free up the allocated memory for the gradient calculation
- Parameters:
dsc -- gradient descriptor
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void lv_gradient_linear_get_line(lv_grad_dsc_t *dsc, int32_t xp, int32_t yp, int32_t width, lv_grad_t *result)
Calculate a line segment of a linear gradient
- Parameters:
dsc -- gradient descriptor
xp -- starting point x coordinate in gradient space
yp -- starting point y coordinate in gradient space
width -- width of the line segment in pixels
result -- color buffer for the resulting line segment
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void lv_gradient_radial_setup(lv_grad_dsc_t *dsc, const lv_area_t *coords)
Calculate constants from the given parameters that are used during rendering
- Parameters:
dsc -- gradient descriptor
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void lv_gradient_radial_cleanup(lv_grad_dsc_t *dsc)
Free up the allocated memory for the gradient calculation
- Parameters:
dsc -- gradient descriptor
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void lv_gradient_radial_get_line(lv_grad_dsc_t *dsc, int32_t xp, int32_t yp, int32_t width, lv_grad_t *result)
Calculate a line segment of a radial gradient
- Parameters:
dsc -- gradient descriptor
xp -- starting point x coordinate in gradient space
yp -- starting point y coordinate in gradient space
width -- width of the line segment in pixels
result -- color buffer for the resulting line segment
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void lv_gradient_conical_setup(lv_grad_dsc_t *dsc, const lv_area_t *coords)
Calculate constants from the given parameters that are used during rendering
- Parameters:
dsc -- gradient descriptor
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void lv_gradient_conical_cleanup(lv_grad_dsc_t *dsc)
Free up the allocated memory for the gradient calculation
- Parameters:
dsc -- gradient descriptor
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void lv_gradient_conical_get_line(lv_grad_dsc_t *dsc, int32_t xp, int32_t yp, int32_t width, lv_grad_t *result)
Calculate a line segment of a conical gradient
- Parameters:
dsc -- gradient descriptor
xp -- starting point x coordinate in gradient space
yp -- starting point y coordinate in gradient space
width -- width of the line segment in pixels
result -- color buffer for the resulting line segment
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struct _lv_gradient_cache_t