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feat(canvas) add lv_canvas_set_px_opa

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fixes #2665
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Gabor Kiss-Vamosi
2021-10-19 13:44:40 +02:00
parent dfa4f5cff5
commit b3b3ffc2b3
5 changed files with 38 additions and 7 deletions
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docs/widgets/core/canvas.md
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@@ -33,10 +33,13 @@ For `LV_IMG_CF_INDEXED_1/2/4/8` color formats a palette needs to be
initialized with `lv_canvas_set_palette(canvas, 3, LV_COLOR_RED)`. It sets pixels with *index=3* to red.
### Drawing
To set a pixel on the canvas, use `lv_canvas_set_px(canvas, x, y, LV_COLOR_RED)`.
With `LV_IMG_CF_INDEXED_...` or `LV_IMG_CF_ALPHA_...`, the index of the color or the alpha value needs to be passed as color.
To set a pixel's color on the canvas, use `lv_canvas_set_px_color(canvas, x, y, LV_COLOR_RED)`.
With `LV_IMG_CF_INDEXED_...` the index of the color needs to be passed as color.
E.g. `lv_color_t c; c.full = 3;`
To set a pixel's opacity with `LV_IMG_CF_TRUE_COLOR_ALPHA` or `LV_IMG_CF_ALPHA_...` format on the canvas, use `lv_canvas_set_px_opa(canvas, x, y, opa)`.
`lv_canvas_fill_bg(canvas, LV_COLOR_BLUE, LV_OPA_50)` fills the whole canvas to blue with 50% opacity. Note that if the current color format doesn't support colors (e.g. `LV_IMG_CF_ALPHA_2BIT`) the color will be ignored.
Similarly, if opacity is not supported (e.g. `LV_IMG_CF_TRUE_COLOR`) it will be ignored.