Does esp_lvgl_port have the rounder_cb function from LVGL? (BSP-703)

[modi12jin]

Board

esp32s3

Hardware Description

amoled_qspi_co5300

IDE Name

vscode

Operating System

ubuntu

Description

I am using an AMOLED screen and have requirements for coordinates.

Without using esp_lvgl_port, I handle it like this in lvgl

void example_lvgl_rounder_cb(struct _lv_disp_drv_t *disp_drv, lv_area_t *area)
{
    uint16_t x1 = area->x1;
    uint16_t x2 = area->x2;

    uint16_t y1 = area->y1;
    uint16_t y2 = area->y2;

    // round the start of coordinate down to the nearest 2M number
    area->x1 = (x1 >> 1) << 1;
    area->y1 = (y1 >> 1) << 1;
    // round the end of coordinate up to the nearest 2N+1 number
    area->x2 = ((x2 >> 1) << 1) + 1;
    area->y2 = ((y2 >> 1) << 1) + 1;
}

Is there a similar approach for esp_lvgl_port?

Sketch

blank

Other Steps to Reproduce

No response

I have checked existing issues, README.md and ESP32 Forum

• I confirm I have checked existing issues, online documentation and Troubleshooting guide.

[github-actions]

Hi @modi12jin! Please be aware that (1) the following suggestions are generated by a bot and haven't been fact-checked by Espressif Systems, (2) burning eFuses and enabling security features are irreversible operations and can damage your ESP32 device. We hope that this message will help you until an Espressif Engineer looks at your issue.

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Yes, you can use a custom rounder_cb function with LVGL when using esp_lvgl_port. The esp_lvgl_port component does not provide a built-in rounder_cb for specific display requirements, but it allows you to register your own callback function with the LVGL display driver, just as you would when using LVGL directly.

For AMOLED or other displays that require coordinates to be aligned (for example, to even numbers), you should implement and register your own rounder_cb function. The code you provided is correct for displays that require both x and y coordinates to be divisible by 2:

void example_lvgl_rounder_cb(struct _lv_disp_drv_t *disp_drv, lv_area_t *area)
{
    uint16_t x1 = area->x1;
    uint16_t x2 = area->x2;
    uint16_t y1 = area->y1;
    uint16_t y2 = area->y2;

    // round the start of coordinate down to the nearest even number
    area->x1 = (x1 >> 1) << 1;
    area->y1 = (y1 >> 1) << 1;
    // round the end of coordinate up to the nearest odd number
    area->x2 = ((x2 >> 1) << 1) + 1;
    area->y2 = ((y2 >> 1) << 1) + 1;
}

You should assign this function to the rounder_cb member of your lv_disp_drv_t structure after initializing the display with esp_lvgl_port. This approach is documented for similar display drivers, such as GC9B71 and SH8601, which have the same alignment requirements for coordinates when using LVGL and esp_panel_lcd_draw_bitmap() [ESP LCD GC9B71], [ESP LCD SH8601].

Summary:

• esp_lvgl_port does not automatically set a rounder_cb for you.
• You should implement and register your own rounder_cb as shown above, according to your display's requirements.

If you need help with where to set this in your code, let me know!

[nurdism]

was just about to open my own issue with this, I have made a PR to address this issue