RT1176 LVGL + VGLITE: Bad font rendering

[P3r3gr1nus]

I am trying to apply VGLITE to my code, based on LVGL on RT1176. I am running the demo benchmark. 

When I set:

#define LV_USE_DRAW_SW 1
#define LV_USE_DRAW_VGLITE 0

the rendering is fine. 

When I enable VGLITE 
#define LV_USE_DRAW_SW 0
#define LV_USE_DRAW_VGLITE 1

the letters are destroyed, they appears as alien fonts, even if in some of the frames these are  correctly rendered.  Modeover when VGLITE is enabled the demo hangs on scene 14. 

From where can I start to investigate?

[P3r3gr1nus]

Here a small video about the issue. It seems to affect only text. Even if after a while the demo freezes. 

[EdwinHz]

Hi @P3r3gr1nus,

As mentioned on the "lvgl_examples_readme.md" file:

"
GPU and PXP don't support 8-bit, unselect `LV_USE_DRAW_VGLITE` and `LV_USE_PXP`
in Kconfig, or modify mcux_config.h like:
```
#define CONFIG_LV_USE_DRAW_VGLITE 0
#define CONFIG_LV_USE_PXP 0
#define CONFIG_LV_ATTRIBUTE_MEM_ALIGN_SIZE 1
#define CONFIG_LV_DRAW_SW_DRAW_UNIT_CNT 1

"

BR,
Edwin.

[P3r3gr1nus]

Hello @EdwinHz , I found that the issue is related to the number of characters in the string. I show in sequence:

String 123
String 1234
String 12345
String 123456
String 1234567
String 12345678
String 123456789
String 1234567890

It happen that the strings from "String 12345" to "String 12345678" are damaged (alien font) the others are fine. The sequence is repeated and the behavior is deterministic. The same when I change font size from lv_font_montserrat_14 to lv_font_montserrat_12.

At this point it should be useful for me to know if the LVGL9 + VGLITE has been already validated. 

[P3r3gr1nus]

Hello @EdwinHz ,

     yes, if I disable the VGLITE as you suggest by setting in conf.h:

LV_USE_DRAW_VGLITE 0 
LV_USE_DRAW_SW  1

everything is fine. 
However my goal is to enable the VGLITE GPU acceleration. I used demo_benckmark as a reference but the final target will be my application. 

Moreover I am not using RGB888, having 
LV_COLOR_DEPTH 16 
the buffer is set ti RGB565. 

I forgot to mention my project is based on RT1176 and I am using FREERTOS. 

Do you think there is any chance to use VGLITE with LVGL?