ColorSwitch for BGR Displays

[GoGIGA]

184 # Feature Request or Enhancement

Thanks a lot, a really nice project!

Could you please add in GUIslice_drv_tft_espi.cpp an option for flipping from RGB TO BGR, because there are some some strange displays with BGR coding?

Additional context

I have patched the function "gslc_DrvAdaptColorToRaw" in my local copy to: uint16_t gslc_DrvAdaptColorToRaw(gslc_tsColor nCol) { uint16_t nColRaw = 0;

ifdef BGR

  // RGB565
  nColRaw |= (((nCol.b & 0xF8) >> 3) << 11); // Mask: 1111 1000 0000 0000
  nColRaw |= (((nCol.g & 0xFC) >> 2) <<  5); // Mask: 0000 0111 1110 0000
  nColRaw |= (((nCol.r & 0xF8) >> 3) <<  0); // Mask: 0000 0000 0001 1111

else

  // RGB565
  nColRaw |= (((nCol.r & 0xF8) >> 3) << 11); // Mask: 1111 1000 0000 0000
  nColRaw |= (((nCol.g & 0xFC) >> 2) <<  5); // Mask: 0000 0111 1110 0000
  nColRaw |= (((nCol.b & 0xF8) >> 3) <<  0); // Mask: 0000 0000 0001 1111

endif

return nColRaw; } And this works fine for text and lines.

[ImpulseAdventure]

Hi @GoGIGA -- sure, we could add an option for this. It looks like certain ILI9341 or ST7789 displays could potentially require this mode.

Would it be safe to assume that your TFT_eSPI User_Setup would configure the TFT_RGB_ORDER flag (ie. TFT_BGR or TFT_RGB)? If so, I could make GUIslice_drv_tft_espi look for this User_Setup setting (and default to TFT_RGB if unset).

[GoGIGA]

Hallo ImpulseAdventure, thank you for your response. I have patched in the lokal copy of GUIslice_drv_tft_espi.cpp the above code and inserted the "#define BGR" in User_setup.h of TFT_eSPI and it worked flawlessly. And yes it is an ILI9341-Display from China ...

[ImpulseAdventure]

Thanks.... I can easily add a check for a new flag “BGR” but wondered if we should reuse the TFT_RGB_ORDER flag that might already exist in the User_Setup template.

Could you attach your original User_Setup file to this issue or let me know whether it might contain a line like the following:

define TFT_RGB_ORDER TFT_BGR

Thanks!

[GoGIGA]

It is your project - It was just my "temporary" selection for testing. Thank a lot for your project again!

[GoGIGA]

Sorry, I was too quick. I have not used a define of the kind: #define TFT_RGB_ORDER TFT_BGR. Is there already a solution in TFT_eSPI for this type of displays?

[GoGIGA]

I do a test without my #define BGR and with #define TFT_RGB_ORDER TFT_BGR in a minute.

[GoGIGA]

Well, the simple test failed. I'm still a beginner, how do I have to change the preprocessor command in my patch if is use #define TFT_RGB_ORDER TFT_BGR for the selection? Thanks!

[GoGIGA]

My workaround is now: --> In "User_setup.h" from TFT_eSPI

define TFT_BGR

#define TFT_RGB_ORDER TFT_BGR

--> Changed Patch in your "GUIslice_drv_tft_espi.cpp" to: // Convert from RGB struct to native screen format // TODO: Use 32bit return type? uint16_t gslc_DrvAdaptColorToRaw(gslc_tsColor nCol) { uint16_t nColRaw = 0;

if defined(TFT_RGB_ORDER) && defined(TFT_BGR)

  // RGB565
  nColRaw |= (((nCol.b & 0xF8) >> 3) << 11); // Mask: 1111 1000 0000 0000
  nColRaw |= (((nCol.g & 0xFC) >> 2) <<  5); // Mask: 0000 0111 1110 0000
  nColRaw |= (((nCol.r & 0xF8) >> 3) <<  0); // Mask: 0000 0000 0001 1111

else

  // RGB565
  nColRaw |= (((nCol.r & 0xF8) >> 3) << 11); // Mask: 1111 1000 0000 0000
  nColRaw |= (((nCol.g & 0xFC) >> 2) <<  5); // Mask: 0000 0111 1110 0000
  nColRaw |= (((nCol.b & 0xF8) >> 3) <<  0); // Mask: 0000 0000 0001 1111

endif

return nColRaw; }

[ImpulseAdventure]

Hi -- thanks for sharing your workaround!

I have not used a define of the kind: #define TFT_RGB_ORDER TFT_BGR. Is there already a solution in TFT_eSPI for this type of displays?

From understanding, yes, the TFT_eSPI library driver already supports the MADCTL Blue/Red swap mode in the ILI9341 controller without needing any changes to GUIslice. This is why I was asking if you might already be setting TFT_RGB_ORDER within your TFT_eSPI User_Setup. So, for your particular TFT display, I believe you should probably set this option first:

1) If you remove all of your GUIslice workaround edits and just set the following in your TFT_eSPI User_Setup file, do the colors look right? #define TFT_RGB_ORDER TFT_BGR

2) If that does not work, then I will add a mode to GUIslice to allow for the swap like you indicated in your workaround.

thanks!

[GoGIGA]

Well, I am really sorry for having wasting your time .... You are absolutely right, when the option is set (and not overwriten later - what was my fault), there is no need for my patch. Thank you for directing my to the right way!

[ImpulseAdventure]

Glad to hear it worked! And no worries about wasting time :) The TFT_RGB_ORDER was a relatively recent feature Bodmer added to his TFT_eSPI library a couple months ago.