STM DMA2D and font

fredlynx · Jan 13th 2017, 4:14pm

Hello,

Is it possible to use DMA2D to copy font characters and use the Color Mode A4 from the DMA2D.

And if Yest How make the declaration of this ?

Thanx
Frédéric

SEGGER - Schoenen · Jan 16th 2017, 9:13am

Hi,

Please take a look into the LCDConf.c attached. The LCDConf.c is for a STM32F429. There we set a function for drawing anti aliased characters. Just search for:

GUI_AA_SetpfDrawCharAA4(_LCD_DrawBitmap4bpp);

Depending on the the emWin version you are using, not all functions might be available but the function GUI_AA_SetpfDrawCharAA4() should be available at least in V5.32 of emWin.

Regards,
Sven

fredlynx · Jan 16th 2017, 9:35am

Perfect

Thanks for your rapid answer.

Best regards
Frédéric

fredlynx · Jan 18th 2017, 11:17am

Hello,

If I well understand all the DrawBitmapA4 function in the sample you give to me, I think there is a little mistake :?: ...

When you compute the size before the swapping nibbles conversion :

Source Code

NumBytes = ((xSize + 1) & ~1) * ySize;

The computed size, is the size of the character in pixel but the encoding is 2 pixel by U8 :P , so you swap the double of U8. Every thing work because the DMA2D use only the need U8, but you lose time in conversion :rolleyes:

Have a nice day
Frédéric

SEGGER - Schoenen · Jan 18th 2017, 2:09pm

Hi Frédéric,

thanks for the hint. We will check that.

Regards,
Sven

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