STemwin官方程序求解

YYH2018

/**
  * @brief  Function for mixing up 2 colors with the given intensity.
  *         If the background color is completely transparent the
  *         foreground color should be used unchanged.
  * @param  Color
  * @param  BkColor
  * @param  Intens
  * @retval LCD_COLOR
  */
static LCD_COLOR DMA_MixColors(LCD_COLOR Color, LCD_COLOR BkColor, U8 Intens)
{
  uint32_t ColorFG, ColorBG, ColorDst;

  if ((BkColor & 0xFF000000) == 0xFF000000)
  {
    return Color;
  }
  ColorFG = Color   ^ 0xFF000000;
  ColorBG = BkColor ^ 0xFF000000;
  
  /* Set up mode */
  DMA2D->CR      = 0x00020000UL | (1 << 9);         /* Control Register (Memory to memory with blending of FG and BG and TCIE) */
  
  /* Set up pointers */
  DMA2D->FGMAR   = (uint32_t)&ColorFG;                   /* Foreground Memory Address Register */
  DMA2D->BGMAR   = (uint32_t)&ColorBG;                   /* Background Memory Address Register */
  DMA2D->OMAR    = (uint32_t)&ColorDst;                  /* Output Memory Address Register (Destination address) */
  
  /* Set up pixel format */
  DMA2D->FGPFCCR = LTDC_Pixelformat_ARGB8888
                 | (1UL << 16)
                 | ((uint32_t)Intens << 24);
  DMA2D->BGPFCCR = LTDC_Pixelformat_ARGB8888
                 | (0UL << 16)
                 | ((uint32_t)(255 - Intens) << 24);
  DMA2D->OPFCCR  = LTDC_Pixelformat_ARGB8888;
  
  /* Set up size */
  DMA2D->NLR     = (uint32_t)(1 << 16) | 1;              /* Number of Line Register (Size configuration of area to be transfered) */
  
  /* Execute operation */
  DMA2D->CR     |= DMA2D_CR_START;                       /* Control Register (Start operation) */
  
  /* Wait until transfer is done */
  while (DMA2D->CR & DMA2D_CR_START)
  {
  }

  return (ColorDst ^ 0xFF000000);
}
/***************************************************/
其中的

ColorFG = Color   ^ 0xFF000000;
ColorBG = BkColor ^ 0xFF000000;
两句为什么要这么处理？

潮小男ㄨ

混合颜色吗？搞不懂

YYH2018

潮小男ㄨ 发表于 2018-9-20 16:45
混合颜色吗？搞不懂

应该是混合单个颜色的程序，就是不知道那两句干嘛的