offscr8bpp.c

基于TI公司Cortex-M3的uart超级通信开发

    //
    // Copy the pixel value into all 4 pixels of the unsigned long.  This will
    // be used later to write multiple pixels into memory (as opposed to one at
    // a time).
    //
    ulValue = (ulValue << 24) | (ulValue << 16) | (ulValue << 8) | ulValue;

    //
    // See if the buffer pointer is not half-word aligned.
    //
    if(((unsigned long)pucData) & 1)
    {
        //
        // Draw one pixel to half-word align the buffer pointer.
        //
        *pucData++ = ulValue & 0xff;
        lX1++;
    }

    //
    // See if the buffer pointer is not word aligned and there are at least two
    // pixels left to draw.
    //
    if(((unsigned long)pucData & 2) && ((lX2 - lX1) > 0))
    {
        //
        // Draw two pixels to word align the buffer pointer.
        //
        *(unsigned short *)pucData = ulValue & 0xffff;
        pucData += 2;
        lX1 += 2;
    }

    //
    // Loop while there are at least four pixels left to draw.
    //
    while((lX1 + 3) <= lX2)
    {
        //
        // Draw four pixels.
        //
        *(unsigned long *)pucData = ulValue;
        pucData += 4;
        lX1 += 4;
    }

    //
    // See if there are at least two pixels left to draw.
    //
    if((lX1 + 1) <= lX2)
    {
        //
        // Draw two pixels, leaving the buffer pointer half-word aligned.
        //
        *(unsigned short *)pucData = ulValue & 0xffff;
        pucData += 2;
        lX1 += 2;
    }

    //
    // See if there is one pixel left to draw.
    //
    if(lX1 == lX2)
    {
        //
        // Draw the final pixel.
        //
        *pucData = ulValue & 0xff;
    }
}

//*****************************************************************************
//
//! Draws a vertical line.
//!
//! \param pvDisplayData is a pointer to the driver-specific data for this
//! display driver.
//! \param lX is the X coordinate of the line.
//! \param lY1 is the Y coordinate of the start of the line.
//! \param lY2 is the Y coordinate of the end of the line.
//! \param ulValue is the color of the line.
//!
//! This function draws a vertical line on the display.  The coordinates of the
//! line are assumed to be within the extents of the display.
//!
//! \return None.
//
//*****************************************************************************
static void
GrOffScreen8BPPLineDrawV(void *pvDisplayData, long lX, long lY1, long lY2,
                         unsigned long ulValue)
{
    unsigned char *pucData;
    long lBytesPerRow;

    //
    // Check the arguments.
    //
    ASSERT(pvDisplayData);

    //
    // Create a character pointer for the display-specific data (which points
    // to the image buffer).
    //
    pucData = (unsigned char *)pvDisplayData;

    //
    // Compute the number of bytes per row in the image buffer.
    //
    lBytesPerRow = *(unsigned short *)(pucData + 1);

    //
    // Get the offset to the byte of the image buffer that contains the
    // starting pixel.
    //
    pucData += (lBytesPerRow * lY1) + lX + 6 + (256 * 3);

    //
    // Loop over the rows of the line.
    //
    for(; lY1 <= lY2; lY1++)
    {
        *pucData = ulValue;
        pucData += lBytesPerRow;
    }
}

//*****************************************************************************
//
//! Fills a rectangle.
//!
//! \param pvDisplayData is a pointer to the driver-specific data for this
//! display driver.
//! \param pRect is a pointer to the structure describing the rectangle.
//! \param ulValue is the color of the rectangle.
//!
//! This function fills a rectangle on the display.  The coordinates of the
//! rectangle are assumed to be within the extents of the display, and the
//! rectangle specification is fully inclusive (in other words, both sXMin and
//! sXMax are drawn, along with sYMin and sYMax).
//!
//! \return None.
//
//*****************************************************************************
static void
GrOffScreen8BPPRectFill(void *pvDisplayData, const tRectangle *pRect,
                        unsigned long ulValue)
{
    unsigned char *pucData, *pucPtr;
    long lBytesPerRow, lX, lY;

    //
    // Check the arguments.
    //
    ASSERT(pvDisplayData);
    ASSERT(pRect);

    //
    // Create a character pointer for the display-specific data (which points
    // to the image buffer).
    //
    pucData = (unsigned char *)pvDisplayData;

    //
    // Compute the number of bytes per row in the image buffer.
    //
    lBytesPerRow = *(unsigned short *)(pucData + 1);

    //
    // Get the offset to the byte of the image buffer that contains the
    // starting pixel.
    //
    pucData += (lBytesPerRow * pRect->sYMin) + pRect->sXMin + 6 + (256 * 3);

    //
    // Copy the pixel value into all 4 pixels of the unsigned long.  This will
    // be used later to write multiple pixels into memory (as opposed to one at
    // a time).
    //
    ulValue = (ulValue << 24) | (ulValue << 16) | (ulValue << 8) | ulValue;

    //
    // Get the starting X coordinate.
    //
    lX = pRect->sXMin;

    //
    // See if the buffer pointer is not half-word aligned.
    //
    if(((unsigned long)pucData) & 1)
    {
        //
        // Draw one pixel column to half-word align the buffer pointer.
        //
        for(lY = pRect->sYMin, pucPtr = pucData; lY <= pRect->sYMax;
            lY++, pucPtr += lBytesPerRow)
        {
            *pucPtr = ulValue & 0xff;
        }
        pucData++;
        lX++;
    }

    //
    // See if the buffer pointer is not word aligned and there are at least two
    // pixel columns left to draw.
    //
    if(((unsigned long)pucData & 2) && ((pRect->sXMax - lX) > 0))
    {
        //
        // Draw two pixel columns to word align the buffer pointer.
        //
        for(lY = pRect->sYMin, pucPtr = pucData; lY <= pRect->sYMax;
            lY++, pucPtr += lBytesPerRow)
        {
            *(unsigned short *)pucPtr = ulValue & 0xffff;
        }
        pucData += 2;
        lX += 2;
    }

    //
    // Loop while there are at least four pixel columns left to draw.
    //
    while((lX + 3) <= pRect->sXMax)
    {
        //
        // Draw four pixel columns.
        //
        for(lY = pRect->sYMin, pucPtr = pucData; lY <= pRect->sYMax;
            lY++, pucPtr += lBytesPerRow)
        {
            *(unsigned long *)pucPtr = ulValue;
        }
        pucData += 4;
        lX += 4;
    }

    //
    // See if ther are at least two pixel columns left to draw.
    //
    if((lX + 1) <= pRect->sXMax)
    {
        //
        // Draw two pixel columns, leaving the buffer pointer half-word
        // aligned.
        //
        ulValue &= 0xffff;
        for(lY = pRect->sYMin, pucPtr = pucData; lY <= pRect->sYMax;
            lY++, pucPtr += lBytesPerRow)
        {
            *(unsigned short *)pucPtr = ulValue;
        }
        pucData += 2;
        lX += 2;
    }

    //
    // See if there is one pixel column left to draw.
    //
    if(lX == pRect->sXMax)
    {
        //
        // Draw the final pixel column.
        //
        ulValue &= 0xff;
        for(lY = pRect->sYMin; lY <= pRect->sYMax;
            lY++, pucData += lBytesPerRow)
        {
            *pucData = ulValue;
        }
    }
}

//*****************************************************************************
//
//! Flushes any cached drawing operations.
//!
//! \param pvDisplayData is a pointer to the driver-specific data for this
//! display driver.
//!
//! This functions flushes any cached drawing operations to the display.  This
//! is useful when a local frame buffer is used for drawing operations, and the
//! flush would copy the local frame buffer to the display.  For the off-screen
//! display buffer driver, the flush is a no operation.
//!
//! \return None.
//
//*****************************************************************************
static void
GrOffScreen8BPPFlush(void *pvDisplayData)
{
    //
    // Check the arguments.
    //
    ASSERT(pvDisplayData);
}

//*****************************************************************************
//
//! Initializes an 8 BPP off-screen buffer.
//!
//! \param pDisplay is a pointer to the display structure to be configured for
//! the 4 BPP off-screen buffer.
//! \param pucImage is a pointer to the image buffer to be used for the
//! off-screen buffer.
//! \param lWidth is the width of the image buffer in pixels.
//! \param lHeight is the height of the image buffer in pixels.
//!
//! This function initializes a display structure, preparing it to draw into
//! the supplied image buffer.  The image buffer is assumed to be large enough
//! to hold an image of the specified geometry.
//!
//! \return None.
//
//*****************************************************************************
void
GrOffScreen8BPPInit(tDisplay *pDisplay, unsigned char *pucImage, long lWidth,
                    long lHeight)
{
    //
    // Check the arguments.
    //
    ASSERT(pDisplay);
    ASSERT(pucImage);

    //
    // Initialize the display structure.
    //
    pDisplay->lSize = sizeof(tDisplay);
    pDisplay->pvDisplayData = pucImage;
    pDisplay->usWidth = lWidth;
    pDisplay->usHeight = lHeight;
    pDisplay->pfnPixelDraw = GrOffScreen8BPPPixelDraw;
    pDisplay->pfnPixelDrawMultiple = GrOffScreen8BPPPixelDrawMultiple;
    pDisplay->pfnLineDrawH = GrOffScreen8BPPLineDrawH;
    pDisplay->pfnLineDrawV = GrOffScreen8BPPLineDrawV;
    pDisplay->pfnRectFill = GrOffScreen8BPPRectFill;
    pDisplay->pfnColorTranslate = GrOffScreen8BPPColorTranslate;
    pDisplay->pfnFlush = GrOffScreen8BPPFlush;

    //
    // Initialize the image buffer.
    //
    pucImage[0] = IMAGE_FMT_8BPP_UNCOMP;
    *(unsigned short *)(pucImage + 1) = lWidth;
    *(unsigned short *)(pucImage + 3) = lHeight;
    pucImage[5] = 255;
}

//*****************************************************************************
//
//! Sets the palette of an 8 BPP off-screen buffer.
//!
//! \param pDisplay is a pointer to the display structure for the 4 BPP
//! off-screen buffer.
//! \param pulPalette is a pointer to the array of 24-bit RGB values to be
//! placed into the palette.
//! \param ulOffset is the starting offset into the image palette.
//! \param ulCount is the number of palette entries to set.
//!
//! This function sets the entries of the palette used by the 8 BPP off-screen
//! buffer.  The palette is used to select colors for drawing via
//! GrOffScreen4BPPColorTranslate(), and for the final rendering of the image
//! to a real display via GrImageDraw().
//!
//! \return None.
//
//*****************************************************************************
void
GrOffScreen8BPPPaletteSet(tDisplay *pDisplay, unsigned long *pulPalette,
                          unsigned long ulOffset, unsigned long ulCount)
{
    unsigned char *pucData;

    //
    // Check the arguments.
    //
    ASSERT(pDisplay);
    ASSERT(pulPalette);
    ASSERT(ulOffset < 256);
    ASSERT((ulOffset + ulCount) <= 256);

    //
    // Get a pointer to the start of the image buffer's palette.
    //
    pucData = (unsigned char *)pDisplay->pvDisplayData + 6;

    //
    // Skip to the specified offset in the palette.
    //
    pucData += ulOffset * 3;

    //
    // Loop while there are more palette entries to add.
    //
    while(ulCount--)
    {
        //
        // Copy this palette entry to the image buffer's palette.
        //
        *pucData++ = (*pulPalette >> ClrBlueShift) & 0xff;
        *pucData++ = (*pulPalette >> ClrGreenShift) & 0xff;
        *pucData++ = (*pulPalette++ >> ClrRedShift) & 0xff;
    }
}

//*****************************************************************************
//
// Close the Doxygen group.
//! @}
//
//*****************************************************************************