offscr1bpp.c

基于TI公司Cortex-M3的uart超级通信开发

//*****************************************************************************
//
// offscr1bpp.c - 1 BPP off-screen display buffer driver.
//
// Copyright (c) 2008-2009 Luminary Micro, Inc.  All rights reserved.
// Software License Agreement
// 
// Luminary Micro, Inc. (LMI) is supplying this software for use solely and
// exclusively on LMI's microcontroller products.
// 
// The software is owned by LMI and/or its suppliers, and is protected under
// applicable copyright laws.  All rights are reserved.  You may not combine
// this software with "viral" open-source software in order to form a larger
// program.  Any use in violation of the foregoing restrictions may subject
// the user to criminal sanctions under applicable laws, as well as to civil
// liability for the breach of the terms and conditions of this license.
// 
// THIS SOFTWARE IS PROVIDED "AS IS".  NO WARRANTIES, WHETHER EXPRESS, IMPLIED
// OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
// LMI SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR
// CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
// 
// This is part of revision 5228 of the Stellaris Graphics Library.
//
//*****************************************************************************

#include "driverlib/debug.h"
#include "grlib/grlib.h"

//*****************************************************************************
//
//! \addtogroup primitives_api
//! @{
//
//*****************************************************************************

//*****************************************************************************
//
// Translates a 24-bit RGB color to a display driver-specific color.
//
// \param c is the 24-bit RGB color.  The least-significant byte is the blue
// channel, the next byte is the green channel, and the third byte is the red
// channel.
//
// This macro translates a 24-bit RGB color into a value that can be written
// into the display's frame buffer in order to reproduce that color, or the
// closest possible approximation of that color.
//
// \return Returns the display-driver specific color.
//
//*****************************************************************************
#define DPYCOLORTRANSLATE(c)    ((((((c) & 0x00ff0000) >> 16) * 19661) + \
                                  ((((c) & 0x0000ff00) >> 8) * 38666) +  \
                                  (((c) & 0x000000ff) * 7209)) /         \
                                 (65536 * 128))

//*****************************************************************************
//
//! Draws a pixel on the screen.
//!
//! \param pvDisplayData is a pointer to the driver-specific data for this
//! display driver.
//! \param lX is the X coordinate of the pixel.
//! \param lY is the Y coordinate of the pixel.
//! \param ulValue is the color of the pixel.
//!
//! This function sets the given pixel to a particular color.  The coordinates
//! of the pixel are assumed to be within the extents of the display.
//!
//! \return None.
//
//*****************************************************************************
static void
GrOffScreen1BPPPixelDraw(void *pvDisplayData, long lX, long lY,
                         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) + 7) / 8;

    //
    // Get the offset to the byte of the image buffer that contains the pixel
    // in question.
    //
    pucData += (lBytesPerRow * lY) + (lX / 8) + 5;

    //
    // Determine how much to shift to get to the bit that contains this pixel.
    //
    lX = 7 - (lX & 7);

    //
    // Write this pixel into the image buffer.
    //
    *pucData = (*pucData & ~(1 << lX)) | (ulValue << lX);
}

//*****************************************************************************
//
//! Draws a horizontal sequence of pixels on the screen.
//!
//! \param pvDisplayData is a pointer to the driver-specific data for this
//! display driver.
//! \param lX is the X coordinate of the first pixel.
//! \param lY is the Y coordinate of the first pixel.
//! \param lX0 is sub-pixel offset within the pixel data, which is valid for 1
//! or 4 bit per pixel formats.
//! \param lCount is the number of pixels to draw.
//! \param lBPP is the number of bits per pixel; must be 1, 4, or 8.
//! \param pucData is a pointer to the pixel data.  For 1 and 4 bit per pixel
//! formats, the most significant bit(s) represent the left-most pixel.
//! \param pucPalette is a pointer to the palette used to draw the pixels.
//!
//! This function draws a horizontal sequence of pixels on the screen, using
//! the supplied palette.  For 1 bit per pixel format, the palette contains
//! pre-translated colors; for 4 and 8 bit per pixel formats, the palette
//! contains 24-bit RGB values that must be translated before being written to
//! the display.
//!
//! \return None.
//
//*****************************************************************************
static void
GrOffScreen1BPPPixelDrawMultiple(void *pvDisplayData, long lX, long lY,
                                 long lX0, long lCount, long lBPP,
                                 const unsigned char *pucData,
                                 const unsigned char *pucPalette)
{
    unsigned char *pucPtr;
    unsigned long ulByte;
    long lBytesPerRow;

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

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

    //
    // Compute the number of bytes per row in the image buffer.
    //
    lBytesPerRow = (*(unsigned short *)(pucPtr + 1) + 7) / 8;

    //
    // Get the offset to the byte of the image buffer that contains the
    // starting pixel.
    //
    pucPtr += (lBytesPerRow * lY) + (lX / 8) + 5;

    //
    // Determine the bit position of the starting pixel.
    //
    lX = 7 - (lX & 7);

    //
    // Determine how to interpret the pixel data based on the number of bits
    // per pixel.
    //
    switch(lBPP)
    {
        //
        // The pixel data is in 1 bit per pixel format.
        //
        case 1:
        {
            //
            // Loop while there are more pixels to draw.
            //
            while(lCount)
            {
                //
                // Get the next byte of image data.
                //
                ulByte = *pucData++;

                //
                // Loop through the pixels in this byte of image data.
                //
                for(; (lX0 < 8) && lCount; lX0++, lCount--)
                {
                    //
                    // Draw this pixel in the appropriate color.
                    //
                    *pucPtr = ((*pucPtr & ~(1 << lX)) |
                               ((((unsigned long *)pucPalette)[(ulByte >>
                                                                (7 - lX0)) &
                                                               1]) << lX));
                    if(lX-- == 0)
                    {
                        lX = 7;
                        pucPtr++;
                    }
                }

                //
                // Start at the beginning of the next byte of image data.
                //
                lX0 = 0;
            }

            //
            // The image data has been drawn.
            //
            break;
        }

        //
        // The pixel data is in 4 bit per pixel format.
        //
        case 4:
        {
            //
            // Loop while there are more pixels to draw.  "Duff's device" is
            // used to jump into the middle of the loop if the first nibble of
            // the pixel data should not be used.  Duff's device makes use of
            // the fact that a case statement is legal anywhere within a
            // sub-block of a switch statement.  See
            // http://en.wikipedia.org/wiki/Duff's_device for detailed
            // information about Duff's device.
            //
            switch(lX0 & 1)
            {
                case 0:
                    while(lCount)
                    {
                        //
                        // Get the upper nibble of the next byte of pixel data
                        // and extract the corresponding entry from the
                        // palette.
                        //
                        ulByte = (*pucData >> 4) * 3;
                        ulByte = (*(unsigned long *)(pucPalette + ulByte) &
                                  0x00ffffff);

                        //
                        // Translate this palette entry and write it to the
                        // screen.
                        //
                        *pucPtr = ((*pucPtr & ~(1 << lX)) |
                                   (DPYCOLORTRANSLATE(ulByte) << lX));
                        if(lX-- == 0)
                        {
                            lX = 7;
                            pucPtr++;
                        }

                        //
                        // Decrement the count of pixels to draw.
                        //
                        lCount--;

                        //
                        // See if there is another pixel to draw.
                        //
                        if(lCount)
                        {
                case 1:
                            //
                            // Get the lower nibble of the next byte of pixel
                            // data and extract the corresponding entry from
                            // the palette.
                            //
                            ulByte = (*pucData++ & 15) * 3;
                            ulByte = (*(unsigned long *)(pucPalette + ulByte) &
                                      0x00ffffff);

                            //
                            // Translate this palette entry and write it to the
                            // screen.
                            //
                            *pucPtr = ((*pucPtr & ~(1 << lX)) |
                                       (DPYCOLORTRANSLATE(ulByte) << lX));
                            if(lX-- == 0)
                            {
                                lX = 7;
                                pucPtr++;
                            }

                            //
                            // Decrement the count of pixels to draw.
                            //
                            lCount--;
                        }
                    }
            }

            //
            // The image data has been drawn.
            //
            break;
        }

        //
        // The pixel data is in 8 bit per pixel format.
        //
        case 8:
        {
            //
            // Loop while there are more pixels to draw.
            //
            while(lCount--)
            {
                //
                // Get the next byte of pixel data and extract the
                // corresponding entry from the palette.
                //
                ulByte = *pucData++ * 3;
                ulByte = *(unsigned long *)(pucPalette + ulByte) & 0x00ffffff;

                //
                // Translate this palette entry and write it to the screen.
                //
                *pucPtr = ((*pucPtr & ~(1 << lX)) |
                           (DPYCOLORTRANSLATE(ulByte) << lX));
                if(lX-- == 0)
                {
                    lX = 7;
                    pucPtr++;
                }
            }

            //
            // The image data has been drawn.
            //
            break;
        }
    }
}

//*****************************************************************************
//
//! Draws a horizontal line.
//!
//! \param pvDisplayData is a pointer to the driver-specific data for this
//! display driver.
//! \param lX1 is the X coordinate of the start of the line.
//! \param lX2 is the X coordinate of the end of the line.
//! \param lY is the Y coordinate of the line.
//! \param ulValue is the color of the line.
//!
//! This function draws a horizontal line on the display.  The coordinates of
//! the line are assumed to be within the extents of the display.
//!
//! \return None.
//
//*****************************************************************************
static void
GrOffScreen1BPPLineDrawH(void *pvDisplayData, long lX1, long lX2, long lY,
                         unsigned long ulValue)
{
    long lBytesPerRow, lMask;
    unsigned char *pucData;

    //
    // 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) + 7) / 8;

    //
    // Get the offset to the byte of the image buffer that contains the
    // starting pixel.
    //
    pucData += (lBytesPerRow * lY) + (lX1 / 8) + 5;

    //
    // Copy the pixel value into all 32 pixels of the unsigned long.  This will
    // be used later to write multiple pixels into memory (as opposed to one at
    // a time).
    //
    if(ulValue)
    {
        ulValue = 0xffffffff;
    }

    //
    // See if the current buffer byte contains pixels that should be left
    // unmodified.
    //
    if(lX1 & 7)
    {
        //
        // Compute the mask to access only the appropriate pixels within this
        // byte.  The line may start and stop within this byte, so the mask may
        // need to be shortened to account for this situation.
        //
        lMask = 8 - (lX1 & 7);
        if(lMask > (lX2 - lX1 + 1))
        {
            lMask = lX2 - lX1 + 1;
        }
        lMask = ((1 << lMask) - 1) << (8 - (lX1 & 7) - lMask);

        //
        // Draw the appropriate pixels within this byte.
        //
        *pucData = (*pucData & ~lMask) | (ulValue & lMask);
        pucData++;
        lX1 = (lX1 + 7) & ~7;
    }

    //
    // See if the buffer pointer is not half-word aligned and there are at
    // least eight pixels left to draw.
    //
    if(((unsigned long)pucData & 1) && ((lX2 - lX1) > 6))
    {
        //
        // Draw eight pixels to half-word align the buffer pointer.
        //
        *pucData++ = ulValue & 0xff;
        lX1 += 8;
    }

    //
    // See if the buffer pointer is not word aligned and there are at least