基于linux下tslib库的手写板程序

     本设计根据tslib中提供的ts_test程序修改而来，本设计中ts_test.c还依赖于tslib中的其他文件，若想直接编译，可置于tslib中的test文件夹中，替换到原来的文件。本设计根据tslib中提供的API取得X,Y坐标，根据得到的X,Y,打开fb0,映射进入内存（出于速度的考虑），进行划线，对线条进行了加粗处理，并随机生成颜色，最终形成灿烂的笔画。

 

ts_test.c

#include "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <sys/fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/time.h>
#include<linux/fb.h>


#include "tslib.h"
#include "fbutils.h"

unsigned char *fbp;
struct fb_var_screeninfo vinfo;
struct fb_fix_screeninfo finfo;


void drawpoint(unsigned int x,unsigned int y,unsigned int *color)
{
    unsigned char *fbp0;
    fbp0=fbp;
    fbp0+=y*vinfo.xres*vinfo.bits_per_pixel/8+x*vinfo.bits_per_pixel/8;
    memcpy(fbp0,color,vinfo.bits_per_pixel/8);
}


void drawline(unsigned int x0,unsigned int y0,unsigned int x1,unsigned int y1,unsigned int *color)
{
    unsigned int x=x0;
    unsigned int y=y0;
    int s0,s1,s2;
    while(x!=x1||y!=y1)
    {
        drawpoint(x,y,color);//以下为加粗直线
        drawpoint(x+1,y,color);
        drawpoint(x,y+1,color);
    drawpoint(x+1,y+1,color);
    drawpoint(x+2,y,color);
    drawpoint(x,y+2,color);
    drawpoint(x+2,y+2,color);

        if(x0>=x1&&y0>=y1) //求直线下一点的算法。
        {
            s0=abs((x-x0-1)*(y0-y1)-(y-y0)*(x0-x1));
            s1=abs((x-x0)*(y0-y1)-(y-y0-1)*(x0-x1));
            s2=abs((x-x0-1)*(y0-y1)-(y-y0-1)*(x0-x1));
            s0<=s1?(s0<=s2?x=x-1:(x=x-1,y=y-1)):(s1<=s2?y=y-1:(x=x-1,y=y-1));
        }
        else if(x0>=x1&&y0<=y1)
        {
            s0=abs((x-x0-1)*(y0-y1)-(y-y0)*(x0-x1));
            s1=abs((x-x0)*(y0-y1)-(y-y0+1)*(x0-x1));
            s2=abs((x-x0-1)*(y0-y1)-(y-y0+1)*(x0-x1));
            s0<=s1?(s0<=s2?x=x-1:(x=x-1,y=y+1)):(s1<=s2?y=y+1:(x=x-1,y=y+1));
        }
        else if(x0<=x1&&y0>=y1)
        {
            s0=abs((x-x0+1)*(y0-y1)-(y-y0)*(x0-x1));
            s1=abs((x-x0)*(y0-y1)-(y-y0-1)*(x0-x1));
            s2=abs((x-x0+1)*(y0-y1)-(y-y0-1)*(x0-x1));
            s0<=s1?(s0<=s2?x=x+1:(x=x+1,y=y-1)):(s1<=s2?y=y-1:(x=x+1,y=y-1));
        }
        else if(x0<=x1&&y0<=y1)
        {
            s0=abs((x-x0+1)*(y0-y1)-(y-y0)*(x0-x1));
            s1=abs((x-x0)*(y0-y1)-(y-y0+1)*(x0-x1));
            s2=abs((x-x0+1)*(y0-y1)-(y-y0+1)*(x0-x1));
            s0<=s1?(s0<=s2?x=x+1:(x=x+1,y=y+1)):(s1<=s2?y=y+1:(x=x+1,y=y+1));
        }
    }
    drawpoint(x,y,color);
}

int mrand(int x,int y) //生成x到y之间的随机数。
{
     int i;
     struct timeval tpstart;
     gettimeofday(&tpstart,NULL);
     srand(tpstart.tv_usec); //微秒级产生随机数种子
     return (rand()%(y-x+1)+x);
}



static int palette [] =
{
    0x000000, 0xffe080, 0xffffff, 0xe0c0a0, 0x304050, 0x80b8c0
};
#define NR_COLORS (sizeof (palette) / sizeof (palette [0]))

struct ts_button {
    int x, y, w, h;
    char *text;
    int flags;
#define BUTTON_ACTIVE 0x00000001
};

/* [inactive] border fill text [active] border fill text */
static int button_palette [6] =
{
    1, 4, 2,
    1, 5, 0
};

#define NR_BUTTONS 2
static struct ts_button buttons [NR_BUTTONS];

static void sig(int sig)
{
    close_framebuffer();
    fflush(stderr);
    printf("signal %d caught\n", sig);
    fflush(stdout);
    exit(1);
}

static void button_draw (struct ts_button *button)
{
    int s = (button->flags & BUTTON_ACTIVE) ? 3 : 0;
    rect (button->x, button->y, button->x + button->w - 1,
          button->y + button->h - 1, button_palette [s]);
    fillrect (button->x + 1, button->y + 1,
          button->x + button->w - 2,
          button->y + button->h - 2, button_palette [s + 1]);
    put_string_center (button->x + button->w / 2,
               button->y + button->h / 2,
               button->text, button_palette [s + 2]);
}

static int button_handle (struct ts_button *button, struct ts_sample *samp)
{
    int inside = (samp->x >= button->x) && (samp->y >= button->y) &&
        (samp->x < button->x + button->w) &&
        (samp->y < button->y + button->h);

    if (samp->pressure > 0) {
        if (inside) {
            if (!(button->flags & BUTTON_ACTIVE)) {
                button->flags |= BUTTON_ACTIVE;
                button_draw (button);
            }
        } else if (button->flags & BUTTON_ACTIVE) {
            button->flags &= ~BUTTON_ACTIVE;
            button_draw (button);
        }
    } else if (button->flags & BUTTON_ACTIVE) {
        button->flags &= ~BUTTON_ACTIVE;
        button_draw (button);
                return 1;
    }

        return 0;
}

static void refresh_screen ()
{
    int i;

    fillrect (0, 0, xres - 1, yres - 1, 0);
    put_string_center (xres/2, yres/4, "Enjoy the writing! ", 1);
    put_string_center (xres/2, yres/4+20,"Touch screen to move crosshair", 2);

    for (i = 0; i < NR_BUTTONS; i++)
        button_draw (&buttons [i]);
}

int main()
{
    int fd;
    long int screensize;
    int color=0x00ff0000;//榛樿?red

    if((fd=open("/dev/fb0",O_RDWR))<0)
    {
        perror("fail to open");
        return 0;
    }
        if (ioctl(fd,FBIOGET_FSCREENINFO, &finfo))
    {
        perror("fail to get");
        return 0;
    }
        if (ioctl(fd,FBIOGET_VSCREENINFO, &vinfo))
         {
        perror("fail to get");
        return 0;
         }
        screensize=vinfo.xres*vinfo.yres*vinfo.bits_per_pixel/8;
        fbp=(unsigned char *)mmap(0,screensize,PROT_READ | PROT_WRITE,MAP_SHARED,fd, 0);


    struct tsdev *ts;
    int x, y;
    unsigned int i;
    unsigned int mode = 0;

    char *tsdevice=NULL;

    signal(SIGSEGV, sig);
    signal(SIGINT, sig);
    signal(SIGTERM, sig);

    if ((tsdevice = getenv("TSLIB_TSDEVICE")) == NULL) {
#ifdef USE_INPUT_API
        tsdevice = strdup ("/dev/input/event0");
#else
        tsdevice = strdup ("/dev/touchscreen/ucb1x00");
#endif /* USE_INPUT_API */
        }

    ts = ts_open (tsdevice, 0);

    if (!ts) {
        perror (tsdevice);
        exit(1);
    }

    if (ts_config(ts)) {
        perror("ts_config");
        exit(1);
    }

    if (open_framebuffer()) {
        close_framebuffer();
        exit(1);
    }

    x = xres/2;
    y = yres/2;

    for (i = 0; i < NR_COLORS; i++)
        setcolor (i, palette [i]);

    /* Initialize buttons */
    memset (&buttons, 0, sizeof (buttons));
    buttons [0].w = buttons [1].w = xres / 4;
    buttons [0].h = buttons [1].h = 20;
    buttons [0].x = xres / 4 - buttons [0].w / 2;
    buttons [1].x = (3 * xres) / 4 - buttons [0].w / 2;
    buttons [0].y = buttons [1].y = 10;
    buttons [0].text = "Drag";
    buttons [1].text = "Draw";

    refresh_screen ();

    while (1) {
        struct ts_sample samp;
        int ret;

        /* Show the cross */
        if ((mode & 15) != 1)
            put_cross(x, y, 2 | XORMODE);

        ret = ts_read(ts, &samp, 1); //璇诲叆

        /* Hide it */
        if ((mode & 15) != 1)
            put_cross(x, y, 2 | XORMODE);

        if (ret < 0) {
            perror("ts_read");
            close_framebuffer();
            exit(1);
        }

        if (ret != 1)
        {
            continue;
        }
        for (i = 0; i < NR_BUTTONS; i++)
            if (button_handle (&buttons [i], &samp))
                switch (i) {
                case 0:
                    mode = 0;
                    refresh_screen ();
                    break;
                case 1:
                    mode = 1;
                    refresh_screen ();
                    break;
                }

        printf("%ld.%06ld: %6d %6d %6d\n", samp.tv.tv_sec, samp.tv.tv_usec,
            samp.x, samp.y, samp.pressure);



        if (samp.pressure > 0)
        {

            if (mode == 0x80000001)


                {
                color=mrand(0x00000000,0x00ffffff);//随机生成颜色，可能因屏幕不同而范围不同。
                drawline(x,y,samp.x,samp.y,&color);
            }
            x = samp.x;
            y = samp.y;

            mode |= 0x80000000;
        }
        else
        {

            mode &= ~0x80000000;
        }
    }
    close_framebuffer();
}