嵌入式Linux-LCD显示多行文字

显示文字这里我用了freetype库。

以左上角显示两行文字：

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <linux/fb.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <math.h>

#include "show_font.h"
#include <ft2build.h>
#include FT_FREETYPE_H
#include <freetype/ftglyph.h>



unsigned char *hzkmem;
unsigned char *fbmem;
unsigned int line_width;
unsigned int pixel_width;

struct fb_var_screeninfo var;

void lcd_put_pixel( int x, int y, unsigned int color )
{
    unsigned char *pen_8 = fbmem +y*line_width + x*pixel_width;
    unsigned short *pen_16;
    unsigned short *pen_32;
    unsigned char red,green,blue;

    pen_16 = (unsigned short *)pen_8;
    pen_32 = (unsigned short *)pen_8;

    switch( pixel_width*8 )
    {
    case 8:
        *pen_8 = color;
        break;

    case 16:
        /* 565 */
        red = (color>>16) & 0xff;
        green = (color>>8) & 0xff;
        blue = (color>>0) & 0xff;
        color = ((red>>3)<<11) | ((green>>2)<<5) |((blue>>3));
        *pen_16 = color;
        break;

    case 32:
        *pen_32 = color;
        break;
    default:
        printf("can't support %ddpp\n",pixel_width*8 );
        break;
    }
}

void draw_bitmap( FT_Bitmap*  bitmap,
             FT_Int      x,
             FT_Int      y)
{
  FT_Int  i, j, p, q;
  FT_Int  x_max = x + bitmap->width;
  FT_Int  y_max = y + bitmap->rows;


  for ( i = x, p = 0; i < x_max; i++, p++ )
  {
    for ( j = y, q = 0; j < y_max; j++, q++ )
    {
      if ( i < 0      || j < 0       ||
           i >= var.xres || j >= var.yres )
        continue;

      //image[j][i] |= bitmap->buffer[q * bitmap->width + p];
      lcd_put_pixel(i,j,bitmap->buffer[q * bitmap->width + p]);
    }
  }
}

int main( int argc, char **argv )
{
    int hzk_fd;
    int fd_fb;
    struct fb_fix_screeninfo fix;

    int screen_size;

    FT_Library    library;
    FT_Error      error;
    FT_Face       face;
    FT_Matrix     matrix;                 /* transformation matrix */
    FT_Vector     pen;                    /* untransformed origin  */
    FT_BBox       bbox;
    FT_Glyph      glyph;

    int i;

    double        angle;

    wchar_t *chinese_char = L"周zhou";
    wchar_t *chinese_char2 = L"嵌入式Linux";

    int line_box_ymin=800;
    int line_box_ymax=0;

    struct stat hzk_stat;


    fd_fb = open("/dev/fb0",  O_RDWR );
    if( fd_fb<0 )
    {
        perror("oepn failed");
        return -1;
    }

    if( ioctl( fd_fb,  FBIOGET_VSCREENINFO, &var ) )
    {
        printf("can't get var\n");
        return -1;
    }

    if( ioctl( fd_fb,  FBIOGET_FSCREENINFO, &fix ) )
    {
        printf("can't get fix\n");
        return -1;
    }
    line_width = var.xres * var.bits_per_pixel / 8;
    pixel_width = var.bits_per_pixel / 8;

    screen_size = var.xres * var.yres * var.bits_per_pixel / 8;
    fbmem = (unsigned char *)mmap( NULL, screen_size,  PROT_READ | PROT_WRITE, MAP_SHARED,fd_fb,0 );
    if( fbmem == (unsigned char *)-1 )
    {
        printf("mmap is failed\n");
        return -1;
    }

    memset( fbmem, 0, screen_size );

    if( argc != 2 )
    {
        printf("Usage: %s  <font_file>\n", argv[0]);
        return -1;
    }

    error = FT_Init_FreeType( &library );              /* initialize library */
    /* error handling omitted */


    error = FT_New_Face( library, argv[1], 0, &face ); /* create face object */

    /* use 50pt at 100dpi */
    error = FT_Set_Pixel_Sizes( face, 30, 0 );                /* set character size */

    angle         = ( 0.0 / 360 ) * 3.14159 * 2;      /* use 25 degrees     */
     /* set up matrix */
    matrix.xx = (FT_Fixed)( cos( angle ) * 0x10000L );
    matrix.xy = (FT_Fixed)(-sin( angle ) * 0x10000L );
    matrix.yx = (FT_Fixed)( sin( angle ) * 0x10000L );
    matrix.yy = (FT_Fixed)( cos( angle ) * 0x10000L );

    /* the pen position in 26.6 cartesian space coordinates; */
    /* start at (0,24) relative to the upper left corner  */
    pen.x = (0) * 64;
    pen.y = ( var.yres - 24 ) * 64;
    for( i=0; i<wcslen(chinese_char); i++ )
    {
        /* set transformation */
        FT_Set_Transform( face, &matrix, &pen );

        /* load glyph image into the slot (erase previous one) */
        error = FT_Load_Char( face, chinese_char[i], FT_LOAD_RENDER );
        if(error)
        {
            printf("FT_load_char error\n");
            return -1;
        }

        error = FT_Get_Glyph(face->glyph, &glyph );
        if(error)
        {
            printf("FT_Get_Glyph error\n");
            return -1;
        }

        FT_Glyph_Get_CBox(glyph, FT_GLYPH_BBOX_TRUNCATE, &bbox);
        if( line_box_ymin > bbox.yMin )
            line_box_ymin = bbox.yMin;
        if( line_box_ymax < bbox.yMax )
            line_box_ymax = bbox.yMax;

        draw_bitmap( &face->glyph->bitmap,
                     face->glyph->bitmap_left,
                     var.yres - face->glyph->bitmap_top );

        /* increment pen position */
        pen.x += face->glyph->advance.x;
        pen.y += face->glyph->advance.y;
    }

    /* the pen position in 26.6 cartesian space coordinates; */
    /* start at (0,24) relative to the upper left corner  */
    pen.x = (0) * 64;
    pen.y = ( var.yres-( line_box_ymax-line_box_ymin+24) ) * 64;
    for( i=0; i<wcslen(chinese_char2); i++ )
    {
        /* set transformation */
        FT_Set_Transform( face, &matrix, &pen );

        /* load glyph image into the slot (erase previous one) */
        error = FT_Load_Char( face, chinese_char2[i], FT_LOAD_RENDER );
        if(error)
        {
            printf("FT_load_char error\n");
            return -1;
        }

        error = FT_Get_Glyph(face->glyph, &glyph );
        if(error)
        {
            printf("FT_Get_Glyph error\n");
            return -1;
        }

        FT_Glyph_Get_CBox(glyph, FT_GLYPH_BBOX_TRUNCATE, &bbox);
        if( line_box_ymin > bbox.yMin )
            line_box_ymin = bbox.yMin;
        if( line_box_ymax < bbox.yMax )
            line_box_ymax = bbox.yMax;

        draw_bitmap( &face->glyph->bitmap,
                     face->glyph->bitmap_left,
                     var.yres - face->glyph->bitmap_top );

        /* increment pen position */
        pen.x += face->glyph->advance.x;
        pen.y += face->glyph->advance.y;
    }

    return 0;


}

 在屏幕的中间左右上下对称显示：

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <linux/fb.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <math.h>

#include "show_font.h"
#include <ft2build.h>
#include FT_FREETYPE_H
#include <freetype/ftglyph.h>

typedef struct  TGlyph_
{
    FT_UInt    index;  /* glyph index                  */
    FT_Vector  pos;    /* glyph origin on the baseline */
    FT_Glyph   image;  /* glyph image                  */

} TGlyph, *PGlyph;

#define MAX_GLYPHS 100




unsigned char *hzkmem;
unsigned char *fbmem;
unsigned int line_width;
unsigned int pixel_width;

struct fb_var_screeninfo var;

void lcd_put_pixel( int x, int y, unsigned int color )
{
    unsigned char *pen_8 = fbmem +y*line_width + x*pixel_width;
    unsigned short *pen_16;
    unsigned short *pen_32;
    unsigned char red,green,blue;

    pen_16 = (unsigned short *)pen_8;
    pen_32 = (unsigned short *)pen_8;

    switch( pixel_width*8 )
    {
    case 8:
        *pen_8 = color;
        break;

    case 16:
        /* 565 */
        red = (color>>16) & 0xff;
        green = (color>>8) & 0xff;
        blue = (color>>0) & 0xff;
        color = ((red>>3)<<11) | ((green>>2)<<5) |((blue>>3));
        *pen_16 = color;
        break;

    case 32:
        *pen_32 = color;
        break;
    default:
        printf("can't support %ddpp\n",pixel_width*8 );
        break;
    }
}

void draw_bitmap( FT_Bitmap*  bitmap,
             FT_Int      x,
             FT_Int      y)
{
  FT_Int  i, j, p, q;
  FT_Int  x_max = x + bitmap->width;
  FT_Int  y_max = y + bitmap->rows;


  for ( i = x, p = 0; i < x_max; i++, p++ )
  {
    for ( j = y, q = 0; j < y_max; j++, q++ )
    {
      if ( i < 0      || j < 0       ||
           i >= var.xres || j >= var.yres )
        continue;

      //image[j][i] |= bitmap->buffer[q * bitmap->width + p];
      lcd_put_pixel(i,j,bitmap->buffer[q * bitmap->width + p]);
    }
  }
}

int Get_Glyphs_From_Wstr( FT_Face face, wchar_t* wstr, TGlyph glyphs[] )
{
    int n;
    PGlyph glyph = glyphs;
    int pen_x=0;
    int pen_y=0;
    int error;


    for( n=0; n<wcslen( wstr ); n++ )
    {
         glyph->index = FT_Get_Char_Index( face, wstr[n] );
        /* store current pen position */
        glyph->pos.x = pen_x;
        glyph->pos.y = pen_y;

        error = FT_Load_Glyph( face, glyph->index, FT_LOAD_DEFAULT );
        if ( error )
            continue;

        error = FT_Get_Glyph( face->glyph, &glyph->image );
        if ( error )
            continue;

          /* translate the glyph image now */
        FT_Glyph_Transform( glyph->image, 0, &glyph->pos );

        pen_x   += face->glyph->advance.x ;

        /* increment number of glyphs */
        glyph++;
    }
     /* count number of glyphs loaded */
   return (glyph - glyphs);
}

void  compute_string_bbox( TGlyph glyphs[],FT_UInt num_glyphs,FT_BBox  *abbox )
{
     FT_BBox  bbox;
     int n;


    bbox.xMin = bbox.yMin =  32000;
    bbox.xMax = bbox.yMax = -32000;
    for ( n = 0; n < num_glyphs; n++ )
    {
        FT_BBox  glyph_bbox;
        FT_Glyph_Get_CBox( glyphs[n].image, FT_GLYPH_BBOX_TRUNCATE,
                         &glyph_bbox );

      if (glyph_bbox.xMin < bbox.xMin)
        bbox.xMin = glyph_bbox.xMin;

      if (glyph_bbox.yMin < bbox.yMin)
        bbox.yMin = glyph_bbox.yMin;

      if (glyph_bbox.xMax > bbox.xMax)
        bbox.xMax = glyph_bbox.xMax;

      if (glyph_bbox.yMax > bbox.yMax)
        bbox.yMax = glyph_bbox.yMax;
    }

    *abbox = bbox;

}

void Draw_Glyphs( TGlyph glyphs[],FT_UInt num_glyphs,FT_Vector  pen )
{
    int n;
    int error;

    for( n=0; n<num_glyphs; n++ )
    {
        FT_Glyph_Transform( glyphs[n].image, 0, &pen );
        /* convert glyph image to bitmap (destroy the glyph copy!) */
        error = FT_Glyph_To_Bitmap( &glyphs[n].image, FT_RENDER_MODE_NORMAL,
              0,                  /* no additional translation */
              1 );                /* destroy copy in "image"   */

         if ( !error )
        {
          FT_BitmapGlyph  bit = (FT_BitmapGlyph)glyphs[n].image;


          draw_bitmap( &bit->bitmap,
                          bit->left,
                          var.yres - bit->top );

          FT_Done_Glyph( glyphs[n].image );
        }
    }
}

int main( int argc, char **argv )
{
    int hzk_fd;
    int fd_fb;
    struct fb_fix_screeninfo fix;

    int screen_size;

    FT_Library    library;
    FT_Error      error;
    FT_Face       face;
    FT_Matrix     matrix;                 /* transformation matrix */
    FT_Vector     pen;                    /* untransformed origin  */
    FT_BBox       bbox;


    TGlyph        glyphs[MAX_GLYPHS];  /* glyphs table */
    PGlyph        glyph;               /* current glyph in table */
    FT_UInt       num_glyphs;

    int i;

    double        angle;

    wchar_t *chinese_char = L"周zhou";
    wchar_t *chinese_char2 = L"嵌入式Linux";

    int line_box_ymin=800;
    int line_box_ymax=0;

    int line_box_width;
    int line_box_hight;

    struct stat hzk_stat;


    fd_fb = open("/dev/fb0",  O_RDWR );
    if( fd_fb<0 )
    {
        perror("oepn failed");
        return -1;
    }

    if( ioctl( fd_fb,  FBIOGET_VSCREENINFO, &var ) )
    {
        printf("can't get var\n");
        return -1;
    }

    if( ioctl( fd_fb,  FBIOGET_FSCREENINFO, &fix ) )
    {
        printf("can't get fix\n");
        return -1;
    }
    line_width = var.xres * var.bits_per_pixel / 8;
    pixel_width = var.bits_per_pixel / 8;

    screen_size = var.xres * var.yres * var.bits_per_pixel / 8;
    fbmem = (unsigned char *)mmap( NULL, screen_size,  PROT_READ | PROT_WRITE, MAP_SHARED,fd_fb,0 );
    if( fbmem == (unsigned char *)-1 )
    {
        printf("mmap is failed\n");
        return -1;
    }

    memset( fbmem, 0, screen_size );

    if( argc != 2 )
    {
        printf("Usage: %s  <font_file>\n", argv[0]);
        return -1;
    }

    error = FT_Init_FreeType( &library );              /* initialize library */
    /* error handling omitted */


    error = FT_New_Face( library, argv[1], 0, &face ); /* create face object */

    /* use 50pt at 100dpi */
    error = FT_Set_Pixel_Sizes( face, 24, 0 );                /* set character size */

    num_glyphs = Get_Glyphs_From_Wstr( face, chinese_char, glyphs);
    compute_string_bbox( glyphs, num_glyphs, &bbox );
    line_box_width = bbox.xMax - bbox.xMin;
    line_box_hight = bbox.yMax - bbox.yMin;
    pen.x = (var.xres - line_box_width)/2*64;
    pen.y = (var.yres - line_box_hight)/2*64;
    Draw_Glyphs( glyphs, num_glyphs, pen );

    num_glyphs = Get_Glyphs_From_Wstr( face, chinese_char2, glyphs);
    compute_string_bbox( glyphs, num_glyphs, &bbox );
    line_box_width = bbox.xMax - bbox.xMin;
    line_box_hight = bbox.yMax - bbox.yMin;
    pen.x = (var.xres - line_box_width)/2*64;
    pen.y = pen.y-24*64;
    Draw_Glyphs( glyphs, num_glyphs, pen );


    return 0;


}

 

 

sd