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
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