Transplantation of freetype Library

freetype The migration of Libraries

freetype Depend on libpng, and libpng Depend on zlib, So we need to migrate three libraries in this migration , Each migration operation is similar , But the order cannot be reversed

1. transplant zlib library

1.1 download zlib library

Download address : zlib Official website

1.2 take zlib Move to linux Virtual machine , And extract the , Unzip and enter the directory

1. tar -xzf zlib-1.2.11.tar.gz
2. cd zlib-l.2.11/

1.3 Use configure To configure the makefile

1. export CC=arm-linux-gnueabihf-gcc   #  Your compiler , Mine may be different from yours 
2. ./configure --prefix=/home/hxd/tools/zlib  # prefix Used to specify the location of library installation 

1.4 Use make && make install Installation Library

1. make
2. make install

After successful installation , You will get three directories under the installation directory you just set , Namely include/, lib/, share/

1.5 What will be obtained include/ Copy all files in the directory to the default search header directory of your compilation tool chain , What will be obtained lib/ Copy all the files in the directory to the directory of the default search library files of your compilation tool chain （ The purpose of this is that you don't need to add the path manually when compiling in the future , So this step can also be omitted ）

1. echo "main(){}" | arm-linux-gnueabihf-gcc -E -v -    #  This command can view the default search path of the compilation tool , Choose the right one by yourself 

• include route , I chose the path of my cross tool chain /usr/lib/gcc-cross/arm-linux-gnueabihf/9/include
  

cp -rfd /home/hxd/tools/zlib/include/* /usr/lib/gcc-cross/arm-linux-gnueabihf/9/include  #  add -d The purpose of is to copy the linked file in this way , Save space 

• lib route , I chose the path of my cross tool chain /usr/lib/gcc-cross/arm-linux-gnueabihf/9
  

cp -rf /home/hxd/tools/zlib/lib/* /usr/lib/gcc-cross/arm-linux-gnueabihf/9/

1.6 Will be compiled zlib Migrate the library to the development board

Only need to lib/ Copy all files in the directory to the development board /usr/lib/ or /lib/ Next

1.  First the zlib Folder copy nfs Under the directory of , Then the development board mounts the nfs
2. rm -rf /usr/lib/libz* /lib/libz*   #  If the library existed before , May interfere with each other , So delete the previous Library 
3. cp -rfd /mnt/zlib/lib/* /usr/lib

2. transplant libpng library

2.1 download libpng library

Download address : Official website

2.2 take libpng Move to linux Virtual machine , And extract the , Unzip and enter the directory

1. tar -xJf libpng-1.6.37.tar.xz
2. cd libpng-l.6.37

2.3 perform ./configure

if  It was done before 1.5 operation 
	1. ./configure --host=arm-linux-gnueabihf --prefix=/home/hxd/tools/libpng
else
	1. export CFLAGS="$CFLAGS -I/home/hxd/tools/zlib/include"   #  With your zlib Installation path 
	2. export CPPFLAGS="$CPPFLAGS -I/home/hxd/tools/zlib/include"
	3. export LDFLAGS="$LDFLAGS -L/home/hxd/tools/zlib/lib"
	4. ./configure --host=arm-linux-gnueabihf --prefix=/home/hxd/tools/libpng

2.4 install

make && make install

2.5 Configure into the compilation chain , Convenient for later compilation （ Specific path 1.5 There's an explanation ）, Also need to freetype2 All files in the directory are moved to freetype2 At the same directory

1. cp -rfd /home/hxd/tools/libpng/include/* /usr/lib/gcc-cross/arm-linux-gnueabihf/9/include  #  add -d The purpose of is to copy the linked file in this way , Save space 
2. cp -rf /home/hxd/tools/libpng/lib/* /usr/lib/gcc-cross/arm-linux-gnueabihf/9/
3. cp -rf /usr/lib/gcc-cross/arm-linux-gnueabihf/9/include/freetype2/* /usr/lib/gcc-cross/arm-linux-gnueabihf/9/include/

2.6 Migrate to development board

Need to put lib/ Copy all files in the directory to the development board /usr/lib/ or /lib/ Next

1.  First the libpng Folder copy nfs Under the directory of , Then the development board mounts the nfs
2. rm -rf /usr/lib/libpng* /lib/libpng*   #  If the library existed before , May interfere with each other , So delete the previous Library 
3. cp -rfd /mnt/libpng/lib/* /usr/lib

3. transplant freetype library

3.1 download

Download address : Official website

3.2 Move to linux Virtual machine , After decompressing , Enter this directory

1. tar -xJf freetype-2.10.2.tar.xz
2. cd freetype-2.10.2

3.3 Use configure To configure makefile

if  Ahead 1.5 and 2.5 They are equipped with 
	1. ./configure --prefix=/home/hxd/tools/freetype --host=arm-linux-gnueabihf
elif  No configuration in front 
	1. export CFLAGS="$CFLAGS -I/home/hxd/tools/zlib/include -I/home/hxd/tools/libpng/include"   #  With your zlib and libpng Installation path 
	2. export CPPFLAGS="$CPPFLAGS -I/home/hxd/tools/zlib/include -I/home/hxd/tools/libpng/include"
	3. export LDFLAGS="$LDFLAGS -L/home/hxd/tools/zlib/lib -L/home/hxd/tools/libpng/lib"
	4. ./configure --prefix=/home/hxd/tools/freetype --host=arm-linux-gnueabihf

3.4 install

make && make install

3.5 Configure it into the cross compilation tool chain , Convenient for later compilation （ Specific path 1.5 There's an explanation ）

1. cp -rfd /home/hxd/tools/freetype/include/* /usr/lib/gcc-cross/arm-linux-gnueabihf/9/include  #  add -d The purpose of is to copy the linked file in this way , Save space 
2. cp -rf /home/hxd/tools/freetype/lib/* /usr/lib/gcc-cross/arm-linux-gnueabihf/9/

3.6 Migrate to the development board

1.  First the libpng Folder copy nfs Under the directory of , Then the development board mounts the nfs
2. rm -rf /usr/lib/libfreetype* /lib/libfreetype*   #  If the library existed before , May interfere with each other , So delete the previous Library 
3. cp -rfd /mnt/libpng/lib/* /usr/lib

4. Use

4.1 If not configured 1.5,2.5,3.5

Compile the example ：

arm-linux-gnueabihf-gcc test.c -o test -lz -lm -lpng -freetype -I/home/hxd/tools/freetype/include/freetype2 -L/home/hxd/tools/freetype/lib -L/home/hxd/tools/zlib/lib -L/home/hxd/tools/libpng/lib

4.2 If the

Compile the example :

arm-linux-gnueabihf-gcc test.c -o test -lz -lm -lpng -freetype

5. example ( Code from Weige )

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

#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_GLYPH_H

int fd_fb;
struct fb_var_screeninfo var;   /* Current var */
struct fb_fix_screeninfo fix;   /* Current fix */
int screen_size;
unsigned char *fbmem;
unsigned int line_width;
unsigned int pixel_width;

/* color : 0x00RRGGBB */
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 int *pen_32;   

    unsigned int red, green, blue;  

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

    switch (var.bits_per_pixel)
    {
    
        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 surport %dbpp\n", var.bits_per_pixel);
            break;
        }
    }
}

/********************************************************************** *  The name of the function ： draw_bitmap *  Function description ：  according to bitmap Bitmap , stay LCD Display Chinese characters at the specified position  *  Input parameters ： x coordinate ,y coordinate , Bitmap pointer  *  Output parameters ：  nothing  *  return   return   value ：  nothing  *  modification date   Version number   Modifier   Modify the content  * ----------------------------------------------- * 2020/05/12 V1.0 zh(angenao)  establish  ***********************************************************************/ 
void
draw_bitmap( FT_Bitmap*  bitmap,
             FT_Int      x,
             FT_Int      y,
             unsigned int color)
{
    
    FT_Int  i, j, p, q;
    FT_Int  x_max = x + bitmap->width;
    FT_Int  y_max = y + bitmap->rows;

    //printf("x = %d, y = %d\n", x, y);

    for ( j = y, q = 0; j < y_max; j++, q++ )
    {
    
        for ( i = x, p = 0; i < x_max; i++, p++ )
        {
    
            if ( i < 0      || j < 0       ||
                i >= var.xres || j >= var.yres )
            continue;
            //image[j][i] |= bitmap->buffer[q * bitmap->width + p];
            if (bitmap->buffer[q * bitmap->width + p]) lcd_put_pixel(i, j, color);
        }
    }
}

int compute_string_bbox(FT_Face face, wchar_t *wstr, FT_BBox  *abbox)
{
    
    int i;
    int error;
    FT_BBox bbox;
    FT_BBox glyph_bbox;
    FT_Vector pen;
    FT_Glyph  glyph;
    FT_GlyphSlot slot = face->glyph;

    /*  initialization  */
    bbox.xMin = bbox.yMin = 32000;
    bbox.xMax = bbox.yMax = -32000;

    /*  Specify the origin as (0, 0) */
    pen.x = 0;
    pen.y = 0;

    /*  Calculate the of each character bounding box */
    /*  First translate,  Again load char,  You can get its outer frame  */
    for (i = 0; i < wcslen(wstr); i++)
    {
    
        /*  transformation ：transformation */
        FT_Set_Transform(face, 0, &pen);

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

        /*  Take out glyph */
        error = FT_Get_Glyph(face->glyph, &glyph);
        if (error)
        {
    
            printf("FT_Get_Glyph error!\n");
            return -1;
        }
        
        /*  from glyph Get the outer frame : bbox */
        FT_Glyph_Get_CBox(glyph, FT_GLYPH_BBOX_TRUNCATE, &glyph_bbox);

        /*  Update the outline  */
        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;
        
        /*  Calculate the origin of the next character : increment pen position */
        pen.x += slot->advance.x;
        pen.y += slot->advance.y;
    }

    /* return string bbox */
    *abbox = bbox;
}


int display_string(FT_Face face, wchar_t *wstr, int lcd_x, int lcd_y, unsigned int color, int angle)
{
    
    int i;
    int error;
    FT_BBox bbox;
    FT_Vector pen;
    FT_Glyph  glyph;
    FT_GlyphSlot slot = face->glyph;
    FT_Matrix     matrix;

    /*  hold LCD Convert coordinates to Cartesian coordinates  */
    int x = lcd_x;
    int y = var.yres - lcd_y;

    /*  Calculation frame  */
    compute_string_bbox(face, wstr, &bbox);

    /*  Push back the origin  */
    pen.x = (x - bbox.xMin) * 64; /*  Company : 1/64 Pixels  */
    pen.y = (y - bbox.yMax) * 64; /*  Company : 1/64 Pixels  */

    /*  Rotation Angle  */
    /* 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 );

    /*  Process each character  */
    for (i = 0; i < wcslen(wstr); i++)
    {
    
        /*  transformation ：transformation */
        FT_Set_Transform(face, &matrix, &pen);

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

        /*  stay LCD Draw on :  Use LCD coordinate  */
        draw_bitmap( &slot->bitmap,
                        slot->bitmap_left,
                        var.yres - slot->bitmap_top, color);

        /*  Calculate the origin of the next character : increment pen position */
        pen.x += slot->advance.x;
        pen.y += slot->advance.y;
    }

    return 0;
}


int main(int argc, char **argv)
{
    
    wchar_t *wstr = L" Hello world ！Hello World!";

    FT_Library    library;
    FT_Face       face;
    int error;
    FT_BBox bbox;
    int font_size = 24;
    int angle = 0;
    int lcd_x, lcd_y;

    if (argc < 4)
    {
    
        printf("Usage : %s <font_file> <lcd_x> <lcd_y> [font_size] [angle]\n", argv[0]);
        return -1;
    }

    lcd_x = strtoul(argv[2], NULL, 0);      
    lcd_y = strtoul(argv[3], NULL, 0);      
    
    if (argc == 5)
        font_size = strtoul(argv[4], NULL, 0);

    if (argc == 6)
    {
    
        font_size = strtoul(argv[4], NULL, 0);
        angle = atoi(argv[5]);    
    }
    fd_fb = open("/dev/fb0", O_RDWR);
    if (fd_fb < 0)
    {
    
        printf("can't open /dev/fb0\n");
        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("can't mmap\n");
        return -1;
    }

    /*  Clear the screen :  All set to black  */
    memset(fbmem, 0, screen_size);

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

    FT_Set_Pixel_Sizes(face, font_size, 0);

    printf("font_size: %d\n", font_size);

    display_string(face, L" Hello world ！Hello World!", lcd_x, lcd_y, 0x112233, angle);
    display_string(face, L" Hello world ！Hello World!", lcd_x, lcd_y+font_size, 0x222233, angle);
    display_string(face, L" Hello world ！Hello World!", lcd_x, lcd_y+font_size*2, 0x332233, angle);
    display_string(face, L" Hello world ！Hello World!", lcd_x, lcd_y+font_size*3, 0x442233, angle);
    
    return 0;   
}