freetype的使用及总结

/*总结
1 首先创建一个库
2 根据字体文件得到face object
3 设置字体大小及第一个坐标值
4 加载face得到字体的glyph及buffer
5 显示 （每次显示一个字符都是根据前一个字符的glyph得到下一个字符坐标的原点值，这样方便显示）

*/
#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 <ft2build.h>
#include FT_FREETYPE_H
#include FT_GLYPH_H
#define DBG_PRINTF printf
static FT_Library g_tLibrary;
static FT_Face g_tFace;
static FT_GlyphSlot g_tSlot;
static unsigned char *filename=NULL;

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;

typedef struct FontBitMap {
int iXLeft;
int iYTop;
int iXMax;
int iYMax;
int iBpp;
int iPitch;   /* 对于单色位图, 两行象素之间的跨度 */
int iCurOriginX;
int iCurOriginY;
int iNextOriginX;
int iNextOriginY;
unsigned char *pucBuffer;
}T_FontBitMap, *PT_FontBitMap;

static int FreeTypeFontInit(char *pcFontFile, unsigned int dwFontSize);
static int FreeTypeGetFontBitmap(unsigned int dwCode, PT_FontBitMap ptFontBitMap);
/* 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;
//  printf("pen_8=%d\n",pen_8);
// printf("var.bits_per_pixel=%d\n",var.bits_per_pixel);
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;
}
}
}

static int FreeTypeGetFontBitmap(unsigned int dwCode, PT_FontBitMap ptFontBitMap)
{
int iError;
int iPenX = ptFontBitMap->iCurOriginX;
int iPenY = ptFontBitMap->iCurOriginY;

/* load glyph image into the slot (erase previous one) */
//iError = FT_Load_Char(g_tFace, dwCode, FT_LOAD_RENDER );
iError = FT_Load_Char(g_tFace, dwCode, FT_LOAD_RENDER | FT_LOAD_MONOCHROME);

//DBG_PRINTF("iPenX = %d, iPenY = %d, bitmap_left = %d, bitmap_top = %d, width = %d, rows = %d\n", iPenX, iPenY, g_tSlot->bitmap_left, g_tSlot->bitmap_top, g_tSlot->bitmap.width, g_tSlot->bitmap.rows);
ptFontBitMap->iXLeft    = iPenX + g_tSlot->bitmap_left;
ptFontBitMap->iYTop     = iPenY - g_tSlot->bitmap_top;
ptFontBitMap->iXMax     = ptFontBitMap->iXLeft + g_tSlot->bitmap.width;
ptFontBitMap->iYMax     = ptFontBitMap->iYTop  + g_tSlot->bitmap.rows;
ptFontBitMap->iBpp      = 1;
ptFontBitMap->iPitch    = g_tSlot->bitmap.pitch;
ptFontBitMap->pucBuffer = g_tSlot->bitmap.buffer;

ptFontBitMap->iNextOriginX = iPenX + g_tSlot->advance.x / 64;
ptFontBitMap->iNextOriginY = iPenY;

return 0;
}

int ShowOneFont(PT_FontBitMap ptFontBitMap)
{
int x;
int y;
unsigned char ucByte = 0;
int i = 0;
int bit;
if (ptFontBitMap->iBpp == 1)
{
for (y = ptFontBitMap->iYTop; y < ptFontBitMap->iYMax; y++)
{
i = (y - ptFontBitMap->iYTop) * ptFontBitMap->iPitch;
for (x = ptFontBitMap->iXLeft, bit = 7; x < ptFontBitMap->iXMax; x++)
{
if (bit == 7)
{
ucByte = ptFontBitMap->pucBuffer[i++];
}

if (ucByte & (1<<bit))
{
lcd_put_pixel(x,y, 0xffffffff);
//g_ptDispOpr->ShowPixel(x, y, COLOR_FOREGROUND);
}
else
{
/* 使用背景色, 不用描画 */
// g_ptDispOpr->ShowPixel(x, y, 0); /* 黑 */
}
bit--;
if (bit == -1)
{
bit = 7;
}
}
}
}
else
{
DBG_PRINTF("ShowOneFont error, can't support %d bpp\n", ptFontBitMap->iBpp);
return -1;
}
return 0;
}
static int FreeTypeFontInit(char *pcFontFile, unsigned int dwFontSize)
{
int iError;
/* 显示矢量字体 */
iError = FT_Init_FreeType(&g_tLibrary );			   /* 初始化库 */
iError = FT_New_Face(g_tLibrary, pcFontFile, 0, &g_tFace); /*根据字体文件得到face */
g_tSlot = g_tFace->glyph;
iError = FT_Set_Pixel_Sizes(g_tFace, dwFontSize, 0); /* 设置字体大小*/
return 0;
}

int main(int argc, char **argv)
{
unsigned char str[] = "中";
int i;
int n;
int error;
filename=argv[1];
T_FontBitMap tFontBitMap;

wchar_t *chinese_str1 = L"我爱你gif";
wchar_t *chines
4000
e_str2 = L"还在";

tFontBitMap.iCurOriginX = 0;
tFontBitMap.iCurOriginY = 50;
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;
printf("line_width=%d\n",line_width);
pixel_width = var.bits_per_pixel / 8;
printf("pixel_width=%d\n",pixel_width);
screen_size = var.xres * var.yres * var.bits_per_pixel / 8;
printf("screen_size=%d\n",screen_size);
fbmem = (unsigned char *)mmap(NULL , screen_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd_fb, 0);
/* 清屏: 全部设为黑色 */
memset(fbmem, 0, screen_size);
error=FreeTypeFontInit(filename,50);

for ( n = 0; n < wcslen(chinese_str1); n++ )
{
FreeTypeGetFontBitmap(chinese_str1
,&tFontBitMap);
ShowOneFont(&tFontBitMap);
tFontBitMap.iCurOriginX = tFontBitMap.iNextOriginX;
tFontBitMap.iCurOriginY = tFontBitMap.iNextOriginY;
}

return 0;
}