freetype的简单使用之 生成一个字体bmp

前言：最近项目上需要在linux上做字体的图像生成，经查找资料选择使用freetype来进行字体的生成

一：bmp的基础定义

1.bmp相关的定义 BMP_API.h

这一步我们可以先进行bmp相关基础的了解

#pragma once
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
using namespace std;


typedef unsigned char BYTE;
typedef unsigned short WORD;
typedef unsigned int DWORD;
typedef long LONG;

//位图文件头定义;
typedef struct  tagBITMAPFILEHEADER{
//      WORD bfType;//单独读取，结构体中就不定义了
        DWORD bfSize;//文件大小
        WORD bfReserved1;//保留字
        WORD bfReserved2;//保留字
        DWORD bfOffBits;//从文件头到实际位图数据的偏移字节数
}BITMAPFILEHEADER;


typedef struct tagBITMAPINFOHEADER{
        DWORD biSize;//信息头大小
        DWORD biWidth;//图像宽度
        DWORD biHeight;//图像高度
        WORD biPlanes;//位平面数，必须为1
        WORD biBitCount;//每像素位数
        DWORD  biCompression; //压缩类型
        DWORD  biSizeImage; //压缩图像大小字节数
        DWORD  biXPelsPerMeter; //水平分辨率
        DWORD  biYPelsPerMeter; //垂直分辨率
        DWORD  biClrUsed; //位图实际用到的色彩数
        DWORD  biClrImportant; //本位图中重要的色彩数
}BITMAPINFOHEADER; //位图信息头定义

//像素信息
typedef struct tagIMAGEDATA
{
        BYTE blue;
        BYTE green;
        BYTE red;
}DATA;

//BMP整体信息
typedef struct tagBMP_BUFFER
{
    WORD                mbfType;
    BITMAPFILEHEADER    hand;
    BITMAPINFOHEADER    info;
    DATA*               BUFFER;
}BMP_BUFFER;

二：生成一个全白的最简单bmp图像（大小1032*672）

#include "BMP_API.h"

int main()
{
    BMP_BUFFER one_bmp_BUFFER;

    one_bmp_BUFFER.mbfType                =0X4d42;
    one_bmp_BUFFERhand.bfOffBits         =54;
    one_bmp_BUFFERhand.bfReserved1       =0;
    one_bmp_BUFFERhand.bfReserved2       =0;
    one_bmp_BUFFERhand.bfSize            =1032*672*3+40+14;
    one_bmp_BUFFERBUFFER                 =new DATA[1032*672];
    one_bmp_BUFFERinfo.biBitCount        =24;
    one_bmp_BUFFERinfo.biClrImportant    =0;
    one_bmp_BUFFERinfo.biClrUsed         =0;
    one_bmp_BUFFERinfo.biCompression     =0;
    one_bmp_BUFFERinfo.biHeight          =1032;
    one_bmp_BUFFERinfo.biPlanes          =1;
    one_bmp_BUFFERinfo.biSize            =40;
    one_bmp_BUFFERinfo.biSizeImage       =1032*672*3;
    one_bmp_BUFFERinfo.biWidth           =672;
    one_bmp_BUFFERinfo.biXPelsPerMeter   =0;
    one_bmp_BUFFERinfo.biYPelsPerMeter   =0;

    int x=0;
    int y=0;
    for(x=0;x<1032;x++)
    {
        for(y=0;y<672;y++)
        {
            one_bmp_BUFFERBUFFER[x*672+y].red=255;
            one_bmp_BUFFERBUFFER[x*672+y].blue=255;
            one_bmp_BUFFERBUFFER[x*672+y].green=255;
        }
    }


    FILE *fpo1;
    fpo1=fopen("./one_bmp_BUFFERbmp","wb");

    fwrite(&one_bmp_BUFFER.mbfType,1,sizeof(WORD),fpo1);
    fwrite(&one_bmp_BUFFER.hand,1,sizeof(tagBITMAPFILEHEADER),fpo1);
    fwrite(&one_bmp_BUFFER.info,1,sizeof(tagBITMAPINFOHEADER),fpo1);
    fwrite(one_bmp_BUFFER.BUFFER,1,sizeof(DATA)*(1032*672),fpo1);

    fclose(fpo1);
}

三：使用freetpe生成一个简单的字体bmp

#include "BMP_API.h"

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include FT_FREETYPE_H
#include FT_GLYPH_H
#include FT_OUTLINE_H



int main()
{
    BMP_BUFFER one_bmp_BUFFER;
	//初始化buffer_k
    one_bmp_BUFFER.mbfType                =0X4d42;
    one_bmp_BUFFER.hand.bfOffBits         =54;
    one_bmp_BUFFER.hand.bfReserved1       =0;
    one_bmp_BUFFER.hand.bfReserved2       =0;
    one_bmp_BUFFER.hand.bfSize            =1032*672*3+40+14;
    one_bmp_BUFFER.BUFFER                 =new DATA[1032*672];
    one_bmp_BUFFER.info.biBitCount        =24;
    one_bmp_BUFFER.info.biClrImportant    =0;
    one_bmp_BUFFER.info.biClrUsed         =0;
    one_bmp_BUFFER.info.biCompression     =0;
    one_bmp_BUFFER.info.biHeight          =1032;
    one_bmp_BUFFER.info.biPlanes          =1;
    one_bmp_BUFFER.info.biSize            =40;
    one_bmp_BUFFER.info.biSizeImage       =1032*672*3;
    one_bmp_BUFFER.info.biWidth           =672;
    one_bmp_BUFFER.info.biXPelsPerMeter   =0;
    one_bmp_BUFFER.info.biYPelsPerMeter   =0;

	//全部使用白色区域
    int x=0;
    int y=0;
    for(x=0;x<1032;x++)
    {
        for(y=0;y<672;y++)
        {
            one_bmp_BUFFER.BUFFER[x*672+y].red=255;
            one_bmp_BUFFER.BUFFER[x*672+y].blue=255;
            one_bmp_BUFFER.BUFFER[x*672+y].green=255;
        }
    }

	
    FT_Library pFTLib = NULL;
    FT_Face pFTFace = NULL;
    FT_Error error = 0;


   //1.初始化一个freetype库
    error = FT_Init_FreeType(&pFTLib);
    if(error){
        pFTLib = 0;
        printf("There is some error when init library\n");
        return -1;
    }

	
	//2.加载字体样式
    error = FT_New_Face(pFTLib, "/home/zhoubing/mywork/freetype_test/simsun.ttc", 0, &pFTFace);
    if(error){
        printf("Open font failed\n");
        return -1;
    }

	//3.设置字体的大小
    FT_Set_Char_Size(pFTFace, 0, 32*16, 300, 300);//通过设置长宽范围设置
    FT_Glyph glyph;

    wchar_t *wszString = L"TEST    BY    TOPSLUO";
    WORD word;


    int bitmap_width_sum = -672;//字体在图像上X轴起始位置
    int bitmap_high_sum = 50;//字体在图像上Y轴起始位置
    int wszStringLen = wcslen(wszString)+1;
    printf("wszStringLen: %d\n",wszStringLen);
    int k=0;

    for(k=0; k < wszStringLen; k++)
    {
	memcpy(&word, wszString+k, 2);
	//转化成位图
        FT_Load_Glyph(pFTFace, FT_Get_Char_Index(pFTFace,word), FT_LOAD_DEFAULT);
        error = FT_Get_Glyph(pFTFace->glyph, &glyph);
        FT_Glyph_To_Bitmap(&glyph, ft_render_mode_normal, 0, 1);
        FT_BitmapGlyph bitmap_glyph = (FT_BitmapGlyph)glyph;
	//取位图数据
        FT_Bitmap  *bitmap = &bitmap_glyph->bitmap;

	int i=0;
	int j=0;

	int font_H=bitmap->rows;
	int font_W=bitmap->width;

        for( i=0;ibuffer[i * font_W +j] != 0)
                {
                    //arrayColor[(i+100)*strInfo.biWidth+j+bitmap_width_sum+100].green = 0;
                    //arrayColor[(i+100)*strInfo.biWidth+j+bitmap_width_sum+100].blue = 0;

                    //arrayColor[(strInfo.biHeight-i)*strInfo.biWidth+j+bitmap_width_sum].green = 0;
                    //arrayColor[(strInfo.biHeight-i)*strInfo.biWidth+j+bitmap_width_sum].blue = 0;

		    
		   //文字竖体
		   // one_bmp_BUFFER.BUFFER[(1032-i-bitmap_width_sum)*672+j].red=0;
            	   // one_bmp_BUFFER.BUFFER[(1032-i-bitmap_width_sum)*672+j].blue=0;
            	   // one_bmp_BUFFER.BUFFER[(1032-i-bitmap_width_sum)*672+j].green=0;
		    //文字横体
		    one_bmp_BUFFER.BUFFER[(1032-i-bitmap_high_sum)*672+j+bitmap_width_sum].red=0;
            	    one_bmp_BUFFER.BUFFER[(1032-i-bitmap_high_sum)*672+j+bitmap_width_sum].blue=0;
            	    one_bmp_BUFFER.BUFFER[(1032-i-bitmap_high_sum)*672+j+bitmap_width_sum].green=0;
	
                }
		else
		{
		  //文字竖体
		   // one_bmp_BUFFER.BUFFER[(1032-i-bitmap_width_sum)*672+j].red=255;
            	    //one_bmp_BUFFER.BUFFER[(1032-i-bitmap_width_sum)*672+j].blue=255;
            	   // one_bmp_BUFFER.BUFFER[(1032-i-bitmap_width_sum)*672+j].green=255;
		    //文字横体
		    one_bmp_BUFFER.BUFFER[(1032-i-bitmap_high_sum)*672+j+bitmap_width_sum].red=255;
            	    one_bmp_BUFFER.BUFFER[(1032-i-bitmap_high_sum)*672+j+bitmap_width_sum].blue=255;
            	    one_bmp_BUFFER.BUFFER[(1032-i-bitmap_high_sum)*672+j+bitmap_width_sum].green=255;
	
		}
            }
        }
       // bitmap_width_sum += bitmap->width + 10;
	  bitmap_width_sum += 16;
    }



    FILE *fpo1;
    fpo1=fopen("./one_bmp_BUFFER.bmp","wb");
    fwrite(&one_bmp_BUFFER.mbfType,1,sizeof(WORD),fpo1);
    fwrite(&one_bmp_BUFFER.hand,1,sizeof(tagBITMAPFILEHEADER),fpo1);
    fwrite(&one_bmp_BUFFER.info,1,sizeof(tagBITMAPINFOHEADER),fpo1);
    fwrite(one_bmp_BUFFER.BUFFER,1,sizeof(DATA)*(1032*672),fpo1);
    fclose(fpo1);

    return 0;
}