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电子产品量产工具（3）- 文字系统实现

2022-08-05 05:16:00 【乛 乛 .】

电子产品量产工具）

3 文字系统设计

3 .1 输入系统头文件front_manager.h

在头文件中抽象出一个结构体来描述一个字符的大小、位置和位图信息。并抽象出一个结构体描述字库的操作比如freetype的操作

3 .1.1 字符信息结构体FontBitMap

typedef struct Region {
    
	int iLeftUpX;
	int iLeftUpY;
	int iWidth;
	int iHeigh;
}Region, *PRegion;

typedef struct FontBitMap {
    
	Region tRegion;
	int iCurOriginX; /*当前字体原点x坐标*/
	int iCurOriginY; /*当前字体原点y坐标*/
	int iNextOriginX; /*下一个字体原点y坐标*/
	int iNextOriginY; /*下一个字体原点y坐标*/
	unsigned char *pucBuffer; /*存有字符的位图信息*/ 
}FontBitMap, *PFontBitMap;

3.1.2 字库操作结构体FontBitMap

typedef struct FontOpr {
    
	char *name; /*字体模块名字*/
	int (*FontInit)(char *aFineName); /*字体模块初始化函数*/
	int (*SetFontSize)(int iFontSize); /*设置字体尺寸*/
	int (*GetFontBitMap)(unsigned int dwCode, PFontBitMap ptFontBitMap);/*根据编码值获得字符位图，并存入ptFontBitMap*/
	struct FontOpr *ptNext;/*若想支持多种字库文件，使用链表管理*/
}FontOpr, *PFontOpr;

3.1.3 front_manager.h完整代码

#ifndef _FONT_MANAGER_H
#define _FONT_MANAGER_H
#include <common.h>

typedef struct FontBitMap {
    
	Region tRegion;
	int iCurOriginX;
	int iCurOriginY;
	int iNextOriginX;
	int iNextOriginY;
	unsigned char *pucBuffer;
}FontBitMap, *PFontBitMap;

typedef struct FontOpr {
    
	char *name;
	int (*FontInit)(char *aFineName);
	int (*SetFontSize)(int iFontSize);
	int (*GetFontBitMap)(unsigned int dwCode, PFontBitMap ptFontBitMap);
	struct FontOpr *ptNext;
}FontOpr, *PFontOpr;

void RegisterFont(PFontOpr ptFontOpr);
void FontsRegister(void);
int SelectAndInitFont(char *aFontOprName, char *aFontFileName);
int SetFontSize(int iFontSize);
int GetFontBitMap(unsigned int dwCode, PFontBitMap ptFontBitMap);
#endif

3.2 文字系统文件freetype.c

3.2 字库操作结构体

实现freetype字库对应的操作结构体

static FontOpr g_tFreetypeOpr = {
    
	.name          = "freetype", /*模块名*/
	.FontInit      = FreeTypeFontInit,   /*模块初始化*/
	.SetFontSize   = FreeTypeSetFontSize, /*字体大小设置*/
	.GetFontBitMap = FreeTypeGetFontBitMap, /*字体位图*/
};

3.2.1 字库初始化函数FreeTypeFontInit

static FT_Face g_tFace;
static int g_iDefaultFontSize = 12;
....
static int FreeTypeFontInit(char *aFineName)
{
    
    FT_Library    library;
    int error;
    error = FT_Init_FreeType( &library );                 /* initialize library */    
	if (error)
	{
    
		printf("FT_Init_FreeType err\n");
		return -1;
	}	
    error = FT_New_Face(library, aFineName, 0, &g_tFace ); /* create face object */
	if (error)
	{
    
		printf("FT_New_Face err\n");
		return -1;
	}
    FT_Set_Pixel_Sizes(g_tFace, g_iDefaultFontSize, 0);
	return 0;
}

3.2.2 字体大小设置函数FreeTypeSetFontSize

static int FreeTypeSetFontSize(int iFontSize)
{
    
    FT_Set_Pixel_Sizes(g_tFace, iFontSize, 0);
	return 0;
}

3.2.3 位图获取函数FreeTypeGetFontBitMap

static int FreeTypeGetFontBitMap(unsigned int dwCode, PFontBitMap ptFontBitMap)
{
    
	int error;
    FT_Vector pen;
    FT_GlyphSlot slot = g_tFace->glyph;

    pen.x = ptFontBitMap->iCurOriginX * 64; /* 单位: 1/64像素 */
    pen.y = ptFontBitMap->iCurOriginY * 64; /* 单位: 1/64像素 */

	/* 转换：transformation */
	FT_Set_Transform(g_tFace, 0, &pen);

	/* 加载位图: load glyph image into the slot (erase previous one) */
	error = FT_Load_Char(g_tFace, dwCode, FT_LOAD_RENDER);
	if (error)
	{
    
		printf("FT_Load_Char error\n");
		return -1;
	}

	ptFontBitMap->pucBuffer = slot->bitmap.buffer;

	ptFontBitMap->tRegion.iLeftUpX = slot->bitmap_left;
	ptFontBitMap->tRegion.iLeftUpY = ptFontBitMap->iCurOriginY*2 - slot->bitmap_top;
	ptFontBitMap->tRegion.iWidth   = slot->bitmap.width;
	ptFontBitMap->tRegion.iHeigh   = slot->bitmap.rows;
	/*下个字符原点*/
	ptFontBitMap->iNextOriginX = ptFontBitMap->iCurOriginX + slot->advance.x / 64;
	ptFontBitMap->iNextOriginY = ptFontBitMap->iCurOriginY;

	return 0;
}

3.2.4 注册函数

将字库操作结构体注册进上层链表

void FreetypeRegister(void)
{
    
	RegisterFont(&g_tFreetypeOpr);
}

3.2.5 freetype.c完整代码

#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 <font_manager.h>
#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_GLYPH_H
static FT_Face g_tFace;

static int FreeTypeFontInit(char *aFineName)
{
    
    FT_Library    library;
    int error;

    error = FT_Init_FreeType( &library );                 /* initialize library */    
	if (error)
	{
    
		printf("FT_Init_FreeType err\n");
		return -1;
	}
	
    error = FT_New_Face(library, aFineName, 0, &g_tFace ); /* create face object */
	if (error)
	{
    
		printf("FT_New_Face err\n");
		return -1;
	}

    FT_Set_Pixel_Sizes(g_tFace, g_iDefaultFontSize, 0);

	return 0;
}

static int FreeTypeSetFontSize(int iFontSize)
{
    
    FT_Set_Pixel_Sizes(g_tFace, iFontSize, 0);
	return 0;
}

static int FreeTypeGetFontBitMap(unsigned int dwCode, PFontBitMap ptFontBitMap)
{
    
	int error;
    FT_Vector pen;
    FT_GlyphSlot slot = g_tFace->glyph;
    pen.x = ptFontBitMap->iCurOriginX * 64; /* 单位: 1/64像素 */
    pen.y = ptFontBitMap->iCurOriginY * 64; /* 单位: 1/64像素 */
	/* 转换：transformation */
	FT_Set_Transform(g_tFace, 0, &pen);
	/* 加载位图: load glyph image into the slot (erase previous one) */
	error = FT_Load_Char(g_tFace, dwCode, FT_LOAD_RENDER);
	if (error)
	{
    
		printf("FT_Load_Char error\n");
		return -1;
	}
	ptFontBitMap->pucBuffer = slot->bitmap.buffer;
	ptFontBitMap->tRegion.iLeftUpX = slot->bitmap_left;
	ptFontBitMap->tRegion.iLeftUpY = ptFontBitMap->iCurOriginY*2 - slot->bitmap_top;
	ptFontBitMap->tRegion.iWidth   = slot->bitmap.width;
	ptFontBitMap->tRegion.iHeigh   = slot->bitmap.rows;
	ptFontBitMap->iNextOriginX = ptFontBitMap->iCurOriginX + slot->advance.x / 64;
	ptFontBitMap->iNextOriginY = ptFontBitMap->iCurOriginY;

	return 0;
}

static FontOpr g_tFreetypeOpr = {
    
	.name          = "freetype",
	.FontInit      = FreeTypeFontInit,
	.SetFontSize   = FreeTypeSetFontSize,
	.GetFontBitMap = FreeTypeGetFontBitMap,
};

void FreetypeRegister(void)
{
    
	RegisterFont(&g_tFreetypeOpr);
}

3.3 字库管理front_manager.c

在这里插入图片描述

3.3.1 注册函数FontsRegister

将下层结构体注册进链表

static PFontOpr g_ptFonts = NULL;
....
void RegisterFont(PFontOpr ptFontOpr)
{
    
	ptFontOpr->ptNext = g_ptFonts;
	g_ptFonts = ptFontOpr;
}

void FontsRegister(void)
{
    
	extern void FreetypeRegister(void);
	FreetypeRegister();
}

3.3.2 选择初始化函数SelectAndInitFont

static PFontOpr g_ptDefaulFontOpr = NULL;
....
int SelectAndInitFont(char *aFontOprName, char *aFontFileName)
{
    
	PFontOpr ptTmp = g_ptFonts;
	while (ptTmp)  /*选择字体*/
	{
    
		if (strcmp(ptTmp->name, aFontOprName) == 0)
			break;
		ptTmp = ptTmp->ptNext;
	}
	if (!ptTmp)
		return -1;
	g_ptDefaulFontOpr = ptTmp; /*保存字体*/
	return ptTmp->FontInit(aFontFileName);
}

3.3.3 字体大小设置函数SetFontSize

int SetFontSize(int iFontSize)
{
    
	return g_ptDefaulFontOpr->SetFontSize(iFontSize);
}

3.2.5 front_manager.c完整代码

#include <font_manager.h>
#include <string.h>
static PFontOpr g_ptFonts = NULL;
static PFontOpr g_ptDefaulFontOpr = NULL;


void RegisterFont(PFontOpr ptFontOpr)
{
    
	ptFontOpr->ptNext = g_ptFonts;
	g_ptFonts = ptFontOpr;
}

void FontsRegister(void)
{
    
	extern void FreetypeRegister(void);
	FreetypeRegister();
}

int SelectAndInitFont(char *aFontOprName, char *aFontFileName)
{
    
	PFontOpr ptTmp = g_ptFonts;
	while (ptTmp)
	{
    
		if (strcmp(ptTmp->name, aFontOprName) == 0)
			break;
		ptTmp = ptTmp->ptNext;
	}

	if (!ptTmp)
		return -1;

	g_ptDefaulFontOpr = ptTmp;
	return ptTmp->FontInit(aFontFileName);
}

int SetFontSize(int iFontSize)
{
    
	return g_ptDefaulFontOpr->SetFontSize(iFontSize);
}

int GetFontBitMap(unsigned int dwCode, PFontBitMap ptFontBitMap)
{
    
	return g_ptDefaulFontOpr->GetFontBitMap(dwCode, ptFontBitMap);
}

3.3.3 位图获取函数GetFontBitMap

int GetFontBitMap(unsigned int dwCode, PFontBitMap ptFontBitMap)
{
    
	return g_ptDefaulFontOpr->GetFontBitMap(dwCode, ptFontBitMap);
}

3.4 字库测试test.c

void lcd_put_ascii(int x, int y, unsigned char c)
{
    
	unsigned char *dots = (unsigned char *)&fontdata_8x16[c*16];
	int i, b;
	unsigned char byte;

	for (i = 0; i < 16; i++)
	{
    
		byte = dots[i];
		for (b = 7; b >= 0; b--)
		{
    
			if (byte & (1<<b))
			{
    
				/* show */
				PutPixel(x+7-b, y+i, 0xffffff); /* 白 */
			}
			else
			{
    
				/* hide */
				PutPixel(x+7-b, y+i, 0); /* 黑 */
			}
		}
	}
}

int main(int argc, char **argv)
{
    
	PDispBuff ptBuffer;
	int error;
	FontBitMap tFontBitMap;
	char *str= "www.100ask.net";
	int i = 0;
	int lcd_x;
	int lcd_y;
	int font_size;		
	if (argc != 5)
	{
    
		printf("Usage: %s <font_file> <lcd_x> <lcd_y> <font_size>\n", argv[0]); /*打印用法*/
		return -1;
	}
	lcd_x = strtol(argv[2], NULL, 0);  /*首个字符x坐标*/
	lcd_y = strtol(argv[3], NULL, 0);	  /*首个字符y坐标*/
	font_size  = strtol(argv[4], NULL, 0);		  /*字符大小*/	
	DisplayInit();  /*显示系统初始化*/
	SelectDefaultDisplay("fb");  /*选择lcd显示设备*/
	InitDefaultDisplay();    /*lcd显示设备初始化*/
	ptBuffer = GetDisplayBuffer(); /*获取内存空间*/
	FontsRegister();	/*注册字体*/
	error = SelectAndInitFont("freetype", argv[1]);	/*选择字体*/
	if (error)
	{
    
		printf("SelectAndInitFont err\n");
		return -1;
	}	
	SetFontSize(font_size);  /*字符大小*/	
	while (str[i])  /*获取每个字符的位图并显示在lcd上*/
	{
    
		/* get bitmap */
		tFontBitMap.iCurOriginX = lcd_x;     /*首个字符x坐标*/
		tFontBitMap.iCurOriginY = lcd_y;    /*首个字符y坐标*/
		error = GetFontBitMap(str[i], &tFontBitMap); /*获取字符位图*/
		if (error)
		{
    
			printf("SelectAndInitFont err\n");
			return -1;
		}	
		DrawFontBitMap(&tFontBitMap, 0xff0000);	/*绘制位图*/
		FlushDisplayRegion(&tFontBitMap.tRegion, ptBuffer); /*刷新至lcd*/
		lcd_x = tFontBitMap.iNextOriginX; /*下个字符x坐标*/
		lcd_y = tFontBitMap.iNextOriginY;	/*下个字符y坐标*/
		i++;
	}

	return 0;	
}
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版权声明
本文为[乛 乛 .]所创，转载请带上原文链接，感谢
https://blog.csdn.net/weixin_63493925/article/details/126064647

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