LPC54608生成PDF文件

主机环境：Win10 64bit

开发环境：MDK5.23

目标板：LPC54608

之前在NXP论坛里得到了一块LPC54608开发板，最吸引人的地方是带了一块屏，如下图：

这也是第一次接触NXP的开发板,之前一直都是用的ST的MCU，NXP的库跟ST的还是差别蛮大的，自我感觉ST的开发入手要快一些，而NXP的相对慢一些，入手开发板之后就看了库里面自带的一些基本驱动例程，只熟悉了一下基本外设的开发，之前有次在群里看到有人询问单片机生成PDF的问题，突然觉得有些兴趣所以就有了前面的libHaru学习笔记,libHaru库是一个十分不错的库，对于PDF的实现来说也是相当齐全的，在PC上使用是完全没有问题的，但在资源紧张的MCU上，还是有些困难的，因此就想找一下适用于MCU的生成PDF的库，结果不太理想，都是一些需要实现动态内存管理的平台才行，而且这些库都是把生成的数据放在了内存中，直到保存文件时才写入到文件中，这对于一般只有几十或者几百KB级别的单片机来说更不可能了，于是乎，萌发了自己动手写一个基本的能用于MCU的生成PDF文件的库，我称之为libpdf，其中的接口参考了libHaru，如下所示：

当然有些接口还没有实现，但基本的操作还是可以的，等以后再逐渐完善吧，pdflib是生成pdf文件的，因此要基于Fatfs来实现文件的操作，pdflib库只有两个文件，也相应的参考了pdfgen库，该库在后面有链接，

头文件如下：

#ifndef __PDFLIB_H__
#define __PDFLIB_H__

#include "ff.h"
/*----- standard C library functions -----------------------------------------*/

#define LPDF_FOPEN                  f_open
#define LPDF_FCLOSE                 f_close
#define LPDF_FREAD                  f_read
#define LPDF_FWRITE                 f_write
#define LPDF_FFLUSH                 f_sync
#define LPDF_FSEEK                  f_seek
#define LPDF_FTELL                  f_tell
#define LPDF_FEOF                   f_eof
#define LPDF_FERROR                 f_error
#define LPDF_RENAME                 f_rename
#define LPDF_REMOVE                 f_unlink
#define LPDF_MALLOC                 malloc
#define LPDF_FREE                   free
#define LPDF_FILE                   FIL
#define LPDF_TIME                   time
#define LPDF_PRINTF                 printf
#define LPDF_SPRINTF                sprintf
#define LPDF_FPRINTF                f_printf
#define LPDF_VOID                   void
#define LPDF_SIN                    sin
#define LPDF_COS                    cos

/*  native OS integer types */
typedef  signed int          LPDF_INT;
typedef  unsigned int        LPDF_UINT;


/*  32bit integer types
 */
typedef  signed int          LPDF_INT32;
typedef  unsigned int        LPDF_UINT32;


/*  16bit integer types
 */
typedef  signed short        LPDF_INT16;
typedef  unsigned short      LPDF_UINT16;


/*  8bit integer types
 */
typedef  signed char         LPDF_INT8;
typedef  unsigned char       LPDF_UINT8;


/*  8bit binary types
 */
typedef  unsigned char       LPDF_BYTE;


/*  float type (32bit IEEE754)
 */
typedef  float               LPDF_REAL;


/*  double type (64bit IEEE754)
 */
typedef  double              LPDF_DOUBLE;


/*  boolean type (0: False, !0: True)
 */
typedef  signed int          LPDF_BOOL;


/*  error-no type (32bit unsigned integer)
 */
typedef  unsigned long       LPDF_STATUS;

#define LPDF_OK                     0
#define LPDF_FAILED                 1

/*----- font state -----------------------------------------------------------*/
#define   LPDF_FONT_INVALID                 0x00FF
#define   LPDF_FONT_COURIER                 0x0000
#define   LPDF_FONT_COURIER_B               0x0001
#define   LPDF_FONT_COURIER_O               0x0002
#define   LPDF_FONT_COURIER_OB              0x0003
#define   LPDF_FONT_HELVETICA               0x0004
#define   LPDF_FONT_HELVETICA_B             0x0005
#define   LPDF_FONT_HELVETICA_O             0x0006
#define   LPDF_FONT_HELVETICA_BO            0x0007
#define   LPDF_FONT_TIMES_R                 0x0008
#define   LPDF_FONT_TIMES_B                 0x0009
#define   LPDF_FONT_TIMES_I                 0x000A
#define   LPDF_FONT_TIMES_BI                0x000B
#define   LPDF_FONT_SYMBOL                  0x000C
#define   LPDF_FONT_ZAP                     0x000D
/*----- Graphis mode ---------------------------------------------------------*/
#define   LPDF_GMODE_PAGE_DESCRIPTION       0x0001
#define   LPDF_GMODE_PATH_OBJECT            0x0002
#define   LPDF_GMODE_TEXT_OBJECT            0x0004
#define   LPDF_GMODE_CLIPPING_PATH          0x0008
#define   LPDF_GMODE_SHADING                0x0010
#define   LPDF_GMODE_INLINE_IMAGE           0x0020
#define   LPDF_GMODE_EXTERNAL_OBJECT        0x0040
#define   LPDF_GMODE_INVALID                0x0080
#define   LPDF_GMODE_OVER                   0x0100

#define OBJ_MAX_NUM     256

/* Page的结构信息是否需要树形结构 */
typedef enum 
{
    OBJ_info,
    OBJ_stream,
    OBJ_font,
    OBJ_page,
    OBJ_catalog,
    OBJ_pages,
    OBJ_image,
}LPDF_ObjType;

typedef struct
{
    LPDF_ObjType objType;
    LPDF_UINT16 objIdx;
    LPDF_UINT16 height;
    LPDF_UINT16 width;
    LPDF_UINT16 length;
    LPDF_UINT gMode;
    LPDF_BYTE fontType;
    LPDF_BYTE fontSize;
    LPDF_BYTE pState;
    LPDF_VOID *doc;
}LPDF_Obj;

typedef struct
{
    LPDF_Obj obj[OBJ_MAX_NUM];
    LPDF_UINT32 offset;
    LPDF_UINT16 objNumber;
    LPDF_FILE file;
}LPDF_Doc_Rec;

typedef LPDF_Doc_Rec *LPDF_Doc;
typedef LPDF_Obj *LPDF_Page;
typedef LPDF_Obj *LPDF_Image;
extern const char *font_list[];
/*----- LPDF Interfaces-------------------------------------------------------*/
const char * LPDF_GetVersion(void);
LPDF_Doc LPDF_New(void);
LPDF_Page LPDF_AddPage(LPDF_Doc pdf);
LPDF_STATUS LPDF_SaveToFile(LPDF_Doc pdf,const char *file_name);
LPDF_STATUS LPDF_Free(LPDF_Doc pdf);
LPDF_STATUS LPDF_Page_CheckState(LPDF_Page page, LPDF_UINT mode);
LPDF_STATUS LPDF_Page_SetFontAndSize(LPDF_Page page,
                           const char *font_name, LPDF_UINT8 size);
LPDF_STATUS LPDF_Page_SaveParams(LPDF_Page page);
LPDF_STATUS LPDF_Page_SaveContext(LPDF_Page page);
LPDF_STATUS LPDF_Page_BeginText(LPDF_Page page);
LPDF_STATUS LPDF_Page_EndText(LPDF_Page page);
LPDF_UINT16 LPDF_Page_GetHeight(LPDF_Page page);
LPDF_UINT16 LPDF_Page_GetWidth(LPDF_Page page);
LPDF_STATUS LPDF_Page_SetHeight(LPDF_Page page, LPDF_UINT16 value);
LPDF_STATUS LPDF_Page_SetWidth(LPDF_Page page, LPDF_UINT16 value);
LPDF_STATUS LPDF_Page_ShowText(LPDF_Page page, const char *text);
LPDF_STATUS LPDF_Page_MoveTextPos(LPDF_Page page,
                         LPDF_INT x, LPDF_INT y);
LPDF_STATUS LPDF_Page_TextOut(LPDF_Page page, 
                         LPDF_UINT16 x, LPDF_UINT16 y,
                         const char *text);
LPDF_STATUS LPDF_Page_SetRGBStroke(LPDF_Page page,
                         LPDF_REAL r,
                         LPDF_REAL g,
                         LPDF_REAL b);
LPDF_STATUS LPDF_Page_SetRGBFill(LPDF_Page page,
                         LPDF_REAL r,
                         LPDF_REAL g,
                         LPDF_REAL b);
LPDF_STATUS LPDF_Page_MoveTo (LPDF_Page page,
                         LPDF_UINT16 x,
                         LPDF_UINT16 y);
LPDF_STATUS LPDF_Page_LineTo (LPDF_Page page,
                         LPDF_UINT16 x,
                         LPDF_UINT16 y);
LPDF_STATUS LPDF_Page_Stroke(LPDF_Page page);
LPDF_STATUS LPDF_Page_ClosePathStroke(LPDF_Page page);
LPDF_STATUS LPDF_Page_DrawImage(LPDF_Page page,
                      LPDF_Image image,
                      LPDF_UINT16 x,
                      LPDF_UINT16 y,
                      LPDF_UINT16 width,
                      LPDF_UINT16 height);
											
#endif

源文件如下：

#include 
#include 
#include 
#include 
#include "pdflib.h"

#define LPDF_INVALID_OBJECT                       0x1033

static char pdf_buf[512];

#define LPDF_VERSIOIN_TEXT          "0.0.1"
#define LPDF_FILE_HEADER_LEN        15
#define LPDF_BASEFONT_NUM           14
const char LPDF_FILE_HEADER[] = "%%PDF-1.4\n%%\xAA\xBB\xCC\xDD\n";
const char *font_list[] = {
    "Courier",
    "Courier-Bold",
    "Courier-Oblique",
    "Courier-BoldOblique",
    "Helvetica",
    "Helvetica-Bold",
    "Helvetica-Oblique",
    "Helvetica-BoldOblique",
    "Times-Roman",
    "Times-Bold",
    "Times-Italic",
    "Times-BoldItalic",
    "Symbol",
    "ZapfDingbats",
    NULL
};


const char * LPDF_GetVersion(void)
{
    return LPDF_VERSIOIN_TEXT;
}

LPDF_Doc LPDF_New(void)
{
    static LPDF_Doc_Rec pdf;
    LPDF_INT length = 0, i = 0;
	LPDF_UINT writeBytes = 0;
	FRESULT fr;
    
    fr = LPDF_FOPEN(&pdf.file,"/tmp.pdf",FA_CREATE_ALWAYS|FA_WRITE);
	if(fr)
	{
		LPDF_PRINTF("create tmp.pdf failed!\r\n");
		return NULL;
	}
    LPDF_FPRINTF(&pdf.file,LPDF_FILE_HEADER);   /* 写入文件头 */
    pdf.offset = LPDF_FILE_HEADER_LEN;
   
    pdf.obj[0].objIdx = pdf.offset;
    length = LPDF_SPRINTF(pdf_buf,"1 0 obj\n<<\n/Type /Catalog\n/Pages 17 0 R\n>>\nendobj\n\n");
    LPDF_FWRITE(&pdf.file,pdf_buf,length,&writeBytes);
    pdf.offset += length;
    
    pdf.obj[1].objIdx = pdf.offset;
    length = LPDF_SPRINTF(pdf_buf,"2 0 obj\n<<\n/Creator (light pdf library 0.0.1)\n"
                    "/Auther (anobodykey)\n>>\nendobj\n\n");
    LPDF_FWRITE(&pdf.file,pdf_buf,length,&writeBytes);
    pdf.offset += length;
    
    for(i = 0; i < LPDF_BASEFONT_NUM-2; i++)
    {
        pdf.obj[2+i].objIdx = pdf.offset;
        length = LPDF_SPRINTF(pdf_buf,"%d 0 obj\n<<\n/Type /Font\n/Subtype /Type1\n"
                        "/BaseFont /%s\n/Encoding /WinAnsiEncoding\n>>\n"
                        "endobj\n\n",3+i,font_list[i]);
        LPDF_FWRITE(&pdf.file,pdf_buf,length,&writeBytes);
        pdf.offset += length;
    }
    for(; i < LPDF_BASEFONT_NUM; i++)
    {
        pdf.obj[2+i].objIdx = pdf.offset;
        length = LPDF_SPRINTF(pdf_buf,"%d 0 obj\n<<\n/Type /Font\n/Subtype /Type1\n"
                        "/BaseFont /%s\n>>\nendobj\n\n",3+i,font_list[i]);
        LPDF_FWRITE(&pdf.file,pdf_buf,length,&writeBytes);
        pdf.offset += length;
    }
    pdf.objNumber = 3+i;
  
    return (LPDF_Doc)&pdf;
}

LPDF_STATUS LPDF_SaveToFile(LPDF_Doc pdf,const char *file_name)
{
    LPDF_UINT16 i = 0, child_pages = 0;
    LPDF_INT length = 0;
	LPDF_UINT writeBytes = 0;

    pdf->obj[16].objIdx = pdf->offset;
    child_pages = (pdf->objNumber-2-LPDF_BASEFONT_NUM)/3 ;
    length = LPDF_SPRINTF(pdf_buf,"17 0 obj\n<<\n/Types /Pages\n/Count %d\n/Kids [ ",child_pages);
    LPDF_FWRITE(&pdf->file,pdf_buf,length,&writeBytes);
    pdf->offset += length;
    for(i = 0; i < child_pages; i++)
    {
        length = LPDF_SPRINTF(pdf_buf,"%d 0 R\n",18+i*3);
        LPDF_FWRITE(&pdf->file,pdf_buf,length,&writeBytes);
        pdf->offset += length;
    }
    length = LPDF_SPRINTF(pdf_buf,"]\n>>\nendobj\n\n");
    LPDF_FWRITE(&pdf->file,pdf_buf,length,&writeBytes);
    pdf->offset += length;
    
    LPDF_FPRINTF(&pdf->file,"xref\n0 %d\n0000000000 65535 f\r\n",pdf->objNumber+1);
    for(i = 0 ; i < pdf->objNumber; i++)
    {
        LPDF_FPRINTF(&pdf->file,"%10.10d 00000 n\r\n",pdf->obj[i].objIdx);
    }
    LPDF_FPRINTF(&pdf->file,"trailer\n<<\n/Size %d\n/Root 1 0 R\n/Info 2 0 R\n>>\nstartxref\n%d\n%%%%EOF",
                pdf->objNumber+1,pdf->offset);
    LPDF_FCLOSE(&pdf->file);
    LPDF_REMOVE(file_name);
    LPDF_RENAME("tmp.pdf",file_name);
    return LPDF_OK;
}

LPDF_STATUS LPDF_Free(LPDF_Doc pdf)
{
    memset(pdf,sizeof(LPDF_Doc_Rec),0);
    return LPDF_OK;
}

LPDF_Page LPDF_AddPage(LPDF_Doc pdf)
{
    LPDF_INT length = 0,i = 0;
    LPDF_Page page = NULL;
	LPDF_UINT writeBytes = 0;
    
    pdf->obj[pdf->objNumber].objIdx = pdf->offset;
    length = LPDF_SPRINTF(pdf_buf,"%d 0 obj\n<<\n/Type /Page\n/Parent 4 0 R\n/Contents %d 0 R\n"
                    "/Resources <<\n/ProcSet [/PDF /TEXT /ImageB /ImageC /ImageI]\n"
                    "/Font <<\n",pdf->objNumber+1,pdf->objNumber+2);
    LPDF_FWRITE(&pdf->file,pdf_buf,length,&writeBytes);
    pdf->offset += length;
    while(font_list[i])
    {
        length = LPDF_SPRINTF(pdf_buf,"/F%d %d 0 R\n",i+1,3+i);
        LPDF_FWRITE(&pdf->file,pdf_buf,length,&writeBytes);
        pdf->offset += length;
        i+=1;
    }
    LPDF_FPRINTF(&pdf->file,">>\n>>\n");
    pdf->offset += 4;
    page = (LPDF_Page)&pdf->obj[pdf->objNumber];
    page->width = 595;
    page->height = 842;
    page->gMode = LPDF_GMODE_INVALID;
    page->fontType = LPDF_FONT_INVALID;
    page->doc = pdf;
    return page;
}

LPDF_STATUS LPDF_Page_SetHeight(LPDF_Page page, LPDF_UINT16 value)
{
    page->height = value;
    return LPDF_OK;
}
LPDF_STATUS LPDF_Page_SetWidth(LPDF_Page page, LPDF_UINT16 value)
{
    page->width = value;
    return LPDF_OK;
}

LPDF_UINT16 LPDF_Page_GetHeight(LPDF_Page page)
{
    if(page)
    {
        return page->height;
    }
    
    return LPDF_OK;
}

LPDF_UINT16 LPDF_Page_GetWidth(LPDF_Page page)
{
    if(page)
    {
        return page->width;
    }
    
    return LPDF_OK;
}

LPDF_STATUS LPDF_Page_CheckState(LPDF_Page page, LPDF_UINT mode)
{
    if(!page)
        return LPDF_INVALID_OBJECT;
    if(!(page->gMode&mode))
        return LPDF_FAILED;

    return LPDF_OK;
}

LPDF_STATUS LPDF_Page_SetFontAndSize(LPDF_Page page,
                           const char *font_name, LPDF_UINT8 size)
{
    LPDF_Doc pdf = (LPDF_Doc)page->doc;
    LPDF_INT i = 0,length = 0;
	LPDF_UINT writeBytes = 0;
    LPDF_STATUS ret = LPDF_Page_CheckState(page,LPDF_GMODE_TEXT_OBJECT|LPDF_GMODE_PAGE_DESCRIPTION);
    if(LPDF_OK != ret)
        return ret;
 
    while(font_list[i])
    {
        if(0 == strcmp(font_list[i],font_name))
        {
            page->fontType = i;
            page->fontSize = size;
            length = LPDF_SPRINTF(pdf_buf,"/F%d %d Tf\n",i+1,size);
            LPDF_FWRITE(&pdf->file,pdf_buf,length,&writeBytes);
            pdf->offset += length;
            page->length += length;
            return LPDF_OK;
        }
        i+=1;
    }
    
    return LPDF_OK;
}

LPDF_STATUS LPDF_Page_SaveParams(LPDF_Page page)
{
    LPDF_INT length;
	LPDF_UINT writeBytes = 0;
    LPDF_Doc pdf = (LPDF_Doc)page->doc;
    LPDF_STATUS ret = LPDF_Page_CheckState(page,LPDF_GMODE_INVALID);
    if(LPDF_OK != ret)
        return ret;
    
    /* 对于每个page来说该接口只能调用一次即在GMODE为INVALID的模式下 */
    length = LPDF_SPRINTF(pdf_buf,"/MediaBox [ 0 0 %d %d ]\n>>\nendobj\n\n",
                        page->width, page->height);
    LPDF_FWRITE(&pdf->file,pdf_buf,length,&writeBytes);
    pdf->offset += length;
    pdf->obj[pdf->objNumber+1].objIdx = pdf->offset;
    length = LPDF_SPRINTF(pdf_buf,"%d 0 obj\n<>\nstream\n",
                        pdf->objNumber+2, pdf->objNumber+3);
    LPDF_FWRITE(&pdf->file,pdf_buf,length,&writeBytes);
    pdf->offset += length;
    page->length = 0;
    page->gMode = LPDF_GMODE_PAGE_DESCRIPTION;
    return LPDF_OK;
}

LPDF_STATUS LPDF_Page_SaveContext(LPDF_Page page)
{
    LPDF_INT length;
	LPDF_UINT writeBytes = 0;
    LPDF_Doc pdf = (LPDF_Doc)page->doc;
    LPDF_STATUS ret = LPDF_Page_CheckState(page,LPDF_GMODE_PAGE_DESCRIPTION);
    if(LPDF_OK != ret)
        return ret;
     /* 对于每个page来说该接口只能调用一次即在GMODE为PAGE_DESCRIPTION的模式下 */
    length = LPDF_SPRINTF(pdf_buf,"endstream\nendobj\n\n");
    LPDF_FWRITE(&pdf->file,pdf_buf,length,&writeBytes); 
    pdf->offset += length;
    pdf->obj[pdf->objNumber+2].objIdx = pdf->offset;
    length = LPDF_SPRINTF(pdf_buf,"%d 0 obj\n%d\nendobj\n\n",
                        pdf->objNumber+3,page->length);
    LPDF_FWRITE(&pdf->file,pdf_buf,length,&writeBytes);
    pdf->offset += length;
    pdf->objNumber += 3;
    page->gMode = LPDF_GMODE_OVER;
    return LPDF_OK;
}

LPDF_STATUS LPDF_Page_BeginText(LPDF_Page page)
{
    LPDF_Doc pdf = (LPDF_Doc)page->doc;
    LPDF_STATUS ret = LPDF_Page_CheckState(page,LPDF_GMODE_PAGE_DESCRIPTION);
    if(LPDF_OK != ret)
        return ret;
    LPDF_FPRINTF(&pdf->file,"BT\n");
    pdf->offset += 3;
    page->length += 3;
    page->gMode = LPDF_GMODE_TEXT_OBJECT;
    return LPDF_OK;
}
LPDF_STATUS LPDF_Page_EndText(LPDF_Page page)
{
    LPDF_Doc pdf = (LPDF_Doc)page->doc;
    LPDF_STATUS ret = LPDF_Page_CheckState(page,LPDF_GMODE_TEXT_OBJECT);
    if(LPDF_OK != ret)
        return ret;
    LPDF_FPRINTF(&pdf->file,"ET\n");
    pdf->offset += 3;
    page->length += 3;
    page->gMode = LPDF_GMODE_PAGE_DESCRIPTION;
    return LPDF_OK;
}

LPDF_STATUS LPDF_Page_ShowText(LPDF_Page page, const char *text)
{
    LPDF_INT length = 0;
	LPDF_UINT writeBytes = 0;
    LPDF_Doc pdf = (LPDF_Doc)page->doc;
    LPDF_STATUS ret = LPDF_Page_CheckState(page,LPDF_GMODE_TEXT_OBJECT);
    if(LPDF_OK != ret)
        return ret;
    if(LPDF_FONT_INVALID == page->fontType)
        return LPDF_OK;
    length = LPDF_SPRINTF(pdf_buf,"(%s) Tj\n",text);
    LPDF_FWRITE(&pdf->file,pdf_buf,length,&writeBytes);
    pdf->offset += length;
    page->length += length;
    return LPDF_OK;
    
}
LPDF_STATUS LPDF_Page_MoveTextPos(LPDF_Page page,
                        LPDF_INT x, LPDF_INT y)
{
    LPDF_INT length = 0;
	LPDF_UINT writeBytes = 0;
    LPDF_Doc pdf = (LPDF_Doc)page->doc;
    LPDF_STATUS ret = LPDF_Page_CheckState(page,LPDF_GMODE_TEXT_OBJECT);
    if(LPDF_OK != ret)
        return ret;
    length = LPDF_SPRINTF(pdf_buf,"%d %d Td\n",x,y);
    LPDF_FWRITE(&pdf->file,pdf_buf,length,&writeBytes);
    pdf->offset += length;
    page->length += length;

    return LPDF_OK;
}
LPDF_STATUS LPDF_Page_TextOut(LPDF_Page page, 
                        LPDF_UINT16 x, LPDF_UINT16 y,
                        const char *text)
{
    return LPDF_OK;
}

LPDF_STATUS LPDF_Page_SetRGBStroke(LPDF_Page page,
                         LPDF_REAL r,
                         LPDF_REAL g,
                         LPDF_REAL b)
{
    LPDF_INT length = 0;
	LPDF_UINT writeBytes = 0;
    LPDF_Doc pdf = (LPDF_Doc)page->doc;
    LPDF_STATUS ret = LPDF_Page_CheckState(page,LPDF_GMODE_TEXT_OBJECT|LPDF_GMODE_PAGE_DESCRIPTION);
    if(LPDF_OK != ret)
        return ret;

    length = LPDF_SPRINTF(pdf_buf,"%.1f %.1f %.1f RG\n",r,g,b);
    LPDF_FWRITE(&pdf->file,pdf_buf,length,&writeBytes);
    pdf->offset += length;
    page->length += length;
    return LPDF_OK;
}

LPDF_STATUS LPDF_Page_SetRGBFill(LPDF_Page page,
                         LPDF_REAL r,
                         LPDF_REAL g,
                         LPDF_REAL b)
{
    LPDF_INT length = 0;
	LPDF_UINT writeBytes = 0;
    LPDF_Doc pdf = (LPDF_Doc)page->doc;
    LPDF_STATUS ret = LPDF_Page_CheckState(page,LPDF_GMODE_TEXT_OBJECT|LPDF_GMODE_PAGE_DESCRIPTION);
    if(LPDF_OK != ret)
        return ret;

    length = LPDF_SPRINTF(pdf_buf,"%.1f %.1f %.1f rg\n",r,g,b);
    LPDF_FWRITE(&pdf->file,pdf_buf,length,&writeBytes);
    pdf->offset += length;
    page->length += length;
    return LPDF_OK;
}
LPDF_STATUS LPDF_Page_MoveTo (LPDF_Page page,
                         LPDF_UINT16 x,
                         LPDF_UINT16 y)
{
    LPDF_INT length = 0;
	LPDF_UINT writeBytes = 0;
    LPDF_Doc pdf = (LPDF_Doc)page->doc;
    LPDF_STATUS ret = LPDF_Page_CheckState(page,LPDF_GMODE_PAGE_DESCRIPTION|LPDF_GMODE_PATH_OBJECT);
    if(LPDF_OK != ret)
        return ret;
    length = LPDF_SPRINTF(pdf_buf,"%d %d m\n",x,y);
    LPDF_FWRITE(&pdf->file,pdf_buf,length,&writeBytes);
    pdf->offset += length;
    page->length += length;
    page->gMode = LPDF_GMODE_PATH_OBJECT;
    return LPDF_OK;
}
LPDF_STATUS LPDF_Page_LineTo (LPDF_Page page,
                         LPDF_UINT16 x,
                         LPDF_UINT16 y)
{
    LPDF_INT length = 0;
	LPDF_UINT writeBytes = 0;
    LPDF_Doc pdf = (LPDF_Doc)page->doc;
    LPDF_STATUS ret = LPDF_Page_CheckState(page,LPDF_GMODE_PATH_OBJECT);
    if(LPDF_OK != ret)
        return ret;
    length = LPDF_SPRINTF(pdf_buf,"%d %d l\n",x,y);
    LPDF_FWRITE(&pdf->file,pdf_buf,length,&writeBytes);
    pdf->offset += length;
    page->length += length;
    return LPDF_OK;
}
LPDF_STATUS LPDF_Page_Stroke(LPDF_Page page)
{
    LPDF_Doc pdf = (LPDF_Doc)page->doc;
    LPDF_STATUS ret = LPDF_Page_CheckState(page,LPDF_GMODE_PATH_OBJECT);
    if(LPDF_OK != ret)
        return ret;
    LPDF_FPRINTF(&pdf->file,"S\n");
    pdf->offset += 2;
    page->length += 2;
    page->gMode = LPDF_GMODE_PAGE_DESCRIPTION;
    return LPDF_OK;
}
LPDF_STATUS LPDF_Page_DrawImage(LPDF_Page page,
                      LPDF_Image image,
                      LPDF_UINT16 x,
                      LPDF_UINT16 y,
                      LPDF_UINT16 width,
                      LPDF_UINT16 height)
{
	return LPDF_OK;
}

对于pdf文件结构可以去查看pdf参考手册，这里我看的是pdf-1.4参考手册，该库的测试代码我是在基于LPC54608库中的sdcard_fatfs示例改编的，关键代码如下:

测试代码很简单，生成了一个含有两个page的pdf文件，在第一页中用了不同的字体来显示同一个字符串，可以参考libHaru中的font_demo示例，第二页中是画了一个立方体图，下载代码到目标板，并运行该示例，串口终端输出如下：

拔下板上的SD卡，插入到PC上，可以看到red.pdf文件

使用pdf阅读器打开该文件，截图如下：

pdflib库目前来说还是比较简单的，需慢慢完善，

pdfgen库链接如下：https://github.com/AndreRenaud/PDFGen

pdflib下载链接：上传了半天没反应，有需要的可以去我的资源里面找下，这里就不放链接了。