C语言库学习（四）：用libredwg解析cad的dwg文件——第一版（qt）
开始
首先下载LibreDWG的源代码，
git clone https://github.com/LibreDWG/libredwg.git
下载完成后，把src文件夹和include文件夹复制到qt工程目录下
jsmn文件夹是空的，也需要下载
git clone https://github.com/zserge/jsmn
第一次失败的尝试
第一次用libredwg-0.10.1.2969-win32.zip里的.a静态库，但是编译的时候出错，猜测可能是编译器版本不一样，既然编译好的库不能用，就只能自己编译源代码了
编译源代码
添加新文件，把下载到的LibreDWG/src下的所有.c.h和有用的文件全部添加到工程中，新建一个窗口，一个QPushButton
引用头文件、编写测试代码
#define restrict
#include "include/dwg.h"
void Widget::add_line (double x1, double x2, double y1, double y2)
{
// Make something with that
qDebug()<<"//add_line"<<x1;
qDebug()<<","<<y1;
qDebug()<<","<<x2;
qDebug()<<","<<y2;
QPainter painter(&pix);
painter.setPen(Qt::red);
painter.drawLine(x1,y1,x2,y2);
update();
}
void Widget::add_circle (double x, double y, double R)
{
// Make something with that
qDebug()<<"//add_circle"<<x;
qDebug()<<","<<y;
qDebug()<<","<<R;
QPainter painter(&pix);
painter.setPen(Qt::blue);
painter.drawEllipse(x,y,R,R);
update();
}
int Widget::load_dwg (char *filename, unsigned int opts)
{
BITCODE_BL i;
int success;
Dwg_Data dwg;
memset (&dwg, 0, sizeof (Dwg_Data));
dwg.opts = opts;
success = dwg_read_file (filename, &dwg);
for (i = 0; i < dwg.num_objects; i++)
{
Dwg_Entity_LINE *line;
Dwg_Entity_CIRCLE *circle;
Dwg_Entity_TEXT *text;
//qDebug()<<"//typeINT:"<
switch (dwg.object[i].type)
{
case DWG_TYPE_LINE:
line = dwg.object[i].tio.entity->tio.LINE;
qDebug()<<"//type:line";
add_line (line->start.x, line->end.x, line->start.y, line->end.y);
break;
case DWG_TYPE_CIRCLE:
circle = dwg.object[i].tio.entity->tio.CIRCLE;
qDebug()<<"//type:DWG_TYPE_CIRCLE";
add_circle (circle->center.x, circle->center.y, circle->radius);
break;
case DWG_TYPE_TEXT:
text = dwg.object[i].tio.entity->tio.TEXT;
qDebug()<<"//type:DWG_TYPE_TEXT";
add_text (text->insertion_pt.x, text->insertion_pt.y,
text->text_value);
break;
default:
break;
}
}
dwg_free (&dwg);
return success;
}
完善其他的代码
头文件(widget.h中)
#ifndef WIDGET_H
#define WIDGET_H
#include
#include
#include
#include
#include
namespace Ui {
class Widget;
}
class Widget : public QWidget
{
Q_OBJECT
public:
explicit Widget(QWidget *parent = 0);
~Widget();
static void setx(double x);
void add_line (double x1, double y1, double x2, double y2);
int load_dwg (char *filename, unsigned int opts);
void add_circle (double x, double y, double R);
protected:
void paintEvent(QPaintEvent *event);
private slots:
void on_pushButton_clicked();
private:
Ui::Widget *ui;
QPixmap pix;
};
#endif // WIDGET_H
重写paintEvent(widget.cpp中)
void Widget::paintEvent(QPaintEvent *event)
{
QPainter paint(this);
paint.drawPixmap(0,0,pix);
}
qpushbutton鼠标点击(widget.cpp中)
void Widget::on_pushButton_clicked()
{
qDebug()<<"start";
QString fileName = QFileDialog::getSaveFileName(this, tr("Excel file"), "./",
tr("Excel Files (*.dwg)"));
if (fileName.isEmpty())
return;
pix = QPixmap(size());
pix.fill(Qt::white);
qDebug()<<"filename:"<<fileName;
load_dwg(fileName.toUtf8().data(),0);
}
运行结果
需要改进的地方
- 屏幕的(0,0)坐标是在左上角，而CAD绘图的(0,0)坐标在左下角，需要把上下对称一下，用屏幕高度-x坐标就可以
- 现在只能识别直线和圆，需要添加更多图形识别，根据LibreDWG的定义如下：
dwg文件中存在的对象和实体类型
/**
Object and Entity types that exist in dwg-files.
*/
typedef enum DWG_OBJECT_TYPE
{
DWG_TYPE_UNUSED = 0x00,
DWG_TYPE_TEXT = 0x01,
DWG_TYPE_ATTRIB = 0x02,
DWG_TYPE_ATTDEF = 0x03,
DWG_TYPE_BLOCK = 0x04,
DWG_TYPE_ENDBLK = 0x05,
DWG_TYPE_SEQEND = 0x06,
DWG_TYPE_INSERT = 0x07,
DWG_TYPE_MINSERT = 0x08,
/* DWG_TYPE_ = 0x09, */
DWG_TYPE_VERTEX_2D = 0x0a,
DWG_TYPE_VERTEX_3D = 0x0b,
DWG_TYPE_VERTEX_MESH = 0x0c,
DWG_TYPE_VERTEX_PFACE = 0x0d,
DWG_TYPE_VERTEX_PFACE_FACE = 0x0e,
DWG_TYPE_POLYLINE_2D = 0x0f,
DWG_TYPE_POLYLINE_3D = 0x10,
DWG_TYPE_ARC = 0x11,
DWG_TYPE_CIRCLE = 0x12,
DWG_TYPE_LINE = 0x13,
DWG_TYPE_DIMENSION_ORDINATE = 0x14,
DWG_TYPE_DIMENSION_LINEAR = 0x15,
DWG_TYPE_DIMENSION_ALIGNED = 0x16,
DWG_TYPE_DIMENSION_ANG3PT = 0x17,
DWG_TYPE_DIMENSION_ANG2LN = 0x18,
DWG_TYPE_DIMENSION_RADIUS = 0x19,
DWG_TYPE_DIMENSION_DIAMETER = 0x1A,
DWG_TYPE_POINT = 0x1b,
DWG_TYPE__3DFACE = 0x1c,
DWG_TYPE_POLYLINE_PFACE = 0x1d,
DWG_TYPE_POLYLINE_MESH = 0x1e,
DWG_TYPE_SOLID = 0x1f,
DWG_TYPE_TRACE = 0x20,
DWG_TYPE_SHAPE = 0x21,
DWG_TYPE_VIEWPORT = 0x22,
DWG_TYPE_ELLIPSE = 0x23,
DWG_TYPE_SPLINE = 0x24,
DWG_TYPE_REGION = 0x25,
DWG_TYPE__3DSOLID = 0x26,
DWG_TYPE_BODY = 0x27,
DWG_TYPE_RAY = 0x28,
DWG_TYPE_XLINE = 0x29,
DWG_TYPE_DICTIONARY = 0x2a,
DWG_TYPE_OLEFRAME = 0x2b,
DWG_TYPE_MTEXT = 0x2c,
DWG_TYPE_LEADER = 0x2d,
DWG_TYPE_TOLERANCE = 0x2e,
DWG_TYPE_MLINE = 0x2f,
DWG_TYPE_BLOCK_CONTROL = 0x30,
DWG_TYPE_BLOCK_HEADER = 0x31,
DWG_TYPE_LAYER_CONTROL = 0x32,
DWG_TYPE_LAYER = 0x33,
DWG_TYPE_STYLE_CONTROL = 0x34,
DWG_TYPE_STYLE = 0x35,
/* DWG_TYPE_ = 0x36, */
/* DWG_TYPE_ = 0x37, */
DWG_TYPE_LTYPE_CONTROL = 0x38,
DWG_TYPE_LTYPE = 0x39,
/* DWG_TYPE_ = 0x3a, */
/* DWG_TYPE_ = 0x3b, */
DWG_TYPE_VIEW_CONTROL = 0x3c,
DWG_TYPE_VIEW = 0x3d,
DWG_TYPE_UCS_CONTROL = 0x3e,
DWG_TYPE_UCS = 0x3f,
DWG_TYPE_VPORT_CONTROL = 0x40,
DWG_TYPE_VPORT = 0x41,
DWG_TYPE_APPID_CONTROL = 0x42,
DWG_TYPE_APPID = 0x43,
DWG_TYPE_DIMSTYLE_CONTROL = 0x44,
DWG_TYPE_DIMSTYLE = 0x45,
DWG_TYPE_VPORT_ENTITY_CONTROL = 0x46,
DWG_TYPE_VPORT_ENTITY_HEADER = 0x47,
DWG_TYPE_GROUP = 0x48,
DWG_TYPE_MLINESTYLE = 0x49,
DWG_TYPE_OLE2FRAME = 0x4a,
DWG_TYPE_DUMMY = 0x4b,
DWG_TYPE_LONG_TRANSACTION = 0x4c,
DWG_TYPE_LWPOLYLINE = 0x4d, /* ?? */
DWG_TYPE_HATCH = 0x4e,
DWG_TYPE_XRECORD = 0x4f,
DWG_TYPE_PLACEHOLDER = 0x50,
DWG_TYPE_VBA_PROJECT = 0x51,
DWG_TYPE_LAYOUT = 0x52,
DWG_TYPE_PROXY_ENTITY = 0x1f2, /* 498 */
DWG_TYPE_PROXY_OBJECT = 0x1f3, /* 499 */
/* non-fixed types > 500. not stored as type, but as fixedtype */
DWG_TYPE_ACDSRECORD = 0x1ff + 1,
DWG_TYPE_ACDSSCHEMA,
DWG_TYPE_ACMECOMMANDHISTORY,
DWG_TYPE_ACMESCOPE,
DWG_TYPE_ACMESTATEMGR,
DWG_TYPE_ACSH_BOX_CLASS,
DWG_TYPE_ACSH_EXTRUSION_CLASS,
DWG_TYPE_ACSH_HISTORY_CLASS,
DWG_TYPE_ACSH_REVOLVE_CLASS,
DWG_TYPE_ACSH_SPHERE_CLASS,
DWG_TYPE_ACSH_SWEEP_CLASS,
DWG_TYPE_ANNOTSCALEOBJECTCONTEXTDATA,
DWG_TYPE_ARCALIGNEDTEXT,
DWG_TYPE_ARC_DIMENSION,
DWG_TYPE_ASSOC2DCONSTRAINTGROUP,
DWG_TYPE_ASSOCACTION,
DWG_TYPE_ASSOCALIGNEDDIMACTIONBODY,
DWG_TYPE_ASSOCDEPENDENCY,
DWG_TYPE_ASSOCGEOMDEPENDENCY,
DWG_TYPE_ASSOCNETWORK,
DWG_TYPE_ASSOCOSNAPPOINTREFACTIONPARAM,
DWG_TYPE_ASSOCPERSSUBENTMANAGER,
DWG_TYPE_ASSOCPLANESURFACEACTIONBODY,
DWG_TYPE_ASSOCVERTEXACTIONPARAM,
DWG_TYPE_CAMERA,
DWG_TYPE_CELLSTYLEMAP,
DWG_TYPE_DATALINK,
DWG_TYPE_DATATABLE,
DWG_TYPE_DBCOLOR,
DWG_TYPE_DETAILVIEWSTYLE,
DWG_TYPE_DICTIONARYVAR,
DWG_TYPE_DICTIONARYWDFLT,
DWG_TYPE_DIMASSOC,
DWG_TYPE_DOCUMENTOPTIONS,
DWG_TYPE_DYNAMICBLOCKPURGEPREVENTER,
DWG_TYPE_EVALUATION_GRAPH,
DWG_TYPE_FIELD,
DWG_TYPE_FIELDLIST,
DWG_TYPE_GEODATA,
DWG_TYPE_GEOMAPIMAGE,
DWG_TYPE_GEOPOSITIONMARKER,
DWG_TYPE_HELIX,
DWG_TYPE_IDBUFFER,
DWG_TYPE_IMAGE,
DWG_TYPE_IMAGEDEF,
DWG_TYPE_IMAGEDEF_REACTOR,
DWG_TYPE_LAYER_FILTER,
DWG_TYPE_LAYER_INDEX,
DWG_TYPE_LAYOUTPRINTCONFIG,
DWG_TYPE_LIGHT,
DWG_TYPE_LIGHTLIST,
DWG_TYPE_MATERIAL,
DWG_TYPE_MESH,
DWG_TYPE_MLEADERSTYLE,
DWG_TYPE_MULTILEADER,
DWG_TYPE_NAVISWORKSMODELDEF,
DWG_TYPE_NPOCOLLECTION,
DWG_TYPE_OBJECTCONTEXTDATA,
DWG_TYPE_OBJECT_PTR,
DWG_TYPE_PERSSUBENTMANAGER,
DWG_TYPE_PLOTSETTINGS,
DWG_TYPE_POINTCLOUD,
DWG_TYPE_RASTERVARIABLES,
DWG_TYPE_RENDERENVIRONMENT,
DWG_TYPE_RENDERGLOBAL,
DWG_TYPE_MENTALRAYRENDERSETTINGS,
DWG_TYPE_RAPIDRTRENDERENVIRONMENT,
DWG_TYPE_RAPIDRTRENDERSETTINGS,
DWG_TYPE_RTEXT,
DWG_TYPE_SCALE,
DWG_TYPE_SECTIONVIEWSTYLE,
DWG_TYPE_SORTENTSTABLE,
DWG_TYPE_SPATIAL_FILTER,
DWG_TYPE_SPATIAL_INDEX,
DWG_TYPE_SUN,
DWG_TYPE_SUNSTUDY,
DWG_TYPE_SURFACE, // or seperate subtypes? DXF has only SURFACE
DWG_TYPE_PLANESURFACE,
DWG_TYPE_EXTRUDEDSURFACE,
DWG_TYPE_LOFTEDSURFACE,
DWG_TYPE_REVOLVEDSURFACE,
DWG_TYPE_SWEPTSURFACE,
DWG_TYPE_TABLE,
DWG_TYPE_TABLECONTENT,
DWG_TYPE_TABLEGEOMETRY,
DWG_TYPE_TABLESTYLE,
DWG_TYPE_UNDERLAY, /* not separate DGN,DWF,PDF types */
DWG_TYPE_UNDERLAYDEFINITION, /* not separate DGN,DWF,PDF types */
DWG_TYPE_VISUALSTYLE,
DWG_TYPE_WIPEOUT,
DWG_TYPE_WIPEOUTVARIABLES,
DWG_TYPE_XREFPANELOBJECT,
// after 1.0 add new types here for binary compat
DWG_TYPE_FREED = 0xfffd,
DWG_TYPE_UNKNOWN_ENT = 0xfffe,
DWG_TYPE_UNKNOWN_OBJ = 0xffff,
} Dwg_Object_Type;
通用实体属性
typedef struct _dwg_object_entity
{
BITCODE_BL objid; /*
union
{
Dwg_Entity_UNUSED *UNUSED;
Dwg_Entity_TEXT *TEXT;
Dwg_Entity_ATTRIB *ATTRIB;
Dwg_Entity_ATTDEF *ATTDEF;
Dwg_Entity_BLOCK *BLOCK;
Dwg_Entity_ENDBLK *ENDBLK;
Dwg_Entity_SEQEND *SEQEND;
Dwg_Entity_INSERT *INSERT;
Dwg_Entity_MINSERT *MINSERT;
Dwg_Entity_VERTEX_2D *VERTEX_2D;
Dwg_Entity_VERTEX_3D *VERTEX_3D;
Dwg_Entity_VERTEX_MESH *VERTEX_MESH;
Dwg_Entity_VERTEX_PFACE *VERTEX_PFACE;
Dwg_Entity_VERTEX_PFACE_FACE *VERTEX_PFACE_FACE;
Dwg_Entity_POLYLINE_2D *POLYLINE_2D;
Dwg_Entity_POLYLINE_3D *POLYLINE_3D;
Dwg_Entity_ARC *ARC;
Dwg_Entity_CIRCLE *CIRCLE;
Dwg_Entity_LINE *LINE;
Dwg_DIMENSION_common *DIMENSION_common;
Dwg_Entity_DIMENSION_ORDINATE *DIMENSION_ORDINATE;
Dwg_Entity_DIMENSION_LINEAR *DIMENSION_LINEAR;
Dwg_Entity_DIMENSION_ALIGNED *DIMENSION_ALIGNED;
Dwg_Entity_DIMENSION_ANG3PT *DIMENSION_ANG3PT;
Dwg_Entity_DIMENSION_ANG2LN *DIMENSION_ANG2LN;
Dwg_Entity_DIMENSION_RADIUS *DIMENSION_RADIUS;
Dwg_Entity_DIMENSION_DIAMETER *DIMENSION_DIAMETER;
Dwg_Entity_POINT *POINT;
Dwg_Entity__3DFACE *_3DFACE;
Dwg_Entity_POLYLINE_PFACE *POLYLINE_PFACE;
Dwg_Entity_POLYLINE_MESH *POLYLINE_MESH;
Dwg_Entity_SOLID *SOLID;
Dwg_Entity_TRACE *TRACE;
Dwg_Entity_SHAPE *SHAPE;
Dwg_Entity_VIEWPORT *VIEWPORT;
Dwg_Entity_ELLIPSE *ELLIPSE;
Dwg_Entity_SPLINE *SPLINE;
Dwg_Entity_3DSOLID *_3DSOLID;
Dwg_Entity_REGION *REGION;
Dwg_Entity_BODY *BODY;
Dwg_Entity_RAY *RAY;
Dwg_Entity_XLINE *XLINE;
Dwg_Entity_OLEFRAME *OLEFRAME;
Dwg_Entity_MTEXT *MTEXT;
Dwg_Entity_LEADER *LEADER;
Dwg_Entity_TOLERANCE *TOLERANCE;
Dwg_Entity_MLINE *MLINE;
Dwg_Entity_OLE2FRAME *OLE2FRAME;
Dwg_Entity_HATCH *HATCH;
Dwg_Entity_CAMERA *CAMERA;
Dwg_Entity_GEOPOSITIONMARKER *GEOPOSITIONMARKER;
Dwg_Entity_HELIX *HELIX;
Dwg_Entity_IMAGE *IMAGE;
Dwg_Entity_LIGHT *LIGHT;
Dwg_Entity_LWPOLYLINE *LWPOLYLINE;
Dwg_Entity_MULTILEADER *MULTILEADER;
Dwg_Entity_PROXY_ENTITY *PROXY_ENTITY;
Dwg_Entity_PROXY_LWPOLYLINE *PROXY_LWPOLYLINE;
Dwg_Entity_SURFACE *SURFACE;
Dwg_Entity_PLANESURFACE *PLANESURFACE;
Dwg_Entity_EXTRUDEDSURFACE *EXTRUDEDSURFACE;
Dwg_Entity_LOFTEDSURFACE *LOFTEDSURFACE;
Dwg_Entity_REVOLVEDSURFACE *REVOLVEDSURFACE;
Dwg_Entity_SWEPTSURFACE *SWEPTSURFACE;
Dwg_Entity_TABLE *TABLE;
Dwg_Entity_UNDERLAY *UNDERLAY;
Dwg_Entity_WIPEOUT *WIPEOUT;
Dwg_Entity_ARC_DIMENSION *ARC_DIMENSION;
Dwg_Entity_MESH *MESH;
Dwg_Entity_UNKNOWN_ENT *UNKNOWN_ENT;
} tio;
实体
/**
2D POLYLINE (15) entity
*/
typedef struct _dwg_entity_POLYLINE_2D
{
COMMON_ENTITY_POLYLINE;
BITCODE_BS flag;
BITCODE_BS curve_type;
BITCODE_BD start_width;
BITCODE_BD end_width;
BITCODE_BT thickness;
BITCODE_BD elevation;
BITCODE_BE extrusion;
} Dwg_Entity_POLYLINE_2D;
/**
ARC (17) entity
*/
typedef struct _dwg_entity_ARC
{
struct _dwg_object_entity *parent;
BITCODE_3BD center;
BITCODE_BD radius;
BITCODE_BT thickness;
BITCODE_BE extrusion;
BITCODE_BD start_angle;
BITCODE_BD end_angle;
} Dwg_Entity_ARC;
/**
CIRCLE (18) entity
*/
typedef struct _dwg_entity_CIRCLE
{
struct _dwg_object_entity *parent;
BITCODE_3BD center;
BITCODE_BD radius;
BITCODE_BT thickness;
BITCODE_BE extrusion;
} Dwg_Entity_CIRCLE;
/**
LINE (19) entity
*/
typedef struct _dwg_entity_LINE
{
struct _dwg_object_entity *parent;
BITCODE_RC z_is_zero;
BITCODE_3BD start;
BITCODE_3BD end;
BITCODE_BT thickness;
BITCODE_BE extrusion;
} Dwg_Entity_LINE;