#include "stdafx.h"
#include "cv.h"
#include "highgui.h"#define SHAPE_LINE 1
#define SHAPE_ERASER 2int g_style;
CvRect rect;CvPoint g_StartPoint;
CvPoint g_EndPoint;
CvPoint p_Start;       //记录鼠标位置左上方点
CvPoint p_End;          //记录鼠标位置右下方点
bool drawing=false;       //是否处于画图状态
bool erasering=false;    //是否处于擦除状态void callback(int event,int x,int y,int flags,void* param);
void DrawLine(IplImage* img);
//简易绘图工具，实现了画线和橡皮擦功能，绘图功能还有待往里添加
int main(int argc,char** argv)
{IplImage* img=cvCreateImage(cvSize(512,512),IPL_DEPTH_8U,3);cvSet(img,cvScalar(255,255,255));IplImage* temp=cvCloneImage(img);cvCopy(img,temp);cvNamedWindow("简易绘图工具");cvSetMouseCallback("简易绘图工具",callback,img);printf("请键入要选择执行的操作:‘l’——”画线“,‘e’——”橡皮“\n");char select='l';while(1){cvCopyImage(img,temp);      //始终在原图image上画结果(和鼠标事件绑定)，先将image复制给temp,然后在临时图temp画出画图的过程(在main函数中画过程图形),然后用temp来显示图像switch(select){case 'l':g_style=SHAPE_LINE;break;case 'e':g_style=SHAPE_ERASER;break;case 27:return 0;}if(g_style==SHAPE_LINE&&drawing)     //画鼠标在按住移动过程中画线cvDrawLine(temp,g_StartPoint,g_EndPoint,cvScalar(0,0,0));if(g_style==SHAPE_ERASER)   {cvRectangle(temp,p_Start,p_End,cvScalar(0,0,0));  //画出橡皮矩形边框}cvShowImage("简易绘图工具",temp);select=cvWaitKey(30);}cvReleaseImage(&img);cvReleaseImage(&temp);cvDestroyWindow("简易绘图工具");return 0;
}void callback(int event,int x,int y,int flags,void* param)
{IplImage* img=(IplImage*)param;switch(event){case CV_EVENT_LBUTTONDOWN:{if(SHAPE_LINE==g_style)   {drawing=true;g_StartPoint=cvPoint(x,y);g_EndPoint=g_StartPoint;   //此处将终点坐标设为同起始点避免记住前一条直线的终点坐标}if(SHAPE_ERASER==g_style){erasering=true;//注意边界问题要适当修改ROI有效区域rect.x=x-20;  rect.y=y-20;      //注意坐标的计算,一般原点在窗口的左上角(这和操作系统等因素有关,IplImage结构中有个origin属性可以设置图像的原点)rect.width=40;  rect.height=40;p_Start.x=x-20; p_Start.y=y-20;p_End.x=x+20;   p_End.y=y+20;if(x>-20&&x<532&&y>-20&&y<532){cvSetImageROI(img,rect);cvSet(img,cvScalar(255,255,255));cvResetImageROI(img);}}}break;case CV_EVENT_MOUSEMOVE:{p_Start.x=x-20; p_Start.y=y-20;      //随时定位鼠标位置画橡皮矩形p_End.x=x+20;   p_End.y=y+20;if(SHAPE_LINE==g_style){if(drawing){g_EndPoint=cvPoint(x,y);}}if(SHAPE_ERASER==g_style){rect.x=x-20;  rect.y=y-20;    rect.width=40;  rect.height=40;if(erasering){if(x>-20&&x<532&&y>-20&&y<532){cvSetImageROI(img,rect);cvSet(img,cvScalar(255,255,255));cvResetImageROI(img);}}}}break;case CV_EVENT_LBUTTONUP:{if(SHAPE_LINE==g_style){drawing=false;cvDrawLine(img,g_StartPoint,g_EndPoint,cvScalar(255,0,0));  //(255,0,0)此处画出的是蓝色,即BGR}if(SHAPE_ERASER==g_style){erasering=false;}}}
}