利用Dfs实现简单递归填充。
核心代码:
// 简单深度搜索填充 (四连通)
void DfsFill(int x, int y)
{
if (x < 0 || y < 0 || x>23 || y>23)
{
return;
}
if (a[x][y] == 0)
{
a[x][y] = 2;
DfsFill(x - 1, y);
DfsFill(x + 1, y);
DfsFill(x, y - 1);
DfsFill(x, y + 1);
}
}
1. 种子点(x,y)入栈。
2. 栈顶元素(x,y)出栈作为种子点。
3. 从种子点(x,y)开始沿着扫描线向左右两个方向逐个像素进行填充,直到到达边界像素为止。
4. 将上述填充区段的左右端点的横坐标分别记为xleft和xright.
5. 在与当前扫描线相邻的上下两条扫描线的[xleft,xright]范围内进行检查,
看看是否全部为边界像素或已填充像素,若存在着非边界且未填充的像素,那么将该区段的最右端像素作为种子点入栈。
void ScanFill(int x, int y)
{
if (a[x][y]!=0)
{
return;
}
Pos first(x, y);
s.push(first);
while (!s.empty())
{
int rightX = 0;
int leftX = 0;
Pos cur = s.top();
s.pop();
a[cur.x][cur.y] = 2;
// 遍历当前行
for (int i = 1; i < 24; i++)
{
if (cur.x + i < 24)
{
if (a[cur.x + i][cur.y] == 0)
a[cur.x + i][cur.y] = 2;
else
{
rightX = cur.x + i - 1;
break;
}
}
if (i==23)
{
rightX = 23;
}
}
for (int i = 1; i < 24; i++)
{
if (cur.x - i > -1)
{
if (a[cur.x - i][cur.y] == 0)
a[cur.x - i][cur.y] = 2;
else
{
leftX = cur.x - i + 1;
break;
}
}
if (i == 0)
{
leftX = 0;
}
}
cout << leftX <<","<=0)
{
downRightX = i;
}
}
if (downRightX != -1)
{
Pos temPos(downRightX, cur.y - 1);
s.push(temPos);
}
}
}
完整代码:
#include
#include
#include "gl/glut.h"
#include "iostream"
using namespace std;
#define PI 3.14
struct Pos
{
int x;
int y;
Pos(int mx, int my) :x(mx), y(my) {};
Pos() :x(0), y(0) {};
};
stack s;
int a[24][24] = { 0 };
void init(void)
{
glClearColor(1.0, 1.0, 1.0, 1.0);
glMatrixMode(GL_PROJECTION);//设置投影矩阵
gluOrtho2D(0.0, 600.0, 0.0, 600.0);//二维视景区域
glPointSize(12.0f);
}
// 画棋子
void Drawtri(int x,int y,int color)
{
double n = 200;//分段数
float R = 10;//半径
int i;
if (color == 1)
{
glColor3f(1.0, 0.0, 0.0);
}
else if (color == 2)
{
glColor3f(0.0, 1.0, 0.0);
}
glBegin(GL_POLYGON);
glVertex2f(x, y);
for (i = 0; i <= n; i++)
glVertex2f(R*cos(2 * PI / n * i)+x, R*sin(2 * PI / n * i)+y);
glEnd();
glPopMatrix();
}
// 绘制格线
void playMap()
{
glColor3f(0.0, 0.0, 0.0);
glBegin(GL_LINES);
for (int i = 0; i < 600; i += 25)
{
glVertex2f(i, 0);
glVertex2f(i, 600);
}
for (int j = 0; j < 600; j += 25)
{
glVertex2f(0, j);
glVertex2f(600, j);
}
glEnd();
for (int k = 0; k < 24; k++)
{
for (int l = 0; l < 24; l++)
{
if (a[k][l] == 1)
{
Drawtri(k * 25 + 12, l * 25 + 12,1);
}
else if (a[k][l] == 2)
{
Drawtri(k * 25 + 12, l * 25 + 12, 2);
}
}
}
}
// 简单深度搜索填充 (四连通)
void DfsFill(int x, int y)
{
if (x < 0 || y < 0 || x>23 || y>23)
{
return;
}
if (a[x][y] == 0)
{
a[x][y] = 2;
DfsFill(x - 1, y);
DfsFill(x + 1, y);
DfsFill(x, y - 1);
DfsFill(x, y + 1);
}
}
// 扫描线种子填充算法(四连通)
void ScanFill(int x, int y)
{
if (a[x][y]!=0)
{
return;
}
Pos first(x, y);
s.push(first);
while (!s.empty())
{
int rightX = 0;
int leftX = 0;
Pos cur = s.top();
s.pop();
a[cur.x][cur.y] = 2;
// 遍历当前行
for (int i = 1; i < 24; i++)
{
if (cur.x + i < 24)
{
if (a[cur.x + i][cur.y] == 0)
a[cur.x + i][cur.y] = 2;
else
{
rightX = cur.x + i - 1;
break;
}
}
if (i==23)
{
rightX = 23;
}
}
for (int i = 1; i < 24; i++)
{
if (cur.x - i > -1)
{
if (a[cur.x - i][cur.y] == 0)
a[cur.x - i][cur.y] = 2;
else
{
leftX = cur.x - i + 1;
break;
}
}
if (i == 0)
{
leftX = 0;
}
}
cout << leftX <<","<=0)
{
downRightX = i;
}
}
if (downRightX != -1)
{
Pos temPos(downRightX, cur.y - 1);
s.push(temPos);
}
}
}
void displayFcn(void)
{
glClear(GL_COLOR_BUFFER_BIT);
playMap();
glFlush();
}
void mouse(GLint button, GLint action, GLint x, GLint y)
{
int curX, curY;
if (button == GLUT_LEFT_BUTTON && action == GLUT_DOWN)
{
curX = x / 25;
curY = (600 - y) / 25;
a[curX][curY] = 1;
glutPostRedisplay();//重绘窗口
}
if (button == GLUT_RIGHT_BUTTON && action == GLUT_DOWN)
{
curX = x / 25;
curY = (600 - y) / 25;
ScanFill(curX, curY);
glutPostRedisplay();//重绘窗口
}
}
void main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
glutInitWindowPosition(300, 100);
glutInitWindowSize(600, 600);
glutCreateWindow("mouse");
init();
glutDisplayFunc(displayFcn);
glutMouseFunc(mouse);
glutMainLoop();
}