图形学实验3——————简单种子填充算法

迷南。 2023-08-17 15:33 64阅读 0赞

容易溢出，我是用Release模式才运行成功的

#include <math.h>
    #include <gl/glut.h>
    
    struct Point {
        //点的位置
    	GLint x;  //typedef int GLint 
    	GLint y;
    };
    
    struct Color {
        //点的颜色信息
    	GLfloat r;//typedef float GLfloat
    	GLfloat g;
    	GLfloat b;
    };
    
    void init() {
        //初始化
    	glClearColor(1.0, 1.0, 1.0, 0.0);
    	glColor3f(0.0, 0.0, 0.0);
    	glPointSize(1.0);
    	glMatrixMode(GL_PROJECTION);
    	glLoadIdentity();
    	gluOrtho2D(0, 640, 0, 480);
    }
    
    Color getPixelColor(GLint x, GLint y) {
        //得到点(x,y)的颜色信息
    	Color color;
    	glReadPixels(x, y, 1, 1, GL_RGB, GL_FLOAT, &color);
    	return color;
    }
    
    void setPixelColor(GLint x, GLint y, Color color) {
        //将点(x,y)颜色置为color
    	glColor3f(color.r, color.g, color.b);
    	glBegin(GL_POINTS);
    	glVertex2i(x, y);
    	glEnd();
    	glFlush();
    }
    
    void floodFill(GLint x, GLint y, Color oldColor, Color newColor) {
        
    	Color color;
    	color = getPixelColor(x, y);
    
    	if (color.r == oldColor.r && color.g == oldColor.g && color.b == oldColor.b)
    	{
        
    		setPixelColor(x, y, newColor);
    		floodFill(x + 1, y, oldColor, newColor);
    		floodFill(x, y + 1, oldColor, newColor);
    		floodFill(x - 1, y, oldColor, newColor);
    		floodFill(x, y - 1, oldColor, newColor);
    	}
    	return;
    }
    
    void draw_circle(Point pC, GLfloat radius) {
        //画一个圆
    	GLfloat step = 1 / radius;
    	GLfloat x, y;
    
    	for (GLfloat theta = 0; theta <= 360; theta += step) {
        
    		x = pC.x + (radius * cos(theta));
    		y = pC.y + (radius * sin(theta));
    		glVertex2i(x, y);
    	}
    }
    
    void display(void) {
        
    	Point pt = {
         320, 240 };//圆心
    	GLfloat radius = 50;    //半径
    
    	glClear(GL_COLOR_BUFFER_BIT);
    	glBegin(GL_POINTS);     //开始画圆
    		draw_circle(pt, radius);
    	glEnd();
    	Color newColor = {
         1.0f, 0.0f, 0.0f };//红色
    	Color oldColor = {
         1.0f, 1.0f, 1.0f };//黑色
    
    	floodFill(320, 240, oldColor, newColor);//填充
    	glFlush();
    }
    
    int main(int argc, char** argv)
    {
        
    	glutInit(&argc, argv);
    	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    	glutInitWindowSize(640, 480);
    	glutInitWindowPosition(200, 200);
    	glutCreateWindow("画圆！");
    	init();
    	glutDisplayFunc(display);
    	glutMainLoop();
    	return 0;
    }

实验结果  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0hwdWVyX1JhbmRvbQ_size_16_color_FFFFFF_t_70]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0hwdWVyX1JhbmRvbQ_size_16_color_FFFFFF_t_70]: /images/20230810/923247a1905c4918a57ca9ab0f97b102.png