我正在编写一个程序,该程序将连续绘制多边形,直到用户右键单击。当且仅当用户在菜单中进行选择时,用户才能绘制,如果用户未在菜单中进行选择,则程序不会绘制。到目前为止,我的程序已经用鼠标成功绘制了一个多边形,但问题是当我右键完成时,程序弹出菜单而不是完成多边形。现在我怎样才能右键单击才能完成多边形,这是我的程序:
const int MAX = 100;
float mouseX, mouseY, ListX[MAX], ListY[MAX];
int numPoints = 0, closed = 0, shape = 0;
void mouse(int button, int state, int x, int y)
{
mouseX = x;
mouseY = y;
if (button == GLUT_LEFT_BUTTON && state == GLUT_DOWN)
{
if (closed || numPoints >= MAX - 1)
numPoints = 0;
closed = 0;
ListX[numPoints] = mouseX;
ListY[numPoints] = mouseY;
numPoints++;
}
if (button == GLUT_RIGHT_BUTTON && state == GLUT_DOWN)
closed = 1;
}
void motion(int x, int y)
{
mouseX = x;
mouseY = y;
glutPostRedisplay();
}
void display()
{
glClear(GL_COLOR_BUFFER_BIT);
if (shape == 1)
{
if (numPoints)
{
glBegin(GL_LINE_STRIP);
for (int i = 0; i < numPoints; ++i)
glVertex2f(ListX[i], ListY[i]);
if (closed)
glVertex2f(ListX[0], ListY[0]);
else
glVertex2f(mouseX, mouseY);
glEnd();
}
}
glFlush();
}
void menu(int choice)
{
switch (choice)
{
case 1:
shape = 1;
break;
}
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize(640, 480);
glutInitWindowPosition(100, 100);
glutCreateWindow("");
gluOrtho2D(0, 640, 480, 0);
glutCreateMenu(menu);
glutAddMenuEntry("Polygon", 1);
glutAttachMenu(GLUT_RIGHT_BUTTON);
glutDisplayFunc(display);
glutMouseFunc(mouse);
glutPassiveMotionFunc(motion);
glutMainLoop();
}
编辑:感谢 genpfault,我通过右键单击完成了多边形,但我不知道如何重新附加它以便我可以重新打开菜单。...
void display()
{
glClear(GL_COLOR_BUFFER_BIT);
if (shape == 1)
{
glutDetachMenu(GLUT_RIGHT_BUTTON); // Add this
...
}
glFlush();
}
void menu(int choice)
{
switch (choice)
{
case 1:
shape = 1;
break;
}
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize(640, 480);
glutInitWindowPosition(100, 100);
glutCreateWindow("");
gluOrtho2D(0, 640, 480, 0);
glutCreateMenu(menu);
glutAddMenuEntry("Polygon", 1);
glutAttachMenu(GLUT_RIGHT_BUTTON);
glutDisplayFunc(display);
glutMouseFunc(mouse);
glutPassiveMotionFunc(mouse_move);
glutMainLoop();
}
最佳答案
glutCreateMenu()
捕获返回值,这是新菜单的句柄。 glutDetachMenu()
在菜单回调中分离菜单并设置一个 bool 值,指示您处于“添加点”模式。 glutSetMenu()
将当前菜单设置为 #1 中的菜单句柄。 ,然后用 glutAttachMenu()
重新附加菜单.将“添加点” bool 值重置为 false
. 全部一起:
#include <GL/glut.h>
const int MAX = 100;
float mouseX, mouseY, ListX[MAX], ListY[MAX];
int numPoints = 0, closed = 0, shape = 0;
int hMenu = 0;
bool addingPoints = false;
void mouse(int button, int state, int x, int y)
{
mouseX = x;
mouseY = y;
if( addingPoints )
{
if( button == GLUT_LEFT_BUTTON && state == GLUT_DOWN )
{
if (closed || numPoints >= MAX - 1)
numPoints = 0;
closed = 0;
ListX[numPoints] = mouseX;
ListY[numPoints] = mouseY;
numPoints++;
}
if( button == GLUT_RIGHT_BUTTON && state == GLUT_DOWN )
{
closed = 1;
addingPoints = false;
glutSetMenu(hMenu);
glutAttachMenu(GLUT_RIGHT_BUTTON);
}
}
}
void motion(int x, int y)
{
mouseX = x;
mouseY = y;
glutPostRedisplay();
}
void display()
{
glClear(GL_COLOR_BUFFER_BIT);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, 640, 480, 0, -1, 1);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
if (shape == 1)
{
if (numPoints)
{
glBegin(GL_LINE_STRIP);
for (int i = 0; i < numPoints; ++i)
glVertex2f(ListX[i], ListY[i]);
if (closed)
glVertex2f(ListX[0], ListY[0]);
else
glVertex2f(mouseX, mouseY);
glEnd();
}
}
glutSwapBuffers();
}
void menu(int choice)
{
switch (choice)
{
case 1:
numPoints = 0;
shape = 1;
addingPoints = true;
glutDetachMenu(GLUT_RIGHT_BUTTON);
break;
}
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
glutInitWindowSize(640, 480);
glutCreateWindow("");
hMenu = glutCreateMenu(menu);
glutSetMenu(hMenu);
glutAddMenuEntry("Polygon", 1);
glutAttachMenu(GLUT_RIGHT_BUTTON);
glutDisplayFunc(display);
glutMouseFunc(mouse);
glutPassiveMotionFunc(motion);
glutMainLoop();
}
关于c++ - 通过右键单击完成多边形的绘制,但显示一个菜单,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/67322575/