2个OpenGL的初级问题,请帮助,谢谢

Question

1、你画图函数是在哪里画的？
2、
      glDisable(GL_TEXTURE_2D);
glEnable(GL_COLOR_MATERIAL);
glColor3d(1.0, 0.0, 0.0, 0.0f);
glPolygonMode(GL_FRONT_AND_BACK,GL_FILL);
glBegin(GL_QUADS);
glVertex3f(0.5, 0.5, 0.0);
glVertex3f(-0.5, 0.5,0.0);
glVertex3f(-0.5, -0.5, 0.0);
glVertex3f(0.5, -0.5, 0.0);
glEnd();
glBegin(GL_QUADS);
glColor3f(1.0,0.0,0.0);
glVertex3f(0.5, 0.5, 0.0);
glVertex3f(-0.5, 0.5,0.0);
glVertex3f(-0.5, -0.5, 0.0);
glVertex3f(0.5, -0.5, 0.0);
glEnd();

Answer 1

MFC中视类下的OnDraw()函数中写的

Answer 2

2楼代码运行的结果是error C2660: 'glColor3d' : function does not take 4 parameters

Answer 3

2楼的代码即使把glColor3d改为glColor4d也是不可以一面为红色,一面为绿色的,是不是我写的代码不对啊?谁能具体讲解一下,先,谢谢了

Answer 4

如果我没记错的话，glVertex3f（）函数的第三个参数是Z轴坐标，而在OpenGL里，Z轴是垂直于屏幕的，原点在屏幕上。
而你的程序中所有四边形的Z坐标都在原点上（都是0.0），等于刚好把两个四边形都叠放在屏幕上，你如何看得到四边形？建议把四边形往屏幕里推一点，比如都设成-2.0：
glDisable(GL_TEXTURE_2D); 
glEnable(GL_COLOR_MATERIAL); 
glColor3d(1.0,   0.0,   0.0,   0.0f); 
glPolygonMode(GL_FRONT_AND_BACK,GL_FILL); 
glBegin(GL_QUADS); 
glVertex3f(0.5,   0.5,   -2.0); 
glVertex3f(-0.5,   0.5,  -2.0); 
glVertex3f(-0.5,   -0.5,  -2.0); 
glVertex3f(0.5,   -0.5,   -2.0); 
glEnd(); 
glBegin(GL_QUADS); 
glColor3f(1.0,0.0,0.0); 
glVertex3f(0.5,   0.5,   -2.0); 
glVertex3f(-0.5,   0.5,  -2.0); 
glVertex3f(-0.5,   -0.5,   -2.0); 
glVertex3f(0.5,   -0.5,   -2.0); 
glEnd();