c++ - 如何在 OpenGL 中绘制立方体？

Question

我需要帮助。我找到了几种在 OpenGl 中绘制立方体的解决方案，但我遇到了问题。

我的代码是:

    wglMakeCurrent(pDC->m_hDC, m_hrc);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();

glTranslatef(1.5f, 0.0f, -7.0f);  // Move right and into the screen

glBegin(GL_QUADS);                // Begin drawing the color cube with 6 quads
                                  // Top face (y = 1.0f)
                                  // Define vertices in counter-clockwise (CCW) order with normal pointing out
glColor3f(0.0f, 1.0f, 0.0f);     // Green
glVertex3f(1.0f, 1.0f, -1.0f);
glVertex3f(-1.0f, 1.0f, -1.0f);
glVertex3f(-1.0f, 1.0f, 1.0f);
glVertex3f(1.0f, 1.0f, 1.0f);

// Bottom face (y = -1.0f)
glColor3f(1.0f, 0.5f, 0.0f);     // Orange
glVertex3f(1.0f, -1.0f, 1.0f);
glVertex3f(-1.0f, -1.0f, 1.0f);
glVertex3f(-1.0f, -1.0f, -1.0f);
glVertex3f(1.0f, -1.0f, -1.0f);

// Front face  (z = 1.0f)
glColor3f(1.0f, 0.0f, 0.0f);     // Red
glVertex3f(1.0f, 1.0f, 1.0f);
glVertex3f(-1.0f, 1.0f, 1.0f);
glVertex3f(-1.0f, -1.0f, 1.0f);
glVertex3f(1.0f, -1.0f, 1.0f);

// Back face (z = -1.0f)
glColor3f(1.0f, 1.0f, 0.0f);     // Yellow
glVertex3f(1.0f, -1.0f, -1.0f);
glVertex3f(-1.0f, -1.0f, -1.0f);
glVertex3f(-1.0f, 1.0f, -1.0f);
glVertex3f(1.0f, 1.0f, -1.0f);

// Left face (x = -1.0f)
glColor3f(0.0f, 0.0f, 1.0f);     // Blue
glVertex3f(-1.0f, 1.0f, 1.0f);
glVertex3f(-1.0f, 1.0f, -1.0f);
glVertex3f(-1.0f, -1.0f, -1.0f);
glVertex3f(-1.0f, -1.0f, 1.0f);

// Right face (x = 1.0f)
glColor3f(1.0f, 0.0f, 1.0f);     // Magenta
glVertex3f(1.0f, 1.0f, -1.0f);
glVertex3f(1.0f, 1.0f, 1.0f);
glVertex3f(1.0f, -1.0f, 1.0f);
glVertex3f(1.0f, -1.0f, -1.0f);
glEnd();  // End of drawing color-cube

glFlush();                  

SwapBuffers(pDC->m_hDC);
wglMakeCurrent(NULL, NULL);

下面是我想要得到的图像和我得到的图像。 expected image and the image I get

如何解决这个问题？

Answer 1

您必须启用深度测试。否则，三角形会按照代码中给出的顺序绘制，这会导致过度绘制，即使一个三角形在另一个三角形后面也是如此。启用深度测试调用

glEnable(GL_DEPTH_TEST);

在发出第一个绘制调用之前。