opengl画立方体
时间: 2023-07-10 14:06:06 浏览: 60
以下是使用 OpenGL 画立方体的基本步骤:
1. 首先,您需要设置 OpenGL 的视口和投影矩阵以确定立方体的位置和大小。
2. 接下来,您需要定义立方体的顶点和面。一个立方体有六个面,每个面由两个三角形组成。每个三角形都由三个顶点定义。
3. 接下来,您需要将这些顶点和面传递给 OpenGL,并设置正确的顶点属性和缓冲区对象。
4. 在设置完所有必要的属性后,您可以使用 glDrawElements 或 glDrawArrays 命令来渲染立方体。
下面是一个简单的 OpenGL 程序,用于画一个红色的立方体:
```c++
#include <GL/glut.h>
GLfloat vertices[] = {-1.0,-1.0,-1.0,1.0,-1.0,-1.0,1.0,1.0,-1.0,-1.0,1.0,-1.0,-1.0,-1.0,1.0,1.0,-1.0,1.0,1.0,-1.0,-1.0,1.0,-1.0,1.0,1.0,1.0,1.0,1.0,-1.0,1.0,-1.0,-1.0,-1.0,-1.0,-1.0,1.0,-1.0,-1.0,1.0,1.0,-1.0,-1.0,1.0,-1.0,1.0,1.0,1.0,1.0,-1.0,1.0,-1.0};
GLfloat colors[] = {1.0,0.0,0.0,1.0,0.0,1.0,0.0,1.0,1.0,0.0,0.0,1.0,0.0,1.0,1.0,1.0,1.0,0.0,1.0,1.0,0.0,1.0,0.0,0.0,1.0,0.0,1.0,1.0,1.0,1.0,1.0,0.0,1.0,0.0,1.0,0.0,1.0,1.0,1.0,0.0,1.0,1.0,0.0,0.0,0.0,1.0,0.0,1.0,1.0,0.0,1.0,0.0,0.0,0.0,1.0,1.0};
GLubyte indices[] = {0,3,2,1,2,3,7,6,0,4,5,6,1,5,4,0,2,6,5,1,7,3,4,7};
void drawCube(void) {
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_COLOR_ARRAY);
glVertexPointer(3, GL_FLOAT, 0, vertices);
glColorPointer(3, GL_FLOAT, 0, colors);
glDrawElements(GL_QUADS, 24, GL_UNSIGNED_BYTE, indices);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_COLOR_ARRAY);
}
void display(void) {
glClear(GL_COLOR_BUFFER_BIT);
glLoadIdentity();
gluLookAt(5,5,5,0,0,0,0,1,0);
drawCube();
glFlush();
}
void reshape(int w, int h) {
glViewport(0, 0, (GLsizei)w, (GLsizei)h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(60, (GLfloat)w / (GLfloat)h, 1.0, 100.0);
glMatrixMode(GL_MODELVIEW);
}
int main(int argc, char** argv) {
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize(500, 500);
glutInitWindowPosition(100, 100);
glutCreateWindow(argv[0]);
glClearColor(0.0, 0.0, 0.0, 0.0);
glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutMainLoop();
return 0;
}
```
这个程序创建一个立方体,并使用红色进行着色。它还设置了视口和投影矩阵,使立方体在屏幕上居中并具有透视效果。您可以通过更改顶点数组和颜色数组来更改立方体的外观。