OpenGL学习——第十课：纹理映射（1）实例

这里使用第九课中的Texture.h和Texture.cpp来实现对一个正方体的六面的纹理效果：

 

需要注意的代码就是相关纹理映射的部分；

（1）代码部分省去了Texture.h和Texture.cpp，因此运行时候需要先把这两个加入到工程目录下。

（2）需要在工程目录下建立一个名为data的文件夹，存放需要作为纹理的图片。

 

下面看主程序部分：

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#include <windows.h>  // Windows的头文件
#include <gl/glew.h>  // 包含最新的gl.h,glu.h库
#include <gl/glut.h>  // 包含OpenGL实用库

#include"Texture.h"  // 包含上一课中提供的头文件

 

//下列三行是自定义的变量 ：

#define MAXTEXTURE 1             // 定义纹理贴图数量
GLuint texture[MAXTEXTURE];            // 纹理数组，保存纹理名字(name)
 static float angle=0.0;    //旋转角度

GLvoid ReSizeGLScene(GLsizei width, GLsizei height)    // 重置OpenGL窗口大小
{
 glViewport(0, 0, (GLsizei)(width), (GLsizei)(height));    // 重置当前视口大小
 glMatrixMode(GL_PROJECTION);          // 切换到投影矩阵模式
 glLoadIdentity();             // 重置投影矩阵
 gluPerspective(45, (float)width/(float)height, 0.1, 100);   // 设置透视投影
 glMatrixMode(GL_MODELVIEW);           // 切换到模型视图矩阵
 glLoadIdentity();             // 重置模型视图矩阵
}

void InitGL(GLvoid)        // 此处开始对OpenGL进行所有设置
{
 //*******此处根据具体绘制环境初始化：

 glClearColor(0.0,0.0,0.0,0.0);
 glShadeModel(GL_SMOOTH);
 glEnable(GL_DEPTH_TEST);
 glEnable(GL_CULL_FACE);
 glFrontFace(GL_CCW);

 //启用2D纹理映射：
 glEnable(GL_TEXTURE_2D); 

  glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);    // 最精细的透视计算 

    

//下面这一行就体现了使用texture.h的好处：直接调用就能生成纹理，并保存在texture[0]中。

//当然，可以多次调用，生成多个纹理，如texture[1]，texture[2]。。。

 BuildTexture("data/waterfall.jpg", texture[0]);  

    

}

void DrawTextureCube(float xPos,float yPos,float zPos)
{
 glPushMatrix();
  glTranslatef(xPos,yPos,zPos);
//顶面：
  glBegin(GL_QUADS);
   glTexCoord2f(0.0,0.0);glVertex3f(-0.5,0.5,0.5);//纹理坐标
   glTexCoord2f(1.0,0.0);glVertex3f(0.5,0.5,0.5);
   glTexCoord2f(1.0,1.0);glVertex3f(0.5,0.5,-0.5);
   glTexCoord2f(0.0,1.0);glVertex3f(-0.5,0.5,-0.5);
  glEnd();

//正面：
  glBegin(GL_QUADS);
   glTexCoord2f(0.0,0.0);glVertex3f(0.5,-0.5,0.5);
   glTexCoord2f(1.0,0.0);glVertex3f(0.5,0.5,0.5);
   glTexCoord2f(1.0,1.0);glVertex3f(-0.5,0.5,0.5);
   glTexCoord2f(0.0,1.0);glVertex3f(-0.5,-0.5,0.5);
  glEnd();

//右面：
  glBegin(GL_QUADS);
   glTexCoord2f(0.0,0.0);glVertex3f(0.5,0.5,-0.5);
   glTexCoord2f(1.0,0.0);glVertex3f(0.5,0.5,0.5);
   glTexCoord2f(1.0,1.0);glVertex3f(0.5,-0.5,0.5);
   glTexCoord2f(0.0,1.0);glVertex3f(0.5,-0.5,-0.5);
  glEnd();

//左面

  glBegin(GL_QUADS);
   glTexCoord2f(0.0,0.0);glVertex3f(-0.5,-0.5,0.5);
   glTexCoord2f(1.0,0.0);glVertex3f(-0.5,0.5,0.5);
   glTexCoord2f(1.0,1.0);glVertex3f(-0.5,0.5,-0.5);
   glTexCoord2f(0.0,1.0);glVertex3f(-0.5,-0.5,-0.5);
  glEnd();
//底面：
  glBegin(GL_QUADS);
   glTexCoord2f(0.0,0.0);glVertex3f(0.5,-0.5,0.5);
   glTexCoord2f(1.0,0.0);glVertex3f(-0.5,-0.5,0.5);
   glTexCoord2f(1.0,1.0);glVertex3f(-0.5,-0.5,-0.5);
   glTexCoord2f(0.0,1.0);glVertex3f(0.5,-0.5,-0.5);
  glEnd();

//后面：
  glBegin(GL_QUADS);
   glTexCoord2f(0.0,0.0);glVertex3f(0.5,0.5,-0.5);
   glTexCoord2f(1.0,0.0);glVertex3f(0.5,-0.5,-0.5);
   glTexCoord2f(1.0,1.0);glVertex3f(-0.5,-0.5,-0.5);
   glTexCoord2f(0.0,1.0);glVertex3f(-0.5,0.5,-0.5);
  glEnd();

 glPopMatrix();

}
void DrawGLScene(GLvoid)        // 从这里开始进行所有的绘制
{
 glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
 glLoadIdentity();

 glTranslatef(0.0,0.0,-3.0);
 glRotatef(angle,1.0,0.0,0.0);
 glRotatef(angle,0.0,1.0,0.0);
 glRotatef(angle,0.0,0.0,1.0);

 DrawTextureCube(0.0,0.0,0.0);

 glutSwapBuffers();

}
void MyIdle()
{
 if(angle>=360)
  angle=0.0;
 angle+=0.2;
 DrawGLScene();

}
int main(int argc, char *argv[])
{
 glutInit(&argc, argv);
 glutInitDisplayMode(GLUT_RGBA| GLUT_DOUBLE|GLUT_DEPTH);
 glutInitWindowPosition(100, 100);
 glutInitWindowSize(400, 400);
 glutCreateWindow(" OpenGL程序:纹理映射");
 InitGL();
 glutDisplayFunc(DrawGLScene);
 glutReshapeFunc(ReSizeGLScene);
 glutIdleFunc(MyIdle);
 glutMainLoop();
 return 0;
}
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输出结果截图：