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：