OpenGL纹理贴图简单例子.docx

【代码】
#include <windows.h>
#include <GL/glut.h>
#include <GL/glext.h>

static double X = 0;
static double Y = 0;
static double Z = 7;

// 定义函数指针，在Windows环境下使用OpenGL扩展
PFNGLACTIVETEXTUREARBPROC glActiveTextureARB = NULL;
PFNGLMULTITEXCOORD2FARBPROC glMultiTexCoord2fARB = NULL;

// 纹理存储数组
static GLubyte T0[64][64][4];
static GLubyte T1[64][64][4];
static GLubyte T2[64][64][4];

// 纹理名字
static GLuint Tname0;
static GLuint Tname1;
static GLuint Tname2;

// 创建纹理
void makeImages()
{
int i, j, c;

// 第一个纹理，渐变绿色，*64
for (i = 0; i < 64; i++) {
for (j = 0; j < 64; j++) {
T0[i][j][0] = (GLubyte) 0;
T0[i][j][1] = (GLubyte) i * 5 + j * 5;
T0[i][j][2] = (GLubyte) 0;
T0[i][j][3] = (GLubyte) 255;
}
}

// 第二个纹理，黑白相间横条，*64
for (i = 0; i < 64; i++) {
for (j = 0; j < 64; j++) {
if (i % 16 < 8) c = 255;
else c = 0;
T1[i][j][0] = (GLubyte) c;
T1[i][j][1] = (GLubyte) c;
T1[i][j][2] = (GLubyte) c;
T1[i][j][3] = (GLubyte) 255;
}
}

// 第三个纹理，黑白相间竖条，*64
for (i = 0; i < 64; i++) {
for (j = 0; j < 64; j++) {
if (j % 16 < 8) c = 255;
else c = 0;
T2[i][j][0] = (GLubyte) c;
T2[i][j][1] = (GLubyte) c;
T2[i][j][2] = (GLubyte) c;
T2[i][j][3] = (GLubyte) 255;
}
}
}

void init()
{
// 获取函数地址
glActiveTextureARB = (PFNGLACTIVETEXTUREARBPROC)wglGetProcAddress("glActiveTextureARB");
glMultiTexCoord2fARB = (PFNGLMULTITEXCOORD2FARBPROC)wglGetProcAddress("glMultiTexCoord2fARB");

// 场景初始化
glClearColor (0.0, 0.0, 0.0, 0.0);
glShadeModel(GL_FLAT);
glEnable(GL_DEPTH_TEST);

makeImages(); // 纹理初始化
glPixelStorei(GL_UNPACK_ALIGNMENT, 1); // 对其像素字节

glGenTextures(1, &Tname0); // 获取纹理名字
glGenTextures(1, &Tname1); // 获取纹理名字
glGenTextures(1, &Tname2); // 获取纹理名字

// 初始化纹理
glBindTexture(GL_TEXTURE_2D, Tname0); // 生成指定名字的纹理对象
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 64, 64, 0, GL_RGBA, GL_UNSIGNED_BYTE, T0); // 设置纹理对象内容
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); // 设置纹理过滤方式
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); // 设置纹理过滤方式
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); // 设置纹理过滤方式
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); // 设置纹理过滤方式

// 同上，初始化纹理
glBindTexture(GL_TEXTURE_2D, Tname1);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 64, 64, 0, GL_RGBA, GL_UNSIGNED_BYTE, T1);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

// 同上，初始化纹理
glBindTexture(GL_TEXTURE_2D, Tname2);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 64, 64, 0, GL_RGBA, GL_UNSIGNED_BYTE, T2);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
}

void display()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
gluLookAt((GLfloat)X, (GLfloat)Y, (GLfloat)Z, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0); // 视图变换

// 激活纹理对象
glActiveTextureARB (GL_TEXTURE0_ARB); // 选中号纹理
glEnable(GL_TEXTURE_2D); // 使纹理可用
glBindTexture(GL_TEXTURE_2D, Tname0); // 激活纹理
glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE); // 设置纹理贴图方式

// 绘制正方形
glBegin(GL_QUADS);
glMultiTexCoord2fARB (GL_TEXTURE0_ARB, 0.0, 0.0);
glVertex3f(-4.0, 1.5, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE0_ARB, 0.0, 1.0);
glVertex3f(-4.0, 3.5, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE0_ARB, 1.0, 1.0);
glVertex3f(-2.0, 3.5, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE0_ARB, 1.0, 0.0);
glVertex3f(-2.0, 1.5, 0.0);
glEnd();
glDisable(GL_TEXTURE_2D);

// 同上，绘制正方形，使用号纹理
glActiveTextureARB (GL_TEXTURE1_ARB);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, Tname1);
glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);

glBegin(GL_QUADS);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 0.0, 0.0);
glVertex3f(-1.0, 1.5, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 0.0, 1.0);
glVertex3f(-1.0, 3.5, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 1.0, 1.0);
glVertex3f(1.0, 3.5, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 1.0, 0.0);
glVertex3f(1.0, 1.5, 0.0);
glEnd();
glDisable(GL_TEXTURE_2D);

// 同上，绘制正方形，使用号纹理
glActiveTextureARB(GL_TEXTURE2_ARB);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, Tname2);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);

glBegin(GL_QUADS);
glMultiTexCoord2fARB (GL_TEXTURE2_ARB, 0.0, 0.0);
glVertex3f(2.0, 1.5, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE2_ARB, 0.0, 1.0);
glVertex3f(2.0, 3.5, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE2_ARB, 1.0, 1.0);
glVertex3f(4.0, 3.5, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE2_ARB, 1.0, 0.0);
glVertex3f(4.0, 1.5, 0.0);
glEnd();
glDisable(GL_TEXTURE_2D);

// 同上，绘制正方形，使用号和号纹理
glActiveTextureARB (GL_TEXTURE0_ARB);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, Tname0);
glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
glActiveTextureARB (GL_TEXTURE1_ARB);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, Tname1);
glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

glBegin(GL_QUADS);
glMultiTexCoord2fARB (GL_TEXTURE0_ARB, 0.0, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 0.0, 0.0);
glVertex3f(-2.5, -1.0, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE0_ARB, 0.0, 1.0);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 0.0, 1.0);
glVertex3f(-2.5, 1.0, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE0_ARB, 1.0, 1.0);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 1.0, 1.0);
glVertex3f(-0.5, 1.0, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE0_ARB, 1.0, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 1.0, 0.0);
glVertex3f(-0.5, -1.0, 0.0);
glEnd();
// 反激活纹理，防止干扰
glActiveTextureARB (GL_TEXTURE0_ARB);
glDisable(GL_TEXTURE_2D);
glActiveTextureARB (GL_TEXTURE1_ARB);
glDisable(GL_TEXTURE_2D);

// 同上，绘制正方形，使用号和号纹理
glActiveTextureARB (GL_TEXTURE1_ARB);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, Tname1);
glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
glActiveTextureARB (GL_TEXTURE2_ARB);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, Tname2);
glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

glBegin(GL_QUADS);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 0.0, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE2_ARB, 0.0, 0.0);
glVertex3f(0.5, -1.0, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 0.0, 1.0);
glMultiTexCoord2fARB (GL_TEXTURE2_ARB, 0.0, 1.0);
glVertex3f(0.5, 1.0, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 1.0, 1.0);
glMultiTexCoord2fARB (GL_TEXTURE2_ARB, 1.0, 1.0);
glVertex3f(2.5, 1.0, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 1.0, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE2_ARB, 1.0, 0.0);
glVertex3f(2.5, -1.0, 0.0);
glEnd();
glActiveTextureARB (GL_TEXTURE1_ARB);
glDisable(GL_TEXTURE_2D);
glActiveTextureARB (GL_TEXTURE2_ARB);
glDisable(GL_TEXTURE_2D);

// 绘制正方形，使用号、号和号纹理
glActiveTextureARB (GL_TEXTURE0_ARB);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, Tname0);
glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
glActiveTextureARB (GL_TEXTURE1_ARB);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, Tname1);
glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
glActiveTextureARB (GL_TEXTURE2_ARB);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, Tname2);
glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

glBegin(GL_QUADS);
glMultiTexCoord2fARB (GL_TEXTURE0_ARB, 0.0, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 0.0, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE2_ARB, 0.0, 0.0);
glVertex3f(-1.0, -3.5, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE0_ARB, 0.0, 1.0);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 0.0, 1.0);
glMultiTexCoord2fARB (GL_TEXTURE2_ARB, 0.0, 1.0);
glVertex3f(-1.0, -1.5, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE0_ARB, 1.0, 1.0);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 1.0, 1.0);
glMultiTexCoord2fARB (GL_TEXTURE2_ARB, 1.0, 1.0);
glVertex3f(1.0, -1.5, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE0_ARB, 1.0, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE1_ARB, 1.0, 0.0);
glMultiTexCoord2fARB (GL_TEXTURE2_ARB, 1.0, 0.0);
glVertex3f(1.0, -3.5, 0.0);
glEnd();
glActiveTextureARB (GL_TEXTURE0_ARB);
glDisable(GL_TEXTURE_2D);
glActiveTextureARB (GL_TEXTURE1_ARB);
glDisable(GL_TEXTURE_2D);
glActiveTextureARB (GL_TEXTURE2_ARB);
glDisable(GL_TEXTURE_2D);

glFlush();
}

void reshape(int w, int h)
{
glViewport(0, 0, (GLsizei) w, (GLsizei) h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(60.0, (GLfloat) w/(GLfloat) h, 1.0, 30.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt((GLfloat)X, (GLfloat)Y, (GLfloat)Z, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0); // 视图变换
}

void pressKey(int key, int x, int y)
{
switch(key)
{
case GLUT_KEY_RIGHT:
X += 1;
glutPostRedisplay();
break;
case GLUT_KEY_LEFT:
X -= 1;
glutPostRedisplay();
break;
case GLUT_KEY_UP:
Y += 1;
glutPostRedisplay();
break;
case GLUT_KEY_DOWN:
Y -= 1;
glutPostRedisplay();
break;
default:
break;
}
}

int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(250, 250);
glutInitWindowPosition(100, 100);
glutCreateWindow(argv[0]);
init();
glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutSpecialFunc(pressKey);
glutMainLoop();
return 0;
}
【程序截图】

【说明】
对于Windows平台下，需要包含glext.h头文件。
方向键为控制投影参考点的位置。
第一行三个正方形分别是只贴一层纹理的效果。
第二行两个正方形分别是贴上面两种纹理的效果。
第三行两个正方形是贴上三种纹理的效果。