2011-12-01 314 views
1

我目前的OpenGL应用程序只是一个球体和一层,照明和阴影正常工作。OpenGL纹理映射禁用底纹

通过红皮书教程加入了2D纹理的地板后:http://fly.cc.fer.hr/~unreal/theredbook/chapter09.html

..我的阴影被禁用。如果我禁用GL_TEXTURE_2D,一切都呈现正确,但纹理显然不显示。这是一个已知问题与已知的解决方法?这里是一个位的代码以供参考:

#define checkImageWidth 64 
#define checkImageHeight 64 
GLubyte checkImage[checkImageWidth][checkImageHeight][3]; 

void makeCheckImage(void) 
{ 
    int i, j, c; 

     for (i = 0; i < checkImageWidth; i++) { 
     for (j = 0; j < checkImageHeight; j++) { 
      c = ((((i&0x8)==0)^(((j&0x8))==0)))*255; 
      checkImage[i][j][0] = (GLubyte) c; 
      checkImage[i][j][1] = (GLubyte) c; 
      checkImage[i][j][2] = (GLubyte) c; 
     } 
    } 
} 


void initImage() { 

    makeCheckImage(); 
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1); 
    glTexImage2D(GL_TEXTURE_2D, 0, 3, checkImageWidth, 
     checkImageHeight, 0, GL_RGB, GL_UNSIGNED_BYTE, 
     &checkImage[0][0][0]); 
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP); 
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP); 
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, 
     GL_NEAREST); 
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, 
     GL_NEAREST); 
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL); 
} 

然后粗糙的地面绘制函数:

void makeGround() { 

    GLfloat mat_specular[]  = { 0.5, 0.5, 0.5, 0.5 }; 
    GLfloat mat_diffuse[]  = { 0.3, 0.3, 0.3, 0.3 }; 
    GLfloat mat_shininess[]  = { 25.0 }; 

    glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular); 
    glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse); 
    glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess); 

    glColor3f(0.2, 0.2, 0.2); 

    glBegin(GL_QUADS); 
     glTexCoord2f(0.0, 0.0); glVertex3f(-100.0f, -1.0f, -100.0f); 
     glTexCoord2f(0.0, 1.0); glVertex3f(-100.0f, -1.0f, 100.0f); 
     glTexCoord2f(1.0, 1.0); glVertex3f(100.0f, -1.0f, 100.0f); 
     glTexCoord2f(1.0, 0.0); glVertex3f(100.0f, -1.0f, -100.0f); 
    glEnd(); 
    glFlush(); 

} 

,如果你需要查看代码的任何其他部分,只是让我知道

回答

4
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL); 

贴花是一种奇怪的环境模式。对于GL_RGB纹理(如您的),它取代的颜色。对于RGBA纹理,它将它与来自纹理的Alpha混合。

如果您只是想用照明调制您的纹理,请使用GL_MODULATE

+0

Spot on。谢谢! – grep