c++ - 想要在 OpenGL 中的短语上放置纹理

Question

我想在我创建的短语上添加纹理。但是，目前我的代码没有纹理映射。它只会在运行时打开一个警告，指出该文件无法打开。为什么？请修复它。

void view() {
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS);
    glMatrixMode(GL_MODELVIEW);
    glEnable(GL_TEXTURE_2D);
    glDisable(GL_TEXTURE_GEN_S);
    glDisable(GL_TEXTURE_GEN_T);
    glLoadIdentity();
    glBindTexture(GL_TEXTURE_2D, id);
    glutSolidSphere(0.4, 20, 20);
}

void main(int argc, char** argv) {
    unsigned int id;
    AUX_RGBImageRec *texture;
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
    glutInitWindowSize(1200, 800);
    glutCreateWindow("test");
    GLfloat plane_coef_s[] = { 1.0, 0.0, 0.0, 1.0 };
    GLfloat plane_coef_t[] = { 0.0, 1.0, 0.0, 1.0 };
    glEnable(GL_TEXTURE_GEN_S);
    glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);
    glTexGenfv(GL_S, GL_OBJECT_PLANE, plane_coef_s);
    glEnable(GL_TEXTURE_GEN_T);
    glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);
    glTexGenfv(GL_T, GL_OBJECT_PLANE, plane_coef_t);
    sphere = gluNewQuadric();
    gluQuadricTexture(sphere, GL_TRUE);
    tex = auxDIBImageLoad("test.bmp");
    glGenTextures(2, &id);
    glBindTexture(GL_TEXTURE_2D, id); 
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexImage2D(GL_TEXTURE_2D, 0, 3, tex->sizeX, tex->sizeY, 0, GL_RGB,
    GL_UNSIGNED_BYTE, tex->data);
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
}

Answer 1

首先，确保 text.bmp 文件与 .cpp 文件位于同一位置。

glutSolidSphere(0.4, 20);好像没有贴图贴图。将 GLUquadric *sphere; 声明为全局变量并更改glugSphere (sphere, 0.4, 20, 20);.

而且你必须将这两个变量声明为全局变量。

所以，切换到下面的代码。

unsigned int id;
AUX_RGBImageRec *texture;
GLUquadric *sphere;

void view() {
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS);
    glMatrixMode(GL_MODELVIEW);
    glEnable(GL_TEXTURE_2D);
    glDisable(GL_TEXTURE_GEN_S);
    glDisable(GL_TEXTURE_GEN_T);
    glLoadIdentity();
    glBindTexture(GL_TEXTURE_2D, id);
    gluSphere(sphere, 0.4, 20, 20);
}

void main(int argc, char** argv) {
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
    glutInitWindowSize(1200, 800);
    glutCreateWindow("test");
    GLfloat plane_coef_s[] = { 1.0, 0.0, 0.0, 1.0 };
    GLfloat plane_coef_t[] = { 0.0, 1.0, 0.0, 1.0 };
    glEnable(GL_TEXTURE_GEN_S);
    glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);
    glTexGenfv(GL_S, GL_OBJECT_PLANE, plane_coef_s);
    glEnable(GL_TEXTURE_GEN_T);
    glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);
    glTexGenfv(GL_T, GL_OBJECT_PLANE, plane_coef_t);
    sphere = gluNewQuadric();
    gluQuadricTexture(sphere, GL_TRUE);
    tex = auxDIBImageLoad("test.bmp");
    glGenTextures(2, &id);
    glBindTexture(GL_TEXTURE_2D, id); 
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexImage2D(GL_TEXTURE_2D, 0, 3, tex->sizeX, tex->sizeY, 0, GL_RGB,
    GL_UNSIGNED_BYTE, tex->data);
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
}