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我正在使用以下代码来显示原始图像文件，但它什么也不显示：

GLuint texture;
GLuint LoadTexture( const char * filename, int width, int height);
void FreeTexture(GLuint texture);

void display()
{
    glClear (GL_COLOR_BUFFER_BIT);
    glBindTexture( GL_TEXTURE_2D, texture ); 
    glBegin (GL_QUADS); //begin drawing our quads
    glTexCoord2d(0.0, 0.0);
    glVertex3f(0.0, 0.0, 0.0); //with our vertices we have to assign a texcoord

    glTexCoord2d(1.0, 0.0);
    glVertex3f(1.0, 0.0, 0.0); //so that our texture has some points to draw to

    glTexCoord2d(1.0, 1.0);
    glVertex3f(1.0, 1.0, 0.0);

    glTexCoord2d(0.0, 1.0);
    glVertex3f(0.0, 1.0, 0.0);
    glEnd();
    glPopMatrix();
    glFlush();
}

void init()
{
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0, 640, 0, 480);
    glEnable( GL_TEXTURE_2D );
}

int main(int argc, char **argv)
{
    glutInit (&argc, argv);
    glutInitDisplayMode (GLUT_SINGLE);
    glutInitWindowSize (640, 480);
    glutInitWindowPosition (100, 100);
    glutCreateWindow ("A basic OpenGL Window");
    glutDisplayFunc (display);
    init();
    texture = LoadTexture("texture.raw", 256, 256);
    glutMainLoop ();
    FreeTexture(texture);

    return 0;
}

我得到的只是一个空屏幕。有什么问题？

4

1 回答 1

2

调用 gluOrtho2d 后，您的视图将从 0,0 映射到 640,480。您正在绘制一个值从 0,0 到 1,1 的四边形，这将是屏幕左下角单个像素的大小。

使用全屏 ( glVertex(640,480);) 或使用 gluOrtho2d 指定 1x1 视口 ( gluOrtho2d(0,1,0,1);)

于 2012-05-20T07:04:58.287 回答