我正在用OpenGL中的一些地图图像渲染一个场景，并直接使用地图的纬度、经度作为坐标。所以我的场景不是从 0,0 开始，而是上升到宽度、高度。虽然我可以看到我的多边形（非常小），但我无法通过更改 gluLookAt() 中眼睛的 z 值来进行缩放。
/*
* My boundary for map quad with texture
*/
#define TOP 41.9061
#define BOTTOM 41.8546
#define LEFT -87.7012
#define RIGHT -87.6054
/*
* window size
*/
const unsigned int window_width = 1024;
const unsigned int window_height = 739;
/*
* drawing a polygon with texture
*/
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, mainMapTextureId);
glBegin( GL_POLYGON );
//bottom left
glTexCoord2f( 0.0f, 1.0f );
glVertex3f(LEFT, BOTTOM, 0.0);
//bottom right
glTexCoord2f( 1.0f, 1.0f );
glVertex3f(RIGHT, BOTTOM, 0.0);
//top right
glTexCoord2f( 1.0f, 0.0f );
glVertex3f(RIGHT, TOP, 0.0);
//top left
glTexCoord2f( 0.0f, 0.0f );
glVertex3f(LEFT, TOP, 0.0);
glEnd();
/*
* Setting up the camera
*/
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(60.0, (GLfloat)window_width/(GLfloat)window_height, 0.0, 10.0);
gluLookAt( (float)(LEFT+RIGHT)/2.0, (float)(TOP+BOTTOM)/2.0, 1.0,
(float)(LEFT+RIGHT)/2.0, (float)(TOP+BOTTOM)/2.0, 0.0,
0.0f, 1.0f, 0.0f);