5
所以我想學習如何使用glViewport(),「多個時間」。下面是我的代碼,我試圖去關注其他的例子,但是它們或者與我正在做的事情無關的其他事情如此複雜,或者我不明白他們在做什麼。順便說一句,我用glut來管理我的窗口系統。所以我學習的最好方法是獲得一個簡單的例子,然後從中推斷出來。下面是我的一個簡單程序的代碼,它將屏幕分爲兩部分,繪製兩個相同的球體,當gluPerspective()對於兩個視圖端口都相同時,我無法弄清楚爲什麼右邊的球體會拉伸。請,如果你只能向我解釋我在代碼中做錯了什麼,那將會大大幫助。外部資源非常好,但我需要簡單,簡單的例子(不是內特羅賓遜的例子)。OpenGL多視口和gluPerspective()
GLfloat width = 800, height = 600, x_0 = 470, y_0 = 0;
int mainWindow;
void resize(int w, int h){
width=w;
height=h;
}
void draw(void){
glEnable(GL_SCISSOR_TEST);
glClearDepth(1.0);
glClearColor(0.0, 0.0, 0.0, 1.0);
glEnable(GL_DEPTH_TEST);
glEnable(GL_LIGHT0);
glEnable(GL_LIGHTING);
GLfloat color[4] = {1.0, 0.0, 0.0, 1.0};
/*
* LEFT VIEW PORT
*/
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glViewport(0, 0, (float)width/2 , height);
gluPerspective(45, ((float)width/2)/(float)height, 1, 2000);
glMatrixMode(GL_MODELVIEW);
glScissor(0, 0, (float)width , height);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
gluLookAt(0.0, 0.0, 50.0,
0.0, 0.0, 0.0,
0.0, 1.0, 0.0);
glPushAttrib(GL_LIGHTING_BIT | GL_CURRENT_BIT);
glPushMatrix();
glMaterialfv(GL_FRONT, GL_DIFFUSE, color);
glutSolidSphere(10.0, 20, 40);
glPopMatrix();
glPopAttrib();
/*
* THE SECOND VIEW PORT
*/
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glViewport((float)width/2, 0, width , height);
gluPerspective(45, ((float)width)/2/((float)height), 1, 2000);
glMatrixMode(GL_MODELVIEW);
glScissor(((float)width/2), 0, width , height);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
gluLookAt(0.0, 0.0, 50.0,
0.0, 0.0, 0.0,
0.0, 1.0, 0.0);
glPushAttrib(GL_LIGHTING_BIT | GL_CURRENT_BIT);
glPushMatrix();
glMaterialfv(GL_FRONT, GL_DIFFUSE, color);
glutSolidSphere(10.0, 20, 40);
glPopMatrix();
glPopAttrib();
glDisable(GL_SCISSOR_TEST);
glFlush();
glutSwapBuffers();
}
void glutAppInitialize(void){
GLfloat light_ambient[] = {0.2, 0.2, 0.2, 1.0};
GLfloat light_diffuse[] = {1.0, 1.0, 1.0, 1.0};
GLfloat light_specular[] = {1.0, 1.0, 1.0, 1.0};
GLfloat light_position[] = {1.0, 1.0, 0.0, 0.0};
glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
glLightfv(GL_LIGHT0, GL_POSITION, light_position);
}
int main(int argc, char* argv[]){
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA);
glutInitWindowPosition(x_0, y_0);
glutInitWindowSize(width ,height);
glutAppInitialize();
mainWindow = glutCreateWindow("Tori App");
glutDisplayFunc(draw);
glutReshapeFunc(resize);
glutMainLoop();
return(0);
}
請注意,我打轉轉,而我等待的迴應,我得到了它做我想要的東西,但解決的辦法是沒有,因爲,請參閱的代碼行,基本上我感動的視口開始位置的四分之一,而不是一半,我不再是兩分之一。
/*
* THE SECOND VIEW PORT
*/
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glViewport(width/4, 0, width , height);
gluPerspective(45, ((float)width)/(((float)height)), 1, 2000);