xiaxiwan

 1 void display(void)  
 2 {  
 3     glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );  
 4     glColor3f (1.0, 1.0, 1.0);    
 5     
 6     glDisable(GL_DEPTH_TEST);  
 7   
 8     // 切換到正交模式  
 9     glMatrixMode(GL_PROJECTION);    
10     glLoadIdentity();    
11     glOrtho(0, g_fWidth, 0, g_fHeight, 0, g_fDepth);    
12     glMatrixMode(GL_MODELVIEW);    
13     glLoadIdentity();    
14       
15     glDisable(GL_LIGHTING);  
16     glEnable(GL_TEXTURE_2D);  
17     glBindTexture( GL_TEXTURE_2D, g_textureID );  
18     glInterleavedArrays( GL_T2F_V3F, 0, g_bgVertices );  
19     glDrawArrays( GL_QUADS, 0, 4 ); // 繪制背景圖片  
20     glEnable(GL_LIGHTING);  
21     glDisable(GL_TEXTURE_2D);  
22   
23     //  切換到三維場景  
24     glMatrixMode (GL_PROJECTION);       //回復原有的設置    
25     glLoadIdentity ();    
26     gluPerspective(30, g_fWidth/g_fHeight, 0.001, 100.0);  
27     glMatrixMode(GL_MODELVIEW);  
28     glLoadIdentity ();               
29     gluLookAt(0, 5, 5, 0, 0, 0, 0, 1, 0);  
30   
31     glEnable(GL_DEPTH_TEST);  
32   
33     glPushMatrix();  
34     {  
35         glTranslatef(0, 0, 0);  
36   
37         glRotatef(g_xAngle, 1, 0, 0);  
38         glRotatef(g_yAngle, 0, 1, 0);  
39   
40         glCallList(g_modelId);  // 繪制三維圖形  
41     } glPopMatrix();  
42   
43     glFlush();  
44     // glutPostRedisplay();  
45 }  

 1 void display(void)  
 2 {  
 3     glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );  
 4     glColor3f (1.0, 1.0, 1.0);    
 5   
 6     ComputeBackgroundQuad();  
 7   
 8     glDisable(GL_DEPTH_TEST);  
 9   
10     // 繪制背景圖片  
11     glDisable(GL_LIGHTING);  
12     glEnable(GL_TEXTURE_2D);  
13     glBindTexture( GL_TEXTURE_2D, g_textureID );  
14   
15     glEnableClientState( GL_VERTEX_ARRAY );  
16     glEnableClientState( GL_TEXTURE_COORD_ARRAY );  
17     glInterleavedArrays( GL_T2F_V3F, 0, g_bgVertices );  
18     glDrawArrays( GL_QUADS, 0, 4 );  
19     glDisableClientState( GL_VERTEX_ARRAY );  
20     glDisableClientState( GL_TEXTURE_COORD_ARRAY );  
21   
22     glDisable(GL_TEXTURE_2D);  
23   
24     glEnable(GL_LIGHTING);  
25   
26     glEnable(GL_DEPTH_TEST);  
27   
28     glPushMatrix();  
29     {  
30         glTranslatef(0, 0, g_fOffset);  
31   
32         glRotatef(g_xAngle, 1, 0, 0);  
33         glRotatef(g_yAngle, 0, 1, 0);  
34   
35         glCallList(g_modelId);  
36     } glPopMatrix();  
37   
38     glFlush();  
39     // glutPostRedisplay();  
40 }

 1 void ComputeBackgroundQuad()  
 2 {  
 3     GLint   viewport[4];  
 4     GLdouble projMatrix[16];  
 5     GLdouble modelMatrix[16];  
 6   
 7     // glGetDoublev(GL_PROJECTION, projMatrix);  缺少matrix但是編譯不報錯~  
 8     glGetDoublev(GL_PROJECTION_MATRIX, projMatrix);  
 9     glGetDoublev(GL_MODELVIEW_MATRIX, modelMatrix);  
10     glGetIntegerv(GL_VIEWPORT, viewport);  
11   
12     //   
13     double objX, objY, objZ;  
14     const double winZ = 0;  // 0 / 1  
15     gluUnProject(0, 0, winZ, modelMatrix, projMatrix, viewport, &objX, &objY, &objZ);  
16     g_bgVertices[0].x = objX;  
17     g_bgVertices[0].y = objY;  
18     g_bgVertices[0].z = objZ;  
19   
20     gluUnProject(g_fWidth, 0, winZ, modelMatrix, projMatrix, viewport, &objX, &objY, &objZ);  
21     g_bgVertices[1].x = objX;  
22     g_bgVertices[1].y = objY;  
23     g_bgVertices[1].z = objZ;  
24   
25     gluUnProject(g_fWidth, g_fHeight, winZ, modelMatrix, projMatrix, viewport, &objX, &objY, &objZ);  
26     g_bgVertices[2].x = objX;  
27     g_bgVertices[2].y = objY;  
28     g_bgVertices[2].z = objZ;  
29   
30     gluUnProject(0, g_fHeight, winZ, modelMatrix, projMatrix, viewport, &objX, &objY, &objZ);  
31     g_bgVertices[3].x = objX;  
32     g_bgVertices[3].y = objY;  
33     g_bgVertices[3].z = objZ;  
34 }