OpenGL对像素图像的一些操作 
  1 #define GLUT_DISABLE_ATEXIT_HACK
  2 #include <stdio.h>
  3 #include <gl/glut.h>
  4 #include <gl/glaux.h>
  5 #pragma comment(lib,"glaux.lib")
  6 
  7 
  8 AUX_RGBImageRec* Image;
  9 GLint iWidth,iHeight,iMode=1;
 10 GLubyte* pImage;
 11 
 12 void Initialization(void);
 13 void MenuCreate(void);
 14 void OnDisplay(void);
 15 void OnReshape(int,int);
 16 void OnMenu(int);
 17 
 18 void main(int argc,char* argv[])
 19 {
 20     glutInit(&argc,argv);
 21     glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB|GLUT_DEPTH);
 22     glutInitWindowSize(400,400);
 23     glutCreateWindow("EXAM703");
 24 
 25     glutCreateMenu(OnMenu);
 26     glutDisplayFunc(OnDisplay);
 27     glutReshapeFunc(OnReshape);
 28     
 29     Initialization();
 30     glutMainLoop();
 31 }
 32 
 33 void Initialization(void)
 34 {
 35     glClearColor(0,0,0,1);
 36 
 37     MenuCreate();
 38 
 39     glPixelStorei(GL_UNPACK_ALIGNMENT,1);
 40     Image=auxDIBImageLoad("11.bmp");
 41     iWidth=Image->sizeX;
 42     iHeight=Image->sizeY;
 43     pImage=Image->data;
 44 }
 45 
 46 void OnDisplay(void)
 47 {
 48     glClear(GL_COLOR_BUFFER_BIT);
 49 
 50     GLbyte *pModified=NULL;
 51     GLfloat invert[256];
 52     GLint i;
 53 
 54     glRasterPos2i(0,0);
 55 
 56     switch(iMode){
 57     case 2:
 58         glPixelZoom(-1.0f,-1.0f);
 59         glRasterPos2i(iWidth-1,iHeight-1);
 60         break;
 61 
 62     case 3:
 63         glPixelZoom(0.5f,0.5f);
 64         break;
 65 
 66     case 4:
 67         glPixelTransferf(GL_RED_SCALE,1.0f);
 68         glPixelTransferf(GL_GREEN_SCALE,0.0f);
 69         glPixelTransferf(GL_BLUE_SCALE,0.0f);
 70         break;
 71 
 72     case 5:
 73         glPixelTransferf(GL_RED_SCALE,0.0f);
 74         glPixelTransferf(GL_GREEN_SCALE,1.0f);
 75         glPixelTransferf(GL_BLUE_SCALE,0.0f);
 76         break;
 77 
 78     case 6:
 79         glPixelTransferf(GL_RED_SCALE,0.0f);
 80         glPixelTransferf(GL_GREEN_SCALE,0.0f);
 81         glPixelTransferf(GL_BLUE_SCALE,1.0f);
 82         break;
 83 
 84     case 7:
 85         glDrawPixels(iWidth,iHeight,GL_RGB,GL_UNSIGNED_BYTE,pImage);
 86         pModified=(GLbyte*)new GLbyte[iWidth*iHeight];
 87         
 88         glPixelTransferf(GL_RED_SCALE,0.3f);
 89         glPixelTransferf(GL_GREEN_SCALE,0.59f);
 90         glPixelTransferf(GL_BLUE_BITS,0.11f);
 91 
 92         glReadPixels(0,0,iWidth,iHeight,GL_LUMINANCE,GL_UNSIGNED_BYTE,pModified);
 93         glPixelTransferf(GL_RED_SCALE,1.0f);
 94         glPixelTransferf(GL_GREEN_SCALE,1.0f);
 95         glPixelTransferf(GL_BLUE_SCALE,1.0f);
 96         break;
 97 
 98     case 8:
 99         invert[0]=1.0f;
100         for(i=1;i<256;i++)
101             invert[i]=1.0f-(1.0f/255.0f*GLfloat(i));
102 
103         glPixelMapfv(GL_PIXEL_MAP_R_TO_R,255,invert);
104         glPixelMapfv(GL_PIXEL_MAP_G_TO_G,255,invert);
105         glPixelMapfv(GL_PIXEL_MAP_B_TO_B,255,invert);
106         glPixelTransferf(GL_MAP_COLOR,GL_TRUE);
107         break;
108 
109     case 1:
110     default:
111         break;
112 
113     }
114 
115     if(pModified==NULL)
116         glDrawPixels(iWidth,iHeight,GL_RGB,GL_UNSIGNED_BYTE,pImage);
117     else{
118         glDrawPixels(iWidth,iHeight,GL_LUMINANCE,GL_UNSIGNED_BYTE,pModified);
119         delete []pModified;
120     }
121 
122     glPixelTransferi(GL_MAP_COLOR,GL_FALSE);
123     glPixelTransferf(GL_RED_SCALE,1.0f);
124     glPixelTransferf(GL_GREEN_SCALE,1.0f);
125     glPixelTransferf(GL_BLUE_SCALE,1.0f);
126     glPixelZoom(1.0f,1.0f);
127 
128     glutSwapBuffers();
129 }
130 
131 void OnReshape(int w,int h)
132 {
133     GLfloat aspectRatio=(GLfloat)w/(GLfloat)h;//计算窗口的纵横比
134     GLfloat winWidth,winHeight;
135     
136     
137     glViewport(0,0,w,h);
138     
139     
140     glMatrixMode(GL_PROJECTION);
141     glLoadIdentity();
142     
143     
144     if(w<=h){                               //根据纵横比计算绘图区域的宽和高
145         winWidth=400;
146         winHeight=400*aspectRatio;
147     }
148     else{
149         winWidth=400*aspectRatio;
150         winHeight=400;
151     }
152     gluOrtho2D(0,winWidth,0,winHeight);
153     
154     
155     glMatrixMode(GL_MODELVIEW);
156     glLoadIdentity();
157 
158 }
159 
160 void OnMenu(int value)
161 {
162     iMode=value;
163     
164     glutPostRedisplay();
165 }
166 
167 void MenuCreate(void)
168 {
169     glutAddMenuEntry("正常显示",1);
170     glutAddMenuEntry("翻转图像",2);
171     glutAddMenuEntry("缩小图像",3);
172     glutAddMenuEntry("红色通道",4);
173     glutAddMenuEntry("绿色通道",5);
174     glutAddMenuEntry("蓝色通道",6);
175     glutAddMenuEntry("灰度图",7);
176     glutAddMenuEntry("反转颜色",8);
177 
178     glutAttachMenu(GLUT_RIGHT_BUTTON);
179 
180 }
 posted on 2012-04-30 10:03  xiacl  阅读(697)  评论(0)  编辑  收藏  举报