用OpenGL显示bmp图片

要先掌握bmp文件的存储格式，读取图像信息后用 $glDrawPixels()$ 函数绘制。

直接上代码。

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#include <windows.h> #ifdef __APPLE__ #include <GLUT/glut.h> #else #include <GL/glut.h> #endif #include <bits/stdc++.h> #include <stdlib.h> using namespace std; const double PI = acos(-1.0); void init(){ glClearColor(0.0, 0.0, 0.0, 0.0); glColor3f(1.0, 1.0, 1.0); glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluOrtho2D(-1.0, 1.0, -1.0, 1.0); } #define GL_BGR_EXT 0x80E0 static GLint imagewidth; static GLint imageheight; static GLint pixellength; static GLubyte* pixeldata; void display(){ glClear(GL_COLOR_BUFFER_BIT); glDrawPixels(imagewidth, imageheight, GL_BGR_EXT, GL_UNSIGNED_BYTE, pixeldata); //绘制像素 glFlush(); glutSwapBuffers(); } int main(int argc, char **argv){ FILE* pfile=fopen("D:\img\2.bmp","rb"); //打开文件 if(pfile == 0) exit(0); fseek(pfile, 0x0012, SEEK_SET); //读取图像大小 fread(&imagewidth,sizeof(imagewidth),1,pfile); fread(&imageheight,sizeof(imageheight),1,pfile); //cout << imagewidth << "***" << imageheight << endl; pixellength = imagewidth*3; //计算像素数据长度 while(pixellength%4 != 0) pixellength++; pixellength *= imageheight; pixeldata = (GLubyte*)malloc(pixellength); //读取像素数据 if(pixeldata == 0) exit(0); fseek(pfile, 54, SEEK_SET); fread(pixeldata, pixellength, 1, pfile); fclose(pfile); //关闭文件 glutInit(&argc, argv); glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB); glutInitWindowSize(imagewidth, imageheight); glutInitWindowPosition(0, 0); glutCreateWindow("用OpenGL显示bmp图片"); glutDisplayFunc(display); init(); glutMainLoop(); free(pixeldata); }