DDA.rar_openGL dda

#include <GL/glut.h> #include <cstdlib> void LineDDA(int x0,int y0,int x1,int y1/*,int color*/) { int k,i; float x,y,dx,dy; if (abs(x1-x0) >= abs(y1-y0)) k=abs(x1-x0); else k=abs(y1-y0); dx=float (x1-x0)/k; dy=float (y1-y0)/k; x=float(x0); y=float(y0); glColor3f (1.0f, 1.0f, 0.0f); //黄 用DDA算法画的线是黄线 glPointSize(1); for(i=0;i<k; i++) { glBegin (GL_POINTS); glVertex2i ((int)(x+0.5),(int)(y+0.5)); glEnd (); x+=dx; y+=dy; } } void myDisplay(void) { glClear(GL_COLOR_BUFFER_BIT); glColor3f (1.0f, 0.0f, 0.0f); glRectf(25.0, 25.0, 75.0, 75.0); glPointSize(5); glBegin (GL_POINTS); glColor3f (0.0f, 1.0f, 0.0f); glVertex2f (0.0f, 0.0f); glEnd (); LineDDA(0, 0, 00, 300); glBegin (GL_LINES); glColor3f (1.0f, 0.0f, 0.0f); glVertex2f (100.0f, 0.0f); glColor3f (0.0f, 1.0f, 0.0f); glVertex2f (180.0f, 240.0f); glEnd (); glFlush(); } void Init() { glClearColor(0.0, 0.0, 0.0, 0.0); glShadeModel(GL_FLAT); } void Reshape(int w, int h) { glViewport(0, 0, (GLsizei) w, (GLsizei) h); glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluOrtho2D(0.0, (GLdouble) w, 0.0, (GLdouble) h); } int main(int argc, char *argv[]) { glutInit(&argc, argv); glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE); glutInitWindowPosition(100, 100); glutInitWindowSize(400, 400); glutCreateWindow("Hello World!"); Init(); glutDisplayFunc(myDisplay); glutReshapeFunc(Reshape); glutMainLoop(); return 0; }