更新时间:2023-11-15 14:11:40
稍微移动坐标系,使线条落在像素中心:
Shift your coordinate frame a bit so your lines fall on pixel centers:
#include <GL/glut.h>
void display()
{
glClear( GL_COLOR_BUFFER_BIT );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
double w = glutGet( GLUT_WINDOW_WIDTH );
double h = glutGet( GLUT_WINDOW_HEIGHT );
glOrtho( 0, w, 0, h, -1, 1);
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
// important
glTranslatef( 0.5, 0.5, 0 );
float offset = 40;
glColor3ub( 255, 0, 0 );
glBegin(GL_LINE_LOOP);
glVertex2f( 0+offset, 0+offset );
glVertex2f( 0+offset, h-offset );
glVertex2f( w-offset, h-offset );
glVertex2f( w-offset, 0+offset );
glEnd();
glutSwapBuffers();
}
int main( int argc, char **argv )
{
glutInit( &argc, argv );
glutInitDisplayMode( GLUT_RGBA | GLUT_DOUBLE );
glutInitWindowSize( 320,240 );
glutCreateWindow( "Rect" );
glutDisplayFunc( display );
glutMainLoop();
return 0;
}