06-OpenGL字体显示

OpenGL 字体显示

在OpenGL中，提供了预定义的字库，可以满足一般的需求，用户也可以自定义字库，OpenGL红宝书中有自定义字库的详细过程。OpenGL预定义字库中提供了位图字符和矢量字符两种显示方式

V oid glutBitmapCharacter(void *font,int character); //位图字符

其中font是GLUT常量，指定点阵字库，如:

GLUT_BITMAP_8_BY_13,GLUT_BITMAP_9_BY_15,

V oid glutStrokeCharacter(void *font,int character); //矢量字符

Font 的取值有glut_stroke_roman 等间距Roman Simplex 字体，glut_stroke_mono_roman 单一间距Roman Simplex 字体。

本例演示了矢量字符的两种间距以及24磅位图字符的显示。

显示效果：

代码：

#include

#include

#include

int width = 200,height = 100;

void init(){

glClearColor(0,0,0,0);

}

void Reshape(int w,int h){

width=w;

height=h;

glViewport(0,0,w,h);

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

gluOrtho2D(0.0,width,0.0,height);

}

void display(){

glClear(GL_COLOR_BUFFER_BIT);

glColor3f(1.0f,1.0f,0.0f);

glLineWidth(2.0); //设置笔画的大小

glTranslatef(0,250,0); //设置字符显示的位置，否则贴底显示不能完全显示部分字符

glutStrokeCharacter(GLUT_STROKE_ROMAN,79); //输出字体为

GLUT_STROKE_ROMAN的OpenGL，从大写O开始，ASSCI码为79

glutStrokeCharacter(GLUT_STROKE_ROMAN,112);

glutStrokeCharacter(GLUT_STROKE_ROMAN,101);

glutStrokeCharacter(GLUT_STROKE_ROMAN,110);

glutStrokeCharacter(GLUT_STROKE_ROMAN,71);

glutStrokeCharacter(GLUT_STROKE_ROMAN,76);

glTranslatef(-460,-150,0); //调整下一行显示的位置

glutStrokeCharacter(GLUT_STROKE_MONO_ROMAN,79); //输出字体为

GLUT_STROKE_MONO_ROMAN的OpenGL，从大写O开始，ASSCI码为79 glutStrokeCharacter(GLUT_STROKE_MONO_ROMAN,112);

glutStrokeCharacter(GLUT_STROKE_MONO_ROMAN,101);

glutStrokeCharacter(GLUT_STROKE_MONO_ROMAN,110);

glutStrokeCharacter(GLUT_STROKE_MONO_ROMAN,71);

glutStrokeCharacter(GLUT_STROKE_MONO_ROMAN,76);

glutBitmapCharacter(GLUT_BITMAP_TIMES_ROMAN_24,'O'); //显示24磅的times Roman 点阵字体

glutBitmapCharacter(GLUT_BITMAP_TIMES_ROMAN_24,'p');

glutBitmapCharacter(GLUT_BITMAP_TIMES_ROMAN_24,'e');

glutBitmapCharacter(GLUT_BITMAP_TIMES_ROMAN_24,'n');

glutBitmapCharacter(GLUT_BITMAP_TIMES_ROMAN_24,'G');

glutBitmapCharacter(GLUT_BITMAP_TIMES_ROMAN_24,'L');

glutSwapBuffers();

}

int main(int argc, char* argv[])

{

glutInit(&argc,argv);

glutInitDisplayMode( GLUT_DOUBLE | GLUT_RGB );

glutInitWindowSize( 650, 400 );

glutInitWindowPosition( 100,100 );

glutCreateWindow("show OpenGL"); //′°?ú???a"rectangle"

init();

glutDisplayFunc(display);

glutReshapeFunc(Reshape);

glutMainLoop();

return 0;

}