OpenGL关于glEnable(GL_LINE_STIPPLE) glLineStipple() glLineWidth() glDisable()的实例

最新推荐文章于 2023-12-21 23:15:19 发布

原创最新推荐文章于 2023-12-21 23:15:19 发布 · 6.4k 阅读

3 ·

CC 4.0 BY-SA版权

文章标签：

#OpenGL #宏定义#define

做个笔记同时被 2 个专栏收录

28 篇文章

订阅专栏

OpenGL

11 篇文章

订阅专栏

本文详细介绍了如何利用OpenGL技术实现图像处理和AR特效的开发过程，包括使用OpenGL ES滤镜、美颜直播特效、视频剪辑、OpenCV图像处理等，通过实例演示了人脸标定AR、人像分割抠像、人体姿态估计等高级功能。

#include <GL/glut.h>
#include <stdlib.h>

#define drawOneLine(x1,y1,x2,y2) glBegin(GL_LINES); \
glVertex2f((x1), (y1)); glVertex2f((x2), (y2)); glEnd();
/*“\”的作用是把一行的内容当做两行来处理*/

void init(void)
{
glClearColor(0.0, 0.0, 0.0, 0.0);
glShadeModel(GL_FLAT);
/* GL_SMOOTH采用的顶点颜色渐变颜色着色
* GLFLAT只用定点颜色着色*/
}

void display(void)
{
int i;

glClear(GL_COLOR_BUFFER_BIT);

/* select white for all lines */
glColor3f(1.0, 1.0, 1.0);

/* in 1st row, 3 lines, each with a different stipple */
glEnable(GL_LINE_STIPPLE); /*执行后，画虚线*/

glLineStipple(1, 0x0101); /* 此时模式为Ox3F07（二进制形式为0000000100000001），它所画出来的直线是这样的：
* 先连续绘制1个像素，然后连续7个像素留空，再连续绘制1个像素，最后7个像素留空
* （注意，首先是从低位开始的）。 */
drawOneLine(50.0, 125.0, 150.0, 125.0);
glLineStipple(1, 0x00FF); /* dashed */
drawOneLine(150.0, 125.0, 250.0, 125.0);
glLineStipple(1, 0x1C47); /* dash/dot/dash */
drawOneLine(250.0, 125.0, 350.0, 125.0);

/* in 2nd row, 3 wide lines, each with different stipple */
glLineWidth(5.0); /* 像素的宽度 */
glLineStipple(1, 0x0101); /* dotted */
drawOneLine(50.0, 100.0, 150.0, 100.0);
glLineStipple(1, 0x00FF); /* dashed */
drawOneLine(150.0, 100.0, 250.0, 100.0);
glLineStipple(1, 0x1C47); /* dash/dot/dash */
drawOneLine(250.0, 100.0, 350.0, 100.0);
glLineWidth(1.0);

/* in 3rd row, 6 lines, with dash/dot/dash stipple */
/* as part of a single connected line strip */
glLineStipple(1, 0x1C47); /* dash/dot/dash */
glBegin(GL_LINE_STRIP);
for (i = 0; i < 7; i++)
glVertex2f(50.0 + ((GLfloat)i * 50.0), 75.0);
glEnd();

/* in 4th row, 6 independent lines with same stipple */
for (i = 0; i < 6; i++) {
drawOneLine(50.0 + ((GLfloat)i * 50.0), 50.0,
50.0 + ((GLfloat)(i + 1) * 50.0), 50.0);
}

/* in 5th row, 1 line, with dash/dot/dash stipple */
/* and a stipple repeat factor of 5 */
glLineStipple(5, 0x1C47); /* dash/dot/dash */
drawOneLine(50.0, 25.0, 350.0, 25.0);

glDisable(GL_LINE_STIPPLE); /*与glEnable参数一致*/
glFlush();
}

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);
}

void keyboard(unsigned char key, int x, int y)
{
switch (key) {
case 27:
exit(0);
break;
}
}

int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize(400, 150);
glutInitWindowPosition(100, 100);
glutCreateWindow(argv[0]);
init();
glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutKeyboardFunc(keyboard);
glutMainLoop();
return 0;
}