Program 2: Write a program to draw objects using Line-Attribute, Fill-Area Attribute, Color functions of OpenGL.

PROGRAM 2: (Line, fill, color attributes)

1.      Header File : same as the previous prog. link: http://simplifiedopengl.blogspot.in/2016/08/simplified-output-primitive-function.html

2.      Display Function

//LINE ATTRIBUTES: line colour, stipple, width.

    GLint factor=1;

    GLushort pattern=0x00ff;

    glEnable(GL_LINE_STIPPLE);

    glLineStipple(factor,pattern);

//then create the object.

glDisable(GL_LINE_STIPPLE);

//COLOR FUNCTION: gradient color and solid color.

Gradient: Give, glColor3f(0.0,0.0,1.0); before every vertex;

Solid: glColor3f(0.0,0.0,1.0); before the object creation.

//POLYGON FILL

//declare: GLubyte mask[128]; outside the display function

GLubyte Lines[] = {

    0x00, 0x00, 0x00, 0x00,

    0xff, 0xff, 0xff, 0xff,

    };

    glEnable(GL_POLYGON_STIPPLE);

     glPolygonStipple(Lines);

//draw polygon

    glDisable(GL_POLYGON_STIPPLE);

3.      Main function same as the firs program.

SAMPLE: PROGRAM 2

//header file: windows and glut

GLubyte mask[128];

void display()

{

    glClearColor(0.0,0.0,0.0,0.0);

    glClear(GL_COLOR_BUFFER_BIT);

    //LINE ATRRIBUTES:

    GLint factor=1;

    GLushort pattern=0x00ff;

    glEnable(GL_LINE_STIPPLE);

    glLineStipple(factor,pattern);

    glColor3f(1.0,1.0,1.0); //solid line color

    glBegin(GL_LINES);

    glVertex2f(0.0,0.0);

    glVertex2f(0.40,0.0);

    glLineWidth(10.0f);// line attribute

    glEnd();

    glDisable(GL_LINE_STIPPLE);

    //COLOR FUNCTION: gradient

    glBegin(GL_LINES);

    glColor3f(0.0,0.0,1.0); //blue

    glVertex2f(0.0,0.10);

    glColor3f(1.0,1.0,0.0);//yellow

    glVertex2f(0.40,0.10);

    glEnd();

    //Fill area:POLYGON FILL

    GLubyte Lines[] = {

    0x00, 0x00, 0x00, 0x00,

    0xff, 0xff, 0xff, 0xff,

    };

    glEnable(GL_POLYGON_STIPPLE);

     glPolygonStipple(Lines);

    glColor4f(1.0f, 0.0f, 0.0f, 0.0f);//red

    glBegin(GL_POLYGON);

    glVertex2f(-0.44,0.45);

    glVertex2f(-0.57,0.45);

    glVertex2f(-0.65,0.10);

    glVertex2f(-0.90,-0.60);

    glVertex2f(-0.10,-0.60);

    glEnd();

    glDisable(GL_POLYGON_STIPPLE);

    glFlush();

}

int main(int argc,char** argv)

{

    glutInit(&argc, argv);

    glutCreateWindow("Prog");

    glutInitWindowSize(320,320);

    glutDisplayFunc(display);

    glutMainLoop();

    return 0;

}