Category Archives: OpenGL

Midpoint algo reference: http://www.eazynotes.com/notes/computer-graphics/algorithms/mid-point-circle-algorithm.pdf
http://suraj1693.blogspot.com/2013/11/c-program-for-drawing-circle-using.html
https://birunthag.blogspot.com/2014/05/openglc-draw-circle-with-midpoint.html
https://www.opengl.org/discussion_boards/showthread.php/169955-using-glutKeyboardFunc

Code:

#include <windows.h>
#include <GL\glut.h>
#include <stdlib.h>
#include<iostream>
#include<stdio.h>
using namespace std;

int r,p,flags=0;

void myInit (void)

{

    glClearColor(0.0,0.0,0.0,0.0); // sets background color to white

    // sets a point to be 4x4 pixels

    glMatrixMode(GL_PROJECTION);

    glLoadIdentity();

    gluOrtho2D(0.0, 500.0, 0.0, 400.0); // the display area in world coordinates.

}
void midpoint()
{
    r=20;
    p=1-r;
    int xk=0;
    int yk=r;
    int xc=200;
    int yc=200;
    while(xk<=yk)
    {
        if(p<0)
        {
            xk++;
            p=p+2*xk+3;
        }
        else if(p>0)
        {
            xk++;
            yk=yk-1;
            p=p+2*xk-2*yk+5;
        }
        glVertex2i(xc+xk,yc+yk);
        glVertex2i(xc-xk,yc+yk);
        glVertex2i(xc+xk,yc-yk);
        glVertex2i(xc-xk,yc-yk);
        glVertex2i(xc+yk,yc+xk);
        glVertex2i(xc-yk,yc+xk);
        glVertex2i(xc+yk,yc-xk);
        glVertex2i(xc-yk,yc-xk);
    }

}

void processKey(unsigned char key, int x, int y)
{
	switch(key){
		case '1':
			flags=1;
			printf("Hello world!");
			break;

		//default:
        // break;
	}
}

void myDisplay(void)
{
    //int nol = rand() % 100;

    glClear(GL_COLOR_BUFFER_BIT); // clears the screen
    // setsthe drawing colour

    glPointSize(4.0);

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

    glVertex2i(0,200);
    glVertex2i(500,200);

    glVertex2i(255,0);
    glVertex2i(255,500);

    glEnd();


glBegin(GL_POINTS);
//midpoint();
if(flags==1){
    midpoint();
}

glEnd();


    glFlush(); // sends all output to display;

}


int main (int argc, char **argv)
{

//scanf("%d,%d,&d,&d",&x,&y,&a,&b);
    glutInit (&argc, argv); // to initialize the toolkit;

    glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB); // sets the display mode

    glutInitWindowSize (640, 480); // sets the window size

    glutInitWindowPosition (10, 10); // sets the starting position for the window

    glutCreateWindow ("My first OpenGL program!"); // creates the window and sets the title
    glutKeyboardFunc(processKey);
    glutDisplayFunc (myDisplay);
    myInit(); // additional initializations as necessary

    glutMainLoop(); // go into a loop until event occurs
    return 0;
}

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

#include <windows.h>

#include <GL\glut.h>

#include <stdlib.h>

#include<iostream>

#include<stdio.h>

using namespace std;

int r,p,flags=0;

void myInit (void)

{

glClearColor(0.0,0.0,0.0,0.0); // sets background color to white

// sets a point to be 4x4 pixels

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

gluOrtho2D(0.0, 500.0, 0.0, 400.0); // the display area in world coordinates.

}

void midpoint()

{

r=20;

p=1-r;

int xk=0;

int yk=r;

int xc=200;

int yc=200;

while(xk<=yk)

{

if(p<0)

{

xk++;

p=p+2*xk+3;

}

else if(p>0)

{

xk++;

yk=yk-1;

p=p+2*xk-2*yk+5;

}

glVertex2i(xc+xk,yc+yk);

glVertex2i(xc-xk,yc+yk);

glVertex2i(xc+xk,yc-yk);

glVertex2i(xc-xk,yc-yk);

glVertex2i(xc+yk,yc+xk);

glVertex2i(xc-yk,yc+xk);

glVertex2i(xc+yk,yc-xk);

glVertex2i(xc-yk,yc-xk);

}

void processKey(unsigned char key, int x, int y)

{

switch(key){

case '1':

flags=1;

printf("Hello world!");

break;

//default:

// break;

}

void myDisplay(void)

{

//int nol = rand() % 100;

glClear(GL_COLOR_BUFFER_BIT); // clears the screen

// setsthe drawing colour

glPointSize(4.0);

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

glBegin(GL_LINES);

glVertex2i(0,200);

glVertex2i(500,200);

glVertex2i(255,0);

glVertex2i(255,500);

glEnd();

glBegin(GL_POINTS);

//midpoint();

if(flags==1){

midpoint();

}

glEnd();

glFlush(); // sends all output to display;

}

int main (int argc, char **argv)

{

//scanf("%d,%d,&d,&d",&x,&y,&a,&b);

glutInit (&argc, argv); // to initialize the toolkit;

glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB); // sets the display mode

glutInitWindowSize (640, 480); // sets the window size

glutInitWindowPosition (10, 10); // sets the starting position for the window

glutCreateWindow ("My first OpenGL program!"); // creates the window and sets the title

glutKeyboardFunc(processKey);

glutDisplayFunc (myDisplay);

myInit(); // additional initializations as necessary

glutMainLoop(); // go into a loop until event occurs

return 0;

}

Leave a comment

Posted in A ll Codes, Geometry, Graphics, Midpoint Circle, OpenGL

Tagged KeyboardFunc, Midpoint Circle Algorithm, OpenGL

Draw Brasenham Line Drawing Algorithms with Random Lines and Colors

Posted on July 17, 2016 | Leave a comment

Code:

#include <windows.h>
#include <GL\glut.h>
#include <stdlib.h>
#include<iostream>
using namespace std;

int x, y, a, b, nol, R, G, B;

void myInit (void)

{

    glClearColor(0.0,0.0,0.0,0.0); // sets background color to white

    // sets a point to be 4x4 pixels

    glMatrixMode(GL_PROJECTION);

    glLoadIdentity();

    gluOrtho2D(0.0, 500.0, 0.0, 400.0); // the display area in world coordinates.

}
void brasenham(int x1, int y1, int x2, int y2)
{

    int dx = x2-x1;
    int dy = y2-y1;
    int p = (2*dy)-dx;
    for(int i =0; i < dx; i++)
    {
        if(p < 0)
        {
            x1++;
            glVertex2i(x1, y1);
            p = p+(2*dy);

        }
        else if(p>0)
        {
            x1++;
            y1++;
            glVertex2i(x1, y1);
            p = p+(2*dy)-(2*dx);

        }


    }

}

void myDisplay(void)

{
    int nol = rand() % 100;

     glClear(GL_COLOR_BUFFER_BIT); // clears the screen
    // setsthe drawing colour

     glPointSize(4.0);

    for(int i = 0; i<nol; i++){
        int x = rand() % 750;
        int y = rand() % 850;
        int a = rand() % 950;
        int b = rand() % 680;
        int R = rand() % 255;
        int G = rand() % 255;
        int B = rand() % 255;
        glColor3ub(R, G, B) ;
     glBegin(GL_POINTS);
        brasenham(x, y, a, b);
     glEnd();
    }


     glFlush(); // sends all output to display;

}


int main (int argc, char **argv)
{

//scanf("%d,%d,&d,&d",&x,&y,&a,&b);



    glutInit (&argc, argv); // to initialize the toolkit;

    glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB); // sets the display mode

    glutInitWindowSize (640, 480); // sets the window size

    glutInitWindowPosition (10, 10); // sets the starting position for the window

    glutCreateWindow ("My first OpenGL program!"); // creates the window and sets the title

    glutDisplayFunc (myDisplay);
    myInit(); // additional initializations as necessary

    glutMainLoop(); // go into a loop until event occurs
    return 0;
}

100

101

102

103

104

105

#include <windows.h>

#include <GL\glut.h>

#include <stdlib.h>

#include<iostream>

using namespace std;

int x, y, a, b, nol, R, G, B;

void myInit (void)

{

glClearColor(0.0,0.0,0.0,0.0); // sets background color to white

// sets a point to be 4x4 pixels

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

gluOrtho2D(0.0, 500.0, 0.0, 400.0); // the display area in world coordinates.

}

void brasenham(int x1, int y1, int x2, int y2)

{

int dx = x2-x1;

int dy = y2-y1;

int p = (2*dy)-dx;

for(int i =0; i < dx; i++)

{

if(p < 0)

{

x1++;

glVertex2i(x1, y1);

p = p+(2*dy);

}

else if(p>0)

{

x1++;

y1++;

glVertex2i(x1, y1);

p = p+(2*dy)-(2*dx);

}

void myDisplay(void)

{

int nol = rand() % 100;

glClear(GL_COLOR_BUFFER_BIT); // clears the screen

// setsthe drawing colour

glPointSize(4.0);

for(int i = 0; i<nol; i++){

int x = rand() % 750;

int y = rand() % 850;

int a = rand() % 950;

int b = rand() % 680;

int R = rand() % 255;

int G = rand() % 255;

int B = rand() % 255;

glColor3ub(R, G, B) ;

glBegin(GL_POINTS);

brasenham(x, y, a, b);

glEnd();

}

glFlush(); // sends all output to display;

}

int main (int argc, char **argv)

{

//scanf("%d,%d,&d,&d",&x,&y,&a,&b);

glutInit (&argc, argv); // to initialize the toolkit;

glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB); // sets the display mode

glutInitWindowSize (640, 480); // sets the window size

glutInitWindowPosition (10, 10); // sets the starting position for the window

glutCreateWindow ("My first OpenGL program!"); // creates the window and sets the title

glutDisplayFunc (myDisplay);

myInit(); // additional initializations as necessary

glutMainLoop(); // go into a loop until event occurs

return 0;

}

Leave a comment

Posted in A ll Codes, Brasenham Line Drawing, Graphics, OpenGL

Tagged Brasenham line drawing algorithm

Star Drawing with OpenGL

Posted on July 17, 2016 | Leave a comment

Draw 4 stars in screen with OpenGL
Screenshot:

Code:

#include <windows.h>
#include <GL\glut.h>

void myInit (void)

{

    glClearColor(0.0,0.0,0.0,0.0); // sets background color to white

    // sets a point to be 4x4 pixels

    glMatrixMode(GL_PROJECTION);

    glLoadIdentity();

    gluOrtho2D(0.0, 500.0, 0.0, 400.0); // the display area in world coordinates.

}


void myDisplay(void)

{

    glClear(GL_COLOR_BUFFER_BIT); // clears the screen
    ;// setsthe drawing colour

    glPointSize(4.0);

//Axis
    glColor3f(1.0f,0.0f,1.0f) ;
    glBegin(GL_LINES);
    glVertex2i(255,0);
    glVertex2i(255,500);

    glVertex2i(0,200);
    glVertex2i(500,200);

    glEnd();

    glColor3f(1.0f,0.0f,0.0f);
//
    glColor3f(1.0f,1.0f,0.0f) ;
    glBegin(GL_POLYGON);
//bottom

    glVertex2i (40,50);
    glVertex2i (60,50);
//left
    glVertex2i (40,50);
    glVertex2i (40,80);
//top
    glVertex2i (40,80);
    glVertex2i (60,80);
//right
    glVertex2i (60,50);
    glVertex2i (60,80);

    glEnd();
//BOTTOM TRIANGLE
    glColor3f(1.0f,0.0f,0.0f) ;
    glBegin(GL_POLYGON);
//bottom

    glVertex2i (40,50);
    glVertex2i (60,50);
//left
    glVertex2i (40,50);
    glVertex2i (50,30);

//RIGHT
    glVertex2i (60,50);
    glVertex2i (50,30);

    glEnd();

//RIGHT TRIANGLE
    glColor3f(1.0f,0.0f,0.0f) ;
    glBegin(GL_POLYGON);
//bottom

    glVertex2i (60,50);
    glVertex2i (60,80);

    glVertex2i (60,50);
    glVertex2i (70,60);

    glVertex2i (60,80);
    glVertex2i (70,60);

    glEnd();

//left triangle
    glColor3f(1.0f,0.0f,0.0f) ;
    glBegin(GL_POLYGON);

    glVertex2i (40,50);
    glVertex2i (40,80);

    glVertex2i (40,50);
    glVertex2i (30,64);

    glVertex2i (40,80);
    glVertex2i (30,62);

    glEnd();


//Top triangle
    glColor3f(1.0f,0.0f,0.0f) ;
    glBegin(GL_POLYGON);

    glVertex2i (40,80);
    glVertex2i (60,80);

    glVertex2i (40,80);
    glVertex2i (50,90);

    glVertex2i (60,80);
    glVertex2i (50,90);


    glEnd();

    glColor3f(1.0f, 0.0f, 0.0f);
    glRectf(120,120, 100, 100);


    glColor3f(1.0f,1.0f,0.0f) ;
    glBegin(GL_POLYGON);
//RIGHT

    glVertex2i (120,120);
    glVertex2i (120,100);

    glVertex2i (120,120);
    glVertex2i (150,110);

    glVertex2i (120,100);
    glVertex2i (150,110);
    glEnd();

    glBegin(GL_LINES);
    //RIGHT
    glVertex2i (120,120);
    glVertex2i (120,100);

    glVertex2i (120,120);
    glVertex2i (150,110);

    glVertex2i (120,100);
    glVertex2i (150,110);
    glEnd();

    //left
    glBegin(GL_POLYGON);
    glVertex2i (100,120);
    glVertex2i (62,107);

    glVertex2i (100,100);
    glVertex2i (62,107);
    glEnd();


    glColor3f(0.0f,0.0f,1.0f) ;
    glBegin(GL_POLYGON);
    glVertex2i (100,120);
    glVertex2i (110,130);

    glVertex2i(110,130);
    glVertex2i (120,120);
    glEnd();


    glColor3f(0.0f,0.0f,1.0f) ;
    glBegin(GL_POLYGON);
    glVertex2i (100,98);
    glVertex2i(110,70);

    glVertex2i (120,98);
    glVertex2i(110,70);


    glEnd();

glColor3f(1.0f,1.0f,1.0f);
glBegin(GL_POLYGON);
    glVertex2i (350,290);
    glVertex2i (350,315);

     glVertex2i (350,290);
     glVertex2i(370,290);

    glVertex2i (370,290);
    glVertex2i (370,315);

glVertex2i (350,315);
glVertex2i (370,315);


glEnd();

glColor3f(0.0f,0.0f,1.0f) ;
glBegin(GL_POLYGON);
glVertex2i (350,315);
glVertex2i (362,325);

glVertex2i (370,315);
glVertex2i (362,325);

glEnd();

//
glColor3f(0.0f,0.0f,1.0f) ;
glBegin(GL_POLYGON);
glVertex2i (370,290);
glVertex2i (385,305);

glVertex2i (370,315);
glVertex2i (385,305);

glEnd();


glColor3f(0.0f,0.0f,1.0f) ;
glBegin(GL_POLYGON);
 glVertex2i (350,290);
  glVertex2i (320,305);

  glVertex2i (350,315);
  glVertex2i (320,305);

glEnd();


glColor3f(0.0f,0.0f,1.0f) ;
glBegin(GL_POLYGON);
glVertex2i (350,290);
glVertex2i (362,270);

glVertex2i (370,290);
glVertex2i (362,270);

glEnd();

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

glVertex2i (70,275);
glVertex2i (70,290);

glVertex2i(70,290);
glVertex2i(85,290);

glVertex2i(85,290);
glVertex2i(85,275);

glVertex2i(85,275);
glVertex2i(70,275);

glEnd();

glColor3f(1.0f,1.0f,1.0f);
glBegin(GL_POLYGON);
glVertex2i(70,275);
glVertex2i(76,220);

glVertex2i(85,275);
glVertex2i(76,220);

glEnd();


glColor3f(1.0f,1.0f,1.0f);
glBegin(GL_POLYGON);

glVertex2i(85,275);
glVertex2i(120,280);

glVertex2i(85,290);
glVertex2i(120,280);
glEnd();


glColor3f(1.0f,1.0f,1.0f);
glBegin(GL_POLYGON);

glVertex2i(70,275);
glVertex2i(38,280);

glVertex2i(70,290);
glVertex2i(38,280);
glEnd();


glColor3f(1.0f,1.0f,1.0f);
glBegin(GL_POLYGON);
glVertex2i(70,290);
glVertex2i(76,335);


glVertex2i(85,290);
glVertex2i(76,335);
glEnd();

    glFlush(); // sends all output to display;

}
int main (int argc, char **argv)
{

    glutInit (&argc, argv); // to initialize the toolkit;

    glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB); // sets the display mode

    glutInitWindowSize (640, 480); // sets the window size

    glutInitWindowPosition (10, 10); // sets the starting position for the window

    glutCreateWindow ("My first OpenGL program!"); // creates the window and sets the title

    glutDisplayFunc (myDisplay);
    myInit(); // additional initializations as necessary
    glutMainLoop(); // go into a loop until event occurs
    return 0;
}

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

#include <windows.h>

#include <GL\glut.h>

void myInit (void)

{

glClearColor(0.0,0.0,0.0,0.0); // sets background color to white

// sets a point to be 4x4 pixels

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

gluOrtho2D(0.0, 500.0, 0.0, 400.0); // the display area in world coordinates.

}

void myDisplay(void)

{

glClear(GL_COLOR_BUFFER_BIT); // clears the screen

;// setsthe drawing colour

glPointSize(4.0);

//Axis

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

glBegin(GL_LINES);

glVertex2i(255,0);

glVertex2i(255,500);

glVertex2i(0,200);

glVertex2i(500,200);

glEnd();

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

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

glBegin(GL_POLYGON);

//bottom

glVertex2i (40,50);

glVertex2i (60,50);

//left

glVertex2i (40,50);

glVertex2i (40,80);

//top

glVertex2i (40,80);

glVertex2i (60,80);

//right

glVertex2i (60,50);

glVertex2i (60,80);

glEnd();

//BOTTOM TRIANGLE

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

glBegin(GL_POLYGON);

//bottom

glVertex2i (40,50);

glVertex2i (60,50);

//left

glVertex2i (40,50);

glVertex2i (50,30);

//RIGHT

glVertex2i (60,50);

glVertex2i (50,30);

glEnd();

//RIGHT TRIANGLE

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

glBegin(GL_POLYGON);

//bottom

glVertex2i (60,50);

glVertex2i (60,80);

glVertex2i (60,50);

glVertex2i (70,60);

glVertex2i (60,80);

glVertex2i (70,60);

glEnd();

//left triangle

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

glBegin(GL_POLYGON);

glVertex2i (40,50);

glVertex2i (40,80);

glVertex2i (40,50);

glVertex2i (30,64);

glVertex2i (40,80);

glVertex2i (30,62);

glEnd();

//Top triangle

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

glBegin(GL_POLYGON);

glVertex2i (40,80);

glVertex2i (60,80);

glVertex2i (40,80);

glVertex2i (50,90);

glVertex2i (60,80);

glVertex2i (50,90);

glEnd();

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

glRectf(120,120, 100, 100);

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

glBegin(GL_POLYGON);

//RIGHT

glVertex2i (120,120);

glVertex2i (120,100);

glVertex2i (120,120);

glVertex2i (150,110);

glVertex2i (120,100);

glVertex2i (150,110);

glEnd();

glBegin(GL_LINES);

//RIGHT

glVertex2i (120,120);

glVertex2i (120,100);

glVertex2i (120,120);

glVertex2i (150,110);

glVertex2i (120,100);

glVertex2i (150,110);

glEnd();

//left

glBegin(GL_POLYGON);

glVertex2i (100,120);

glVertex2i (62,107);

glVertex2i (100,100);

glVertex2i (62,107);

glEnd();

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

glBegin(GL_POLYGON);

glVertex2i (100,120);

glVertex2i (110,130);

glVertex2i(110,130);

glVertex2i (120,120);

glEnd();

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

glBegin(GL_POLYGON);

glVertex2i (100,98);

glVertex2i(110,70);

glVertex2i (120,98);

glVertex2i(110,70);

glEnd();

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

glBegin(GL_POLYGON);

glVertex2i (350,290);

glVertex2i (350,315);

glVertex2i (350,290);

glVertex2i(370,290);

glVertex2i (370,290);

glVertex2i (370,315);

glVertex2i (350,315);

glVertex2i (370,315);

glEnd();

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

glBegin(GL_POLYGON);

glVertex2i (350,315);

glVertex2i (362,325);

glVertex2i (370,315);

glVertex2i (362,325);

glEnd();

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

glBegin(GL_POLYGON);

glVertex2i (370,290);

glVertex2i (385,305);

glVertex2i (370,315);

glVertex2i (385,305);

glEnd();

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

glBegin(GL_POLYGON);

glVertex2i (350,290);

glVertex2i (320,305);

glVertex2i (350,315);

glVertex2i (320,305);

glEnd();

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

glBegin(GL_POLYGON);

glVertex2i (350,290);

glVertex2i (362,270);

glVertex2i (370,290);

glVertex2i (362,270);

glEnd();

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

glBegin(GL_POLYGON);

glVertex2i (70,275);

glVertex2i (70,290);

glVertex2i(70,290);

glVertex2i(85,290);

glVertex2i(85,275);

glVertex2i(70,275);

glEnd();

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

glBegin(GL_POLYGON);

glVertex2i(70,275);

glVertex2i(76,220);

glVertex2i(85,275);

glVertex2i(76,220);

glEnd();

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

glBegin(GL_POLYGON);

glVertex2i(85,275);

glVertex2i(120,280);

glVertex2i(85,290);

glVertex2i(120,280);

glEnd();

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

glBegin(GL_POLYGON);

glVertex2i(70,275);

glVertex2i(38,280);

glVertex2i(70,290);

glVertex2i(38,280);

glEnd();

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

glBegin(GL_POLYGON);

glVertex2i(70,290);

glVertex2i(76,335);

glVertex2i(85,290);

glVertex2i(76,335);

glEnd();

glFlush(); // sends all output to display;

}

int main (int argc, char **argv)

{

glutInit (&argc, argv); // to initialize the toolkit;

glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB); // sets the display mode

glutInitWindowSize (640, 480); // sets the window size

glutInitWindowPosition (10, 10); // sets the starting position for the window

glutCreateWindow ("My first OpenGL program!"); // creates the window and sets the title

glutDisplayFunc (myDisplay);

myInit(); // additional initializations as necessary

glutMainLoop(); // go into a loop until event occurs

return 0;

}

Leave a comment

Posted in A ll Codes, Graphics, OpenGL

Tagged Star Drawing

OpenGL Graphics Code: Build a house with GLUT

Posted on May 30, 2016 | Leave a comment

#include <windows.h>
#include <GL\glut.h>

void myInit (void)

{

     glClearColor(0.0,0.0,0.0,0.0); // sets background color to white

     // sets a point to be 4x4 pixels

     glMatrixMode(GL_PROJECTION);

     glLoadIdentity();

     gluOrtho2D(0.0, 500.0, 0.0, 400.0); // the display area in world coordinates.

}


void myDisplay(void)

{

     glClear(GL_COLOR_BUFFER_BIT); // clears the screen
    glColor3f(0.5f,0.5f,0.5f) ;// setsthe drawing colour

     glPointSize(4.0);

     glBegin(GL_POLYGON);
//bottom

          glVertex2i (20, 20);
          glVertex2i (320, 20);

          //top
          glVertex2i (20, 200);
          glVertex2i (320, 200);
        //left
          glVertex2i (20, 200);
          glVertex2i (20, 20);
        //right
          glVertex2i (320, 200);
          glVertex2i (320, 20);

          //glVertex2i (10, -50);

    glEnd();


//Left Window

 glColor3f(1.0f,0.0f,0.0f) ;
glPointSize(4.0);
 glRectf(30,30,100,100);

 //Right Window
 glColor3f(1.0f,0.0f,0.0f) ;
glBegin(GL_POLYGON);
//bottom

        glVertex2i (200,30);
          glVertex2i (200, 100);

//top
          glVertex2i (200, 100);
          glVertex2i (300, 100);

//left
          glVertex2i (300, 100);
          glVertex2i (300, 30);
 //right
         glVertex2i (300, 30);
          glVertex2i (200, 30);

          //glVertex2i (10, -50);

    glEnd();


//door
glColor3f(0.0f,0.0f,1.0f) ;
glBegin(GL_POLYGON);
//left

        glVertex2i (120,30);
          glVertex2i (120, 100);

//top
          glVertex2i (120, 100);
          glVertex2i (170, 100);

//right
          glVertex2i (170, 100);
          glVertex2i (170, 30);

 //bottom
         glVertex2i (120, 30);
          glVertex2i (170, 30);

          //glVertex2i (10, -50);

    glEnd();

    //Triangle

    glColor3f(0.0f,1.0f,0.0f) ;
    glBegin(GL_POLYGON);
//bottom

          glVertex2i (20, 200);
          glVertex2i (320, 200);

          //top
          glVertex2i (200, 310);
          glVertex2i (320, 200);

        //left
          glVertex2i (20, 200);
          glVertex2i (200, 310);


          //glVertex2i (10, -50);

    glEnd();




     glFlush(); // sends all output to display;

}
int main (int argc, char **argv)
{

     glutInit (&argc, argv); // to initialize the toolkit;

     glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB); // sets the display mode

     glutInitWindowSize (640, 480); // sets the window size

     glutInitWindowPosition (10, 10); // sets the starting position for the window

     glutCreateWindow ("My first OpenGL program!"); // creates the window and sets the title

     glutDisplayFunc (myDisplay);
     myInit(); // additional initializations as necessary
     glutMainLoop(); // go into a loop until event occurs
     return 0;
}

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

#include <windows.h>

#include <GL\glut.h>

void myInit (void)

{

glClearColor(0.0,0.0,0.0,0.0); // sets background color to white

// sets a point to be 4x4 pixels

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

gluOrtho2D(0.0, 500.0, 0.0, 400.0); // the display area in world coordinates.

}

void myDisplay(void)

{

glClear(GL_COLOR_BUFFER_BIT); // clears the screen

glColor3f(0.5f,0.5f,0.5f) ;// setsthe drawing colour

glPointSize(4.0);

glBegin(GL_POLYGON);

//bottom

glVertex2i (20, 20);

glVertex2i (320, 20);

//top

glVertex2i (20, 200);

glVertex2i (320, 200);

//left

glVertex2i (20, 200);

glVertex2i (20, 20);

//right

glVertex2i (320, 200);

glVertex2i (320, 20);

//glVertex2i (10, -50);

glEnd();

//Left Window

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

glPointSize(4.0);

glRectf(30,30,100,100);

//Right Window

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

glBegin(GL_POLYGON);

//bottom

glVertex2i (200,30);

glVertex2i (200, 100);

//top

glVertex2i (200, 100);

glVertex2i (300, 100);

//left

glVertex2i (300, 100);

glVertex2i (300, 30);

//right

glVertex2i (300, 30);

glVertex2i (200, 30);

//glVertex2i (10, -50);

glEnd();

//door

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

glBegin(GL_POLYGON);

//left

glVertex2i (120,30);

glVertex2i (120, 100);

//top

glVertex2i (120, 100);

glVertex2i (170, 100);

//right

glVertex2i (170, 100);

glVertex2i (170, 30);

//bottom

glVertex2i (120, 30);

glVertex2i (170, 30);

//glVertex2i (10, -50);

glEnd();

//Triangle

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

glBegin(GL_POLYGON);

//bottom

glVertex2i (20, 200);

glVertex2i (320, 200);

//top

glVertex2i (200, 310);

glVertex2i (320, 200);

//left

glVertex2i (20, 200);

glVertex2i (200, 310);

//glVertex2i (10, -50);

glEnd();

glFlush(); // sends all output to display;

}

int main (int argc, char **argv)

{

glutInit (&argc, argv); // to initialize the toolkit;

glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB); // sets the display mode

glutInitWindowSize (640, 480); // sets the window size

glutInitWindowPosition (10, 10); // sets the starting position for the window

glutCreateWindow ("My first OpenGL program!"); // creates the window and sets the title

glutDisplayFunc (myDisplay);

myInit(); // additional initializations as necessary

glutMainLoop(); // go into a loop until event occurs

return 0;

}

Screenshot:

Leave a comment

Posted in A ll Codes, Graphics, OpenGL, Programming

Tagged House, OpenGL

OpenGL GLUT Tutorials – C Graphics

Posted on May 15, 2016 | Leave a comment

Lectures:
About OpenGL colors:
http://www.cs.brandeis.edu/~cs155/OpenGL%20Lecture_02.pdf
https://en.wikibooks.org/wiki/OpenGL_Programming/Basics/Color

Setup:
https://openglprojects.com/setting-up-opengl-in-windows-linux-mac/
Tut:
http://www.lighthouse3d.com/tutorials/glut-tutorial/
http://ogldev.atspace.co.uk/www/tutorial03/tutorial03.html
https://www3.ntu.edu.sg/home/ehchua/programming/opengl/CG_Introduction.html

Vid:

Projects:
http://www.openglprojects.in/2015/08/bubble-shooter-game-computer-graphics-programs-in-c.html#gsc.tab=0

https://openglprojects.com/opengl-project-ideas/
http://vtupro.blogspot.com/2014/10/opengl-mini-project-for-csisit-students.html

Leave a comment

Posted in Graphics, OpenGL, Programming

Tagged Glut, Graphics, OpenGL

Draw a rectangle with OpenGL

Posted on May 14, 2016 | Leave a comment

Code:

#include<windows.h>
#include <GL/gl.h>
#include <GL/glut.h>
void display(void)
{
/* clear all pixels */
glClear (GL_COLOR_BUFFER_BIT);
/* draw white polygon (rectangle) with corners at
* (0.25, 0.25, 0.0) and (0.75, 0.75, 0.0)
*/
glColor3f (1.0, 0.25, 1.0);
glBegin(GL_POLYGON);
glVertex3f (0.25, 0.25, 0.0);
glVertex3f (0.75, 0.25, 0.0);
glVertex3f (0.75, 0.75, 0.0);
glVertex3f (0.25, 0.75, 0.0);
glEnd();
/* don't wait!
* start processing buffered OpenGL routines
*/
glFlush ();
}
void init (void)
{
/* select clearing (background) color */
glClearColor (0.0, 0.0, 0.0, 0.0);
/* initialize viewing values */
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0.0, 1.0, 0.0, 1.0, -1.0, 1.0);
}
/*
* Declare initial window size, position, and display mode
* (single buffer and RGBA). Open window with "hello"
* in its title bar. Call initialization routines.
* Register callback function to display graphics.
* Enter main loop and process events.
*/
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize (500, 500);
glutInitWindowPosition (100, 100);
glutCreateWindow ("hello");
init ();
glutDisplayFunc(display);
glutMainLoop();
return 0; /* ISO C requires main to return int. */
}

#include<windows.h>

#include <GL/gl.h>

#include <GL/glut.h>

void display(void)

{

/* clear all pixels */

glClear (GL_COLOR_BUFFER_BIT);

/* draw white polygon (rectangle) with corners at

* (0.25, 0.25, 0.0) and (0.75, 0.75, 0.0)

glColor3f (1.0, 0.25, 1.0);

glBegin(GL_POLYGON);

glVertex3f (0.25, 0.25, 0.0);

glVertex3f (0.75, 0.25, 0.0);

glVertex3f (0.75, 0.75, 0.0);

glVertex3f (0.25, 0.75, 0.0);

glEnd();

/* don't wait!

* start processing buffered OpenGL routines

glFlush ();

}

void init (void)

{

/* select clearing (background) color */

glClearColor (0.0, 0.0, 0.0, 0.0);

/* initialize viewing values */

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

glOrtho(0.0, 1.0, 0.0, 1.0, -1.0, 1.0);

}

* Declare initial window size, position, and display mode

* (single buffer and RGBA). Open window with "hello"

* in its title bar. Call initialization routines.

* Register callback function to display graphics.

* Enter main loop and process events.

int main(int argc, char** argv)

{

glutInit(&argc, argv);

glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);

glutInitWindowSize (500, 500);

glutInitWindowPosition (100, 100);

glutCreateWindow ("hello");

init ();

glutDisplayFunc(display);

glutMainLoop();

return 0; /* ISO C requires main to return int. */

}

Output:

Leave a comment

Posted in A ll Codes, Graphics, OpenGL

Tagged OpenGL, Rectangle

Category Archives: OpenGL

Use codeblocks with OpenGl

Draw Midpoint Circle Algorithm with Keyboard Function

Draw Brasenham Line Drawing Algorithms with Random Lines and Colors

Star Drawing with OpenGL

OpenGL Graphics Code: Build a house with GLUT

OpenGL GLUT Tutorials – C Graphics

Draw a rectangle with OpenGL

Caution and Tips:

About Me & MyBlog

Category

Recent Posts

Recent Comments

My Facebook

Follow Me

My Algorithmic Progress in OJ’s

My Github

My Linkedin

Count per Day

Archives

This site is powered by:

Bookmarks

My Coding Page

Category Archives: OpenGL

Caution and Tips:

About Me & MyBlog

Category

Recent Posts

Recent Comments

My Facebook

My Github

My Linkedin

Tags

Count per Day

Archives

This site is powered by:

Bookmarks

My Coding Page