opengl jueves 29 Agosto

Actividad práctica

1. Investigue que es opengl
2. Como instalar las librerías
3. Probar el siguiente código
4. Los resultados de la actividad deben publicarse en su blog , incluyendo una captura de la pantalla donde se muestra los resultados de la ejecución del programa, la secuencia de pasos que realizó desde la instalación de la s librerías, fecha de revision  lunes 2 de Septiembre

/*cubetex.c           */

/* Rotating cube with texture mapping */

/* mouse buttons control direction of

/* rotation, keyboard allows start/top/quit */

/* E. Angel, Interactive Computer Graphics */

/* A Top-Down Approach with OpenGL, Third Edition */

/* Addison-Wesley Longman, 2003 */

#include <stdlib.h>

#include <GL/glut.h>

GLfloat planes[]= {-1.0, 0.0, 1.0, 0.0};

GLfloat planet[]= {0.0, -1.0,  0.0, 1.0};

 GLfloat vertices[][3] = {{-1.0,-1.0,-1.0},{1.0,-1.0,-1.0},

 {1.0,1.0,-1.0}, {-1.0,1.0,-1.0}, {-1.0,-1.0,1.0},

 {1.0,-1.0,1.0}, {1.0,1.0,1.0}, {-1.0,1.0,1.0}};

 GLfloat colors[][4] = {{0.0,0.0,0.0,0.5},{1.0,0.0,0.0,0.5},

 {1.0,1.0,0.0,0.5}, {0.0,1.0,0.0,0.5}, {0.0,0.0,1.0,0.5},

 {1.0,0.0,1.0,0.5}, {1.0,1.0,1.0,0.5}, {0.0,1.0,1.0,0.5}};

void polygon(int a, int b, int c , int d)

{

/* draw a polygon via list of vertices */

  glBegin(GL_POLYGON);

 glColor4fv(colors[a]);

 glTexCoord2f(0.0,0.0);

 glVertex3fv(vertices[a]);

 glColor4fv(colors[b]);

 glTexCoord2f(0.0,1.0);

 glVertex3fv(vertices[b]);

 glColor4fv(colors[c]);

 glTexCoord2f(1.0,1.0);

 glVertex3fv(vertices[c]);

 glColor4fv(colors[d]);

 glTexCoord2f(1.0,0.0);

 glVertex3fv(vertices[d]);

 glEnd();

                          }

void colorcube(void)

{

/* map vertices to faces */

 polygon(0,3,2,1);

 polygon(2,3,7,6);

 polygon(0,4,7,3);

 polygon(1,2,6,5);

 polygon(4,5,6,7);

 polygon(0,1,5,4);

}

static GLfloat theta[] = {0.0,0.0,0.0};

static GLint axis = 2;

void display(void)

{

/* display callback, clear frame buffer and z buffer,

   rotate cube and draw, swap buffers */

 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

 glLoadIdentity();

 glRotatef(theta[0], 1.0, 0.0, 0.0);

 glRotatef(theta[1], 0.0, 1.0, 0.0);

 glRotatef(theta[2], 0.0, 0.0, 1.0);

 colorcube();

 glutSwapBuffers();

}

void spinCube()

{

/* Idle callback, spin cube 2 degrees about selected axis */

 theta[axis] += 2.0;

 if( theta[axis] > 360.0 ) theta[axis] -= 360.0;

 glutPostRedisplay();

}

void mouse(int btn, int state, int x, int y)

{

/* mouse callback, selects an axis about which to rotate */

 if(btn==GLUT_LEFT_BUTTON && state == GLUT_DOWN) axis = 0;

 if(btn==GLUT_MIDDLE_BUTTON && state == GLUT_DOWN) axis = 1;

 if(btn==GLUT_RIGHT_BUTTON && state == GLUT_DOWN) axis = 2;

}

void myReshape(int w, int h)

{

    glViewport(0, 0, w, h);

    glMatrixMode(GL_PROJECTION);

    glLoadIdentity();

    if (w <= h)

        glOrtho(-2.0, 2.0, -2.0 * (GLfloat) h / (GLfloat) w,

            2.0 * (GLfloat) h / (GLfloat) w, -10.0, 10.0);

    else

        glOrtho(-2.0 * (GLfloat) w / (GLfloat) h,

            2.0 * (GLfloat) w / (GLfloat) h, -2.0, 2.0, -10.0, 10.0);

    glMatrixMode(GL_MODELVIEW);

}

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

{

 if(k == '1') glutIdleFunc(spinCube);

 if(k == '2') glutIdleFunc(NULL);

 if(k == 'q') exit(0);

}

void

main(int argc, char **argv)

{

   GLubyte image[64][64][3];

   int i, j, r, c;

   for(i=0;i<64;i++)

   {

     for(j=0;j<64;j++)

     {

       c = ((((i&0x8)==0)^((j&0x8))==0))*255;

       image[i][j][0]= (GLubyte) c;

       image[i][j][1]= (GLubyte) c;

       image[i][j][2]= (GLubyte) c;

     }

   }

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);

    glutInitWindowSize(500, 500);

    glutCreateWindow("colorcube");

/* need both double buffering and z buffer */

    glutReshapeFunc(myReshape);

    glutDisplayFunc(display);

   glutIdleFunc(spinCube);

   glutMouseFunc(mouse);

   glEnable(GL_DEPTH_TEST);

   glEnable(GL_TEXTURE_2D);

   glTexImage2D(GL_TEXTURE_2D,0,3,64,64,0,GL_RGB,GL_UNSIGNED_BYTE, image);

   glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_REPEAT);

   glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_REPEAT);

   glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);

   glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);

   glutKeyboardFunc(key);

   glClearColor(1.0,1.0,1.0,1.0);

   glutMainLoop();

}