cubetex.c

计算机图形学～想必是很多人需要的～在此共享一下

/*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();
}