cpplab/app/gl2.cpp

147 lines
No EOL
3.3 KiB
C++

#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glut.h>
#include <stdlib.h>
#include <string.h>
#define PT 1
#define STROKE 2
#define END 3
typedef struct charpoint
{
GLfloat x, y;
int type;
} CP;
CP Adata[] = {
{0, 0, PT}, {0, 9, PT}, {1, 10, PT}, {4, 10, PT}, {5, 9, PT}, {5, 0, STROKE}, {0, 5, PT}, {5, 5, END}};
CP Edata[] = {
{5, 0, PT}, {0, 0, PT}, {0, 10, PT}, {5, 10, STROKE}, {0, 5, PT}, {4, 5, END}};
CP Pdata[] = {
{0, 0, PT}, {0, 10, PT}, {4, 10, PT}, {5, 9, PT}, {5, 6, PT}, {4, 5, PT}, {0, 5, END}};
CP Rdata[] = {
{0, 0, PT}, {0, 10, PT}, {4, 10, PT}, {5, 9, PT}, {5, 6, PT}, {4, 5, PT}, {0, 5, STROKE}, {3, 5, PT}, {5, 0, END}};
CP Sdata[] = {
{0, 1, PT}, {1, 0, PT}, {4, 0, PT}, {5, 1, PT}, {5, 4, PT}, {4, 5, PT}, {1, 5, PT}, {0, 6, PT}, {0, 9, PT}, {1, 10, PT}, {4, 10, PT}, {5, 9, END}};
/* drawLetter() interprets the instructions from the array
* for that letter and renders the letter with line segments.
*/
static void drawLetter(CP *l)
{
glBegin(GL_LINE_STRIP);
while (1)
{
switch (l->type)
{
case PT:
glVertex2fv(&l->x);
break;
case STROKE:
glVertex2fv(&l->x);
glEnd();
glBegin(GL_LINE_STRIP);
break;
case END:
glVertex2fv(&l->x);
glEnd();
glTranslatef(8.0, 0.0, 0.0);
return;
}
l++;
}
}
/* Create a display list for each of 6 characters */
static void init(void)
{
GLuint base;
glShadeModel(GL_FLAT);
base = glGenLists(128);
glListBase(base);
glNewList(base + 'A', GL_COMPILE);
drawLetter(Adata);
glEndList();
glNewList(base + 'E', GL_COMPILE);
drawLetter(Edata);
glEndList();
glNewList(base + 'P', GL_COMPILE);
drawLetter(Pdata);
glEndList();
glNewList(base + 'R', GL_COMPILE);
drawLetter(Rdata);
glEndList();
glNewList(base + 'S', GL_COMPILE);
drawLetter(Sdata);
glEndList();
glNewList(base + ' ', GL_COMPILE);
glTranslatef(8.0, 0.0, 0.0);
glEndList();
}
const char *test1 = "A SPARE SERAPE APPEARS AS";
const char *test2 = "APES PREPARE RARE PEPPERS";
static void printStrokedString(char *s)
{
GLsizei len = strlen(s);
glCallLists(len, GL_BYTE, (GLbyte *)s);
}
void display(void)
{
glClear(GL_COLOR_BUFFER_BIT);
glColor3f(1.0, 1.0, 1.0);
glPushMatrix();
glScalef(2.0, 2.0, 2.0);
glTranslatef(10.0, 30.0, 0.0);
printStrokedString((char *)test1);
glPopMatrix();
glPushMatrix();
glScalef(2.0, 2.0, 2.0);
glTranslatef(10.0, 13.0, 0.0);
printStrokedString((char *)test2);
glPopMatrix();
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 ' ':
glutPostRedisplay();
break;
case 27:
exit(0);
}
}
int main(int argc, char **argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize(440, 120);
glutCreateWindow(argv[0]);
init();
glutReshapeFunc(reshape);
glutKeyboardFunc(keyboard);
glutDisplayFunc(display);
glutMainLoop();
return 0;
}