#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <GL/glut.h>
#define CI_OFFSET 16
GLenum rgb, doubleBuffer;
GLenum mode1, mode2;
GLint size;
float pntA[3] = {
-160.0, 0.0, 0.0
};
float pntB[3] = {
-130.0, 0.0, 0.0
};
float pntC[3] = {
-40.0, -50.0, 0.0
};
float pntD[3] = {
30.0, 60.0, 0.0
};
static void Init(void)
{
GLint i;
if (!rgb) {
for (i = 0; i < 16; i++) {
glutSetColor(i+CI_OFFSET, i/15.0, i/15.0, 0.0);
}
}
glClearColor(0.0, 0.0, 0.0, 0.0);
glLineStipple(1, 0xF0E0);
glBlendFunc(GL_SRC_ALPHA, GL_ONE);
mode1 = GL_FALSE;
mode2 = GL_FALSE;
size = 1;
}
static void Reshape(int width, int height)
{
glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluOrtho2D(-175, 175, -175, 175);
glMatrixMode(GL_MODELVIEW);
}
static void Key(unsigned char key, int x, int y)
{
switch (key) {
case '1':
mode1 = !mode1;
glutPostRedisplay();
break;
case '2':
mode2 = !mode2;
glutPostRedisplay();
break;
case 27:
exit(0);
}
}
static void SpecialKey(int key, int x, int y)
{
switch (key) {
case GLUT_KEY_UP:
size++;
glutPostRedisplay();
break;
case GLUT_KEY_DOWN:
size--;
if (size < 1) {
size = 1;
}
glutPostRedisplay();
break;
}
}
static void Draw(void)
{
GLint ci, i;
glClear(GL_COLOR_BUFFER_BIT);
glLineWidth(size);
if (mode1) {
glEnable(GL_LINE_STIPPLE);
} else {
glDisable(GL_LINE_STIPPLE);
}
if (mode2) {
ci = CI_OFFSET;
glEnable(GL_LINE_SMOOTH);
glEnable(GL_BLEND);
} else {
ci = 3;
glDisable(GL_LINE_SMOOTH);
glDisable(GL_BLEND);
}
glPushMatrix();
for (i = 0; i < 360; i += 5) {
glRotatef(5.0, 0,0,1);
(rgb) ? glColor3f(1.0, 1.0, 0.0) : glIndexi(ci);
glBegin(GL_LINE_STRIP);
glVertex3fv(pntA);
glVertex3fv(pntB);
glEnd();
glPointSize(1);
(rgb) ? glColor3f(0.0, 1.0, 0.0) : glIndexi(2);
glBegin(GL_POINTS);
glVertex3fv(pntA);
glVertex3fv(pntB);
glEnd();
}
glPopMatrix();
if (doubleBuffer) {
glutSwapBuffers();
} else {
glFlush();
}
}
static void Args(int argc, char **argv)
{
GLint i;
rgb = GL_TRUE;
doubleBuffer = GL_FALSE;
for (i = 1; i < argc; i++) {
if (strcmp(argv[i], "-ci") == 0) {
rgb = GL_FALSE;
} else if (strcmp(argv[i], "-rgb") == 0) {
rgb = GL_TRUE;
} else if (strcmp(argv[i], "-sb") == 0) {
doubleBuffer = GL_FALSE;
} else if (strcmp(argv[i], "-db") == 0) {
doubleBuffer = GL_TRUE;
}
}
}
int main(int argc, char **argv)
{
GLenum type;
Args(argc, argv);
type = (rgb) ? GLUT_RGB : GLUT_INDEX;
type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
glutInitDisplayMode(type);
glutInitWindowSize(300, 300);
glutCreateWindow("Line Test");
Init();
glutReshapeFunc(Reshape);
glutKeyboardFunc(Key);
glutSpecialFunc(SpecialKey);
glutDisplayFunc(Draw);
glutMainLoop();
}