--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/freeglut/progs/demos/spaceball/spaceball.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,177 @@
+/* Spaceball demo
+ *
+ * Written by John Tsiombikas <nuclear@member.fsf.org>
+ * (converted from the libspnav cube example)
+ *
+ * Use the spaceball to move and rotate the colored cube.
+ * Pressing any button will reset the cube at its original location.
+ *
+ * Press escape or q to exit.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <GL/freeglut.h>
+#include "vmath.h"
+
+#ifndef M_PI
+#define M_PI    3.14159265358979323846264338327950
+#endif
+
+void draw_cube(void);
+
+/* callbacks */
+void disp(void);
+void reshape(int x, int y);
+void keyb(unsigned char key, int x, int y);
+void sbmot(int x, int y, int z);  /* spaceball translation */
+void sbrot(int x, int y, int z);  /* spaceball rotation */
+void sbbut(int bn, int state);    /* spaceball button */
+
+vec3_t pos = {0, 0, -6};
+quat_t rot = {0, 0, 0, 1};
+
+int main(int argc, char **argv)
+{
+  glutInit(&argc, argv);
+  glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
+  glutCreateWindow("spaceball demo");
+
+  glutDisplayFunc(disp);
+  glutReshapeFunc(reshape);
+  glutKeyboardFunc(keyb);
+  glutSpaceballMotionFunc(sbmot);
+  glutSpaceballRotateFunc(sbrot);
+  glutSpaceballButtonFunc(sbbut);
+
+  glEnable(GL_CULL_FACE);
+
+  glutMainLoop();
+  return 0;
+}
+
+void disp(void)
+{
+  mat4_t xform;
+
+  quat_to_mat(xform, rot);
+
+  glClear(GL_COLOR_BUFFER_BIT);
+
+  glMatrixMode(GL_MODELVIEW);
+  glLoadIdentity();
+  glTranslatef(pos.x, pos.y, pos.z);
+  glMultMatrixf((float*)xform);
+
+  draw_cube();
+
+  glutSwapBuffers();
+}
+
+void draw_cube(void)
+{
+  glBegin(GL_QUADS);
+  /* face +Z */
+  glNormal3f(0, 0, 1);
+  glColor3f(1, 0, 0);
+  glVertex3f(-1, -1, 1);
+  glVertex3f(1, -1, 1);
+  glVertex3f(1, 1, 1);
+  glVertex3f(-1, 1, 1);
+  /* face +X */
+  glNormal3f(1, 0, 0);
+  glColor3f(0, 1, 0);
+  glVertex3f(1, -1, 1);
+  glVertex3f(1, -1, -1);
+  glVertex3f(1, 1, -1);
+  glVertex3f(1, 1, 1);
+  /* face -Z */
+  glNormal3f(0, 0, -1);
+  glColor3f(0, 0, 1);
+  glVertex3f(1, -1, -1);
+  glVertex3f(-1, -1, -1);
+  glVertex3f(-1, 1, -1);
+  glVertex3f(1, 1, -1);
+  /* face -X */
+  glNormal3f(-1, 0, 0);
+  glColor3f(1, 1, 0);
+  glVertex3f(-1, -1, -1);
+  glVertex3f(-1, -1, 1);
+  glVertex3f(-1, 1, 1);
+  glVertex3f(-1, 1, -1);
+  /* face +Y */
+  glNormal3f(0, 1, 0);
+  glColor3f(0, 1, 1);
+  glVertex3f(-1, 1, 1);
+  glVertex3f(1, 1, 1);
+  glVertex3f(1, 1, -1);
+  glVertex3f(-1, 1, -1);
+  /* face -Y */
+  glNormal3f(0, -1, 0);
+  glColor3f(1, 0, 1);
+  glVertex3f(-1, -1, -1);
+  glVertex3f(1, -1, -1);
+  glVertex3f(1, -1, 1);
+  glVertex3f(-1, -1, 1);
+  glEnd();
+}
+
+/* 45deg fov */
+#define FOV    (M_PI / 4.0)
+
+void reshape(int x, int y)
+{
+  float aspect = (float)x / (float)y;
+  float halfy = (float)tan(FOV / 2.0);
+  float halfx = halfy * aspect;
+
+  glViewport(0, 0, x, y);
+
+  glMatrixMode(GL_PROJECTION);
+  glLoadIdentity();
+  glFrustum(-halfx, halfx, -halfy, halfy, 1.0, 1000.0);
+}
+
+void keyb(unsigned char key, int x, int y)
+{
+  switch(key) {
+  case 'q':
+  case 'Q':
+  case 27:
+    exit(0);
+
+  case ' ':
+    /* reset initial view */
+    pos = v3_cons(0, 0, -6);
+    rot = quat_cons(1, 0, 0, 0);
+    glutPostRedisplay();
+
+  default:
+    break;
+  }
+}
+
+void sbmot(int x, int y, int z)
+{
+  pos.x += x * 0.001f;
+  pos.y += y * 0.001f;
+  pos.z -= z * 0.001f;
+  glutPostRedisplay();
+}
+
+void sbrot(int x, int y, int z)
+{
+  float axis_len = (float)sqrt(x * x + y * y + z * z);
+  rot = quat_rotate(rot, axis_len * 0.001f, -x / axis_len, -y / axis_len, z / axis_len);
+  glutPostRedisplay();
+}
+
+void sbbut(int bn, int state)
+{
+  if(state == GLUT_DOWN) {
+    pos = v3_cons(0, 0, -6);
+    rot = quat_cons(1, 0, 0, 0);
+    glutPostRedisplay();
+  }
+}