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//
// Demonstrates how to play an animated GIF file
// under application control frame by frame if
// this is needed.
// Also demonstrates how to use a single animation
// object to load multiple animations.
//
// animgifimage <file> [-r] [-s speed_factor]
//
// Multiple files can be specified e.g. testsuite/*
//
// Use keys '+'/'-'/Enter to change speed, ' ' to pause.
// Right key changes to next frame in paused mode.
// 'n' changes to next file, 'r' toggles reverse play.
//
#include <FL/Fl_Anim_GIF_Image.H>
#include <FL/Fl_Box.H>
#include <FL/Fl_Double_Window.H>
#include <FL/Fl.H>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
static double speed_factor = 1.; // slow down/speed up playback by factor
static bool reverse = false; // true = play animation backwards
static bool paused = false; // flag for paused animation
static bool frame_info = false; // flag to update current frame info in title
static Fl_Anim_GIF_Image animgif; // the animation object
static char **Argv = 0; // copy of main() argv[]
static int Argc = 0; // copy of main() argc
static int current_arg = 0; // current index in argv[]
static int next_arg() {
while (1) {
current_arg++;
if (current_arg >= Argc) {
current_arg = 1;
}
if (Argv[current_arg]) break;
}
return current_arg;
}
static const char *next_file() {
while (Argv[next_arg()][0] == '-') ;
return Argv[current_arg];
}
static void set_title() {
char buf[200];
char fi[50];
if (frame_info)
snprintf(fi, sizeof(fi), "frame %d/%d", animgif.frame() + 1, animgif.frames());
else
snprintf(fi, sizeof(fi), "%d frames", animgif.frames());
snprintf(buf, sizeof(buf), "%s (%s) x %3.2f %s%s",
Argv[current_arg], fi,
speed_factor, reverse ? "reverse" : "",
paused ? " PAUSED" : "");
Fl::first_window()->copy_label(buf);
}
static void cb_anim(void *d_) {
Fl_Anim_GIF_Image *animgif = (Fl_Anim_GIF_Image *)d_;
int frame(animgif->frame());
// switch to next/previous frame
if (reverse) {
animgif->canvas()->window()->redraw();
frame--;
if (frame < 0) {
frame = animgif->frames() - 1;
}
}
else {
frame++;
if (frame >= animgif->frames()) {
frame = 0;
}
}
// set the frame (and update canvas)
animgif->frame(frame);
// setup timer for next frame
if (!paused && animgif->delay(frame)) {
Fl::repeat_timeout(animgif->delay(frame) / speed_factor, cb_anim, d_);
}
if (frame_info)
set_title();
}
static void next_frame() {
cb_anim(&animgif);
}
static void toggle_pause() {
paused = !paused;
set_title();
if (paused)
Fl::remove_timeout(cb_anim, &animgif);
else
next_frame();
set_title();
}
static void toggle_info() {
frame_info = !frame_info;
set_title();
}
static void toggle_reverse() {
reverse = !reverse;
set_title();
}
static void zoom(bool out) {
int W = animgif.w();
int H = animgif.h();
// Note: deliberately no range check (use key 'N' to reset)
static const double f = 1.05;
if (out)
animgif.resize(int(W/f), int(H/f));
else
animgif.resize(int(f*W), int(f*H));
}
static void change_speed(int dir_) {
if (dir_> 0) {
speed_factor += (speed_factor < 1) ? 0.01 : 0.1;
if (speed_factor > 100)
speed_factor = 100.;
}
else if (dir_ < 0) {
speed_factor -= (speed_factor > 1) ? 0.1 : 0.01;
if (speed_factor < 0.01)
speed_factor = 0.01;
}
else {
speed_factor = 1.;
}
set_title();
}
static void load_next() {
Fl::remove_timeout(cb_anim, &animgif);
paused = false;
animgif.load(next_file());
animgif.canvas()->window()->redraw();
// check if loading succeeded
printf("valid: %d frames: %d\n", animgif.valid(), animgif.frames());
if (animgif.valid()) {
printf("play '%s'%s with %3.2f x speed\n", animgif.name(),
(reverse ? " reverse" : ""), speed_factor);
animgif.frame(reverse ? animgif.frames() - 1 : 0);
// setup first timeout, but check for zero-delay (normal GIF)!
if (animgif.delay(animgif.frame())) {
Fl::add_timeout(animgif.delay(animgif.frame()) / speed_factor, cb_anim, &animgif);
}
}
set_title();
}
static int events(int event_) {
if (event_ == FL_SHORTCUT && Fl::first_window()) {
switch (Fl::event_key()) {
case '+': change_speed(1); break;
case '-': change_speed(-1); break;
case FL_Enter: change_speed(0); break;
case 'n': load_next(); break;
case 'z': zoom(Fl::event_shift()); break;
case 'i': toggle_info(); break; // Note: this can raise cpu usage considerably!
case 'r': toggle_reverse(); break;
case ' ': toggle_pause(); break;
case FL_Right:
if (paused && Fl::get_key(FL_Right)) next_frame();
break;
default:
return 0;
}
Fl::first_window()->redraw();
return 1;
}
return 0;
}
int main(int argc, char *argv[]) {
// setup play parameters from args
Argv = argv;
Argc = argc;
int n = 0;
for (int i = 1; i < argc; i++) {
if (!strcmp(argv[i], "-r"))
reverse = !reverse;
else if (!strcmp(argv[i], "-s") && i + 1 < argc) {
i++;
speed_factor = atof(argv[i]);
argv[i] = 0;
}
else if (argv[i][0] != '-') {
n++;
continue;
}
else {
printf("Invalid argument: '%s'\n", argv[i]);
exit(1);
}
}
if (!n) {
fprintf(stderr, "Test program for application controlled GIF animation.\n");
fprintf(stderr, "Please specify one or more image files!\n");
exit(0);
}
if (speed_factor < 0.01 || speed_factor > 100)
speed_factor = 1.;
Fl_Double_Window win(800, 600);
// prepare a canvas for the animation
// (we want to show it in the center of the window)
Fl_Box canvas(0, 0, win.w(), win.h());
Fl_Box help(0, win.h()-20, win.w(), 20, "Keys: N=next file, I=toggle info, R=play reverse, +/-/Enter/Space=change speed, Z=Zoom");
win.resizable(win);
win.end();
win.show();
Fl::add_handler(events);
// use the 'DONT_RESIZE_CANVAS' flag to tell the animation
// not to change the canvas size (which is the default).
unsigned short flags = Fl_Anim_GIF_Image::DONT_RESIZE_CANVAS;
// flags |= Fl_Anim_GIF_Image::DEBUG_FLAG|Fl_Anim_GIF_Image::LOG_FLAG;
animgif.canvas(&canvas, flags);
load_next();
return Fl::run();
}
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