FLTK - FLTK1.4.1 - demo - animgifimage-play

概述

看的官方demo越多，在每个新demo中能看到的新增知识点越少。这是好事。
不可能一次将细节都记住，只要知道每个官方demo能干啥，有些啥新增知识点，这就够了。
就像一本好书一样，至少也要看几遍。
再不济，翻一遍，知道有啥，等需要的时候，再来拿。

// 播放多张gif, 并能控制(缩放，速度，正反向播放, 下一张图片)

// 新增知识点
// gif图像切换当前帧
// 所有的新窗体，都是作为当前窗体的子窗体存在, 所以fltk的窗体不用指定父窗体是谁

笔记

int APIENTRY wWinMain(_In_ HINSTANCE hInstance,_In_opt_ HINSTANCE hPrevInstance,_In_ LPWSTR    lpCmdLine,_In_ int       nCmdShow)
{UNREFERENCED_PARAMETER(hPrevInstance);UNREFERENCED_PARAMETER(lpCmdLine);char* argv[4] = {};argv[0] = (char*)"app-name";argv[1] = (char*)"003_ over_rest.gif";argv[2] = (char*)"004_no_contact.gif";argv[3] = (char*)"005_bonded.gif";return fl_demo_main(4, argv);// return 0;
}

// FLTK - FLTK1.4.1 - demo - animgifimage-play// 播放多张gif, 并能控制(缩放，速度，正反向播放, 下一张图片)// 新增知识点
// gif图像切换当前帧
// 所有的新窗体，都是作为当前窗体的子窗体存在, 所以fltk的窗体不用指定父窗体是谁#include "fltk_test.h"// 如果要将fl demo的实现搬过来测试，就注释掉下面的宏
// #define DONT_USE_FL_DEMO#ifdef DONT_USE_FL_DEMO
int fl_demo_main(int argc, char** argv)
{return 0;
}#else#endif // TEST_FL_DEMO//
//  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 = true; // 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());elsesnprintf(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 frameif (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)// gif图像切换当前帧animgif->frame(frame);// setup timer for next frameif (!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);elsenext_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;// 设置图像在画布上的大小if (out)animgif.resize(int(W / f), int(H / f));elseanimgif.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 succeededprintf("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 fl_demo_main(int argc, char* argv[]) {// setup play parameters from argsArgv = 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());// 所有的新窗体，都是作为当前窗体的子窗体存在, 所以fltk的窗体不用指定父窗体是谁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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