Android 开机动画源码分析
Android系统在启动SystemServer进程时，通过两个阶段来启动系统所有服务，在第一阶段启动本地服务，如SurfaceFlinger，SensorService等，在第二阶段则启动一系列的Java服务。开机动画是在什么时候启动的呢？通过查看源码，Android开机动画是在启动SurfaceFlinger服务时启动的。SystemServer的main函数首先调用init1来启动本地服务，init1函数通过JNI调用C语言中的system_init()函数来实现服务启动。
property_set("ctl.start", "bootanim")就是启动bootanim进程来显示开机动画，该进程对应的源码位于frameworks\base\cmds\bootanimation\bootanimation_main.cpp
bool BootAnimation::movie(){ ZipFileRO& zip(mZip);//获取zip压缩文件中的文件数目 size_t numEntries = zip.getNumEntries();//打开zip压缩文件中的desc.txt文件 ZipEntryRO desc = zip.findEntryByName("desc.txt"); FileMap* descMap = zip.createEntryFileMap(desc); ALOGE_IF(!descMap, "descMap is null"); if (!descMap) { return false; }//读取desc.txt文件内容 String8 desString((char const*)descMap->getDataPtr(),descMap->getDataLength()); char const* s = desString.string(); Animation animation;//读取persist.sys.silence属性来决定是否播放开机音乐 char silence[PROPERTY_VALUE_MAX]; property_get("persist.sys.silence", silence, "0"); if(strcmp("1", silence)==0){ // do something. }else{ soundplay(); }//解析desc.txt文件内容 for (;;) { //从字符串s中查找是否有字符串"\n"，如果有，返回s中"\n"起始位置的指针，如果没有，返回null。 const char* endl = strstr(s, "\n"); if (!endl) break;//取得文件一行内容 String8 line(s, endl - s); const char* l = line.string(); int fps, width, height, count, pause; char path[256]; char pathType;//从文件第一行中读取宽度，高度，帧数//480 854 10 <---> width height fps if (sscanf(l, "%d %d %d", &width, &height, &fps) == 3) { //LOGD("> w=%d, h=%d, fps=%d", fps, width, height); animation.width = (width > 0 ? width : mWidth); animation.height = (height > 0 ? height : mHeight); animation.fps = fps;//p 1 2 folder1 <---> pathType count pause path }else if (sscanf(l, " %c %d %d %s", &pathType, &count, &pause, path) == 4) { //LOGD("> type=%c, count=%d, pause=%d, path=%s", pathType, count, pause, path); Animation::Part part;//一个part描述一个动画文件夹内容 part.playUntilComplete = pathType == 'c'; part.count = count; part.pause = pause; part.path = path; animation.parts.add(part); } s = ++endl; } //读取动画个数 const size_t pcount = animation.parts.size();//遍历zip压缩包中的所有文件 for (size_t i=0 ; i<numEntries ; i++) { char name[256]; ZipEntryRO entry = zip.findEntryByIndex(i);//读取压缩包中的文件名称，所在目录的路径 if (zip.getEntryFileName(entry, name, 256) == 0) { const String8 entryName(name); const String8 path(entryName.getPathDir()); const String8 leaf(entryName.getPathLeaf()); if (leaf.size() > 0) { for (int j=0 ; j<pcount ; j++) { if (path == animation.parts[j].path) { int method; //获取文件信息 if (zip.getEntryInfo(entry, &method, 0, 0, 0, 0, 0)) { if (method == ZipFileRO::kCompressStored) { FileMap* map = zip.createEntryFileMap(entry); if (map) { Animation::Frame frame; frame.name = leaf; frame.map = map; Animation::Part& part(animation.parts.editItemAt(j)); part.frames.add(frame); } } } } } } } } // clear screen glShadeModel(GL_FLAT); glDisable(GL_DITHER); glDisable(GL_SCISSOR_TEST); glDisable(GL_BLEND); glClearColor(0,0,0,1); glClear(GL_COLOR_BUFFER_BIT); eglSwapBuffers(mDisplay, mSurface); glBindTexture(GL_TEXTURE_2D, 0); glEnable(GL_TEXTURE_2D); glTexEnvx(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE); glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); const int xc = (mWidth - animation.width) / 2; const int yc = ((mHeight - animation.height) / 2); nsecs_t lastFrame = systemTime(); nsecs_t frameDuration = s2ns(1) / animation.fps; Region clearReg(Rect(mWidth, mHeight)); clearReg.subtractSelf(Rect(xc, yc, xc+animation.width, yc+animation.height)); for (int i=0 ; i<pcount ; i++) { const Animation::Part& part(animation.parts[i]); const size_t fcount = part.frames.size(); glBindTexture(GL_TEXTURE_2D, 0); for (int r=0 ; !part.count || r<part.count ; r++) { // Exit any non playuntil complete parts immediately if(exitPending() && !part.playUntilComplete) break; for (int j=0 ; j<fcount && (!exitPending() || part.playUntilComplete) ; j++) { const Animation::Frame& frame(part.frames[j]); nsecs_t lastFrame = systemTime(); if (r > 0) { glBindTexture(GL_TEXTURE_2D, frame.tid); } else { if (part.count != 1) { glGenTextures(1, &frame.tid); glBindTexture(GL_TEXTURE_2D, frame.tid); glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); } initTexture( frame.map->getDataPtr(), frame.map->getDataLength()); } if (!clearReg.isEmpty()) { Region::const_iterator head(clearReg.begin()); Region::const_iterator tail(clearReg.end()); glEnable(GL_SCISSOR_TEST); while (head != tail) { const Rect& r(*head++); glScissor(r.left, mHeight - r.bottom, r.width(), r.height()); glClear(GL_COLOR_BUFFER_BIT); } glDisable(GL_SCISSOR_TEST); } glDrawTexiOES(xc, yc, 0, animation.width, animation.height); eglSwapBuffers(mDisplay, mSurface); nsecs_t now = systemTime(); nsecs_t delay = frameDuration - (now - lastFrame); //ALOGD("%lld, %lld", ns2ms(now - lastFrame), ns2ms(delay)); lastFrame = now; if (delay > 0) { struct timespec spec; spec.tv_sec = (now + delay) / 1000000000; spec.tv_nsec = (now + delay) % 1000000000; int err; do { err = clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &spec, NULL); } while (err<0 && errno == EINTR); } checkExit(); } usleep(part.pause * ns2us(frameDuration)); // For infinite parts, we've now played them at least once, so perhaps exit if(exitPending() && !part.count) break; } // free the textures for this part if (part.count != 1) { for (int j=0 ; j<fcount ; j++) { const Animation::Frame& frame(part.frames[j]); glDeleteTextures(1, &frame.tid); } } } soundstop(); return false;}
