Tag:Off screen

  • Flutter optimization record (continuous improvement ~)


    This article records the app optimization method, which can check some performance and rendering problems with tools Debug performance issues 1. Track start time flutter run –trace-startup –profile The trace output is saved as start_ up_ info. JSON, the output lists the time from application startup to these trace events (captured in microseconds): When entering […]

  • 2021 byte client (IOS)


    Link: http://www.mianshigee.com/art… Recommended reading: summary of IOS interview questions (the column is continuously updated) One video surface (50min) The interviewer is very good. He has a good grasp of the interview time in the whole process, and then he will not have contempt or other emotions when encountering problems. He really won’t take the initiative […]

  • Off screen rendering in IOS development


    image.png Original drawing address:https://zhuanlan.zhihu.com/p/72653360 offscreen rendering To display content on the screen, you need a frame buffer as large as the amount of screen pixel data. The frame buffer is the place where GPU stores and renders. Sometimes the GPU cannot write the rendering results directly to the frame buffer, but needs to be temporarily […]

  • IOS off screen rendering analysis / optimization


    Questions before starting:1. What is off screen rendering?2. In which step does off screen rendering take place?3. What is the impact of off screen rendering?4. Will setting rounded corners trigger off screen rendering?5. How to optimize off screen rendering? An in-depth understanding of the above questions is enough to answer the interviewer’s questions. Image rendering […]

  • IOS off screen rendering


    Preface: debug – > color off screen rendered eg: – (void)viewDidLoad { [super viewDidLoad]; //1. Button background picture (off screen rendering appears) UIButton *btn1 = [UIButton new]; btn1.frame = CGRectMake(100, 30, 100, 100); btn1.layer.cornerRadius = 50; [self.view addSubview:btn1]; [btn1 setImage:[UIImage imageNamed:@”sun.png”] forState:UIControlStateNormal]; btn1.clipsToBounds = YES; //2. Button background color UIButton *btn2 = [UIButton new]; btn2.frame […]

  • About graphics rendering and off screen rendering


    1. CPU and GPU Difference between CPU and GPU Different design objectives, they are respectively aimed at two different application scenarios. The CPU needs strong universality to deal with various data types. At the same time, it also needs logical judgment, and will introduce a large number of branch jump and interrupt processing. All these […]

  • IOS interview question: talk about off screen rendering in IOS?


    Come on, IOS GPU rendering mechanism: the CPU calculates the display content and submits it to the GPU. After GPU rendering, the rendering result is put into the frame buffer. Then, the video controller will read the data of the frame buffer line by line according to the Vsync signal and transmit it to the […]

  • IOS — detailed explanation of off screen rendering


    catalog: 1. Image display principle 2. Image display principle 2.1 image to screen process 2.2 display process 3. Jamming and frame dropping 3.1 vertical synchronization Vsync + double buffering 2.3 essence of frame dropping and screen jamming 4. Off screen rendering 4.1 what is the process of off screen rendering and off screen rendering 4.2 […]

  • IOS setting rounded corners will cause off screen rendering. Do you really understand?


    1. How to set fillet to trigger off screen rendering We often see that rounded corners trigger off screen rendering. But in fact, this statement is not accurate, because rounded corners trigger off screen rendering is also conditional! Let’s take a look at the description of CornerRadius in Apple’s official documents: Setting the radius to […]

  • Reasons for IOS off screen rendering


    Normal rendering flow In the rendering process of GPU, according toFrom far to nearThe images are displayed on the screen in order, and the results are stored inframe buffer Video controller fromframe bufferAfter reading the data in and displaying it on the screen, the frame change data will be lost immediately Normal rendering flow offscreen […]

  • Off screen canvas


    Off screen canvas can solve the performance problem of canvas Operation steps: 1. Create off screen canvas; 2. Set the width and height of off screen canvas; 3. Draw in off screen canvas; 4. Draw all or part of the off screen canvas onto the canvas being displayed domo: var canvas = document.getElementById(‘canvas’), context = […]

  • IOS development interview only needs to know these, and the technology basically passes the customs! (UI)


    1、 Uiview and calayer Single responsibility principle UIViewbyCALayerProvide content, handle touch and other events, and participate in the response chain CALayerResponsible for displaying contentcontents 2、 Event delivery and view response chain: If the event is passed all the way to UIApplictionIf it’s still not handled, it will be ignored 3、 Image display principle 1.CPU: output […]