OpenGL es: (1) origin of OpenGL es (transfer)

1. What is a computer used for ？

Computers are also called computers , Then the most important job is to calculate . Students who have seen trisomy know , There are countless nano scale computing units in the computer , adopt 0 and 1 Transformation , Complete the operation of addition, subtraction, multiplication and division .

2. What makes the computer work ？

drive , Drive the hardware to complete the work .

3. Who writes the driver ？

The companies that make computers write their own drivers , Because they are most familiar with their underlying hardware architecture .

4. Who can use drivers ？

All software engineers use drivers directly or indirectly . So here comes the question , If there are different computer companies , Make different hardware , Use different drive , Provide different interfaces for software engineers to use , Then the software engineer will crash .

therefore , There must be a standard , Let's unify .

5. So where to unify ？

There is no way to unify the hardware , Every computer company in order to optimize their own computer performance and power consumption , Manufactured Different hardware architectures , It takes countless painstaking efforts to complete , If it's unified , Then you don't need to be so Many computer companies .

So we can only unify the driver interface .

Computer components are roughly divided into :CPU、GPU、 Memory 、 Bus etc. . and OpenGL Namely GPU drive A set of standard interfaces (OpenGL ES For embedded devices GPU Driver's standard interface , Like mobile phone. , OpenGL ES Full name :OpenGL for Embedded Systems).

So to sum up , I use the 5 A question , Raises the OpenGL Usefulness : Namely The complex 、 All kinds of GPU Package the hardware , Computer companies write their own drivers , And then provide it A set of unified interfaces , For the upper software engineer to call . such , The world will be at peace .

6. Who's so good , Defined OpenGL This set of standards ?

Khronos. Whenever I type these letters , Will have a sense of awe , Because it It's not a company , It's an organization , It is a combination of many large companies , such as Apple、 Intel、AMD、Google、ARM、Qualcomm、Nvidia Etc., etc. . Each big company has invested a lot A lot of manpower 、 Funds and so on created this organization . For computers GPU Defines a unified interface OpenGL, Yes mobile phone GPU Defines a unified interface OpenGL ES( I am also very lucky , stay Intel During work , Follow Intel Stationed Khronos Of 3D The person in charge worked together for some time , A weekly cross ocean call , Will benefit me a lot )

This organization has defined OpenGL Beyond the interface , Many other interfaces are also defined . Currently for GPU Another set of lower layer interfaces is proposed Vulkan, This is a set of comparison OpenGL Lower level interfaces , It can be easier to optimize , However, the drivers of hardware manufacturers have yet to be developed , May popularize Vulkan It will be many years . like OpenGL ES It has developed to 3.1, And many mobile phones on the market are still Can only support OpenGL ES 2.0 equally . So new technologies are proposed , To implementation , To mass production , To use , To popularization , It's a long way .

therefore , We are now learning OpenGL ES 2.0 Is timely , And is very necessary ( Don't understand, 2.0, It is more difficult to learn directly 3.0、3.1、Vulkan, It is difficult to ).

Give me a preview ,OpenGL ES 2.0 There will be thirteen courses , After that , I will send it immediately OpenGL ES 3.0 stay OpenGL ES 2.0 Change on the basis of .

7. OpenGL Play with us （Android ） What does it matter to developers ?

The computer / What is displayed on the mobile screen , Or 2D Of , Or 3D Of , So if it is 3D Of , Whether it's App Good , The game is good. , A simple picture interface is also good , The bottom floor is all through GPU、 adopt OpenGL(ES) Drawn out .

Development App When , By creating controls , The control has already encapsulated the underlying layer , therefore App Developers rarely touch OpenGL(ES).

The development of the game is through the game engine , And the bottom of the game engine , It's a direct call to OpenGL(ES), Direct pair GPU Control .

So game engine engineers must understand OpenGL(ES), And game developers , Want to better understand and optimize the game , I also suggest learning some OpenGL(ES).

8. DirectX What is it? ?

Last question . We found that Khronos Among the members of the organization , I didn't mention the famous micro soft , Because Microsoft is not in the organization , And it puts forward its own GPU Driving standards : DirectX. So now mobile phones , Whether it's iOS still Android, All support. OpenGL ES. The computer ,Windows System support DirectX and OpenGL,Linux/Mac(Unix) System support OpenGL.

Reference link ：

1. Android Display System(2)

2. OpenGL ES 2.0 Knowledge collusion

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