How the video adapter works
How the video adapter works
The first video adapters were the simplestsignal converters. A few decades passed, and the video adapter, having acquired a huge number of different functions, evolved into a high-performance device.
You will need
- A modern graphics card and a working computer.
Instructions
1
The principle of the video adapter is easy to understand,tracing the history of the appearance of this device. The invention of monitors substantially simplified the life of users of personal computers. But to work together, the monitor and the system unit needed a device that converted data from the computer's memory into a video signal for the display. Such a device was a graphics card (video card, video adapter). The first video adapters did not make any calculations, and the color of each pixel in the frame was calculated by the CPU.
2
However, the requirements for realism, clarity andcolor images grew, which created an increased load on the CPU. The solution to the problem of processor unloading was the invention of graphics accelerators - a new kind of graphics cards that could provide certain graphics functions at the hardware level. That is, they could make pixel color calculations when displaying the cursor, when moving windows or pouring a selected area of the image. Thus, the video adapter was already responsible for the process of creating the image. In the 90-ies of the last century a new problem arose associated with the acceleration of gaming 3D engines. To solve this issue, 3D accelerators were invented. These devices functioned only together with the video adapter. When 3D applications were launched, 3D accelerators calculated 3D image models and converted them into two-dimensional ones. The calculations were sent to the video adapter, which "completed" the frame with the interface and sent it to the display. In the recent past, video adapters and 3D accelerators connected to one device. Actually, this is the current video adapter.
3
How the video adapter works is convenientIllustrate the example of building a frame of a three-dimensional application. In computer modeling, any 3D object has a set of triangles - faces, or "polygons". A variety of models of shrubs, buildings, weapons and moving creatures are just artfully conjugated with each other with stretched textures on them. When calculating the image, the CPU sends the coordinates of the points - the vertices of the graphic object and the texture - into the memory of the video card. The texture will cover the framework of the computed 3D model. The rest is behind the video adapter.
4
The three-dimensional model is just a monotonica set of uniformly colored faces. The process of design of the framework of vertices and textures in the resulting image of the frame is called a graphic pipeline. First, the vertices get to the vertex processor, which rotates, translates, scales and determines the color of each vertex with light (Transforming & Lighting) taken into account. Then comes the projection - converting the coordinates of the 3D environment into a two-dimensional coordinate system of the display. Next is rasterization. This is a set of operations with image pixels. Removing invisible surfaces, for example, the reverse sides of image objects. For each point of the frame, its virtual distance from the plane of the display is calculated and the appropriate shading is performed. At this stage, texture selection and smoothing are performed.
5
Modern video adapters are electronicdevices with grand computing performance. In this regard, there are many ideas for the alternative use of video adapters in medicine and meteorological forecasting.
