Framebuffer: Difference between revisions

Revision as of 06:09, 10 July 2019

Revision as of 20:08, 27 August 2019

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Early accelerators focused on improving the performance of 2D [[Graphical user interface|GUI]] systems. While retaining these 2D capabilities, most modern accelerators focus on producing 3D imagery in real time. A common design uses a [[graphics library]] such as [[OpenGL]] or [[Direct3D]] which interfaces with the graphics driver to translate received commands to instructions for the accelerator's [[graphics processing unit]] (GPU). The GPU uses those instructions to compute the rasterized results and the results are [[bit blit]]ted to the framebuffer. The framebuffer's signal is then produced in combination with built-in video overlay devices (usually used to produce the mouse cursor without modifying the framebuffer's data) and any final special effects that are produced by modifying the output signal. An example of such final special effects was the [[spatial anti-aliasing]] technique used by the [[3dfx Voodoo]] cards. These cards add a slight blur to output signal that makes aliasing of the rasterized graphics much less obvious.

At one time there were many manufacturers of graphics accelerators, including: [[3dfx Interactive]]; [[ATI Technologies|ATI]]; [[Hercules Computer Technology|Hercules]]; [[Trident Microsystems|Trident]]; [[Nvidia]]; [[Radius (hardware company)|Radius]]; [[S3 Graphics]]; [[Silicon Integrated Systems|SiS]] and [[Silicon Graphics]]. {{as of|2015}} the market for graphics accelerators for x86-based systems is dominated by Nvidia (acquired 3dfx in 2002), [[AMD]] (who acquired ATI in 2006), and [[Intel]] (which currently produces only [[Graphics processing unit#Integrated graphics solutions|integrated GPUs]] rather than discrete video cards).<!--[[User:Kvng/RTH]]-->

==Comparisons to other display technologies==

Framebuffers differ significantly from the [[vector display]]s that were common prior to the advent of raster graphics (and, consequently, to the concept of a framebuffer). With a vector display, only the [[vertex (geometry)|vertices]] of the graphics primitives are stored. The [[Cathode ray|electron beam]] of the output display is then commanded to move from vertex to vertex, tracing an analog line across the area between these points. With a framebuffer, the electron beam (if the display technology uses one) is commanded to traceperform a left-to-right,[[raster top-to-bottom path across the entire screenscan]], the way a [[television]] renders a broadcast signal. The color information for each point thus displayed on the screen is pulled directly from the framebuffer during the scan, creating a set of discrete picture elements, i.e. pixels.

Framebuffers differ significantly from the [[vector display]]s that were common prior to the advent of raster graphics (and, consequently, to the concept of a framebuffer). With a vector display, only the [[vertex (geometry)|vertices]] of the graphics primitives are stored. The [[Cathode ray|electron beam]] of the output display is then commanded to move from vertex to vertex, tracing a line across the area between these points.

Likewise, framebuffers differ from the technology used in early text displays, where a buffer holds codes for characters, not individual pixels. The video display device drives the electron beam in a raster pattern the same as with a framebuffer, but generates the pixels of each character in the buffer as it directs the beam.

Likewise, framebuffers differ from the technology used in early [[text mode]] displays, where a buffer holds codes for characters, not individual pixels. The video display device drivesperforms the electron beam in asame raster pattern the samescan as with a framebuffer, but generates the pixels of each character in the buffer as it directs the beam.<!--[[User:Kvng/RTH]]-->

== See also ==