[ad_1]
OpenGL® drawing is the use of Open Graphics Library® to render objects or interfaces. It involves assembling dots and lines into polygons. The virtual stylus within OpenGL® can be moved to draw continuous series of dots. High-level functions can simplify complex scenes, and rasterization renders the scene on a display device.
“OpenGL® drawing” is a generic term that can be used to mean that an application has been set up to use the Open Graphics Library® for display rendering. It can also be used in programming to describe the use of different functions within a library to create the items in a scene. Most often, OpenGL® drawing involves assembling dots and lines into triangles, quadrilaterals, or other polygons to create recognizable objects or interfaces that a user can see or interact with. An OpenGL® drawing can also be the final rendered scene as it appears on a screen or other device.
From a programming standpoint, OpenGL® drawing is very similar to drawing on paper with a pen. There is a kind of virtual stylus within OpenGL® that can be moved from one position to another but always remembers exactly where it is currently. The stylus can be moved and reset but, at the same time, it can be used to draw continuous series of dots.
An example of using the locator for drawing is an object called a triangular stripe. This is a sequence of triangles where each one shares a side with the next triangle. Using OpenGL® drawing functions, one point is drawn, followed by two more to create a basic triangle. The next two points to which the virtual stylus is moved will be connected, forming a second triangle. This process can be used to draw entire elaborate objects moving from one point to another.
Through the use of utility libraries or extensions, a number of high-level OpenGL® drawing functions are available that can be used to simplify the construction of complex scenes. These functions can draw a cube, sphere, or other primitive shape, eliminating the need to laboriously generate standard code to draw the shape. Points, which are just single points at a given location, can be manipulated via drawing functions so that a raster image such as a photograph can be translated into three-dimensional (3D) coordinates.
After the geometry of a scene has been determined and passed to the graphics hardware, OpenGL® drawing routines help render the scene on a display device. When mathematical information describing the points, lines and surfaces of a scene is drawn on a monitor, the process is known as rasterization, in which the image is made two-dimensional (2D) so it can be displayed. The resulting 2D rasterized image created from the 3D data can be called an OpenGL® drawing.
[ad_2]