2 Output PrimitivesOutput Primitives: Basic geometric structures used to describe scenes.(points, straight line segment, circles and other conic sections, quadric surfaces, spline curve and surfaces, polygon color areas, and character strings)These picture components are often defined in a continuous space.
3 Output PrimitivesIn order to draw the primitive objects, one has to first scan convert the object.Scan convert: Refers to the operation of finding out the location of pixels to be intensified and then setting the values of corresponding bits, in the graphic memory, to the desired intensity code.
4 Scan Converting A Point A random-scan (vector) systemstores point-plotting instructions in the display list, and coordinate values inthese instructions are converted to deflection voltages that position the electron beam at the screen locations to be plotted during each refresh cycle.
25 Character GenerationThere are three basic methods to generate characters,Hardware based: Logic is built into the graphics terminal and drawn quickly.Bitmap based: utilizes pixels and copies appropriate portion from frame buffer to displayVector based: provides with unlimited possibilities with character style, size, shape