Abstract: A method of plotting traces of data on two or more graphs, wherein each trace is related to the output of a process sensor, includes generating a list of sensors and grouping the sensors according to a unit of measure each sensor is configured to detect. One axis of a first graph is associated with the unit of measure of a first group of sensors and one axis of a second graph is associated with the unit of measure of a second group of sensors. Each sensor of the first group is associated with a trace to be displayed on the first graph and each sensor of the second group is associated with the trace to be displayed on the second graph. The traces are displayed on the first and second graphs, with each trace being related to the output of a sensor over time.

Abstract: A drawing generation apparatus includes: positioning markers provided in each source component drawing and destination component drawing involved and displayed to indicate a source. reference position and a destination reference position, respectively; a component drawing database for storing the component drawings; a component information database that allows selection of the component drawings based on one of the input specification information and the drawing information, and outputting component drawing information relating to the component drawings; and an engine unit for retrieving the component drawings from said component drawing database based on the component drawing information from said component information database, and combining the component drawings such that the positioning markers are aligned.

Abstract: Embodiments of the invention obtain dual points by examining the intersection between each line and a perpendicular projection from the line to a point of origin. The dual points are sorted in accordance with a modified quadtree or octtree. The drawing is recursively broken up into equal subdivisions until the maximum allowed number of points for a subdivision has been reached or until the size of the subdivision is less than a tolerance value. Once the number of points in a subdivision is less than the maximum allowed number of points, the points are individually compared to each other. If the subdivision is less than a tolerance value, the subdivision is small enough such that all of the lines within the subdivision are coincident. If the number of points is greater than the maximum allowed number of points and the subdivision is larger than the tolerance, the area is recursively subdivided.

Abstract: A method for rendering a line segment extending in the positive-x direction and positive-y direction on a computer display given a starting point and an ending point, the starting point having the form (xs, ys) and the ending point having the form (xe, ye). In this method, &Dgr;x and &Dgr;y are computed using the formula &Dgr;x=|xe−xs| and &Dgr;y=|ye−ys|, respectively. Then dt(0)=(yf*&Dgr;x)−(xf*&Dgr;y) is computed, where xf is the fractional portion of xs and yf is the fractional portion of ys, which allows for more precision. If the line segment extends in the postive-x and positive-y directions, then for each column n containing a portion of said line segment the process: plots said current pixel if dt(n)<=0.5*&Dgr;x and plotting the pixel above said current pixel if dt(n)>0.5*&Dgr;x; moves said current pixel to the right one pixel if dt(n)<=0.5*&Dgr;x and moves said pixel to the right and up one pixel if dt(n)>0.

Abstract: A method for rendering patterned lines in an environment that need not support rendering of patterned lines through a standard viewing mechanism, but that does support the rendering of graphical primitives in an off-screen imaging area. A solid line is rendered in the off-screen imaging area that has been filled with a background color by turning the pixels corresponding to the solid line from the background color to a line color. A pattern is next applied to the solid line to render a patterned line by use of a filtering mechanism that filters out pixels that correspond to off-segments of the pattern. The patterned line is next transferred from the off-screen imaging area to a viewing device where it is displayed.

Abstract: A method, apparatus, and system are described for rasterizing a triangle. Pixel parameter values are interpolated by adding or subtracting a vertical delta or by adding or subtracting a horizontal delta within a 4×4 tile of 16 pixels.

Abstract: In one embodiment, selecting a pixel in a screen region on a screen of a monitor of a computer graphics display system to activate in rendering a straight line segment by a rasterizer assigned to the screen region. Steps of aligning a rectangular grid to pixel boundaries, wherein the screen comprises a screen space divided into at least one screen region, wherein the screen region comprises multiple pixels, identifying each pixel in the screen region through which the straight line segment passes, and selecting each identified pixel to activate for rendering the straight line segment on the screen when the straight line segment passes through a diamond shaped area of the pixel whose boundary is defined by the lower, upper, left, and right pixel grid mid-points are disclosed.

Abstract: In one embodiment, selecting a screen region on a screen of a monitor of a computer graphics display system to activate in rendering a straight line segment. Steps of aligning a rectangular grid to screen region boundaries, wherein the screen includes a screen space divided into at least one screen region, locating a first and second endpoints of the straight line segment on the screen space, defining a rectangular bounding box in the screen space having vertices at the first and second endpoints, identifying each screen region that at least partially overlaps the bounding box, and selecting each identified screen region through which the straight line segment passes to activate for rendering the straight line segment on the screen are disclosed.

Abstract: A technique for filling a memory area that represents a rectangle. The rectangle or a first section thereof may be divided into i+j horizontal subsections. The i horizontal subsections may be filled in a first pass using i region fill processors. And the j horizontal subsections may be filled in a second pass using j region fill processors. A second section of the rectangle may be filled by dividing the second section into n vertical subsections having equal width and filling the n vertical subsections using n region fill processors.

Abstract: An improved device, of the type utilizing a display having pixels identified by a two-axis coordinate system, displays line segments referenced to the same coordinate system under control of a digital computer. The coordinate system, for example, having standard rectangular X and Y Cartesian coordinates, is configured so that each pixel lies at the intersection of a coordinate line from each of the axes. The improvement has an arrangement for determining as a major axis the axis of the coordinate system with respect to which the line moves most, and for defining the other one of the axes as the minor axis. For each major axis coordinate line crossing of the line segment, a pixel selection arrangement selects for display a pixel that both lies on the major axis coordinate line and has a minor axis coordinate that is closest to the line segment.

Abstract: A graphics processor uses a line draw facility to receive first and second values indicative of the coordinates of respective first and second end points of a line. The reception of the second value is sensed by the line draw facility and line data is generated responsive to the sensing of the second value.

Abstract: A thickening process of figure data (outline font data) is performed, an intersection where line segments on outlines cross is obtained, the outlines are separated at the intersection, the separated outline portions are synthesized, the rounding direction of the outlines after the outline synthesis is compared with the original rounding direction of the outlines, and the outlines in which the rounding directions are different from the original rounding direction are deleted. Thus, the outlines overlapped by the thickening process are correctly connected and the inside can be correctly painted.

Abstract: A system (10) and method (500) of black line insertion for overly tall imagers having random row access includes the step (502) of periodically writing in a predetermined number of input video lines into a memory (12) and the step (504) of speeding up the reading of the predetermined number of input video lines out from the memory to provide a time enhancement. The method further includes the step (506) of multiplexing (14) a black input line with the sped-up predetermined number of input video lines during the time enhancement to provide an output image. The method can include the step (508) of presenting on the overly tall imager (16) the output image using the random row access to place the lines in the correct vertical position.

Abstract: Reduction of aliasing artifacts along discontinuity edges of a rendered polygon mesh is achieved by overdrawing the edges as antialiased lines. The discontinuity edges are oriented consistently and blended as they approach silhouettes in the mesh to avoid popping at the edge, thereby achieving a temporal smoothness at the silhouettes. This temporal smoothness is balanced with a competing desire to maintain spatial sharpness by utilizing an asymmetric blending technique. To further improve results, the discontinuity edges can be sorted by depth prior to overdrawing them. These processes are effective at reducing the temporal artifact known as “crawling jaggies”.

Abstract: A method for rapid rendering of a desired line in a volumetric display having a rotatable screen includes stepping the rotatable screen through a sequence of angular positions and, at each angular position, rendering, on the rotatable screen, a rasterized approximation of a line segment containing an intersection of the desired line and the rotatable screen.

Abstract: An apparatus includes a memory which stores therein data of a dotted-line pattern, a unit which identifies successive pixels on a straight line to be drawn with respect to each line of a plurality of straight lines that are drawn side by side, a pattern reference unit which refers to the data of a dotted-line pattern while changing a reference address for accessing the memory in accordance with a slope of a dotted line to be drawn, and a drawing unit which draws the successive pixels in response to the data of a dotted-line pattern referred to by the pattern reference unit.

Abstract: A method and system compensates for the line width growth or shrinkage in an image rendering system that supports high-addressability. The amount of width adjustment can be a function of the line width. The method is applied after rendering, to the sub-pixel, bit patterns and is compatible with antialiasing and other sub-pixel rendering techniques such as half-bitting. The method and system also require less scan buffering for marker line width compensation than conventional methods. More specifically, the method and system require N+3 scans to detect and adjust widths up to N pixels for leading edges or trailing edges rather than the 2N+3 necessary conventionally. Moreover, the detection and adjustment of widths up to N pixels may be performed for both leading edges and trailing edges using a buffer that can handle 2N+3 scans.

Abstract: An apparatus, method and computer readable medium containing a program are described for generating a line corresponding to a desired straight line, including identifying a plurality of segments between two endpoints of the desired straight line to be generated, and generating the line corresponding to the desired straight line comprising identifying, in parallel, pixels in each of more than one of the segments. By processing in parallel, processor time is reduced. Also, anti-aliasing techniques can be similarly performed in parallel to reduce processor time.

Abstract: A line segment detector includes first and second weighted average sections, differentiating section, dot detecting section, and comparing section. The first weighted average section calculates the weighted average of the pixel values in the first detection window set in the first neighboring area of a target pixel. The second weighted average section calculates the weighted average of the pixel values in the second detection window set in the second neighboring area point symmetrical with the first neighboring area. The differentiating section calculates the absolute value of a difference between outputs from the first and second weighted average sections. The dot detecting section calculates the average of the absolute values of differential values between pixels in a direction of a vertical line, horizontal line, left-to-right downward slanting line, or left-to-right upward slanting line within the third detection window set in an area containing the target pixel.

Abstract: A geometry tiler identifies tiles on a computer's screen that are covered by a graphics primitive by use of edges of the graphics primitive. Precise identification of tiles of various types (such as edge tiles covered by a segment) eliminates identification of one or more tiles that are merely located adjacent to the graphics primitive, but are not touched by the graphics primitive. For example, the geometry tiler can identify each of three types of tiles: vertex tiles, edge tiles and interior tiles.

Abstract: Methods and apparatus implementing a technique for forming a trap polygon which does not interfere with the print quality of other trap polygons or objects. Edges in close proximity to a color transition edge (“CTE”) are checked for potential interference. A trap polygon is formed for the CTE that avoids any interfering edges or trap polygons for those edges. The technique can be applied to form a trap polygon for each edge in a page to be printed.

Abstract: In a method of displaying an emitted light beam seemingly irregularly folded, the emitted light beam is divided into a plurality of segments each of which has an angle which is regularly varied at each segment in accordance with a predetermined simple algorithm with a length and light intensity kept constant. Such segments which are regularly changed in angle can accomplish a powerful image of the emitted light beam when the segments are displayed on a screen of a display device by attaching a polygon and a texture to each segment. Such a display can be realized by simple calculation.

Abstract: There is provided an information processing apparatus in which when a route to a destination is searched, a road of the route is displayed with emphasis while a color or shape indicating the type of the road can be checked. When the route to the destination is searched, both sides of the road of the searched route are displayed with emphasis lines. The inside of both the sides of the road is displayed such that the type of the road, such as an expressway or an open load, can be recognized. By this, a user can easily check the searched route, and can check the type of the road of the route. For example, in the route from a current location to a destination, the user can check that a route A is an expressway, and other route B, route C, and route D are open roads.

Abstract: A surface reconstruction system generates a “crust” to re-construct d dimensional surfaces from a set of sample points. A Voronoi diagram, which comprises a plurality of Voronoi cells and Voronoi vertices, is generated from the sample points to define the geometric shape of the Voronoi cells. The surface features of the original surface are re-constructed from the geometric shape of the Voronoi cell through selection of a subset of Voronoi vertices of the Voronoi diagram so as to approximate the medial axis of the original surface. In one embodiment, a subset of Voronoi vertices of the Voronoi diagram are selected by designating at least one pole for a corresponding Voronoi cell. The surface reconstruction technique also computes a Deluanay triangulation from the sample points and the poles, and then filters triangles from the Deluanay triangulation in which all three vertices are not sample points.

Abstract: A system and method for intuitively generating computer-assisted animation utilizes a transformation space in which a computer input device such as a three-dimensional drawing wand is moved to generated constructed poses from a plurality of source poses. The transformation space may be in the form of a tetrahedron with each of the four vertices representative of a source pose. At any point within the three-dimensional volume of the tetrahedron, a constructed pose may be defined based on weighted averages of the four source poses. The animator may create a sequence of animation simply by moving the drawing wand within the tetrahedron. The rate of change of the transformations of the constructed poses is controlled by the rate of movement of the drawing wand but may be altered after the sequence of constructed poses is defined.

Abstract: An image processing device and method for processing an image defined by a combination of unit graphic forms or polygons are provided with an interpolated line completion unit which determines an interpolated line which is the line that interpolates a space between two vertices from an interpolation vector used to determine a line interpolating a space between a given vertex and another vertex among vertices of the unit graphic forms and from the coordinates of those vertices. An interpolated point computation unit is provided which determines as vertices of sub-unit graphic forms or subpolygons into which the polygons are to be split by the processing image device, interpolated points which are the points on the interpolated line. The interpolated line is a Bezier curve.

Abstract: A method is provided for increasing the speed at which a graphics image is displayed on a raster, such as in a liquid crystal display. The method incorporates off-line created look-up tables which are stored in memory means associated with a graphics processor unit. Thus, real time calculations are reduced resulting in a faster graphics image response time.

Abstract: A method, apparatus, article of manufacture, for implementing a relative polar angle snap tool. The relative polar angle snap tool allows the user to define lines and shapes that are at pre-settable angles relative to existing lines and shapes, and at pre-settable lengths.

Abstract: A method and apparatus for processing line anti-aliasing begins by walking a mathematical line based on the Bresenham technique. While walking the mathematical line at each pixel along the mathematical line- pixel coverage area is determined for each pixel of a set of pixels, where the set of pixels traverse a minor direction of the mathematical line. Note that for the mathematical line, the minor direction is the X direction when &Dgr;Y is greater than &Dgr;X and is in the Y direction when &Dgr;X is greater than &Dgr;Y. Once the coverage pixel coverage area of each pixel in the set of pixels has been determined, the intensity for each pixel in the set of pixels is determined. The intensity corresponds to the particular RGB value being generated for subsequent display.

Abstract: A graphics system and method for displaying lines on a display device. The system may comprise a sample buffer, a rendering unit and a sample-to-pixel calculation unit. The rendering unit may (a) generate a plurality of sample positions in a two-dimensional space, (b) determine a sample normal distance for each of the sample positions with respect to a line defined by the line-draw command, (c) assign sample values to the sample positions based on the sample normal distance of each of the sample positions, and (d) store the sample values in the sample buffer. The sample-to-pixel calculation unit may read sample values from the sample buffer, filter them to determine a pixel value, and transmit the pixel value to the display device. The rendering unit may render the line sample values with a narrower width to pre-compensate for the line-expanding effect of the filtering performed by the sample-to-pixel calculation unit.

Abstract: A technique and system for the realistic simulation of visual scenes reduces the three-dimensional computation to two additions and further reduces the need for three-dimensional computations by displaying several screen pixels per three-dimensional computation. The approach when implemented in hardware or software significantly speeds up scene generation time while improving the resolution and realism of the rendered scene.

Abstract: A computer graphics system renders an image on a display device using improved pre-filtering techniques that minimize aliasing artifacts in the image, particularly at the endpoints of lines. To anti-alias the image, a plurality of edges are placed near a line in the image. An edge function represents the edge. This edge function is multiplied by a scale factor to produce a distance function. This scale factor is the reciprocal of the Euclidean length of the line. The distance function is evaluated to determine the distance of selected pixels from each edge in units of pixels. These distances determine the intensity value for each selected pixel. Pixels on or beyond an edge, with respect to the line, are given a minimum intensity value; pixels inside all edges are given intensity values corresponding to their distances from the edge. An intensity function describing a relationship between pixel distances from the edges and their corresponding intensity values is developed.

Abstract: A method and a video game system that are capable of generating a field map with more natural geographical feature. The method and the video game system firstly divides the field map including a plurality of blocks into a first zone and a second zone by a boundary which consists of sides and comers in the blocks, then determines a first point for each side included in the boundary and a second point for each corner included in the boundary. Finally, the boundary is transformed into a more complex land shape by connecting the first points and the second points.

Abstract: Accurate display of line stipple in line segments, situated off the vertical or horizontal planes, is achieved by employing a calculated constant as a slope correction factor. The calculated constant, termed line style count, is determined utilizing the absolute length of the line segment, a ratio implementing the absolute length of the line segment, the major axis component of the line segment and fraction bits in the line counter. For each step along the major axis on a data processing system display, a constant value of 1.0 and the calculated constant, line style count, is added to a line style pointer to slope correct line stipple. A pre-computed square-root table is stored in texture memory and accessed for pre-calculated values to assist in reducing the time required to calculate accurate line style pointers.

Abstract: An accelerated video controller operates in conjunction with a video driver to accelerate certain video operations. If the operating environment requests a polygon operation, the driver (or software on the video controller) will determine whether the specified polygon is simple convex. The determination of whether a convex polygon is simple convex is accomplished by tracing between the vertices of the polygon and comparing the changes in direction relative to a predetermine coordinate axis to a threshold number. If the polygon is simple convex, certain operations can be performed using simpler code or hardware accelerated features. For a polygon fill, if the polygon is simple convex, the edges of the polygon are inspected to determine whether the polygon can be decomposed into a rectangle and a smaller polygon. If so, the video controllers bit engine will be used to perform the fill of the rectangle at high speed, thus reducing the time of the operation.

Abstract: A technique in which processing is applied indiscriminately to the line segments that construct a figure is replaced by a technique through which the optimum processing stage is selected depending upon drawing attributes (line width, slope of the line segment and shape, etc.) of the line segments per se and the particular figure in which the line segments are being used. This makes it possible to execute efficient drawing of graphics. To this end, it is determined whether a given line segment is horizontal or vertical, and ordinary processing is executed if the line segment is horizontal or vertical. In a case where the line segment is neither horizontal nor vertical and the width of the line segment is less than 2, a pen step conforming to the slope is used. If the line width is equal to or greater than 2, the corresponding pen step is used.

Abstract: General polygons are broken into trapezoids and/or triangles and exported to a graphics adapter for rendering. Intersecting line segments are broken at the point of inter-section. Simple polygons are then derived from the general polygon by starting at an outside corner and selecting line segments defining the general polygon utilizing criteria which will identify closed paths bounding a single area (e.g., always selecting the line segment which extends in a direction identical to or clockwise from the direction of the last selected line segment). Selected line segments are added to a current polygon definition. Each time an inter-section point is entered twice, the selected line segments from the first exit to the second entry of that intersection point are segregated into a separate polygon definition in the polygon list. Once all simple polygons have been identified, each polygon is broken into trapezoids and/or triangles.

Abstract: This invention is a three-dimensional image drawing apparatus that comprises a frame buffer for storing display data corresponding to a display screen in a display apparatus, and a two-dimensional drawing circuit for performing coordinate operations in order to draw specific two-dimensional images in the frame buffer. The apparatus also uses a Z buffer for storing depth data in order to perform three-dimensional drawing to the frame buffer, and a three-dimensional straight line drawing circuit for making three-dimensional drawings to the frame buffer based on the depth data stored in the Z buffer. The apparatus also uses a memory control circuit for controlling access to the buffers, and a bit number altering circuit for altering the number of bits per pixel in the coordinate operations of the two-dimensional drawing circuit either to a number of bits corresponding to the drawing data in the frame buffer or to a number of bits corresponding to the depth data in the Z buffer.

Abstract: In a graphics system, an apparatus and method reduce the computational complexity for clipping in a graphics environment by determining the relationship between a line and a graphics element, and performing an optimized number of calculations based on the determined relationship. More specifically, it is first determined whether a clipping operation must be performed at all. This is done by forming a rectangle using the line as a diagonal and comparing that rectangle to the graphics element area to determine overlap. If there is no overlap, no clipping needs to be performed. If there is overlap, the overlapping area is determined and categorized, and a corresponding clipping operation is then performed.

Abstract: The present invention intends to generate non-intersecting entire outline data from intersection-involving stroke data at a high speed, thereby outputting characters and graphics of higher quality at a higher speed. Every pair of the strokes are extracted from all the strokes of a registered character, then the curve data of the extracted strokes are straightened, and there is discriminated whether the line segments of the every extracted pair of the strokes mutually intersect. If an intersection is present, the coordinate of such intersection is calculated and stored. Then the outline is re-connected according to a predetermined rule, based on the stored coordinate of intersection.

Abstract: A two-dimensional image coordinate system is divided into areas each composed of N pixels in a first direction and M pixels in a second direction perpendicular to the first direction. Variations of rendering data for pixels are calculated with respect to the first and second directions and are used for interpolating values of the rendering data for each pixel from predetermined apex data of a predetermined graphic. An initial value of the rendering data on the side of the predetermined graphic is calculated using the value of a predetermined apex and the variation of the rendering data with respect to the first direction. First N×M rendering data is calculated using the initial value and the variations of the rendering data. Other N×M rendering data is calculated based on the variations of the rendering data with respect to the first direction and the second direction.

Abstract: A method and apparatus for overloading operators in Page Description Language (PDL) defined graphics adjusts widths of lines in a manner that yields preferred line widths, such as to compensate for certain undesirable line growth characteristics of a target printer or display device. Line width can be controlled based on various attributes, such as color, size, width, pattern or orientation. Line width can be redefined to be wider, narrower or of a differing color to achieve a desired printed graphic. The method, performed within a decomposer, examines individual lines of a PDL defined graphic, determines if compensation is needed to achieve a desired printed output, and redefines a modification attribute to achieve the compensation.

Abstract: A map editing apparatus is provided with various sections having respective editing functions which can be selectively specified for operating on one or more user-selected elements of a displayed map, with each editing function serving to automatically execute a specific editing operation, which may utilize one or more predetermined parameters. The apparatus includes a conformity management section having a function for detecting when execution of an editing operation will result in nonconformity in the map, such as mutual overlapping of map elements, and for automatically causing such an editing operation to be executed in a modified form, such as to prevent occurrence of the nonconformity.

Abstract: In a method for classifying line segment arrangements. A first line segment has endpoints A and B and a second line segment has endpoints C and D. A first triangle is traced along endpoints ABC, a second triangle is traced along endpoints ABD, a third triangle is traced along endpoints CDA, and a fourth triangle is traced along endpoints CDB. The signed areas of each of the four triangles are determined from the coordinates of the triangles. The arrangement of the line segments is classified according to the signed areas.

Abstract: A method, apparatus, and article of manufacture provides an interactive, dynamic, automatic dimension arrangement generator for a computer-aided drafting (CAD) system. The dimension arrangement generator selects one or more geometric entities displayed on the monitor of the CAD system and extracts one or more relevant dimension points for the selected geometric entities. The dimension arrangement generator selects one or more dimension line positions for the relevant dimension points, and then generates and displays the dimension arrangement for the selected geometric entities on the monitor of the CAD system in accordance with the extracted dimension points and selected dimension line positions.

Abstract: A routable operand and selectable operation processor multimedia extension unit is employed to draw lines in a video system using an efficient, parallel technique. A first series of integral y pixel values and error values are calculated according to Bresenham's line drawing algorithm. Then, subsequent pixels and error values are calculated in parallel based on the previously calculated values.

Abstract: A method and apparatus for overloading operators in Page Description Language (PDL) defined graphics redefines the graphic, such as to compensate for certain undesirable line growth characteristics of a target printer or display device. Line width can be controlled based on various attributes, such as color, size, width, pattern or orientation. Line width can be redefined to be wider, narrower or of a differing color to achieve a desired printed graphic. Also, the method and apparatus can compensate for fill in of reverse-line and “cookie-cutter” holes. The method, performed within a decomposer, examines individual lines of a PDL defined graphic, determines if compensation is needed to achieve a desired printed output, and redefines an operator to achieve the compensation. The compensation can include addition of wider reverse (white) lines under colored lines to prevent the fill in.

Abstract: A method and apparatus for providing video graphics processing that includes anti-aliasing begins when a video graphics processor receives vertex parameters of an object-element and walks a first edge of the object element and a second edge of the object element. The video graphics processor walks the first and second edges based on calculations involving a decision corner and an error term. The calculations indicate which direction to walk on a pixel by pixel basis, i.e., whether the walking should be in the major direction or the minor direction. The calculations also identify pixels that contain fragment pixel information, i.e., the pixels along the edges of the object element. For each fragment pixel, subpixel masks are created for each object element that is present in the fragmented pixel. From the subpixel masks, subpixel sequences are determined, which are used to produce pixel information of the fragment pixel.

Abstract: A method and apparatus for creating a display list permitting multiple states of the same type for a single primitive. By introducing a plurality of state variables of the same type in a predetermined order in a display list before a primitive description, different state variables of the same type are applied to different vertex descriptors of the primitive. In one embodiment, the state variables introduced are starting addresses of the groups of vertices addressable by vertex indices of the primitive. In a case where the primitive is a triangle, up to three different starting addresses might be introduced into the display list (one corresponding to each vertex of the triangle). By introducing multiple starting addresses, the vertex indices of the triangle description can be significantly shortened, the concern about variable length inputs can be eliminated, and each index is independent of its predecessor in the master display list.

Abstract: In a distributed computer system, a method for lossless compression of a graphical line within an application server allows the compressed line data to be transmitted over a low bandwidth transport mechanism to a graphical user interface for display on a workstation. The application server determines, from graphical line data representative of the graphical line, coordinate locations for the endpoints of each sub-path of the graphical line and attributes of each sub-path. The application server generates a compressed line data packet of variable length which includes the coordinate location data and attribute data for each sub-path of the graphical line.