Abstract: A system updates the z-values corresponding to pixels of a computer graphics screen. An integral part of the system comprises a controller/memory module which employs preliminary determinations as to whether or not a z-value has been previously stored for a pixel, multiple comparators, and partial read and write operations to achieve a significantly higher memory bandwidth. The bandwidth can be further increased by configuring a plurality of such modules in a parallel architecture.

Abstract: The present invention provides an apparatus and method for converting font outlines to rasterized bit maps. The method accesses stored outline data representing the object in a first coordinate space and transforms the outline data to corresponding data representing the object in a second coordinate space, maintaining regional relationship information in both coordinate spaces, through a non-linear transformation expressed as a plurality of linear transformation matrices, to generate a bit map suitable for displaying the object.The present invention includes an apparatus to analyze Bezier curves and subdivide them as necessary until each portion is sufficiently flat to be approximated as a straight line, and then to calculate where line segments cross pixel midlines in order to fill the outline and generate the bit map.

Abstract: An information transferring system operating in an information processing system capable of performing highly efficient and reliable exchanges of data between two or more windows respectively operating on different window systems without the necessity of changing the window systems, using a data area in the form of a clipboard or a similar memory area specified for temporary data storage and transferring the data for such exchanges by way of an exclusive-use communication line or a shared memory medium, with or without the use of selection protocols, thereby achieving further improved reliability and higher efficiency in the data exchanging operations between window systems and application programs operating within the window systems.

Abstract: A figure filling device fills a figure in memory defined by X-Y coordinate scan line by scan line with reference to a specified pattern. In the filling of a new scan line, the coordinate data for the ends of the new scan line, for the ends of the previously processed scan line and for the reference point of the previous pattern are subjected to a certain processing so that the coordinate data for the reference point of the new pattern is determined. The filling device determines the address in the memory corresponding to the coordinates for the reference point of the new pattern and the address on the memory corresponding to the coordinates for the ends of the new scan line. A filling pattern is read out of the pattern address in the memory and the scan line data is read out of the scan line address on the memory so that they are subjected to a predetermined operation. The result is written to the scan line address.

Abstract: Modern electronic office environments often include hundreds of different document format types. Format/object transformation applications exist which are capable of transforming a first selected document/object format into a second selected document/object format; however, the existence of thousands of such transformation applications make it difficult to identify the existence of multiple stage format transformations. Accordingly, a matrix is established having multiple rows and columns of zero value cells. An identification of selected document/object formats is associated with each row and column of the matrix. Thereafter, for each existing transformation capable of directly converting a selected document/object format into a second selected document/object format a value of one is entered into a cell at the intersection of a row of the matrix associated with the selected document/object format and a column of the matrix associated with the second selected document/object format.

Abstract: A method for automated re-layout of two-dimensional drawings from a solid model, wherein the solid model can be revised to incorporate design changes, for example. The re-layout process is invoked to automatically generate revised two-dimensional drawings which exactly duplicate an original set of two-dimensional drawings, except that geometry modified in the solid model will be automatically modified in the re-layout drawings. Dimensional data from the original set of drawings associated with unchanged geometry will be automatically associated with and added to the re-layout drawings. The invention permits the solid model to remain the master throughout the design process, while reliably carrying through design changes to the two-dimensional drawings. The user is not required to manually re-enter unchanged dimensional data from one drawing to the next revision.

Abstract: A method for displaying statements of a computer program during an animation of the program's execution, the display using multiple colors to identify statements based on their respective frequency of execution, is disclosed. As a program statement becomes the current executed statement during the animation, the statement's frequency of execution is calculated as the number of times the statement has been executed so far during the animation, divided by the total number of statement executions throughout the animation. A display color is assigned based on whether the statement's execution frequency has reached one of two or more thresholds. The multi-hued display of program statements based on thresholds of execution frequency assists the programmer in understanding the operation of the program.

Abstract: A three-dimensional pixel cache for use in a computer graphics system comprises source, pattern, and destination tile caches and a barrel shift register, or rotator, that serves as an interface between the tile caches and a frame buffer. The rotator has the capability of performing three types of rotation of data read/written from/to the tile caches horizontal rotation, vertical rotation, and rotation of nibbles within each pixel.

Abstract: Image data including depth data on a pixel basis representing a sphere or column are previously generated and stored in a mapping memory. When the sphere or column is to be displayed on a display screen, the image data are read out from the mapping memory. The image data thus read out are mapped to a predetermined region of a memory for display and are processed for hidden surface removal simultaneously.

Abstract: A character pattern generating apparatus providing a character pattern which can be reduced or enlarged in size providing high fidelity. The apparatus stores outline data of the dot patterns to be displayed. The outline data includes line segments and/or subcurves and associated correction data. In computing the display coordinates for the selected outline data, the line segments and/or subcurves forming the outline are multiplied by a scaling factor modified by the correction data.

Abstract: An image rotation method and an image rotation processing apparatus in an image processing apparatus are disclosed. The image rotation method obtains the image coordinates (x',y') of a rotated image which is recorded in a second memory, by sequentially scanning a first memory where the M.times.N original image is recorded and adding the increments of x and y corresponding to a rotation angle .theta. repeatedly, and transmits the image element data of the coordinates (x,y) of the first memory to the coordinates (x',y') of the second memory with one-to-one correspondence, thereby obtaining the rotated image through the rotation angle .theta. from the original image. Thus, the present invention can obtain the rotated image using only addition operations and without any multiplication operations, so that high-speed operation is possible and an image can be rotated through a specified angle .theta. through software in common computer graphic systems having no floating point multiplier.

Abstract: A mathematically describable outline font and system for generating cursively concatenated text output using context-sensitive letter forms drawn from a single, standard ASCII character set. In creating such letter forms, each letter of the alphabet, is reduced to its basemost, non-context-sensitive form and joined by context dependent connector characters, as determined upon base letterform pairs. Special characters and connectors are also substituted in the presence of predetermined adjacent character pairs, providing an unbroken sequence of output characters which simulates human cursive handwriting as taught by the Zanerian method. Unlike script fonts currently available in the art which rely on overlapping or disjointed connector components in an attempt to simulate handwriting, the font and system of type generation disclosed by the present invention produces electronically set type having interconnected cursive characters and a common stroke width.

Abstract: The apparatus provides a way of receiving graphic symbols whose sizes are mutually different, and whose positions are irregularly arranged, such as a handwritten flow chart. For example, the apparatus automatically generates a flow chart image in which sizes of the graphic symbols are adjusted to be balanced, and in which the positions of the centers of the graphic symbols are aligned. First, the apparatus transforms the input graphic image into vectors representing the graphic symbols. Then, a set of symbol parameters are recognized for each graphic symbol. Center positions of the groups of graphic symbols which fall within a predetermined range, are aligned. Also, the heights and widths of the group of graphic symbol are adjusted through use of the symbol parameters. Finally, aligned, size-adjusted graphic symbols are output in an output image.

Abstract: Display control logic for a terminal controller with support for such features as windows and interlace. A display list processor (DLP) (20) communicates with a program memory (12) containing DLP instructions, a display memory (12) containing character codes and attributes for the display, and a font memory (13). As the DLP program executes, it causes accesses to the display memory and brings in character codes and attributes for ultimate display on the screen. These character codes and attributes, as well as information representative of the scan line are input to a video data queue (95). The queue entries are clocked out of the queue by a character clock (170) and are used to generate addresses to font memory. Bitmaps from font memory are read into a dot shifter (190). The DLP instruction set includes a DISPLAY STRING instruction which allows a portion of a scan line to be built up by specifying the length of the scan line segment and the starting address in memory.

Abstract: A graphic data processing apparatus including an input device for entering graphic data, a graphic data processing device for generating a visible pattern such as a drawing consisting of points represented by the graphic data, and lines connecting the points, and a display for displaying the generated pattern. The apparatus further includes a pattern data memory for storing pattern data representative of the visible pattern, an assessment data memory for storing assessment data for assessing the visible pattern, and a design assessing device for retrieving from the pattern data memory a portion of the pattern data which relates to at least one specified assessment item. The design assessing device operates to assess the portion of the pattern data against the assessment data, to determine whether the pattern data is adequate or not.

Abstract: A printer and method of operating same which receives print jobs from a host computer encoded in any one of several printer control languages. The printer has the capability of interpreting print jobs in each printer control language. The printer samples a portion of each print job and, using a resident algorithm and data sets obtained by statistical techniques, analyzes the sampled portion of the print job to identify the printer control language in which the print job is encoded.

Abstract: An iconic programming system allowing a user to specify data input constraints and names for any terminal of any icon of an iconic network program defined within the system. The system allows names of any length and allows a programmer to change the names at any time after the iconic network is created. The system further provides a facility to lock the names so that they cannot be changed later.

Abstract: A method for determining the proper occulation relationship between a calligraphic point and at least one of another calligraphic point and a surface in a raster image, divides the total image screen into an array of spans, each containing an ordered set of pixels which may be further divided into an array of subpixels; determines which of the subpixels on the total screen lie inside each of the raster surfaces and calligraphic points which must be considered for the image totality; then orders the distance of each of the raster surfaces from the viewing point and also orders the distance of each of the point features from the viewing point; and then compares the ordered distances of each point to at least one of the raster surface distances and other point distances to determine which of subpixels of the point or surface/other point are occluded and which subpixels are visible.

Abstract: A method of drawing a straight or curved line of predetermined thickness on a raster device having a display or printed page consisting of a rectangular array of pels. Initially, a spine list is generated which comprises a digitization of a spine that can be swept by a preselected pen of thickness 2t centered on the spine to draw the line or "stroke." The next step is to generate penleft and penright lists representing the X and Y coordinate values of the left and right sides of the pen. Thereafter, left and right lists representing a pair of boundaries of the stroke are generated by starting at a first end of the spine list and sequentially moving toward a second end of the spine list. For each position in the spine list, the X, Y coordinate values thereof are added to the X and Y coordinate values in the penleft list. The left list is updated when any of the resulting sums yield an X value less than the current X value for the corresponding Y value in the left list.

Abstract: A graphics processing system arranged to display on a display screen of a display unit a line image produced on the basis of image data stored in a storage and graphics produced on the basis of vector data stored in the storage in an overlapping manner contains a line image delete processing unit for implementing delete processing of the line image in a segment in which a pixel displaying the graphics is displayed so as to overlap with a pixel displaying the line image, wherein the line image delete processing unit is arranged so as to leave only the pixel displaying the graphics undeleted yet to delete the pixel displaying the line image within a range from a range which is broader than a predetermined line width of a distorted line to a line width of the line image.