Data processing method and apparatus

Abstract: In a picture data processing system for improving processing speed, a main CPU (111) transmits coordinates of a center point in a three-dimensional space over a main bus (101) to a programmable pre-processor (120) which generates figure data for drawing plural unit figures (polygons) around the center point transmitted from the CPU (111) and sends the figure data to a graphic processing unit (115). The graphic processing unit (115) performs rendering processing in accordance with figure data supplied from the programmable pre-processor (120) for drawing a picture defined by the combination of the unit figures in a graphic memory (118).

Description: This invention relates generally to data processing methods and apparatus, and in particular to picture information processing techniques which may, for example, be employed with advantage in a graphics computer such as video equipment employing a computer, a special effects device (effector) or a video game machine. It is common practice in the prior art to employ a video game machine wherein a main central processing unit (CPU) encloses a geometry transfer engine (GTE) which is a calculation processor for executing geometry processing such as coordinate transformation, perspective transformation, clipping or light source calculations. The main CPU defines a three-dimensional model as a combination of basic unit figures, such as triangles or quadrangles (three-dimensional model) for generating data for delineating a three-dimensional image. When displaying, for example, a three-dimensional object, the main CPU resolves the object into plural unit figures and causes a GTE to perform geometry processing to generate figure data for drawing each unit figure. The main CPU is connected to a main bus and causes the figure data generated by the GTE to be transferred over the main bus 101 to a graphic processing unit (GPU). On reception of the figure data from the main CPU, the GPU performs rendering processing of writing pixel-based picture data in a graphic memory from Z-values specifying the color data and the length of apex points of unit figures contained in the figure data (the information on the distance from the beginning point along the length), taking into account the color and the Z-values of all pixels making up the unit figure. The unit figure is drawn in this manner in the graphic memory. In addition, the CPU performs control for reading out the picture data written in the graphics memory to supply the picture data thus read out as video signals via a display controller, such as a CRT controller (CRTC) as video signal, for display on a display device, such as a television receiver, a cathode ray tube (CRT), liquid crystal or the like monitor. This permits the background of a video game, characters or the like to be displayed. Meanwhile, the data of the unit figures, geometry-processed by the GTE under control by the cPU, are coordinates in the three-dimensional space of the apex points of the unit figure. Therefore, the data volume is irrelevant to the size of the unit figure. On the other hand, the drawing rate with which the unit figure is drawn on the pixel basis in the graphic memory is dependent on the size of the unit figure, that is the number of pixels making up the unit figure. Hence, if there are a large number of pixels making up the unit figure, drawing the unit figure is time-consuming, whereas, if the unit figure is made up of a smaller number of pixels, drawing the unit figure is not time-consuming. Therefore, in continuously processing plural small-sized unit figures, it is a frequent occurrence that the figure data is not transferred in time from the main CPU over the main bus, despite the fact that the GPU has completed the rendering processing and is ready for performing the next processing. In other words, when a large number of small-sized unit figures are transferred from the main CPU to the GPU over the main bus, the transfer rate is limited by the main bus, with the result that it becomes difficult to improve the overall processing speed of the device Haralick R.M., Shapiro L. G.: Computer and Robot Vision, chapter 9.1, 1992; US 4 975 860 (KITAYA); and GEYMAYER B ET AL: 'ANIMATION OF LANDSCAPES USING SATELLITE IMAGERY' EUROGRAPHICS, VIENNA, SEPT. 2 - 6, 1991, no. CONF. 12, 2 September 1991, POST F H;BARTH W, pages 437-446, XP000300288 disclose graphical drawing systems. In one aspect, the present invention provides a picture information system comprising: a first processor for generating a drawing command and figure data having a first centre point and for outputting the drawing command and figure data on a bus which has a limited data transferring speed; a second processor for receiving the drawing command and figure data via the bus, for generating a plurality of second centre points positioned relative to the first centre point and for generating, for each of the plurality of second centre points, further figure data for a unit figure, the further figure data including a plurality of apex points positioned relative to a corresponding one of the plurality of second centre points; and a graphic processor for drawing each of the unit figures in accordance with the further figure data; in which the second processor supplies the generated further figure data to the graphi processor directly without using the bus. This invention also provides a picture information method used in a system comprising a first processor for generating a drawing command and figure data having a first centre point, a second processing connected to the first processor via a bus which has a limited data transferring speed, and a graphic processor, the method comprising the steps of: supplying the drawing command and figure data generated by the first processor to the second processor via the bus; the second processor generating a plurality of second centre points positioned relative to the first centre point according to the drawing command; the second processor generating, for each of the plurality of second centre points, further figure data for a unit figure, the further figure data including a plurality of apex points positioned relative to a corresponding one of the plurality of second centre points; and supplying the further figure data generated by the second processor from the second processor to the graphic processor directly without using the bus, so that the unit figures are drawn in a graphic memory. In a picture information processing method and apparatus according to a preferred embodiment of the invention, figure data transmitted by output means over a pre-set bus are received and figure data for drawing plural unit figures are generated from the sole figure data and sent to drawing means, thus allowing an increase in the overall processing speed of the entire system. Hence, the preferred embodiment of the present invention may satisfy a long existing need for enhanced data processing at increased processing speed. The invention will now be described by way of example with reference to the accompanying drawings, throughout which like parts are referred to by like references, and in which: Fig. 1 is a block diagram illustrating a known video game machine; Fig. 2 is a plan view showing the structure of a video game machine embodying the present invention; Fig. 3 is a front view of the video game machine of Fig. 2; Fig. 4 is a side view of the video game machine of Fig. 2; Fig. 5 is a plan view showing a CD-ROM; Fig. 6 is a system block diagram for a game machine incorporating the invention; Fig. 7 is a flowchart for illustrating the processing of a programmed pre-processor (PPP) as shown in Fig. 6; Figs. 8A and 8B illustrate a unit figure generated by random numbers; Fig. 9 shows a unit figure generated by dividing the unit figure in a two-dimensional space; Fig. 10 shows a unit figure generated by dividing the unit figure in a three-dimensional space; and Fig. 11 illustrates a screen clip. A typical example of a prior art video game machine is shown in Fig. 1, wherein a main central processing unit (CPU) 111 encloses a geometry transfer engine (GTE) which is a calculation processor for executing geometry processing such as coordinate transformation, perspective transformation, clipping or light source calculations. The main CPU 111 defines a three-dimensional model as a combination of basic unit figures, such as triangles or quadrangles (three-dimensional model) for generating data for delineating a three-dimensional image. When displaying, for example, a three-dimensional object, the main CPU 111 resolves the object into plural unit figures and causes a GTE 117 to perform geometry processing to generate figure data for drawing each unit figure. The main CPU 111 is connected to a main bus 101 and causes the figure data generated by the GTE 117 to be transferred over the main bus 101 to a graphic processing unit (GPU) 115. On reception of the figure data from the main CPU 111, the GPU 115 performs rendering processing of writing pixel-based picture data in a graphic memory 118 from Z-values specifying the color data and the length of apex points of unit figures contained in the figure data (the information on the distance from the beginning point along the length), taking into account the color and the Z-values of all pixels making up the unit figure. The unit figure is drawn in this manner in the graphic memory. In addition, the CPU 111 performs control for reading out the picture data written in the graphics memory 118 to supply the picture data thus read out as video signals via a display controller, such as a CRT controller (CRTC) as video signal, for display on a display device, such as a television receiver, a cathode ray tube (CRT), liquid crystal or the like monitor. This permits the background of a video game, characters or the like to be displayed. Meanwhile, the data of the unit figures, geometry-processed by the GTE 117 under control by the CPU 111, are coordinates in the three-dimensional space of the apex points of the unit figure. Therefore, the data volume is irrelevant to the size of the unit figure. On the other hand, the drawing rate with which the unit figure is drawn on the pixel basis in the graphic memory 118 is dependent on the size of the unit figure, that is the number of pixels making up the unit figure. Hence, if there are a large number of pixels making up the unit figure, drawing the unit figure is time-consuming, whereas, if the unit figure is made up of a smaller number of pixels, drawing the unit figure is not time-consuming. Therefore, in continuously processing plural small-sized unit figures, it is a frequent occurrence that the figure data is not transferred in time from the main CPU 111 over the main bus 101, despite the fact that the GPU 115 has completed the rendering processing and is ready for performing the next processing. In other words, when the large number of small-sized unit figures are transferred from the main CPU 111 to the GPU 115 over the main bus 101, the transfer rate is limited by the main bus 101, with the result that it becomes difficult to improve the overall processing speed of the device. Referring now more particularly to Figs. 2-4 of the drawings, a video game machine embodying the invention is made up of a main body portion of the machine 2, an actuating unit 17 having a substantially tetragonally-shaped connection terminal portion 26 connected to the main body portion of the machine 2 and a recording device 38 similarly connected to the main body portion of the machine 2. The main body portion of the machine 2 is substantially tetragonally-shaped and is provided at a mid portion thereof with a disc loading unit 3 for loading thereon a recording medium for game having recorded thereon programs or data for playing the game. In the present embodiment, a CD (compact disc) -ROM 51 shown for example in Fig. 5 is detachably mounted on the disc loading unit 3. The recording medium for a game, however, is not limited to a disc. On the left-hand side of the game loading unit 3 are mounted a reset switch 4, actuated when resetting the game and a power source switch 5 actuated when turning the power source on or off. On the right-hand side of the game loading unit 3 is mounted a disc actuating switch 6 actuated for opening/closing the disc loading unit 3. On the front side of the main body portion of the machine 2 are mounted connecting units 7A, 7B to which the actuating unit 17 and the recording device 38 can be connected as a set. Although the connecting units 7A, 7B are mounted for connecting the two sets of the actuating units 17 and the recording devices 38, it is possible to provide a number of the connecting units necessary for connecting more than two sets of the actuating units 17 and the recording devices 38. The connecting units 7A, 7B are formed in two tiers, as shown in Figs. 3 and 4. The upper tier includes a recording inserting unit 8 connected to the recording device 38, while the lower tier includes a connection terminal inserting unit 12 connected to the connection terminal 26 of the actuating unit 17. The insertion opening of the recording inserting unit 8 is of a transversely elongated rectangular shape. The lower side corners of the inserting opening are rounded more prominently than the upper side corners thereof for preventing the recording device 38 from being inserted n the upside-down position. The recording inserting unit 8 is also provided with a shutter 9 for protecting connection terminals (not shown) for assuring internal electrical connection. The shutter 9 is mounted in such a state in which it is perpetually biased towards outside under the force of a spring shaped as a torsion coil spring. Therefore, when inserting the recording device 38, the shutter 9 is opened towards the rear at a forward side of inserting the recording device 38. When the recording device 38 is pulled out, the shutter 9 is reset under the bias of the spring and automatically set to the closed state for protecting the internal connection terminal from dust and dirt and from external shock. Referring again to Figs. 3 and 4, the connection terminal inserting unit 12 has an inserting opening of a transversely elongated rectangular shape. The lower side corners of the inserting opening are rounded more prominently than the upper side corners thereof for preventing the connection terminal portion 26 of the actuating unit 17 from being inserted n the upside-down position. In addition, the inserting opening is different in profile from the inserting opening of the recording inserting unit 8 for preventing the recording device from being inserted therein. In this manner, the inserting openings for the recording device 38 and the actuating unit 17 are distinct in size and profile from each other for preventing mistaken insertion. As shown in Fig. 2, the actuating unit 17 is configured so as to be held between palms of both hands so that five fingers of both hands are movable freely. The actuating unit 17 is made up of interconnected first and second rounded operating portions 18, 19, symmetrically shaped in the left-and-right direction, first and second square-shaped supporting portions 20, 21 protuberantly formed from the first and second rounded operating portions 18, 19, a selection switch 22 and a start switch 23, provided in mid constricted portions of the first and second rounded operating portions 18, 19, third and fourth operating portions 24, 25 protuberantly formed on the front sides of the first and second operating portions 18, 19 and a connection terminal portion 26 electrically connected to the main body portion of the machine 2 over a cable 27. The cable 27, however, may be omitted, if the overall structure is so configured. The connecting terminal portion 26 is mounted on the distal end of the cable 27 adapted for being electrically connected to the main body portion of the machine 2. The connecting terminal portion 26 has a gripping portion 26A having its lateral surfaces roughed for slip-proofing effects, such as by knurling. The gripping portion of the connecting terminal portion 26 is formed as a so-called telescopic portion and has its size, that is the width W and the length L, equal to that of a grip 38A of the recording device 38, as later explained. The recording device 38 has enclosed therein a non-volatile memory, such as a flash memory. The recording device 38 has the grip 38A (Fig. 4) configured similarly to the grip of the connection terminal 26 so that the recording device can be easily mounted on or dismounted from the main body portion of the machine 2. The recording device 38 is designed so that, when the game is discontinued temporarily, the prevailing state of the game is stored in the recording device. Thus, when re-starting the game, data is read out from the recording device 38 so that the game can be re-started from the state corresponding to the stored state, that is from the suspended state. When the game is played by the above-described video game machine, the user connects the actuating unit 17 to the main body portion of the machine 2 and, if necessary, the recording device 38 is also connected to the main body portion of the machine 2. In addition, the user actuates the disc operating switch 6 for setting the CD-ROM 51 as the recording medium for game on the disc loading unit 3. The user also actuates the power source switch 5 for turning on the power source of the main body portion of the machine 2. since the main body portion of the machine 2 now reproduces the picture and the speech for the game, the user actuates the actuating unit 17 to play the game. The overall electrical system shown in Fig. 6 shares many of the components and basic functions as those shown in Fig. 1 as depicted by the same numerals. That is, the present main body portion of the machine 2 is basically configured in the same way as the video game machine of Fig. 1 except that a programmable pre-processor (PPP) 120 is newly provided between a main bus 101 and the GPU 115, to facilitate practice of the present invention. The main body portion of the machine 2 has two types of buses, that is a main bus 101 and a sub-bus 102, for exchanging data between respective subsystem blocks. The main bus 101 and the sub-bus 102 are interconnected by a bus controller 116 To the main bus 101, there are connected, in addition to the bus controller 116, a main CPU 111 (output means), comprised of, for example, a microprocessor, a main memory 112, comprised of, for example, a random access memory (RAM), a main direct memory access controller (DMAC) 113, an MPEG (Moving Picture Experts Group) decoder (MDEC) 114, a GPU (drawing means) 115 and a PPP (programmed pre-processor) as a generating means 120. To the sub-bus 102, there are connected, in addition to the bus controller 116, the GPU 115, such as a CPU 121 configured similarly to the main CPU 111, a sub-memory 122, configured similarly to the main memory 121, a sub-DMAC 123, a read-only memory (ROM) 124 having stored therein an operating system or the like, a sound processing system (SPU) 125, an asynchronous transmission mode (ATM) communication unit 126, a subsidiary storage device 127 and an interface (I/F) for input device 128. The main bus 101 is designed for high-speed data communication, while the sub-bus 102 is designed for low-speed data communication. That is, the sub-bus 102 is used for data that can be exchanged at a low speed for assuring high-speed operation on the main bus 101. The main bus 101 can be disconnected from the sub-bus 102, while the sub-bus 102 can be connected to the main bus 101, under control by the bus controller 116. If the main bus 101 and the sub-bus 102 are disconnected from each other, only the devices connected to the main bus 101 can be accessed from the main bus 101, while only the devices connected to the sub-bus 102 can be accessed from the sub-bus 102. However, if the sub-bus 102 is connected to the main bus 101, any devices can be accessed from the main bus 101 or from the sub-bus 102. Meanwhile, in an initial state, such as immediately after turning on the power source of the system, the bus controller 116, is in the open state (that is, the main bus 101 remains connected to the sub-bus 102). The main CPU 111 is designed for performing various processing operations in accordance with a program stored in the main memory 112. When the system is started, the main CPU 111 reads out a boot program via the bus controller 116 from the ROM 124 connected to the sub-bus 102 and executes the read-out program. This causes the main CPU 111 to load the application program, herein the boot program, and necessary data, in the main memory 112 or in the sub-memory 122 from the subsidiary storage device 127. The main CPU 111 thus executes the program loaded on the main memory 112. The main CPU 111 has enclosed therein the GTE 117 as explained previously. This GTE 117 has a parallel operating subsystem, for executing plural processing operations in parallel, and executes geometry processing, such as coordinate transformation, light source calculations, matrix operations or vector operations, at a fast rate, responsive to requests from the main CPU 111. The GTE 117 thus performs processing corresponding to the requests from the main CPU 111 (geometry processing) for generating figure data of the unit figures to supply the figure data to the main CPU 111. On reception of the figure data from the GTE 117, the main CPU 111 generates a packet containing the figure data and transfers the packet over the main bus 101 to the GPU 115 or to the PPP 120. Meanwhile, the main CPU 111 has enclosed therein a cache memory 119 and has access to this cache memory 119 instead of the main memory 112 for speeding up the processing. The main DMAC 113 performs DMA transfer control on the devices connected to the main bus 101. If the bus controller 16 is in the open state, the main DMAC 113 also performs control on the devices connected to the sub-bus 102. The MDEC 114 is an I/O device capable of operating in parallel with the main CPU 111 and is configured for operating as a picture expanding engine. That is, the MDEC 114 s configured for decoding the encoded and compressed moving picture data. The GPU 115 is configured for operating as a rendering processor. That is, the GPU 115 is configured for performing rendering processing of receiving a packet transmitted from the main CPU 111, main DMAC 113 or from the PPP 120 and writing picture data corresponding to the unit figure in the graphic memory 118 based on the Z-values arrayed as figure data in the packet for specifying color data and the length of the apex points of the unit figure. The GPU 115 is also configured for reading out picture data written in the graphic memory 118 for outputting the picture data thus read out as video signals. The GPU 115 is also configured for receiving packets from the devices connected to the sub-bus 102 if need be for performing rendering in accordance with figure data arrayed in the packets. The graphic memory 118 is comprised of, for example, a DRAM for temporarily storing picture data supplied from the GPU 115. The graphic memory has such properties that it can be accessed on the page basis at a fast rate but it can be accessed across the pages only at an extremely retarded rate. Meanwhile, the graphic memory 118 has an area sufficient to store picture data for two frames so that picture data can be read out from one of the areas whilst picture data is being written in the other area. The PPP 120 receives a packet transmitted from the main CPU 111 or from the main DMAC 113 and generates figure data for drawing plural unit figures from the sole figure data arrayed in the packet to packetize the figure data and to supply the resulting packet to the GPU 115. The sub-CPU 121 reads out and executes the program stored in the sub-memory 122 in order to perform various processing operations. Similarly to the main memory 112, the sub-memory 122 is designed for storing programs or necessary data. The sub-DMAC 123 is designed for controlling DMA transfer for the devices connected to the sub-bus 102. The sub-DMAC 123 is designed to acquire bus rights only when the bus controller 116 is in the closed state, that is when the main bus 101 is disconnected from the sub-bus 102. The ROM 124 holds on memory the boot program and the operating system as explained previously. Meanwhile, the ROM 124 holds on memory both the program for the main CPU 111 and the program for the sub-CPU 121. The ROM 124 is of slow accessing speed and, hence, is connected to the sub-bus 102. The SPU 125 is configured for receiving a packet transmitted from the sub-CPU 121 or the sub-DMAC 123 for reading out the speech data from the sound memory 129 in accordance with the sound command arrayed in the packet. The SPU 125 is configured for supplying and outputting the read-out speech data to a speaker, not shown. The ATM communication unit 126 is configured for controlling the communication over a public network, not shown (ATM communication). This enables the user of the video game machine to play the video game with a user of another video game machine directly or by having data exchanged with the user of the other video game machine via a pre-set center station. The subsidiary storage device 127 is configured for reproducing the information (programs and data) stored in the CD-ROM 51 (Figs. 2 and 5) in, for example, a disc drive. The subsidiary storage device 127 is also configured for recording or reading out data for the recording device 38 (Fig. 2). The I/F for input device 128 is an interface for accepting an input from outside, such as a signal corresponding to actuation of the actuating unit 17 as a control pad (Fig. 2) or a picture or speech reproduced by another device, and is configured for outputting a signal corresponding to the input from outside over the sub-bus 102. The sound memory 129 holds the speech data in memory. In the above-described main body portion of the game machine 102, the boot program is read out from the ROM 124 in the main CPU 111 and executed on power up of the system for reading out the program and data from the CD-ROM 51 set in the subsidiary storage device 127 so as to be developed in the main memory 112 and the sub-memory 122. The program developed on the main memory 112 and the sub-memory 122 is executed in the main CPU 111 or in the sub-CPU 121 for reproducing the picture and the speech of the game. In the main CPU 111, unit figure data for drawing a unit figure constituting a three-dimensional picture is generated in accordance with data stored in the main memory 112. These unit figure data are packetized and sent over the main bus 101 to the GPU 115 or to the PPP 120. On reception of a packet from the main CPU 111, the PPP 120 first unpacketizes the packet at step S1 in the flowchart of Fig. 7 for taking out the figure data corresponding to a unit figure arrayed therein. The PPP 120 further generates at step S2 figure data corresponding to plural unit figures from the sole figure data to perform coordinate transformation or perspective transformation on the generated figure data if need be. The PPP 120 packetizes the plural figure data thus obtained and, at step S3, sends the packet to the GPU 115. The GPU 115 receives the packet from the main CPU 111 or PPP 120 and performs rendering processing in accordance with figure data arrayed in the packet for writing the picture data in the graphic memory 118. The GPU 115 reads out previously written picture data from the graphic memory 118 and outputs the picture data as video signals. This displays a picture of the game. On the other hand, the sub-CPU 121 generates a sound command for instructing speech generation in accordance with data stored in the sub-memory 122. This sound command is packetized and sent over sub-bus 102 to the SPU 125. The SPU 125 reads out and outputs speech data from the sound memory 129 in accordance with the sound command from the sub-CPU 121. This outputs the background music (BM) or the other speech for the game. Referring to Figs. 8A, 8B to 11, processing by the PPP 120 is further explained. The main CPU 111 is configured for transmitting a packet over the main bus 101 to the PPP 120. The packet includes the coordinates of a pre-set center point O (x0, y0, z0) in a three-dimensional space as a figure data and a command for instructing to draw plural triangles around the center point O. On reception of the packet, the PPP 120 generates a point O' at a point spaced a random distance from the center point O in a random direction, as shown in Fig. 8A. This point O' proves to be the center of the unit figure which herein is a triangle. That is, the PPP 120 generates three random numbers ox, oy and oz, and the point O' is a point represented by a coordinate (x0 + ox, y0 + oy, z0 + oz). In addition, the PPP 120 generates three points A, B and C, as apex points of the unit figure, at points each spaced a random distance in a random direction from the point O', as shown in Fig. 8A. That is, the PPP 120 generates nine random numbers rx0, rx1, rx2, ry0, ry1, ry2, rz0, rz1, rz2. The points represented by the coordinates (X0 + ox + rX0, y0 + oy + ry0, z0 + oz + rz0), (X0 + ox + rx1, y0 + oy + ry1, z0 + oz + rz1), (X0 + ox + rx2, y0 + oy + ry2, z0 + oz + rz2) as points A, B and C, respectively. The PPP 120 repeats the above processing for generating figure data for drawing plural unit figures around the center point O, as shown in Fig. 8B. If the coordinates in the three-dimensional space of three apex points A to C of a unit figure corresponding to the generated figure data are (X0, Y0. Z0) to (X2, Y2, Z2), the PPP 120 performs coordinate transformation of the coordinates in accordance with, for example, the following equations: SXk = R11Xk + R12Yk + R13Zk + TRX SYk = R21Xk + R22Yk + R23Zk + TRY SZk = R31Xk + R32Yk + R33Zk + TRZ where k = 0. 1, 2. Rij denotes elements of a row i and a column j of a pre-set rotation matrix R and (TRX, TRY, TRZ) denotes translation vectors. After finding the coordinates (SXk, SYk, SZk) on the three-dimensional space after coordinate transformation, the PPP 120 performs perspective transformation on the coordinates (SXk, SYk, SZk) in accordance with the following equations: SSXk = SXk(h/SZk) SSYk = SYk(h/SZk) for transformation into coordinates (SSXk, SSYk) on a two-dimensional space. The PPP 120 performs coordinate transformation or perspective transformation on all of the plural unit figures, herein triangles, drawn around the center point O, in accordance with the equations (1) or (2). The PPP 120 packetizes the resulting coordinates (SSXk, SSYk) on the two-dimensional space and routes the packet to the GPU 115. In this case, the GPU 115 performs rendering in accordance with the coordinates (SSXk, SSYk) on the two-dimensional space furnished from the PPP 120. Heretofore, the above-described processing in the PPP 120 is performed in the CPU 111, so that figure data corresponding to a large number of small-sized figure units as shown in Fig. 8B are transferred over the main bus 101 to the GPU 115. The result is that the processing speed of the overall system is limited by the main bus 101. In a presently preferred embodiment of the invention, since only the figure data corresponding to the sole center point O is transmitted from the CPU 111 over the main bus 101, the figure data can be transmitted promptly (that is, the bandwidth can be reduced). In addition, since the GPU 115 performs rendering on the small-sized unit figure, the processing can be performed speedily leading to increased processing speed of the overall system. In addition, the PPP 120 performs part of the processing so far performed by the CPU 111, thus relieving the load otherwise imposed on the CPU 111 promptly, thus improving the processing speed of the entire system. since it is unnecessary for the main memory 112 to store all of the figure data corresponding to the large number of the unit figures as shown in Fig. 8B, the storage capacity of the main memory 112 can be reduced as compared to the case in which all of the figure data are stored. The above-described technique of drawing a figure is particularly effective for representing the manner of an explosion of a unit figure. In the above explanation, unit figures scattered about a point as center are drawn. It is however possible to draw unit figures scattered about a pre-set reference figure, such as a segment of a line, a triangle or a quadrangle. Also, in the above explanation, plural triangles are drawn about a center point. However, the unit figures drawn in this manner are not limited to triangles, but may also be points, straight lines (line segments) or quadrangles. If picture data corresponding to a unit figure on the two-dimensional space, herein a quadrangle ABCD, as shown in Fig. 9, are written in a DRAM constituting the graphic memory 118 in the GPU 115, and the writing is done across a page boundary of the DRAM, accessing to the DRAM becomes time-consuming, thus obstructing the speedup of the processing. Therefore, if, in drawing the quadrangle ABCD on the two-dimensional space as shown in Fig. 9, the areas defined by six horizontal line segments, numbered 1 to 6, extending parallel to the transverse direction of the screen (horizontal lines 1 to 6) and seven vertical line segments, numbered 1 to 7, extending parallel to the vertical direction of the screen (vertical lines 1 to 7), each corresponding to 1 page of the DRAM, the figure corresponding to picture data written in each page is desirably processed as a unit in view of expediting the processing. The main CPU 111 is configured for transmitting a packet inclusive of figure data comprised of plural unit figures on the three-dimensional space over the main bus 101 to the PPP 120. If the PPP 120 should receive such a packet in which writing of picture data resulting from transformation into the unit figure on the two-dimensional space occurs across the page boundary of the DRAM, as shown in Fig. 9, the PPP 120 transforms the apex points in the three-dimensional space of the unit figure arranged as figure data n the packet by coordinate transformation or perspective transformation in accordance with the equations (1) or (2). The PPP 120 is configured for generating figure data corresponding to plural figure units obtained on dividing the quadrangle ABCD on the two-dimensional space (two-dimensional plane), shown in Fig. 9, in terms of an area corresponding to a 1 page of the DRAM as a unit. If now the coordinates of four apex points A to D of the quadrangle ABCD on the two-dimensional space, obtained after perspective transformation, are denoted by (SSX0, SSY0) to (SSX3, SSY3), the horizontal lines 1 to 6 are denoted by equations y = a + bm, where m = 0, 1, 2, 3, 4, 5 and the vertical lines 1 to 7 are denoted by equations x = c + dn, where n = 0, 1, 2, 3, 4, 5, 6, the PPP 120 solves the simultaneous equations of the equations (3) and (4): (SSX0 - SSX1)(y - SSY0) = (SSY0 - SSY1)(y - SSX0) y = a + bm (SSX0 - SSX1)(y - SSY0) = (SSY0 - SSY1)(y - SSX0) x= c + dn for various values of m or n to find points of intersection of the line segment AB with the horizontal lines 1 to 6 or the vertical lines 1 to 7. The PPP 120 also formulates similar simultaneous equations for line segments BC, CD and DA to find points of intersection thereof with the horizontal lines 1 to 6 or the vertical lines 1 to 7. In the present case, the PPP 120 solves 52 (=4 (6 + 7)) simultaneous equations. After finding the points of intersection of the line segments AB, BC, CD and DA with the horizontal lines 1 to 6 or the vertical lines 1 to 7, for example, points P or T in Fig. 9, the PPP 120 divides, in addition to these points of intersection, the quadrangle ABCD, in terms of a page of the DRAM as a unit, based on the points of intersections thus found and the points of intersection of the horizontal lines 1 to 6 with the vertical lines 1 to 7. This generates figure data corresponding to a large number of small-sized figure units. Hence, the PPP 120 divides the quadrangle ABC into plural figure units sized to be within one page of the DRAM such as a hectangle APQRST shown in Fig. 9 and packetizes figure data corresponding to the figure unit to transmit the figure data corresponding to the figure unit to the GPU 115. In this case, the GPU 115 performs rendering processing based on a figure unit comprised within one DRAM page supplied from the PPP 120. Heretofore, since the processing by the PPP 120 as described above is performed by the CPU 111, figure data corresponding to a large number of small-sized figure units as shown in Fig. 9 are transmitted over the main bus 101 to the GPU 115, if it is desired to increase the accessing speed to the graphic memory 118. Thus, the processing speed of the entire system is limited by the main bus 101. However, since the unit figure data transmitted from the CPU 111 over the main bus 101 is that corresponding to the sole large-sized quadrangle ABCD, unit figure data can be transmitted promptly. In addition, in the GPU 115, since the rendering processing for a small-sized unit figure is performed by the GPU 115, and the writing of the picture data corresponding to the sole unit figure is not performed beyond the DRAM page boundary, the processing can be expedited, thus increasing the processing speed of the entire system. Since the PPP 120 shares the processing, so far performed by the man CPU 111, with the CPU 111, the load imposed on the CPU 111 can be correspondingly relieved. Next, if, in displaying the unit figure on a screen, the unit figure is protruded out of the screen, the protruded portion tends to affect the display. This protruded portion needs to be screen-clipped. The main CPU 111 is configured for transmitting a packet, inclusive of figure data on the three-dimensional space of the unit figure in need of screen clipping, over the main bus 101 to the PPP 120. On reception of such packet, the PPP 120 divides the unit figure corresponding to the figure data arrayed in the packet into several unit figures on the three-dimensional space. This generates figure data corresponding to plural unit figures. In this regard, on reception of coordinates (x0, y0, z0) to (x3, y3, z3) of apex points A, B, C and D on the three-dimensional space shown for example n Fig.10 as figure data, the PPP 120 internally divides the coordinates of the apex points by 8 x 8 to generate 64 small-sized unit figures, such as quadrangles APQR, in accordance with the following equations: Xij = ((8 - i) (8 - j)x0 + (8 - i)jx1 + i (8 - j)x3 + ijx2)/64 Yij = ((8 - i) (8 - j)y0 + (8 - i)jyl + i (8 - j)y3 + ijy2)/64 Zij = ((8 - i) (8 - j)z0 + (8 - i)jz1 + i (8 - j)z3 + ijz2)/64 where i and j are integers from 0 to 8. The PPP 120 calculates coordinates (Xij, Yij, Zij) of the apex points of these 64 unit figures. The PPP 120 transforms the apex points (Xij, Yij, Zij) in the three-dimensional space, thus found, by coordinate transformation or perspective transformation, in accordance with the equations (1) or (2) to generate plural small-sized unit figures on the two-dimensional space. These unit figures are obtained by 8 x 8 internal division of the quadrangle ABCD to form 64 unit figures followed by coordinate transformation and perspective transformation in this order. The PPP 120 then packetizes the coordinates (SSXij, SSYij) as figure data and transmits the resulting packet to the GPU 115. In this case, the GPU 115 performs rendering only on figure data corresponding to the 64 unit figures from the PPP 120 and containing portions displayed in the screen frame, as shown shaded in Fig. 11. This prevents wasteful picture drawing for picture portions not displayed on the screen. Heretofore, since the processing by the PPP 120 is performed by the CPU 111, figure data corresponding to the large number of small-sized figure units shown in Fig. 10 are transmitted over the main bus 101 to the GPU 115. This leads to limitation of the processing speed of the entire device by the main bus 101. However, since the unit figure data transmitted from the CPU 111 over the main bus 101 corresponds to that of the sole large-sized quadrangle ABCD, the unit figure data can be transmitted promptly. Since the GPU 115 performs rendering on the small-sized unit figures, the processing can be expedited, thus leading to improved processing speed of the entire system. Since the PPP 120 again shares the processing, usually performed by the main CPU 111, with the CPU 111, the load imposed on the CPU 111 can be correspondingly relieved. Although the present invention has been explained with reference to the case of application to a video game machine, the present invention may also be applied to an effector for giving special effect to a picture, or a device for computer graphics processing, such as CAD. Meanwhile, the method for generating plural unit figures is not limited to the method described above. In the above-described embodiment, the packet is transferred from the main CPU 111 to the PPP 120. However, if the unit figure to be drawn need not be processed by the PPP 120, such as when the unit figures to be drawn are small-sized and few in number, the main CPU 111 directly transmits the packet corresponding to the unit figure to the GPU 115 without transmitting the packet to the PPP 120. In such case, pictures are drawn as conventionally. Hence, the present invention satisfies a long existing need for enhanced data processing at increased processing speed. It will be apparent from the foregoing that, while particular forms of the invention have been illustrated and described, various modifications can be made without departing from the scope of the invention as defined by the appended claims. Accordingly, it is not intended that the invention be limited, except as by the appended claims.

Claims: A picture information processing system comprising: a first processor (111) for generating a drawing command and figure data having a first centre point and for outputting the drawing command and figure data on a bus (101) which has a limited data transferring speed; a second processor (120) for receiving the drawing command and figure data via the bus, for generating a plurality of second centre points positioned relative to the first centre point and for generating, for each of the plurality of second centre points, further figure data for a unit figure, the further figure data including a plurality of apex points positioned relative to a corresponding one of the plurality of second centre points; and a graphic processor (115) for drawing each of the unit figures in accordance with the further figure data; in which the second processor (120) supplies the generated further figure data to the graphic processor directly without using the bus (101). A system according to claim 1, in which the first centre point and each of the plurality of second centre points have three-dimensional co-ordinate data. A system according to claim 1 or claim 2, in which the second processor (120) generates the plurality of second centre points in order that each of the plurality of second centre points is spaced a random distance in a random direction relative to the first centre point. A system according to any one of claims 1 to 3, in which the second processor (120) generates the plurality of apex points in order that each of the plurality of apex points is spaced a random distance in a random direction relative to the corresponding one of the plurality of second points. A system according to any one of the preceding claims, in which the first processor (111) is a main processor and the second processor is a pre-processor (120). A system according to claim 4, in which the second processor generates the plurality of second centre points in order that the unit figures surround the first centre point. A system according to any one of the preceding claims, in which: the graphic processor (115) has an associated graphic memory (118); and the second processor (120) is operable to generate a plurality of unit figure co-ordinates corresponding to a respective plurality of unit figures and to supply the plurality of unit figure co-ordinates for writing in the graphic memory; and the graphic processor is operable to render unit figures in accordance with the plurality of unit figure co-ordinates thereby generating an image composed of the plurality of unit figures which are positioned around the centre point. A system according to claim 7, in which: the graphic memory (118) has page boundaries according to which data is accessed by the graphic processor; and if a desired figure crosses at least one of the page boundaries, the second processor is operable to divide the desired figure into a plurality of unit figures such that none of the plurality of unit figures cross any of the page boundaries. A system according to claim 7, in which: if a desired figure has a size which exceeds a display size of a screen, the second processor (120) is operable to divide the desired figure into a plurality of unit figures and to generate the plurality of unit figure co-ordinates for writing in the graphic memory such that they are readable by the graphic processor; and the graphic processor is operable to select at least one unit figure from the unit figures generated by dividing the desired figure, each of the at least one unit figure having an overlap portion with the screen, and to render only the selected at least one unit figure. A system according to claim 7, in which: the graphic processor (115) is connected with the bus (101); the first processor (111) is operable to determine whether or not the drawing command and figure data satisfy a predetermined condition; and when the drawing command and figure data satisfy the predetermined condition, the first processor is operable to directly output the drawing command and figure data to the graphic processor via the bus. A system according to any one of the preceding claims, in which the first processor (111) is operable to generate a data packet, the drawing command and figure data being included in the data packet. A picture information processing method used for a system comprising a first processor for generating a drawing command and figure data having a first centre point, a second processor connected to the first processor via a bus which has a limited data transferring speed, and a graphic processor, the method comprising the steps of: supplying the drawing command and figure data generated by the first processor to the second processor via the bus; the second processor generating a plurality of second centre points positioned relative to the first centre point according to the drawing command; the second processor generating, for each of the plurality of second centre points, further figure data for a unit figure, the further figure data including a plurality of apex points positioned relative to a corresponding one of the plurality of second centre points; and supplying the further figure data generated by the second processor from the second processor to the graphic processor directly without using the bus, so that the unit figures are drawn in a graphic memory. A method according to claim 12, in which the first centre point and each of the plurality of second centre points have three-dimensional co-ordinate data. A method according to claim 12 or claim 13, in which the plurality of second centre points are generated by the second processor in order that each of the plurality of second centre points is spaced a random distance in a random direction relative to the first centre point. A method according to any one of claims 12 to 14, in which the figure data is generated by the second processor in order that each of the plurality of apex points is spaced a random distance in a random direction relative to the corresponding one of the plurality of second centre points. A method according to any one of claims 12 to 15, used for a system in which the first processor is a main processor and the second processor is a pre-processor. A method according to any one of claims 12 to 16, further comprising the step of: the second processor, after the plurality of apex points are generated, co-ordinate-transforming of the unit figures in multi-dimensional space. A method according to claim 17, further comprising the step of: the second processor, after the co-ordinate-transforming is executed, perspective transforming of the unit figures. A method according to any one of claims 12 to 18, used for a system in which the graphic memory has page boundaries according to which data is accessed by the graphic processor, the method comprising the step of: if a desired figure crosses at least one of the page boundaries, the second processor dividing the desired figure into a plurality of unit figures such that none of the plurality of unit figures cross any of the page boundaries. A method according to claim 18, comprising the steps of: if a desired figure has a size which exceeds a display size of a screen, the second processor dividing the desired figure into a plurality of unit figures and generating a plurality of unit figure co-ordinates for writing in the graphic memory such that they are readable by the graphic processor instructing the graphic processor to draw the unit figures into the graphic memory respectively; and the graphic processor selecting at least one unit figure from the unit figures generated by dividing the desired figure, each of the at least one unit figure having an overlap portion with the screen, and to render only the selected at least one unit figure. A method according to claim 18, used for a system in which the graphic processor is connected with the bus; the method comprising the steps of: the first processor determining whether or not the drawing command and figure data satisfy a predetermined condition; and when the drawing command and figure data satisfy the predetermined condition, the first processor outputting them directly to the graphic processor via the bus. A method according to any one of claims 12 to 21 used for a system in which the first processor is operable to generate a data packet, the drawing command and figure data being included in the data packet.

Inventors: OKA MASAAKI, OKA, MASAAKI, Oka, Masaaki, c/o Sony Computer Entertainment Inc.
Applicants: SONY COMP ENTERTAINMENT INC, SONY COMPUTER ENTERTAINMENT INC.
Application year: 1997
Main classification: G06T15
IPC codes: G06T17, G06F3, G06T15, G06T11, G09G5