Method and apparatus for display control

• US 5,347,624 A
• Filed: 05/07/1990
• Issued: 09/13/1994
• Est. Priority Date: 03/05/1987
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Takahashi, Tooru, Akaosugi, Takashi, Shirahama, Ritsuo, Kojima, Tomihiko, Nakamura, Shouji, Takanashi, Katsuya
• Primary Examiner(s): Nguyen, Phu K.
• Application Number:
  US07/518,334
• Time in Patent Office: 1,590 Days
• Field of Search: 364/518, 364/519, 364/521, 364/523, 340/723, 395/157, 395/155, 395/156, 395/161, 395/133, 395/135, 345/113, 345/114
• US Class Current: 345/641
• CPC Class Codes: G09G 5/14 Display of multiple viewports

Abstract

A graphic display method and apparatus including a plurality of virtual device coordinate systems independent of a coordinate system of a physical screen in which a graphic image to be displayed is independently drawn in a virtual device space of the corresponding virtual device coordinate system so as to map a specified area of each virtual device space onto the virtual screen at a specified position, thereby displaying a specified area of a virtual memory in a physical screen. Furthermore, code data of characters and graphics and image data are written in a logical screen buffer as drawing elements to be located at arbitrary positions of the logical screen such that a unit, specifying an area which is located at an arbitrary position and which has an arbitrary size in the logical screen causes the combining and editing of character, graphic, and image data already written in the specified area of the logical screen and the generating, as a result, of new image data. The new image data is written as a drawing element of the virtual screen in the virtual screen buffer at a specified arbitrary position.

Claims

1. A display control apparatus for mapping data to be displayed on to a virtual screen using an application program and displaying a specified area of the virtual screen in a physical screen, said apparatus comprising:

first means for individually effecting a drawing operation using image data, vectorized graphic data and coded character data of said data to be displayed in a plurality of virtual devices, respectively, each virtual device having a virtual device space defined by a normalized coordinate system independent of a coordinate system of the physical screen, said image data, vectorized graphic data and coded character data being described according to at least said normalized coordinate system for use by said application program;

second means for mapping specified data of each of said virtual device spaces onto said virtual screen at desired map positions in a form of at least one of said image data, vectorized graphic data and coded character data, thereby generating new data;

third means for writing said new data in a specified area of a memory of said virtual screen;

fourth means for mapping said specified data, mapped on said virtual screen, onto said physical screen on a bit-map basis; and

fifth means for displaying on a display equipment data of said physical screen.

2. A display control apparatus according to claim 1 wherein said first means controls segment data in a memory of said virtual screen corresponding to input data.

3. A display control apparatus according to claim 1, wherein said second means includes control table means for generating a physical screen control table indicating correspondence relationships between said memory of said virtual screen and a physical screen memory.

4. A display control apparatus according to claim 3 wherein said fourth means includes means for generating a command stream in said physical screen memory based on said physical screen control table.

5. A display control apparatus according to claim 4 wherein said fifth means includes means for effecting a dot development into a full dot memory based on the command stream located in the physical screen memory.

6. A display control method for mapping data to be displayed onto a virtual screen using an application program and displaying a specified area of the virtual screen in a physical screen, said method comprising the steps of:

individually effecting a drawing operation using image data, vectorized graphic data and coded character data of said data to be displayed in a plurality of virtual devices, respectively, each virtual device having a virtual device space defined by a normalized coordinate system independent of a coordinate system of the physical screen, said image data, vectorized graphic data and coded character data being described according to at least one of said normalized coordinate systems for use by said application program;

mapping specified data of each of said virtual device spaces onto said virtual screen at desired map positions in a form of at least one of said image data, vectorized graphic data and coded character data, thereby generating new data;

writing said new data in a specified area of a memory of said virtual screen;

mapping said specified data, mapped on said virtual screen, onto said physical screen on a bit-map basis; and

displaying on a display equipment data of said physical screen.

7. A display control method according to claim 6, wherein said individually effecting step includes a step of controlling segment data in a memory of said virtual screen corresponding to input data.

8. A display control method according to claim 6, wherein said mapping specified data on said virtual screen step includes a step of generating a physical screen control table indicating correspondence relationships between said memory of said virtual screen a physical screen memory.

9. A display control method according to claim 8 wherein said mapping specified data on said physical screen step includes a step of generating a command stream in said physical screen memory based on said physical screen control table.

10. A display control method according to claim 9 wherein said displaying step includes a step of effecting a dot development into a full dot memory based on the command stream located in the physical screen memory.

11. A display control apparatus for mapping onto a memory of a virtual screen, data to be displayed and displaying a specified area of the virtual screen on a memory of a physical screen, said apparatus comprising:

first means, including a plurality of virtual devices each having a virtual device space defined by a normalized coordinate system, for drawing image data, coded character data and vectorized graphic data of said data to be displayed, respectively, on memory areas of said virtual device spaces under control of an application program, said normalized coordinate system of each of said virtual device spaces being independent from a coordinate system of the physical screen;

second means, coupled to said first means, for mapping a specified area of each of said plurality of virtual device spaces onto a memory area of said virtual screen at a specified position thereof;

said second means including third means for combining data already written in arbitrary areas of said virtual screen by superimposing elements of said data on top of each other in accordance with predetermined priorities to generate new data and for writing said new data in a specified memory area of said virtual screen;

fourth means for mapping said specified area of said virtual screen onto said physical screen; and

fifth means for displaying data of said physical screen on a display device.

12. A display control apparatus for mapping onto a memory of a virtual screen, data to be displayed and displaying a specified area of the virtual screen on a memory of a physical screen, said apparatus comprising:

first means, including a plurality of virtual devices each having a virtual device space defined by a normalized coordinate system, for drawing image data, coded character data and vectorized graphic data of said data to be displayed, respectively, on memory areas of said virtual device spaces under control of an application program, said normalized coordinate systems of each of said virtual device spaces being independent from a coordinate system of the physical screen;

second means, coupled to said first means, for mapping a specified area of each of said plurality of virtual device spaces onto a memory area of said virtual screen at a specified position thereof;

third means for mapping said specified area of said virtual screen in said second means onto said physical screen; and

fourth means for displaying data of said physical screen on a display device;

fifth means coupled between said second means and said third means for selectively combining data located in said memory area of the virtual screen by superimposing elements of said data on top of each other in accordance with predetermined priorities to produce new data of an image data type, and writing said new data in a specified memory area of said virtual screen.

13. A display control apparatus according to claim 12, wherein said fifth means comprises:

means for extracting data in a desired area of said second memory area and developing vectorized graphic data and coded character data, among said data extracted, into sets of image dots so as to convert said image dots into data of an image data type.