Method for processing graphics data by a graphic controller
In a drawing processing apparatus and a drawing processing method for superposing a plurality of graphics present on the same plane, a data format is previously extracted in a data format extraction control section. A write data extracting section converts write data from a DDA section into the extracted data format. A read data extracting section converts read data from a drawing frame memory into the extracted data format. A data comparing section compares the data format-converted write data from the write data extracting section with the data format-converted read data from the read data extracting section. When the two pieces of data are the same, a drawing output section omits a process of writing the write data form the DDA section into the drawing frame memory.
1 . An image processing method for generating graphic drawing data in accordance with a graphic drawing command for image data and storing the graphic drawing data into a drawing frame memory, comprising:
a data format extracting step of extracting a data format suitable for the graphic drawing data to be generated, depending on a graphic drawing command for a graphic to be drawn;
a conversion step of converting write data to be drawn, and read data in the drawing frame memory corresponding to a graphic position of the write data into the extracted data format; and
a drawing omission determining step of determining whether or not the write data and read data converted by the conversion step are the same, and based on the result of the matching determination, determining whether or not a process of writing the write data into the drawing frame memory can be omitted.
2 . The image processing method of claim 1 , wherein the data format extracting step extracts a data format suitable for the graphic drawing data to be generated, depending on a drawing attribute, a drawing color format or the like designated by a graphic drawing command for a graphic to be drawn.
3 . The image processing method of claim 1 , wherein the data format extracting step extracts, as the data format, a data format having a drawing attribute which employs only a data included in drawing data, or a data format having a drawing attribute which employs data other than the α data.
4 . An image processing method for generating graphic drawing data in accordance with a graphic drawing command for image data and storing the graphic drawing data into a drawing frame memory, comprising:
a data format extracting step of extracting a data format suitable for the graphic drawing data to be generated, depending on a graphic drawing command for a graphic to be drawn;
a conversion step of converting write data to be drawn, and read data in the drawing frame memory corresponding to a graphic position of the write data into the extracted data format; and
a drawing omission determining step of determining whether or not a difference between the write data and read data converted by the conversion step is within a predetermined range, and based on the result of the determination, determining whether or not a process of writing the write data into the drawing frame memory can be omitted.
5 . An image processing method for generating graphic drawing data in accordance with a graphic drawing command for image data and storing the graphic drawing data into a drawing frame memory, wherein
drawing data to be drawn includes α data, and a predetermined bit of the α data is used as a sequence identification number, and
the method comprises a drawing omission determining step of, when two or more graphics to be drawn are superposed and drawn on the same plane, comparing a sequence identification number of a pixel to be drawn with a sequence identification number in the drawing frame memory corresponding to a graphic position of the pixel, and based on the result of the comparison, determining whether or not a process of writing data of the pixel into the drawing frame memory can be omitted.
6 . The image processing method of claim 5 , wherein, when two or more graphics to be drawn are superposed on the same plane, and the graphics are rearranged in order of vertical position with the lowest first before being superposed and drawn, the drawing omission determining step determines whether or not two predetermined graphics overlap, and when the result of the determination shows that the two graphics overlap, determines that one of the graphics can be omitted, based on the sequence identification numbers.
7 . An image processing method for receiving a command list for image data, generating graphic drawing data in accordance with a graphic drawing command in the command list, and storing the graphic drawing data into a drawing frame memory, wherein
the command list defines a start command and an end command, and graphics generated by two or more graphic drawing commands provided between the start and end commands are defined to be present on the same plane,
α data included in drawing data for the graphics generated by the graphic drawing commands between the start and end commands is used as sequence identification numbers indicating a graphic superposition sequence, and
the method comprises:
a control step of processing the command list;
a write data extracting step of extracting a sequence identification number of a pixel of a graphic to be drawn which is generated by the graphic drawing command;
a read data extracting step of extracting a sequence identification number in the drawing frame memory having the same coordinates as those of the pixel of the graphics to be drawn; and
a drawing omission determining step of comparing the two extracted sequence identification numbers, and depending on the result of the comparison, determining whether or not a write process with respect to the drawing frame memory can be omitted.
8 . An image processing method for receiving a command list for image data, generating graphic drawing data in accordance with a graphic drawing command in the command list, and storing the graphic drawing data into a drawing frame memory, wherein
the command list defines a start command and an end command, and graphics generated by two or more graphic drawing commands provided between the start and end commands are defined to be present on the same plane,
α data included in drawing data for the graphics generated by the graphic drawing commands between the start and end commands is used as sequence identification numbers indicating a graphic superposition sequence, and
the method comprises:
a control step of processing the command list to rearrange the two or more graphic drawing commands in order of vertical position with the lowest or highest first, based on the sequence identification numbers of the two or more graphic drawing commands between the start and end commands; and
a drawing processing step of drawing the graphics based on the graphic drawing commands in accordance with the rearranged sequence of the graphic drawing commands.
9 . The image processing method of claim 8 , wherein the control step extracts a graphic drawing command located at the highest position, and
the drawing processing step draws only a graphic based on the graphic drawing command located at the highest position.
10 . An image processing method for generating graphic drawing data in accordance with a graphic drawing command for image data and storing the graphic drawing data into a drawing frame memory, comprising:
a control step of processing the graphic drawing command when graphics are superposed and drawn, the graphic drawing command having bits of α data included in drawing data as a plane identification number and a sequence identification number;
a write data extracting step of extracting a plane identification number of a pixel of a graphic generated in accordance with the graphic drawing command processed in the control step;
a read data extracting step of extracting a plane identification number in the drawing frame memory having the same coordinates as those of the pixel of the generated graphic; and
a data comparing step of comparing the two extracted plane identification numbers, and depending on the result of the comparison, determining whether or not the two pixels having the two plane identification numbers are of graphics present on the same plane.
11 . The image processing method of claim 10 , comprising:
a write data extracting step of extracting a sequence identification number of a graphic determined to be present on the same plane;
a read data extracting step of extracting a sequence identification number in the drawing frame memory having the same coordinates as those of the graphic determined to be present on the same plane; and
a drawing omission determining step of comparing the two extracted sequence identification numbers, and depending on the result of the comparison, determining whether or not a write process with respect to the drawing frame memory can be omitted.
12 . The image processing method of claim 1 , wherein the drawing omission determining step determines whether or not generation of drawing data is invariably performed with respect to the drawing frame memory which has not been drawn, and when the result of the determination is positive, omits reading of data from the drawing frame memory.
13 . A program for causing a computer to a procedure for the drawing processing method of claim 1 .
14 . A computer readable recording medium storing the program of claim 13.