Method for updating a display bitmap with a character string or the like

Claim 1

A method of updating a display bitmap in a column-wise manner to display a string of characters in a selected font with a font height, a bitmap being a matrix of bits defining a display pattern and having an associated width, each character comprising a plurality of virtual characters and having a character width, each virtual character having a virtual character bitmap and a virtual character width, each virtual character bitmap having a height equal to the font height and a width equal to the virtual character width, each character having a character bitmap comprising the virtual character bitmaps for the virtual characters for the character, each virtual character having an associated phase based on the position within a byte in the display bitmap at which the first bit of the virtual character is to be displayed, the display bitmap being logically divided into one-byte wide columns and into scan lines, the method comprising the steps of: generating a list having an entry for each virtual character that comprises the characters in the string, the entry containing the phase, the width, and a pointer to the virtual character bitmap; and for each column in the display bitmap to be updated with the character string, repeating the steps of: selecting the column; combining the virtual character bitmaps for the virtual characters to be displayed in the selected column based on the phase, the width, and the pointer stored in the list for each character; and updating each byte in the selected column to effect the display of a portion of the character string.

Claim 2

A method of updating a display bitmap in a column-wise manner to display a string of characters in a selected font with a font height, a bitmap being a matrix of bits defining a display pattern and having an associated width, each character comprising a plurality of virtual characters and having a character width, each virtual character having a virtual character bitmap and a virtual character width, each virtual character bitmap having a height equal to the font height and a width equal to the virtual character width, each character having a character bitmap comprising the virtual character bitmaps for the virtual characters for the character, each virtual character having an associated phase based on the position within a byte in the display bitmap at which the first bit of the virtual character is to be displayed, the display bitmap being logically divided into one-byte wide columns and into scan lines, the method comprising the steps of: generating a list having an entry for each virtual character that comprises the characters in the string, the entry containing the phase, the width, and a pointer to the virtual character bitmap; and for each column in the display bitmap to be updated with the character string, repeating the steps of: selecting the column; combining the virtual character bitmaps for the virtual characters to be displayed in the selected column based on the phase, the width, and the pointer stored in the list for each character; and updating each byte in the selected column to effect the display of a portion of the character string.

Claim 6

A method of updating a display bitmap in a column-wise manner to display a string of characters in a selected font, a bitmap being a matrix of bits defining a display pattern and having an associated width and height, each character comprising a plurality of virtual characters and having a character width and character height, each virtual character having a virtual character bitmap and a virtual character width, each virtual character bitmap having a height equal to the character height and a width equal to the virtual character width, each character having a character bitmap comprising the virtual character bitmaps for the virtual characters for the character, each virtual character having an associated phase based on the position within a byte in the display bitmap at which the first bit of the virtual character is to be displayed, the display bitmap being logically divided into one-byte wide columns and into scan lines, the method comprising the steps of: (A) for each virtual character composing the characters in the string, repeating the steps of: (1) determining the phase of the virtual character; (2) determining the width of the virtual character; (3) generating a pointer to the virtual character bitmap; and (4) storing the phase of the virtual character, the width of the virtual character, and the pointer to the virtual character bitmap as an entry in a list so that the list is logically in the same order as the characters in the string; (B) for each column in the display bitmap to be updated with the character string, repeating the steps of: (1) determining the number of virtual characters to be displayed in the column based on the entries stored at the beginning of the list; (2) for each scan line to be updated in the column to be updated, the number of scan lines being equal to the character height, repeating the steps of: (a) for each virtual character to be displayed in the column, the number of virtual characters being determined in step (B) (1), retrieving the byte from the virtual character bitmap that corresponds to the scan line to be updated, the byte being retrieved based on the pointer in the entry for the virtual character in the list; (b) combining the retrieved bytes based on the phase and the width of the virtual characters to be displayed in the column; and (c) updating the column at the scan line with the combined byte to effect an update of the display bitmap; and (3) removing from the beginning of the list the entries for the virtual characters fully displayed in the display bitmap after all scan lines in the column are updated.

Claim 7

A method of updating a display bitmap in a column-wise manner to display a string of characters in a selected font, a bitmap being a matrix of bits defining a display pattern and having an associated width and height, each character comprising a plurality of virtual characters and having a character width and character height, each virtual character having a virtual character bitmap and a virtual character width, each virtual character bitmap having a height equal to the character height and a width equal to the virtual character width, each character having a character bitmap comprising the virtual character bitmaps for the virtual characters for the character, each virtual character having an associated phase based on the position within a byte in the display bitmap at which the first bit of the virtual character is to be displayed, the display bitmap being logically divided into one-byte wide columns and into scan lines, the method comprising the steps of: (A) for each virtual character composing the characters in the string, repeating the steps of: (1) determining the phase of the virtual character; (2) determining the width of the virtual character; (3) generating a pointer to the virtual character bitmap; and (4) storing the phase of the virtual character, the width of the virtual character, and the pointer to the virtual character bitmap as an entry in a list so that the list is logically in the same order as the characters in the string; (B) for each column in the display bitmap to be updated with the character string, repeating the steps of: (1) determining the number of virtual characters to be displayed in the column based on the entries stored at the beginning of the list; (2) for each scan line to be updated in the column to be updated, the number of scan lines being equal to the character height, repeating the steps of: (a) for each virtual character to be displayed in the column, the number of virtual characters being determined in step (B) (1), retrieving the byte from the virtual character bitmap that corresponds to the scan line to be updated, the byte being retrieved based on the pointer in the entry for the virtual character in the list; (b) combining the retrieved bytes based on the phase and the width of the virtual characters to be displayed in the column; and (c) updating the column at the scan line with the combined byte to effect an update of the display bitmap; and (3) removing from the beginning of the list the entries for the virtual characters fully displayed in the display bitmap after all scan lines in the column are updated.

Claim 17

A method of storing a character bitmap in column-wise manner in a computer memory, the computer memory comprising bytes, the computer memory being byte addressable, each byte comprising a specified number of bits, the character bitmap being a matrix of bits of a specified number of rows and specified number of columns, the rows being logically numbered sequentially from zero to the specified number of rows minus one, the columns being logically numbered sequentially from zero to the specified number of columns minus one, comprising the steps of: (a) selecting a memory location at which to store the character bitmap; (b) selecting column number zero; (c) for each row in the selected column, selecting the bit in the selected row at the selected column and selecting the bits in the selected row at the adjacent columns, the adjacent columns being those columns whose column number is greater than the column number of the selected column but less than column number of the selected column plus the number of bits in a byte and less than the number of columns in the character bitmap; storing the selected bits in the selected memory location; and selecting the next sequential memory location; (d) selecting a column whose column number is equal to the currently selected column number plus the number of bits in a byte; and (e) repeating steps (c) and (d) until the selected column number is greater than or equal to the number of columns in the character bitmap.

Claim 18

A method of storing a character bitmap in column-wise manner in a computer memory, the computer memory comprising bytes, the computer memory being byte addressable, each byte comprising a specified number of bits, the character bitmap being a matrix of bits of a specified number of rows and specified number of columns, the rows being logically numbered sequentially from zero to the specified number of rows minus one, the columns being logically numbered sequentially from zero to the specified number of columns minus one, comprising the steps of: (a) selecting a memory location at which to store the character bitmap; (b) selecting column number zero; (c) for each row in the selected column, selecting the bit in the selected row at the selected column and selecting the bits in the selected row at the adjacent columns, the adjacent columns being those columns whose column number is greater than the column number of the selected column but less than column number of the selected column plus the number of bits in a byte and less than the number of columns in the character bitmap; storing the selected bits in the selected memory location; and selecting the next sequential memory location; (d) selecting a column whose column number is equal to the currently selected column number plus the number of bits in a byte; and (e) repeating steps (c) and (d) until the selected column number is greater than or equal to the number of columns in the character bitmap.