Graphics
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1-601
Function Name: GraphicsString
Purpose: Process several graphics commands designated by a table.
Call address: $C136
Input requirements:
$02-$03 R0 Pointer to the table of commands.
Description: This routine executes the graphic commands present
in a table. This routine is used by PutChar (Control-P),PutString (By
calling PutChar), and DoDlgBox (Command 15). The following table
describes the available commands.
Graphic Command Table
Command #Bytes Description
$00 1 Stop, end of table.
$01 4 MOVEPENTO: Set column and row variables.
.word COLUMN
.byte ROW
$02 4 LINETO: Draw a line.
.word DESTCOLUMN
.byte DESTROW
$03 4 RECTAGLETO: Pattern fill a region.
.word BOTRIGHTCOLUMN
.byte BOTRIGHTROW
$04 1 No operation.
$05 2 NEWPATTERN: Set fill pattern.
$06 4+ ESC_PUTSTRING: Set position and display text.
MUST BE last command because the zero
byte that ends the text also ends this
command table.
.word COLUMN
.byte ROW
.byte "Hello World!",0
$07 4 FRAME_RECTO: Draw a solid lined box.
.word BOTRIGHTCOLUMN
.byte BOTRIGHTROW
$08 3 PEN_X_DELTA: Add an offset to column variable.
.word COLUMNOFFSET
$09 2 PEN_Y_DELTA: Add an offset to row variable.
.byte ROWOFFSET
$0A 4 Add offsets to both column and row
variables.
.word COLUMNOFFSET
.byte ROWOFFSET
Command 1 is used to set the column and row variables used by all
of the other commands which require two points. The format of the
commands is that all of the necessary data follows the command
byte. For example, the commands to erase the entire screen would
look like this:
.byte $05,$00
.byte $01
.word 0
.byte 0
.byte $03
.word 320
.byte 199
.byte $00
In the case of command 6, after the column and row bytes in the
command comes the text that is to be displayed. For example:
.byte $06
.word 50
.byte 50
.byte 'Hello world!'
.byte $00
1-602
Function Name: i_GraphicsString
Purpose: Identical to GraphicsString, but with inline data.
Call address: $C1A8
Description: This routine takes an inline data table, creates a
pointer to it, then calls GraphicsString to process it. See
i_Rectangle for an example of inline data tables.
1-603
Function Name: SetPattern
Purpose: Sets the current fill pattern.
Call address: $C139
Input requirements:
A The pattern number (0-31).
Description: This routine sets the fill pattern used by Rectangle,
i_Rectangle.
1-604
Function Name: FrameRectangle
Purpose: Draws the outline of a rectangular box in a given
pattern.
Call address: $C127
Input requirements:
A The actual bit pattern for the box.
$06 R2L The top margin.
$07 R2H The bottom margin.
$08-$09 R3 The left margin.
$0A-$0B R4 The right margin.
Description: This routine draws the outline of a rectangular box
in a given pattern. This routine calls HorizontalLine and
VerticalLine to draw the outline. See also GetScanLine.
1-605
Function Name: i_FrameRectangle
Purpose: Identical to FrameRectangle, but with inline data.
Call address: $C1A2
Description: This routine draws a solid outline of a box, which
is described by inline code. See i_Rectangle for an example.
1-606
Function Name: Rectangle
Purpose: Fills a rectangular box with a selected design.
Call address: $C124
Input requirements:
$06 R2L The top margin.
$07 R2H The bottom margin.
$08-$09 R3 The left margin.
$0A-$0B R4 The right margin.
Preparatory routines: SetPattern
Description: This routine fills a rectangular box in a given
design. This routine calls HorizontalLine repeatedly. See also
GetScanLine.
1-607
Function Name: i_Rectangle
Purpose: Identical to Rectangle, but with inline data.
Call address: $C19F
Preparatory routines: SetPattern
Description: This routine is identical to Rectangle except that data
that describes the box is part of the inline code. For example:
JSR i_Rectangle
.byte Top margin
.byte Bottom margin
.word Left margin
.word Right margin
Control returns here after box is filled.
1-608
Function Name: RecoverRectangle
Purpose: Copies a box from screen 2 to screen 1.
Call address: $C12D
Input requirements:
$06 R2L The top margin.
$07 R2H The bottom margin.
$08-$09 R3 The left margin.
$0A-$0B R4 The right margin.
Description: This routine copies a box from screen 2 ($6000) to
screen 1 ($A000). Location $2F is unaffected. This routine calls
RecoverLine repeatedly to copy each line of the box.
1-609
Function Name: i_RecoverRectangle
Purpose: Identical to RecoverRectangle, but with inline data.
Call address: $C1A5
Description: This routine copies a box from screen 2 ($6000) to
screen 1 ($A000). The box descriptor is inline with the calling
code. See i_Rectangle for an example.
1-610
Function Name: ImprintRectangle
Purpose: Copies a box from screen 2 to screen 1.
Call address: $C250
Input requirements:
$06 R2L The top margin.
$07 R2H The bottom margin.
$08-$09 R3 The left margin.
$0A-$0B R4 The right margin.
Description: This routine copies a box from screen 1 ($A000) to
screen 2 ($6000). Location $2F is unaffected. This routine calls
RecoverLine repeatedly to copy each line of the box.
1-611
Function Name: i_ImprintRectangle
Purpose: Identical to ImprintRectangle, but with inline data.
Call address: $C253
Description: This routine copies a box from screen 1 ($A000) to
screen 2 ($6000). The box descriptor is inline with the calling
code. See i_Rectangle for an example.
1-612
Function Name: InvertRectangle
Purpose: Inverts the pixels in a box.
Call address: $C12A
Input requirements:
$06 R2L The top margin.
$07 R2H The bottom margin.
$08-$09 R3 The left margin.
$0A-$0B R4 The right margin.
Description: This routine reverses the pixels in a given box by
repeatedly calling InvertLine. See also GetScanLine.
1-613
Function Name: RecoverLine
Purpose: Copies a horizontal line from screen 2 to screen 1.
Call address: $C11E
Input requirements:
$08-$09 R3 The left margin.
$0A-$0B R4 The right margin.
$18 R11L The row number.
Description: This routine copies a horizontal line from screen 2
($6000) to screen 1 ($A000). Location $2F is unaffected.
1-614
Function Name: InvertLine
Purpose: Inverts a horizontal line on the screen.
Call address: $C11B
Input requirements:
$08-$09 R3 The left margin.
$0A-$0B R4 The right margin.
$18 R11L The row number.
Description: This routine reverses the pixels on a horizontal
line on the hires screen. If the pixel was on it will now be off;
if it was off it will now be turned on. See also GetScanLine.
1-615
Function Name: DrawLine
Purpose: Draws, erases or copies a line on the hires screen.
Call address: $C130
Input requirements:
N flag C Flag Operation
1 X Copy
0 1 Draw
0 0 Erase
$08-$09 R3 The column for the first endpoint.
$0A-$0B R4 The column for the second endpoint.
$18 R11L The row for the first endpoint.
$19 R11H The row for the second endpoint.
Description: This is a very versatile routine. It can copy an
arbitrary line from one screen to another, as well as draw or
erase lines. This routine places no restrictions on the relative
positions of the endpoints. This routine calls DrawPoint to plot
the points. See also GetScanLine.
1-616
Function Name: HorizontalLine
Purpose: Draws a horizontal line on the screen.
Call address: $C118
Input requirements:
A The actual bit pattern for the line.
$08-$09 R3 The left margin.
$0A-$0B R4 The right margin.
$18 R11L The row number.
Description: This routine draws a horizontal line on the hires
screen in a given pattern. See also GetScanLine.
1-617
Function Name: VerticalLine
Purpose: Draws a vertical line on the screen.
Call address: $C121
Input requirements:
A The actual bit pattern for the line.
$08 R3L The top margin.
$09 R3H The bottom margin.
$0A-$0B R4 The right margin.
Description: This routine draws a vertical line on the hires
screen in a given pattern. See also GetScanLine.
1-618
Function Name: GetScanLine
Purpose: Computes the address of a given row on the hires
screens.
Call address: $C13C
Input requirements:
X The row number.
$2F dispBufferOn: See description.
Output:
$0C-$0D R5 Pointer to the row on the destination screen.
$0E-$0F R6 Pointer to the row on the source screen.
Description: This routine computes the address of column 0 on a
given row of the hires screens. All of the graphics routines rely
on this routine to get the address of the hires screens. They all
take the data pointed to by $0E-$0F and store their data to both
$0C-$0D R5 and $0E-$0F R6. Location $2F determines which screen
is pointed to by which pointer. This is as follows:
Bit 7 Bit 6 $0C-$0D $0E-$0F
0 0 $AF00 $AF00 Approximately the
middle of screen 1
0 1 Screen 2 Screen 2 ST_WR_BACK
1 0 Screen 1 Screen 1 ST_WR_FORE
1 1 Screen 1 Screen 2 (Default at reset)
1-619
Function Name: TestPoint
Purpose: Tests the value of a point on the hires screen.
Call address: $C13F
Input requirements:
$08-$09 R3 The column number.
$18 R11L The row number.
Output:
C flag is set to the value of the pixel.
Description: Tests whether or not a given pixel is on or not. The
carry flag is set to the value of the pixel.
1-620
Function Name: DrawPoint
Purpose: Draws, erases or copies a pixel on the hires screen.
Call address: $C133
Input requirements:
N flag C Flag Operation
1 X Copy
0 1 Draw
0 0 Erase
$08-$09 R3 The column number.
$18 R11L The row number.
Description: This is a very versatile routine. It can copy a
point from one screen to another, as well as draw or erase it.
This routine is called by DrawLine to draw lines. See also GetScanLine.
1-621
Function Name: BitmapUp
Purpose: Draws a click box on the screen.
Call address: $C142
Input requirements:
$02-$03 R0 Pointer to the graphic data.
$04 R1L Column in characters.
$05 R1H The row in pixels.
$06 R2L The width in bytes.
$07 R2H The height in pixels.
Description: This routine draws a click box on the screen. A
click box is a box like Ok, Open, etc. These boxes are generally
part of a window description. The graphic data is in a coded
format. This format consists of a code byte followed by 1 or more
data bytes.
1) Code bytes less than 128 mean that the following byte is
to be repeated that many times.
2) Code bytes ranging from 128 to 219 mean that if 128 is
subtracted from the code byte, then the result is the
number of data bytes that follow.
3) Code bytes ranging from 220 to 225 are special. First 219
is subtracted from the code byte, the result is the
number of bytes in the pattern. Following this code byte
is a repetition count for the pattern. Following this are
the bytes that constitute the pattern. These could
include either of the previous two code types.
1-622
Function Name: i_BitmapUp
Purpose: Identical to BitmapUp, but with inline data.
Call address: $C1AB
Description: This routine takes a click box descriptor from
inline data and draws it. The inline data does NOT include the
processing vector, i.e.
JSR DRWCB2
.word address of graphic image
.byte start column in bytes
.byte start margin in pixels
.byte width of box in bytes
.byte height of box in pixels
Control returns here after the box is drawn.
1-623
Function Name: BitmapClip
Purpose: Draw a section of a coded graphic image.
Call address: $C2AA
Input requirements:
$02-$03 R0 Pointer to graphic image data.
$04 R1L Column to start on, in bytes.
$05 R1H Row to start drawing the image on.
$06 R2L Image width in bytes (<= actual width).
$07 R2H Image height in pixels (<= actual height).
$18 R11L # bytes to skip on the left side.
$19 R11H # bytes on the right side.
$1A-$1B R12 # rows to skip from the bottom.
Description: The coding of the image is the same as that of the
click boxes, see BitmapUp for more information. This routine seems to
be for drawing pieces of Photo Scraps. Photo Scraps have this
coded format. The parameters for this routine allow a section of
the image to be drawn by specifying how many rows to skip down, as
well as how many bytes to skip on the left and the right of the
desired section. This is not used by GEOpaint unless GEOpaint
converts its files because they are in a different format;
however, Photo Scraps are in this format.
1-624
Function Name: BitOtherClip
Purpose: Draw a section of a coded graphic image.
Call address: $C2C5
Input requirements:
$02-$03 R0 Pointer to graphic image buffer (134 bytes).
$04 R1L Column to start on, in bytes.
$05 R1H Row to start drawing the image on.
$06 R2L Image width in bytes. (<= actual width)
$07 R2H Image height in pixels (<= actual height)
$18 R11L # bytes to skip on the left side.
$19 R11H # bytes on the right side.
$1A-$1B R12 # rows to skip from the bottom.
$1C-$1D R13 Byte read and save routine vector.
$1E-$1F R14 Sync routine vector.
Description: This routine is identical to BitmapClip, except that
before each byte is read, the first user routine is called. It
should return its byte in A and save that byte to the address
currently pointed to by R0 before returning. The second routine
need only reload R0 with the address of the image buffer.
1-625
Function Name: DrawSprite
Purpose: Copies a sprite into GEOS's storage area.
Call address: $C1C6
Input requirements:
$08 R3L The sprite number (0-7).
$0A-$0B R4 Pointer to the sprite data.
Description: This routine simply copies 63 bytes of data pointed
to by $0A-$0B (R4) to the specified sprite block. GEOS uses sprite
blocks 40 to 47.
1-626
Function Name: PosSprite
Purpose: Sets the position of a sprite.
Call address: $C1CF
Input requirements:
$08 R3L Sprite number (0-7).
$0A-$0B R4 Sprite X position.
$0C R5L Sprite Y position.
Preparatory routines: DrawSprite
Description: This routine copies the sprite's position to the VIC
chip, relieving the user of the burden of handling the crossover
in the screen from column 255 to column 256.
1-627
Function Name: EnablSprite
Purpose: Turns on a sprite.
Call address: $C1D2
Input requirements:
$08 R3L Sprite number (0-7).
Preparatory routines: DrawSprite, PosSprite
Description: This routine turns the sprite on, so that it is
visible.
1-628
Function Name: DisablSprite
Purpose: Turns off a sprite.
Call address: $C1D5
Input requirements:
$08 R3L Sprite number (0-7).
Preparatory routines: DrawSprite, PosSprite, EnablSprite
Description: This routine turns the sprite off, so that it is no
longer visible.