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Routines |
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Used by the routine at Draw_Special_Room_Parts.
Draws a picture of a corner of the frame of a special room at x position 00 and y position 10 which is the top left corner. The picture is three bytes wide and 20 lines high, and starts with its attributes (see Room_Graphics).
The entries at Draw_Top_Right_Corner_Picture, Draw_Bottom_Left_Corner_Picture and Draw_Bottom_Right_Corner_Picture draw the other three corners, using the shared code from Draw_Corner_Picture onwards.
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| Draw_Top_Left_Corner_Picture | 9CF2 | LD HL,$1000 | Set the x position to 00 and the y position to 10 (1000). | |||||
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This entry point is used by the routines at Draw_Top_Right_Corner_Picture, Draw_Bottom_Left_Corner_Picture and Draw_Bottom_Right_Corner_Picture.
Copy the attributes of the picture, four rows of three cells.
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| Draw_Corner_Picture | 9CF5 | PUSH HL | Stash the position on the stack. | |||||
| 9CF6 | CALL AttributeAddress | Convert the position into an attribute buffer address. | ||||||
| 9CF9 | LD C,$04 | Set the number of rows to 04. | ||||||
| Draw_Top_Left_Corner_Picture_Row_Loop | 9CFB | PUSH HL | Stash the address of the start of the row on the stack. | |||||
| 9CFC | LD B,$03 | Set the number of cells in a row to 03. | ||||||
| Draw_Top_Left_Corner_Picture_Cell_Loop | 9CFE | LD A,(DE) | Fetch an attribute from the picture. | |||||
| 9CFF | LD (HL),A | Write it to the cell. | ||||||
| 9D00 | INC DE | Move on to the next attribute of the picture. | ||||||
| 9D01 | INC L | Move on to the next cell. | ||||||
| 9D02 | DJNZ Draw_Top_Left_Corner_Picture_Cell_Loop | Decrease the cell counter and loop back until the row is copied. | ||||||
| 9D04 | POP HL | Restore the address of the start of the row. | ||||||
| 9D05 | LD A,L | Fetch the low byte of the address. | ||||||
| 9D06 | ADD A,$20 | Add the size of a row of cells. | ||||||
| 9D08 | LD L,A | Store the low byte of the address. | ||||||
| 9D09 | LD A,H | Fetch the high byte of the address. | ||||||
| 9D0A | ADC A,$00 | Add the carry. | ||||||
| 9D0C | LD H,A | Store the high byte of the address. | ||||||
| 9D0D | DEC C | Decrease the row counter and loop back until all of the rows of attributes are copied. | ||||||
| 9D0E | JR NZ,Draw_Top_Left_Corner_Picture_Row_Loop | |||||||
| 9D10 | POP HL | Restore the position from the stack. | ||||||
| 9D11 | CALL ScreenAddress | Convert the position into a screen address. | ||||||
| 9D14 | LD C,$20 | Set the number of lines to 20. | ||||||
| 9D16 | JP Draw_Three_Byte_Lines | Jump to Draw_Three_Byte_Lines to copy the pixels. | ||||||
| Prev: 9CE8 | Up: Map | Next: 9D19 |