|
Routines |
| Prev: 9A33 | Up: Map | Next: 9A96 |
|
Used by the routine at Draw_Room.
Draws the top right corner of the frame of the room if bit 1 of the frame flags is set, or clears its area if it is not.
The corner is three bytes wide and 20 lines high and is drawn at x position E8 y position 10. The shape depends on whether the ceiling (bit 0) and the right wall (bit 2) are present, and on the room x and y: the table at Top_Right_Corner_Table has a set of four shapes for each of four combinations of the room coordinates. The routine also draws the other corners, which jump to Draw_Corner_Shape.
|
||||||||||
| Draw_Top_Right_Corner | 9A53 | PUSH DE | Stash the frame flags on the stack. | |||||||
| 9A54 | LD HL,$10E8 | Set the x position to E8 and the y position to 10 (10E8). | ||||||||
| 9A57 | LD A,E | Copy the frame flags to A. | ||||||||
| 9A58 | LD DE,$9A96 | Point at the table of corner shapes (Top_Right_Corner_Table). | ||||||||
| 9A5B | BIT 1,A | Jump to 9A62 to clear the area if the corner is not present. | ||||||||
| 9A5D | JP Z,Clear_Panel | |||||||||
| 9A5F | SBC A,C | |||||||||
| Draw_Corner | 9A60 | PUSH HL | Stash the position on the stack. | |||||||
| 9A61 | EX DE,HL | Exchange the registers so that HL holds the address of the table. | ||||||||
| 9A62 | BIT 0,A | Jump to Draw_Top_Right_Corner_Check_Right_Wall if the ceiling is not present. | ||||||||
| 9A64 | JR Z,Draw_Top_Right_Corner_Check_Right_Wall | |||||||||
| 9A66 | INC HL | Skip the shapes for a ceiling. | ||||||||
| 9A67 | INC HL | |||||||||
| Draw_Top_Right_Corner_Check_Right_Wall | 9A68 | BIT 2,A | Jump to Draw_Corner_Shape if the right wall is not present. | |||||||
| 9A6A | JR Z,Draw_Corner_Shape | |||||||||
| 9A6C | INC HL | Skip the shapes for a right wall. | ||||||||
| 9A6D | INC HL | |||||||||
| 9A6E | INC HL | |||||||||
| 9A6F | INC HL | |||||||||
|
This entry point is used by the routines at Draw_Bottom_Right_Corner, Draw_Bottom_Left_Corner and Draw_Top_Left_Corner.
|
||||||||||
| Draw_Corner_Shape | 9A70 | LD A,(IX+$02) | Fetch the room x of Sabreman. | |||||||
| 9A73 | ADD A,(IX+$04) | Add the room y of Sabreman. | ||||||||
| 9A76 | ADD A,A | Multiply the sum by eight. | ||||||||
| 9A77 | ADD A,A | |||||||||
| 9A78 | ADD A,A | |||||||||
| 9A79 | AND %00011000 | Keep only bits 3 and 4. | ||||||||
| 9A7B | LD C,A | Store the offset in C. | ||||||||
| 9A7C | LD B,$00 | Clear the high byte of the offset. | ||||||||
| 9A7E | ADD HL,BC | Add the offset to the address in the table. | ||||||||
| 9A7F | LD A,(HL) | Fetch the low byte of the address of the shape. | ||||||||
| 9A80 | INC HL | Move on to the high byte. | ||||||||
| 9A81 | LD H,(HL) | Fetch the high byte of the address of the shape. | ||||||||
| 9A82 | LD L,A | Copy the low byte to L. | ||||||||
| 9A83 | EX DE,HL | Exchange the registers so that DE holds the address of the shape. | ||||||||
| 9A84 | LD BC,$0320 | Set the size of the area to three bytes wide, 20 lines high (0320). | ||||||||
| 9A87 | CALL ScreenAddress | Convert the position into a screen address. | ||||||||
| 9A8A | CALL Draw_Tile_Without_Header | Draw the shape. | ||||||||
| 9A8D | POP HL | Restore the position from the stack. | ||||||||
| 9A8E | LD BC,$0320 | Set the size of the area to 0320. | ||||||||
| 9A91 | CALL Set_Area_Attributes | Set the attributes of the area. | ||||||||
| 9A94 | POP DE | Restore the frame flags from the stack. | ||||||||
| 9A95 | RET | Return. | ||||||||
| Prev: 9A33 | Up: Map | Next: 9A96 |