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Routines |
| Prev: ADD8 | Up: Map | Next: AF01 |
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Works out the area of attribute cells that is covered by the sprite that has just been drawn, as a width and height in cells, and fills it with the attribute at AF03 by calling FillAttributes.
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| SetObjectAttributes | AE98 | LD A,($A1D8) | The rows of the sprite. | |
| AE9B | DEC A | Step A back. | ||
| AE9C | RET M | Return if the sign flag is set. | ||
| AE9D | LD D,A | D=A. | ||
| AE9E | LD HL,($A1D5) | Fetch the word at A1D5 into HL. | ||
| AEA1 | LD A,($5C29) | The width of the sprite in bytes. | ||
| AEA4 | LD B,A | B=A. | ||
| AEA5 | LD A,($A2FA) | The sprite reaches past the right of the screen. | ||
| AEA8 | AND A | Jump to SetObjectAttributes_Width if A is zero. | ||
| AEA9 | JR Z,SetObjectAttributes_Width | |||
| AEAB | LD A,L | A=L. | ||
| AEAC | ADD A,B | A gains B. | ||
| AEAD | SUB $A4 | Subtract A4 from A. | ||
| AEAF | LD L,$08 | L=08. | ||
| AEB1 | JR SetObjectAttributes_Cells | Jump to SetObjectAttributes_Cells. | ||
| SetObjectAttributes_Width | AEB3 | LD A,L | A=L. | |
| AEB4 | CP $08 | Jump to SetObjectAttributes_Right if A is 08 or more. | ||
| AEB6 | JR NC,SetObjectAttributes_Right | |||
| AEB8 | ADD A,$08 | Add 08 to A. | ||
| AEBA | LD L,A | L=A. | ||
| AEBB | LD A,B | A=B. | ||
| AEBC | SUB $08 | Subtract 08 from A. | ||
| AEBE | LD B,A | B=A. | ||
| SetObjectAttributes_Right | AEBF | LD A,L | A=L. | |
| AEC0 | ADD A,$17 | Add 17 to A. | ||
| AEC2 | ADD A,B | A gains B. | ||
| AEC3 | JR NC,SetObjectAttributes_Aligned | Jump to SetObjectAttributes_Aligned if the carry flag is clear. | ||
| AEC5 | LD A,$EE | A=EE. | ||
| AEC7 | SUB L | Subtract L from A. | ||
| AEC8 | JR SetObjectAttributes_Cells | Jump to SetObjectAttributes_Cells. | ||
| SetObjectAttributes_Aligned | AECA | LD A,L | A=L. | |
| AECB | AND %00000111 | Keep the bits of A that are set in 07. | ||
| AECD | JR Z,SetObjectAttributes_Sum | Jump to SetObjectAttributes_Sum if the zero flag is set. | ||
| AECF | LD A,B | A=B. | ||
| AED0 | ADD A,$08 | Add 08 to A. | ||
| AED2 | LD B,A | B=A. | ||
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This entry point is used by the routine at DrawShot.
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| SetObjectAttributes_Sum | AED3 | LD A,L | A=L. | |
| AED4 | ADD A,B | A gains B. | ||
| AED5 | SUB L | Subtract L from A. | ||
| SetObjectAttributes_Cells | AED6 | SRL A | Shift A right. | |
| AED8 | SRL A | Shift A right. | ||
| AEDA | SRL A | Shift A right. | ||
| AEDC | LD ($AF01),A | Update the attribute area. | ||
| AEDF | DEC A | Step A back. | ||
| AEE0 | RET M | Return if the sign flag is set. | ||
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This entry point is used by the routine at SetPairAttributes.
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| SetObjectAttributes_Height | AEE1 | LD A,H | A=H. | |
| AEE2 | SUB D | Subtract D from A. | ||
| AEE3 | SUB $07 | Subtract 07 from A. | ||
| AEE5 | LD E,A | E=A. | ||
| AEE6 | CP $17 | Jump to SetObjectAttributes_Rows if A is 17 or more. | ||
| AEE8 | JR NC,SetObjectAttributes_Rows | |||
| AEEA | LD E,$17 | E=17. | ||
| SetObjectAttributes_Rows | AEEC | LD A,H | A=H. | |
| AEED | OR %00000111 | Set the bits of A that are set in 07. | ||
| AEEF | SUB E | Subtract E from A. | ||
| AEF0 | SRL A | Shift A right. | ||
| AEF2 | SRL A | Shift A right. | ||
| AEF4 | SRL A | Shift A right. | ||
| AEF6 | LD ($AF02),A | The height of the attribute area. | ||
| AEF9 | DEC A | Step A back. | ||
| AEFA | RET M | Return if the sign flag is set. | ||
| AEFB | LD DE,$AF01 | The attribute area. | ||
| AEFE | JP FillAttributes | Jump to FillAttributes. | ||
| Prev: ADD8 | Up: Map | Next: AF01 |