[41] | 1 | ; Project name : Assembly Library |
---|
| 2 | ; Description : Functions for managing display cursor. |
---|
| 3 | |
---|
| 4 | ; Section containing code |
---|
| 5 | SECTION .text |
---|
| 6 | |
---|
| 7 | ;-------------------------------------------------------------------- |
---|
| 8 | ; DisplayCursor_SetShapeFromAX |
---|
| 9 | ; Parameters: |
---|
| 10 | ; AX: Cursor shape (AH=Start scan line, AL=End scan line) |
---|
| 11 | ; DS: BDA segment (zero) |
---|
| 12 | ; Returns: |
---|
| 13 | ; Nothing |
---|
| 14 | ; Corrupts registers: |
---|
| 15 | ; Nothing |
---|
| 16 | ;-------------------------------------------------------------------- |
---|
[369] | 17 | ALIGN DISPLAY_JUMP_ALIGN |
---|
[41] | 18 | DisplayCursor_SetShapeFromAX: |
---|
| 19 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCursorShape], ax |
---|
| 20 | ret |
---|
| 21 | |
---|
| 22 | |
---|
| 23 | ;-------------------------------------------------------------------- |
---|
| 24 | ; DisplayCursor_SetCoordinatesFromAX |
---|
| 25 | ; Parameters: |
---|
| 26 | ; AL: Cursor column (X-coordinate) |
---|
| 27 | ; AH: Cursor row (Y-coordinate) |
---|
| 28 | ; DS: BDA segment (zero) |
---|
| 29 | ; Returns: |
---|
| 30 | ; DI: Offset to cursor location in video RAM |
---|
| 31 | ; Corrupts registers: |
---|
| 32 | ; AX, DX |
---|
| 33 | ;-------------------------------------------------------------------- |
---|
[369] | 34 | ALIGN DISPLAY_JUMP_ALIGN |
---|
[41] | 35 | DisplayCursor_SetCoordinatesFromAX: |
---|
| 36 | xchg dx, ax |
---|
| 37 | mov ax, [VIDEO_BDA.wColumns] ; Column count, 40 or 80 |
---|
| 38 | mul dh ; AX = Column count * row index |
---|
[101] | 39 | xor dh, dh |
---|
| 40 | add ax, dx ; Add column offset |
---|
[41] | 41 | shl ax, 1 ; Convert to WORD offset |
---|
[101] | 42 | add ax, [VIDEO_BDA.wPageOffset] ; AX = Video RAM offset |
---|
| 43 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition], ax |
---|
| 44 | xchg di, ax |
---|
[41] | 45 | ret |
---|
| 46 | |
---|
| 47 | |
---|
| 48 | ;-------------------------------------------------------------------- |
---|
| 49 | ; DisplayCursor_GetSoftwareCoordinatesToAX |
---|
| 50 | ; Parameters: |
---|
| 51 | ; AX: Offset to cursor location in selected page |
---|
| 52 | ; DS: BDA segment (zero) |
---|
| 53 | ; Returns: |
---|
| 54 | ; AL: Cursor column (X-coordinate) |
---|
| 55 | ; AH: Cursor row (Y-coordinate) |
---|
| 56 | ; Corrupts registers: |
---|
| 57 | ; Nothing |
---|
| 58 | ;-------------------------------------------------------------------- |
---|
[369] | 59 | ALIGN DISPLAY_JUMP_ALIGN |
---|
[41] | 60 | DisplayCursor_GetSoftwareCoordinatesToAX: |
---|
| 61 | mov ax, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition] |
---|
| 62 | sub ax, [VIDEO_BDA.wPageOffset] |
---|
| 63 | shr ax, 1 ; WORD offset to character offset |
---|
| 64 | div BYTE [VIDEO_BDA.wColumns] ; AL = full rows, AH = column index for last row |
---|
| 65 | xchg al, ah |
---|
| 66 | ret |
---|
| 67 | |
---|
| 68 | |
---|
| 69 | ;-------------------------------------------------------------------- |
---|
| 70 | ; DisplayCursor_GetHardwareCoordinatesToAX |
---|
| 71 | ; Parameters: |
---|
| 72 | ; DS: BDA segment (zero) |
---|
| 73 | ; Returns: |
---|
| 74 | ; AL: Hardware cursor column (X-coordinate) |
---|
| 75 | ; AH: Hardware cursor row (Y-coordinate) |
---|
| 76 | ; Corrupts registers: |
---|
| 77 | ; DX |
---|
| 78 | ;-------------------------------------------------------------------- |
---|
[369] | 79 | ALIGN DISPLAY_JUMP_ALIGN |
---|
[41] | 80 | DisplayCursor_GetHardwareCoordinatesToAX: |
---|
| 81 | push cx |
---|
| 82 | push bx |
---|
| 83 | |
---|
| 84 | mov ah, GET_CURSOR_POSITION_AND_SIZE |
---|
| 85 | mov bh, [VIDEO_BDA.bActivePage] |
---|
| 86 | int BIOS_VIDEO_INTERRUPT_10h |
---|
| 87 | xchg ax, dx |
---|
| 88 | |
---|
| 89 | pop bx |
---|
| 90 | pop cx |
---|
| 91 | ret |
---|
| 92 | |
---|
| 93 | |
---|
| 94 | ;-------------------------------------------------------------------- |
---|
| 95 | ; DisplayCursor_SynchronizeShapeToHardware |
---|
| 96 | ; Parameters: |
---|
| 97 | ; DS: BDA segment (zero) |
---|
| 98 | ; Returns: |
---|
| 99 | ; Nothing |
---|
| 100 | ; Corrupts registers: |
---|
| 101 | ; AX, DX |
---|
| 102 | ;-------------------------------------------------------------------- |
---|
[369] | 103 | ALIGN DISPLAY_JUMP_ALIGN |
---|
[41] | 104 | DisplayCursor_SynchronizeShapeToHardware: |
---|
| 105 | mov dx, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCursorShape] |
---|
| 106 | ; Fall to .SetHardwareCursorShapeFromDX |
---|
| 107 | |
---|
| 108 | ;-------------------------------------------------------------------- |
---|
| 109 | ; .SetHardwareCursorShapeFromDX |
---|
| 110 | ; Parameters: |
---|
| 111 | ; DX: Cursor shape |
---|
| 112 | ; DS: BDA segment (zero) |
---|
| 113 | ; Returns: |
---|
| 114 | ; Nothing |
---|
| 115 | ; Corrupts registers: |
---|
| 116 | ; AX |
---|
| 117 | ;-------------------------------------------------------------------- |
---|
| 118 | .SetHardwareCursorShapeFromDX: |
---|
| 119 | cmp dx, [VIDEO_BDA.wCursorShape] |
---|
| 120 | je SHORT .Return ; Return if no changes |
---|
| 121 | push cx |
---|
| 122 | mov cx, dx ; BIOS wants cursor shape in CX |
---|
| 123 | mov al, [VIDEO_BDA.bMode] ; Load video mode to prevent lock ups on some BIOSes |
---|
| 124 | mov ah, SET_TEXT_MODE_CURSOR_SHAPE |
---|
| 125 | int BIOS_VIDEO_INTERRUPT_10h |
---|
| 126 | pop cx |
---|
| 127 | .Return: |
---|
| 128 | ret |
---|
| 129 | |
---|
| 130 | |
---|
| 131 | ;-------------------------------------------------------------------- |
---|
| 132 | ; DisplayCursor_SynchronizeCoordinatesToHardware |
---|
| 133 | ; Parameters: |
---|
| 134 | ; DS: BDA segment (zero) |
---|
| 135 | ; Returns: |
---|
| 136 | ; Nothing |
---|
| 137 | ; Corrupts registers: |
---|
| 138 | ; AX, DX |
---|
| 139 | ;-------------------------------------------------------------------- |
---|
[369] | 140 | ALIGN DISPLAY_JUMP_ALIGN |
---|
[41] | 141 | DisplayCursor_SynchronizeCoordinatesToHardware: |
---|
| 142 | call DisplayCursor_GetSoftwareCoordinatesToAX |
---|
| 143 | ; Fall to .SetHardwareCursorCoordinatesFromAX |
---|
| 144 | |
---|
| 145 | ;-------------------------------------------------------------------- |
---|
| 146 | ; .SetHardwareCursorCoordinatesFromAX |
---|
| 147 | ; Parameters: |
---|
| 148 | ; AL: Cursor column (X-coordinate) |
---|
| 149 | ; AH: Cursor row (Y-coordinate) |
---|
| 150 | ; DS: BDA segment (zero) |
---|
| 151 | ; Returns: |
---|
| 152 | ; Nothing |
---|
| 153 | ; Corrupts registers: |
---|
| 154 | ; AX, DX |
---|
| 155 | ;-------------------------------------------------------------------- |
---|
| 156 | .SetHardwareCursorCoordinatesFromAX: |
---|
| 157 | push bx |
---|
| 158 | xchg dx, ax ; BIOS wants coordinates in DX |
---|
| 159 | mov ah, SET_CURSOR_POSITION |
---|
| 160 | mov bh, [VIDEO_BDA.bActivePage] |
---|
| 161 | int BIOS_VIDEO_INTERRUPT_10h |
---|
| 162 | pop bx |
---|
| 163 | ret |
---|