source cleanup
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saintfrater
parent
af01a603de
commit
959980b6a7
1 changed files with 0 additions and 324 deletions
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@ -1,324 +0,0 @@
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; ============================================================
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; gfx_cursor_draw_rm16_i386_self
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; Entrée:
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; DS = BDA_DATA_SEG
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; Sortie: rien
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; Détruit: registres sauvegardés/restaurés (PUSHA/POPA)
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; ============================================================
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cga_cursor_draw:
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push ds
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push es
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push fs
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push gs
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pushad
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; -----------------------------
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; ES = VRAM
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; -----------------------------
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mov ax, VIDEO_SEG
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mov es, ax
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mov ax, BDA_DATA_SEG
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mov ds, ax
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; -----------------------------
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; GS:SI = sprite (AND puis XOR à +32)
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; -----------------------------
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mov ax, [BDA_MOUSE + mouse.cur_seg]
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mov gs, ax
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mov si, [BDA_MOUSE + mouse.cur_ofs]
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; -----------------------------
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; Charger x,y
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; CX = x, DX = y
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; -----------------------------
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mov cx, [BDA_MOUSE + mouse.x]
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mov dx, [BDA_MOUSE + mouse.y]
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; off = x & 7 (stocké dans BL)
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mov bl, cl
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and bl, 7
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; width = min(16, 640-x) -> DL
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mov ax, GFX_WIDTH
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sub ax, cx
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cmp ax, 16
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jbe .w_ok
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mov ax, 16
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.w_ok:
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test al, al
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jz .done
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mov dl, al ; DL = width (1..16)
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; height = min(16, 200-y) -> BP (compteur)
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mov bp, GFX_HEIGHT
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sub bp, dx
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cmp bp, 16
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jbe .h_ok
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mov bp, 16
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.h_ok:
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test bp, bp
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jz .done
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; bytes_to_touch = ((off + width + 7) >> 3) -> BH
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mov ah, bl
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add ah, dl
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add ah, 7
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shr ah, 3
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mov bh, ah ; BH = 1..3
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; clipmask16 = 0xFFFF << (16-width) -> (on le recalculera par ligne)
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; parité initiale (y&1) -> CH
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mov ch, byte [BDA_MOUSE + mouse.y]
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and ch, 1
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; -----------------------------
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; Calcul DI = adresse VRAM pour (x,y)
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; DI = (y>>1)*80 + (x>>3) + (y&1)*0x2000
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; -----------------------------
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mov ax, dx
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shr ax, 1 ; ax = y/2
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mov di, ax
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shl di, 4 ; (y/2)*16
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shl ax, 6 ; (y/2)*64
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add di, ax ; *80
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mov ax, cx
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shr ax, 3 ; x/8
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add di, ax
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test byte [BDA_MOUSE + mouse.y], 1
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jz .addr_even
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add di, CGA_ODD_BANK
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.addr_even:
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; row index dans AL
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xor ax, ax ; AL = 0 (row)
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.row_loop:
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; conserver row + (off/bytes) sur pile, pour libérer BL/BH si besoin
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push ax
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push bx ; BL=off, BH=bytes_to_touch
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; -----------------------------------------
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; Charger AND/XOR pour la ligne (row=AL)
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; CX = AND, DX = XOR
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; -----------------------------------------
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xor ah, ah
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shl ax, 1 ; AX = row*2
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mov bx, si
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add bx, ax
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mov cx, [gs:bx] ; AND word
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add bx, 32
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mov dx, [gs:bx] ; XOR word
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; restaurer row dans AL
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pop bx ; restore off/bytes into BL/BH
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pop ax ; restore row in AL
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; -----------------------------------------
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; clipmask16 = 0xFFFF << (16-width)
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; width est dans DL
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; clipmask -> BX
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; -----------------------------------------
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mov bx, 0FFFFh
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mov cl, 16
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sub cl, dl
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shl bx, cl ; BX = clipmask
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; AND' = AND | (~clipmask)
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mov ax, bx
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not ax
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or cx, ax ; CX = AND'
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; XOR' = XOR & clipmask
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and dx, bx ; DX = XOR'
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; -----------------------------------------
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; Construire seg 16-bit depuis VRAM (ES:DI)
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; w0 = (b0<<8)|b1
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; seg = (w0<<off) | (b2>>(8-off)) si off!=0 et bytes==3
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; seg -> AX
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; -----------------------------------------
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; AX = w0
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mov ah, [es:di] ; b0
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mov al, [es:di+1] ; b1
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; if off==0 -> seg ready
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test bl, bl
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jz .seg_ready
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; seg = w0 << off
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mov cl, bl
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shl ax, cl
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; if bytes==3, OR b2>>(8-off)
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cmp bh, 3
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jne .seg_ready
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mov cl, 8
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sub cl, bl ; 8-off
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xor bh, bh ; BH=0, BL=off (on évite bpl etc)
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mov bl, [es:di+2] ; BL=b2
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shr bx, cl ; BX = b2>>(8-off)
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or ax, bx
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; restaurer BL=off, BH=bytes: (on ne peut pas, on a écrasé)
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; => ne jamais écraser BL/BH. Donc on refait proprement:
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; (ce bloc est remplacé ci-dessous)
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; --- on ne doit pas passer ici ---
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.seg_ready:
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; *** IMPORTANT ***
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; Le bloc ci-dessus a montré le piège (écraser BL/BH).
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; On fait le chemin correct ci-dessous, sans toucher BL/BH.
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; Refaire seg proprement sans écraser BL/BH:
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; AX = w0 (recharge)
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mov ah, [es:di]
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mov al, [es:di+1]
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test bl, bl
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jz .seg2_ready
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mov cl, bl
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shl ax, cl
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cmp bh, 3
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jne .seg2_ready
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mov cl, 8
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sub cl, bl ; 8-off
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xor ah, ah
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mov al, [es:di+2] ; AL=b2
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; AX = b2
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shr ax, cl ; AX = b2>>(8-off)
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; OR into seg: need seg in another reg -> use BX temp
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mov bx, [es:di] ; not ok (word read uses little endian, avoid)
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; simplest: use stack temp
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push ax ; save (b2>>(8-off))
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; reload seg again and OR
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mov ah, [es:di]
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mov al, [es:di+1]
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mov cl, bl
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shl ax, cl
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pop bx
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or ax, bx
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.seg2_ready:
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; -----------------------------------------
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; newseg = (seg & AND') ^ XOR'
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; seg in AX
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; -----------------------------------------
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and ax, cx
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xor ax, dx ; AX=newseg
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; -----------------------------------------
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; Ecriture vers VRAM
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; - off==0 : b0=AH, b1=AL (si bytes>=2)
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; - off!=0 : b0 partiel, b1 complet si bytes>=2, b2 partiel si bytes==3
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; -----------------------------------------
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test bl, bl
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jnz .write_unaligned
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.write_aligned:
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mov [es:di], ah
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cmp bh, 1
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je .after_write
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mov [es:di+1], al
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jmp .after_write
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.write_unaligned:
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; mask0 = (1<<(8-off))-1 (bits bas de b0)
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mov cl, 8
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sub cl, bl
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mov dh, 1
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shl dh, cl
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dec dh ; DH = mask0
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; val0 = newseg >> (8+off)
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mov bx, ax ; BX = newseg
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mov cl, bl
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add cl, 8
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shr bx, cl ; BL = val0 (low 8)
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; b0 = (old & ~mask0) | (val0 & mask0)
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mov dl, [es:di] ; old b0
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mov cl, dh ; CL=mask0
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not cl
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and dl, cl ; keep upper bits
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not cl ; CL=mask0
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and bl, cl ; val0 masked
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or dl, bl
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mov [es:di], dl
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cmp bh, 1
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je .after_write
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; b1 = (newseg >> off) & 0xFF
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mov bx, ax
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mov cl, bl ; BUG: BL now val0, not off
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; => on doit recharger off depuis BDA_MOUSE.x &7, ou le sauver.
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; On le sauve au début de la fonction dans une variable: ici on le recharge (coût faible)
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mov bl, [BDA_MOUSE + mouse.x] ; low byte x
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and bl, 7
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mov cl, bl
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shr bx, cl
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mov [es:di+1], bl
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cmp bh, 2
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je .after_write
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; b2 partiel (bits hauts off)
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; mask2 = 0xFF << (8-off)
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mov cl, 8
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sub cl, bl ; bl=off
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mov dl, 0FFh
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shl dl, cl ; DL=mask2
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; part2 = (newseg << (8-off)) & 0xFF
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mov bx, ax ; BX=newseg
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shl bx, cl ; BL=part2
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; b2 = (old & ~mask2) | (part2 & mask2)
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mov dh, [es:di+2] ; old b2
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mov cl, dl ; CL=mask2
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not cl
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and dh, cl
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not cl
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and bl, cl
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or dh, bl
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mov [es:di+2], dh
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.after_write:
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; -----------------------------------------
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; next row
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; -----------------------------------------
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inc al
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dec bp
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jz .done
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; stepping CGA:
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; even->odd: +0x2000
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; odd ->even: -0x2000 + 80
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test ch, ch
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jz .even_to_odd
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; odd -> even
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sub di, CGA_ODD_BANK
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add di, CGA_STRIDE
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xor ch, ch
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jmp .row_loop
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.even_to_odd:
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add di, CGA_ODD_BANK
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mov ch, 1
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jmp .row_loop
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.done:
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popad
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pop gs
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pop fs
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pop es
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pop ds
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ret
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