set_tile_map_xy.s (2069B)
1 .include "global.s" 2 3 .title "VRAM utilities" 4 .module VRAMUtils 5 6 .ez80 7 8 .area _HOME 9 10 ;; Set background tile table from (BC) at XY = DE of size WH = HL 11.set_tile_map_xy:: 12 push hl 13 ld hl, #.VDP_TILEMAP 14 15 ;; Set background tile from (BC) at YX = DE, size WH on stack, to VRAM from address (HL) 16.set_tile_map_xy_tt:: 17 push bc ; Store source 18 19 ld a, d 20 rrca ; rrca(2) == rlca(6) 21 rrca 22 ld d, a 23 and #0x07 24 add h 25 ld b, a 26 ld a, #0xC0 27 and d 28 sla e 29 add e 30 ld c, a ; dest BC = HL + ((0x20 * Y) * 2) + (X * 2) 31 32 ld a, b 33 cp #>(.VDP_TILEMAP+0x0700) 34 jr c, 5$ 35 ld b, #>.VDP_TILEMAP 365$: 37 pop hl ; HL = source 38 pop de ; DE = HW 39 push ix ; save IX 40 push de ; store HW 41 42 ld ixh, b 43 ld ixl, c 44 push ix ; store dest 45 46 DISABLE_VBLANK_COPY ; switch OFF copy shadow SAT 47 481$: ; copy H rows 49 VDP_WRITE_CMD ixh, ixl 50 ld c, #.VDP_DATA 512$: ; copy W tiles 52 outi 53 VDP_DELAY 54 outi 55 56 ld a, ixl 57 and #0x3F 58 inc a 59 inc a 60 bit 6, a 61 jp z, 3$ 62 and #0x3F 63 ld b, a 64 ld a, ixl 65 and #0xC0 66 or b 67 ld ixl, a 68 VDP_WRITE_CMD ixh, ixl 69 dec e 70 jp nz, 2$ 71 jp 7$ 723$: 73 inc ixl 74 inc ixl 75 dec e 76 jp nz, 2$ 777$: 78 pop ix 79 pop de 80 81 dec d 82 jr z, 6$ 83 84 push de 85 86 ld bc, #0x40 87 add ix, bc 88 ld a, ixh 89 cp #>(.VDP_TILEMAP+0x0700) 90 jp c, 4$ 91 ld ixh, #>.VDP_TILEMAP 924$: 93 push ix 94 jp 1$ 956$: 96 ENABLE_VBLANK_COPY ; switch ON copy shadow SAT 97 pop ix ; restore IX 98 ret