gb_test2
annotate test.asm @ 2:a8b7297e7e2c
corrected comment
| author | John Tsiombikas <nuclear@member.fsf.org> |
|---|---|
| date | Thu, 10 Jan 2019 04:48:34 +0200 |
| parents | d63782badb6b |
| children | d7c6e1165028 |
| rev | line source |
|---|---|
| nuclear@0 | 1 ; vi:ft=rgbasm: |
| nuclear@0 | 2 include "hw.inc" |
| nuclear@0 | 3 |
| nuclear@0 | 4 xoffs_center equ 4 |
| nuclear@0 | 5 yoffs_center equ 12 |
| nuclear@0 | 6 |
| nuclear@0 | 7 frame_ptr equ $ff80 |
| nuclear@0 | 8 |
| nuclear@0 | 9 section "hdr", ROM0[$100] |
| nuclear@0 | 10 nop |
| nuclear@0 | 11 jp main |
| nuclear@0 | 12 |
| nuclear@0 | 13 rept $150 - $104 |
| nuclear@0 | 14 db 0 |
| nuclear@0 | 15 endr |
| nuclear@0 | 16 |
| nuclear@0 | 17 section "text", ROM0 |
| nuclear@0 | 18 |
| nuclear@0 | 19 main: |
| nuclear@0 | 20 call init |
| nuclear@0 | 21 |
| nuclear@0 | 22 xor a, a |
| nuclear@0 | 23 ldh [frame_ptr], a |
| nuclear@0 | 24 .mainloop: |
| nuclear@0 | 25 ldh a, [REG_LY] |
| nuclear@0 | 26 cp a, 144 |
| nuclear@0 | 27 jr c, .wait_hsync |
| nuclear@0 | 28 |
| nuclear@0 | 29 ; we're in vsync, increment frame counter and wait for the next frame |
| nuclear@0 | 30 ldh a, [frame_ptr] |
| nuclear@0 | 31 inc a |
| nuclear@0 | 32 ldh [frame_ptr], a |
| nuclear@0 | 33 .wait_newframe: |
| nuclear@0 | 34 ldh a, [REG_LY] |
| nuclear@0 | 35 cp a, 0 |
| nuclear@0 | 36 jr nz, .wait_newframe |
| nuclear@0 | 37 |
| nuclear@0 | 38 ; scanline code |
| nuclear@0 | 39 .wait_hsync: |
| nuclear@0 | 40 ldh a, [REG_STAT] |
| nuclear@0 | 41 and a, STAT_MODE_MASK |
| nuclear@0 | 42 jr nz, .wait_hsync |
| nuclear@0 | 43 |
| nuclear@0 | 44 ldh a, [frame_ptr] |
| nuclear@0 | 45 ld d, a |
| nuclear@0 | 46 |
| nuclear@0 | 47 xor a, a |
| nuclear@0 | 48 ld b, a |
| nuclear@1 | 49 |
| nuclear@0 | 50 ldh a, [REG_LY] |
| nuclear@1 | 51 add a, d ; add frame number |
| nuclear@0 | 52 ld c, a |
| nuclear@0 | 53 |
| nuclear@0 | 54 ld hl, sintab |
| nuclear@1 | 55 add hl, bc ; hl now points to the sine value |
| nuclear@0 | 56 |
| nuclear@1 | 57 ld a, [hl] |
| nuclear@1 | 58 |
| nuclear@1 | 59 ; add a half-octave sine |
| nuclear@1 | 60 ld e, a ; save first sine to e |
| nuclear@1 | 61 sla d |
| nuclear@1 | 62 ld a, [REG_LY] |
| nuclear@1 | 63 sla a |
| nuclear@1 | 64 add a, d |
| nuclear@1 | 65 ld c, a |
| nuclear@1 | 66 srl d |
| nuclear@1 | 67 |
| nuclear@1 | 68 ld hl, sintab |
| nuclear@1 | 69 add hl, bc |
| nuclear@1 | 70 ld a, [hl] |
| nuclear@1 | 71 sra a |
| nuclear@1 | 72 add a, e ; add previously saved sine |
| nuclear@1 | 73 |
| nuclear@1 | 74 add a, yoffs_center |
| nuclear@0 | 75 ldh [REG_SCY], a |
| nuclear@0 | 76 |
| nuclear@1 | 77 ; do something for SCX too |
| nuclear@1 | 78 ld a, d |
| nuclear@1 | 79 sla a |
| nuclear@1 | 80 ld d, a |
| nuclear@1 | 81 |
| nuclear@1 | 82 ldh a, [REG_LY] |
| nuclear@1 | 83 add a, 32 |
| nuclear@1 | 84 add a, d ; add frame number |
| nuclear@1 | 85 ld c, a |
| nuclear@1 | 86 |
| nuclear@1 | 87 ld hl, sintab |
| nuclear@1 | 88 add hl, bc |
| nuclear@1 | 89 |
| nuclear@1 | 90 ld a, [hl] |
| nuclear@1 | 91 sra a |
| nuclear@1 | 92 add a, xoffs_center |
| nuclear@1 | 93 ldh [REG_SCX], a |
| nuclear@1 | 94 |
| nuclear@0 | 95 ; done, wait until we're out of hsync |
| nuclear@0 | 96 .wait_endhsync: |
| nuclear@0 | 97 ldh a, [REG_STAT] |
| nuclear@0 | 98 and a, STAT_MODE_MASK |
| nuclear@0 | 99 jr z, .wait_endhsync |
| nuclear@0 | 100 |
| nuclear@0 | 101 jr .mainloop |
| nuclear@0 | 102 |
| nuclear@0 | 103 |
| nuclear@0 | 104 di |
| nuclear@0 | 105 .end: halt |
| nuclear@0 | 106 nop |
| nuclear@0 | 107 jp .end |
| nuclear@0 | 108 |
| nuclear@0 | 109 init: |
| nuclear@0 | 110 call wait_vsync |
| nuclear@0 | 111 xor a, a |
| nuclear@0 | 112 ldh [REG_LCDC], a |
| nuclear@0 | 113 |
| nuclear@2 | 114 ; setup palette |
| nuclear@0 | 115 ld a, $1b |
| nuclear@0 | 116 ldh [REG_BGP], a |
| nuclear@0 | 117 |
| nuclear@0 | 118 ; copy tiles |
| nuclear@0 | 119 ld hl, $8000 |
| nuclear@0 | 120 ld de, tiles |
| nuclear@0 | 121 ld bc, tiles_end - tiles |
| nuclear@0 | 122 .copytiles: |
| nuclear@0 | 123 ld a, [de] |
| nuclear@0 | 124 ld [hl+], a |
| nuclear@0 | 125 inc de |
| nuclear@0 | 126 dec bc |
| nuclear@0 | 127 ld a, b |
| nuclear@0 | 128 or c |
| nuclear@0 | 129 jp nz, .copytiles |
| nuclear@0 | 130 |
| nuclear@0 | 131 ; copy tilemap |
| nuclear@0 | 132 ld hl, $9800 |
| nuclear@0 | 133 ld de, tilemap |
| nuclear@0 | 134 ld b, 21 |
| nuclear@0 | 135 .copymap: |
| nuclear@0 | 136 ld c, 21 |
| nuclear@0 | 137 .copymaprow: |
| nuclear@0 | 138 ld a, [de] |
| nuclear@0 | 139 inc de |
| nuclear@0 | 140 ld [hl+], a |
| nuclear@0 | 141 dec c |
| nuclear@0 | 142 jr nz, .copymaprow |
| nuclear@0 | 143 |
| nuclear@0 | 144 push bc |
| nuclear@0 | 145 ld bc, 11 |
| nuclear@0 | 146 add hl, bc |
| nuclear@0 | 147 pop bc |
| nuclear@0 | 148 |
| nuclear@0 | 149 dec b |
| nuclear@0 | 150 jr nz, .copymap |
| nuclear@0 | 151 |
| nuclear@0 | 152 ; center viewport |
| nuclear@0 | 153 ld a, yoffs_center |
| nuclear@0 | 154 ldh [REG_SCY], a |
| nuclear@0 | 155 ld a, xoffs_center |
| nuclear@0 | 156 ldh [REG_SCX], a |
| nuclear@0 | 157 |
| nuclear@0 | 158 ; configure LCD |
| nuclear@0 | 159 ld a, LCDC_DISPON | LCDC_CHAR_8000 | LCDC_BGON |
| nuclear@0 | 160 ldh [REG_LCDC], a |
| nuclear@0 | 161 ret |
| nuclear@0 | 162 |
| nuclear@0 | 163 wait_vsync: |
| nuclear@0 | 164 ldh a, [REG_LY] |
| nuclear@0 | 165 cp a, 144 |
| nuclear@0 | 166 jr c, wait_vsync |
| nuclear@0 | 167 ret |
| nuclear@0 | 168 |
| nuclear@0 | 169 section "data", ROM0, align[8] |
| nuclear@0 | 170 sintab: |
| nuclear@0 | 171 include "sin.inc" |
| nuclear@0 | 172 |
| nuclear@0 | 173 tiles: |
| nuclear@0 | 174 incbin "logo.tiles" |
| nuclear@0 | 175 tiles_end: |
| nuclear@0 | 176 tilemap: |
| nuclear@0 | 177 incbin "logo.tilemap" |
| nuclear@0 | 178 tilemap_end: |