Slightly frustrating, but illuminating, attempt to title screen.
Chris Pressey
7 years ago
| 4 | 4 | // ---------------------------------------------------------------- |
| 5 | 5 | // Global Variables and System Locations |
| 6 | 6 | // ---------------------------------------------------------------- |
| 7 | ||
| 8 | byte vic_border @ 53280 | |
| 9 | byte vic_bg @ 53281 | |
| 7 | 10 | |
| 8 | 11 | byte table screen1 @ 1024 |
| 9 | 12 | byte table screen2 @ 1274 |
| 21 | 24 | pointer ptr @ 254 |
| 22 | 25 | word pos |
| 23 | 26 | word delta |
| 27 | ||
| 28 | // | |
| 29 | // Points to the routine that implements the current game state. | |
| 30 | // | |
| 31 | ||
| 32 | vector dispatch_game_state | |
| 33 | inputs joy2, pos | |
| 34 | outputs delta, pos, screen, vic_border, vic_bg, screen1 | |
| 35 | trashes a, x, y, c, z, n, v, ptr | |
| 24 | 36 | |
| 25 | 37 | // |
| 26 | 38 | // The constraints on these 2 vectors are kind-of sort-of big fibs. |
| 36 | 48 | |
| 37 | 49 | vector cinv |
| 38 | 50 | inputs joy2, pos |
| 39 | outputs delta, pos, screen | |
| 51 | outputs delta, pos, screen, vic_border, vic_bg, screen1 | |
| 40 | 52 | trashes a, x, y, c, z, n, v, ptr |
| 41 | 53 | @ 788 |
| 42 | 54 | |
| 43 | 55 | vector save_cinv |
| 44 | 56 | inputs joy2, pos |
| 45 | outputs delta, pos, screen | |
| 46 | trashes a, x, y, c, z, n, v, ptr | |
| 47 | ||
| 48 | // (This one is less fibby.) | |
| 49 | ||
| 50 | vector dispatch_game_state | |
| 51 | inputs joy2, pos | |
| 52 | outputs delta, pos, screen | |
| 53 | trashes a, x, y, c, z, n, v, ptr | |
| 57 | outputs delta, pos, screen, vic_border, vic_bg, screen1 | |
| 58 | trashes a, x, y, c, z, n, v, ptr | |
| 59 | ||
| 54 | 60 | |
| 55 | 61 | // ---------------------------------------------------------------- |
| 56 | 62 | // Utility Routines |
| 118 | 124 | |
| 119 | 125 | routine game_state_play |
| 120 | 126 | inputs joy2, pos |
| 121 | outputs delta, pos, screen | |
| 127 | outputs delta, pos, screen, vic_border, vic_bg, screen1 | |
| 122 | 128 | trashes a, x, y, c, z, n, v, ptr |
| 123 | 129 | { |
| 124 | 130 | call read_stick |
| 136 | 142 | goto save_cinv |
| 137 | 143 | } |
| 138 | 144 | |
| 145 | routine game_state_title_screen | |
| 146 | inputs joy2, pos | |
| 147 | outputs delta, pos, screen, vic_border, vic_bg, screen1 | |
| 148 | trashes a, x, y, c, z, n, v, ptr | |
| 149 | { | |
| 150 | ld a, 5 | |
| 151 | st a, vic_border | |
| 152 | ld a, 0 | |
| 153 | st a, vic_bg | |
| 154 | ld y, 0 | |
| 155 | ||
| 156 | repeat { | |
| 157 | ld a, 82 | |
| 158 | st a, screen1 + y | |
| 159 | inc y | |
| 160 | cmp y, 18 | |
| 161 | } until not z | |
| 162 | ||
| 163 | st off, c | |
| 164 | // jsr check_button | |
| 165 | ||
| 166 | if c { | |
| 167 | // call clear_screen | |
| 168 | // jsr init_game | |
| 169 | // FIXME various reasons we can't do this, mainly that self-reference | |
| 170 | // is disallowed: we would need to put "outputs dispatch_game_state" in | |
| 171 | // the signature of dispatch_game_state! | |
| 172 | // copy game_state_play, dispatch_game_state | |
| 173 | } | |
| 174 | ||
| 175 | goto save_cinv | |
| 176 | } | |
| 177 | ||
| 139 | 178 | // ************************* |
| 140 | 179 | // * Main Game Loop Driver * |
| 141 | 180 | // ************************* |
| 142 | 181 | |
| 143 | 182 | routine our_cinv |
| 144 | 183 | inputs joy2, pos |
| 145 | outputs delta, pos, screen | |
| 184 | outputs delta, pos, screen, vic_border, vic_bg, screen1 | |
| 146 | 185 | trashes a, x, y, c, z, n, v, ptr |
| 147 | 186 | { |
| 148 | 187 | goto dispatch_game_state |
| 152 | 191 | inputs cinv |
| 153 | 192 | outputs cinv, save_cinv, pos, dispatch_game_state, |
| 154 | 193 | screen1, screen2, screen3, screen4, colormap1, colormap2, colormap3, colormap4 |
| 155 | trashes a, y, n, c, z | |
| 194 | trashes a, y, n, c, z, vic_border, vic_bg | |
| 156 | 195 | { |
| 157 | 196 | call clear_screen |
| 158 | copy game_state_play, dispatch_game_state | |
| 197 | copy game_state_title_screen, dispatch_game_state | |
| 159 | 198 | |
| 160 | 199 | copy word 0, pos |
| 161 | 200 | with interrupts off { |