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@ -218,6 +218,10 @@ InitWorld: |
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lda #4 |
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sta backgroundBlue |
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; Initial enemy ship-spawn cooldown. |
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lda #30 |
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sta enemyShipSpawnCooldown |
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; Player's initial starting location and health. |
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lda #(256 / 4) |
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sta playerX |
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@ -498,11 +502,19 @@ UpdateShotCooldown: |
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SpawnEnemyShips: |
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GetRandomByte |
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bit #%01111111 ; Spawn ships every this-many frames (on average). |
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lda enemyShipSpawnCooldown |
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cmp #0 |
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beq + |
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dec A |
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sta enemyShipSpawnCooldown |
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rts |
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+ |
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GetRandomByte |
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and #%00111111 |
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clc |
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adc #32 |
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sta enemyShipSpawnCooldown |
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; Find an empty spot in the array. |
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ldy #0 |
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- |
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@ -520,7 +532,7 @@ SpawnEnemyShips: |
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lda #4 ; Sprite number. |
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sta enemyShipArray, Y |
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lda #(256 - 32) |
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lda #254 |
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sta enemyShipArray + 1, Y ; x. |
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- |
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