Update scores on screen

Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>

9 files changed, 114 insertions, 6 deletions

diff --git a/.nasm/memory.txt b/.nasm/memory.txt
index 7a2ccaa..b7a16bc 100644
--- a/.nasm/memory.txt
+++ b/.nasm/memory.txt
@@ -23,6 +23,7 @@ $22: zp_buttons
 $24: zp_level
 $25: zp_level_kind
 $26: zp_multiplayer
+$27: zp_extra_flags
 $2E: zp_blink_status
 $2F: zp_blink_timer
 $30: zp_title_timer
@@ -83,4 +84,4 @@ $4016: m_joypad
 $4017: m_frame_counter
 
 --- Summary (in bytes) ---
-- Internal RAM: 437/2048 (21.34%)
+- Internal RAM: 438/2048 (21.39%)
diff --git a/.nasm/segments.txt b/.nasm/segments.txt
index 486c2fa..eb919f2 100644
--- a/.nasm/segments.txt
+++ b/.nasm/segments.txt
@@ -1,4 +1,4 @@
 - HEADER: 16/16 (100%)
-- ROM0: 8864/32762 (27.06%)
+- ROM0: 9005/32762 (27.49%)
 - ROMV: 6/6 (100%)
 - ROM2: 8192/8192 (100%)
diff --git a/include/globals.s b/include/globals.s
index 1861e07..a958778 100644
--- a/include/globals.s
+++ b/include/globals.s
@@ -56,4 +56,15 @@
     ;; |   1 | player's 1 state | 0: over; 1: alive        |
     ;; |   0 | active           | 0: player 1; 1: player 2 |
     zp_multiplayer = $26
+
+    ;; Extra bitmap that was needed beyond the ones that we already have. Yeah,
+    ;; I know, bad planning from my side, but now it's a bit complex to untangle
+    ;; variables like 'Globals::zp_flags'.
+    ;;
+    ;; | Bit | Short name       | Meaning                          |
+    ;; |-----+------------------+----------------------------------|
+    ;; |   7 | score            | The score has been updated.      |
+    ;; |   6 | high             | The high score has been updated. |
+    ;; | 5-0 | -                | Unused.                          |
+    zp_extra_flags = $27
 .endscope
diff --git a/src/bullets.s b/src/bullets.s
index 3cc74b9..802edb7 100644
--- a/src/bullets.s
+++ b/src/bullets.s
@@ -297,8 +297,9 @@
         jsr Enemies::collides
         beq @next_enemy_collision
 
-        ;; Yes! Kill the enemy and break the loop.
+        ;; Yes! Kill the enemy, keep the score and break the loop.
         jsr Enemies::bite_the_dust
+        ADD_ENEMY_SCORE
         jmp @save_bullet_move
 
     @next_enemy_collision:
diff --git a/src/driver.s b/src/driver.s
index 8e26fbe..a9a2fbd 100644
--- a/src/driver.s
+++ b/src/driver.s
@@ -138,6 +138,10 @@
         and #%11111011
         sta Globals::zp_flags
 
+        ;; And the scores should be updated on the game screen as well.
+        lda #$80
+        sta Globals::zp_extra_flags
+
         rts
     .endproc
 
diff --git a/src/interrupts.s b/src/interrupts.s
index 9c2cb45..7026223 100644
--- a/src/interrupts.s
+++ b/src/interrupts.s
@@ -27,6 +27,12 @@
     lda #$02
     sta OAM::m_dma
 
+    ;; Should scores be updated?
+    bit Globals::zp_extra_flags
+    bpl @check_pause
+    jsr Score::nmi_update_scores
+
+@check_pause:
     ;; Toggle pause message from the HUD.
     bit Driver::zp_flags
     bvc @increase_rand
diff --git a/src/items.s b/src/items.s
index 12f551f..084bd1b 100644
--- a/src/items.s
+++ b/src/items.s
@@ -521,6 +521,14 @@
         lsr
         sta Items::zp_current_tiles + 1, x
 
+        ;; Account for this on the player's score.
+        ;;
+        ;; NOTE: this is in opposition as to how it was handled in the original
+        ;; game where the score was accounted on part/tank pickup, not
+        ;; dropping. I find this more reliable and easier to code, and in the
+        ;; end it's the same.
+        ADD_PART_FUEL_SCORE
+
         jmp @next
 
         ;;;
@@ -966,7 +974,8 @@
         lda #$FF
         sta Items::zp_pool_base, x
 
-        ;; TODO: score
+        ;; Account for this on the player's score.
+        ADD_ITEM_SCORE
 
         rts
     .endproc
diff --git a/src/jetpac.s b/src/jetpac.s
index b356192..a50ba6a 100644
--- a/src/jetpac.s
+++ b/src/jetpac.s
@@ -107,7 +107,7 @@
     bpl @vblankwait2
 
     ;; NOTE: palettes are not initialized here as it's going to be one of the
-    ;; first things done on `main` code.
+    ;; first things done in main().
 
     __fallthrough__ main
 .endproc
@@ -123,6 +123,12 @@
     sta Score::m_hi + 5
 
 @init:
+    ;; Force the scores to appear.
+    lda #$80
+    sta Globals::zp_extra_flags
+
+    ;; TODO: update high score (see zp_extra_flags)
+
     ;; Disable the PPU and zero out variables which shadow PPU registers.
     lda #0
     sta PPU::m_mask
diff --git a/src/score.s b/src/score.s
index ed36283..5b5c455 100644
--- a/src/score.s
+++ b/src/score.s
@@ -118,9 +118,79 @@
 
         BCD_JUST_CARRY
 
-        ;; TODO: set a flag about updating the score on the HUD.
+        ;;;
+        ;; And set the 'score' flag, signaling a need of updating the score.
+
+        lda Globals::zp_extra_flags
+        ora #$80
+        sta Globals::zp_extra_flags
+
+        rts
+    .endproc
+
+    ;; Update the score for both players. This might be a bit too much on single
+    ;; player mode but we have to show both scores on the title screen
+    ;; anyways. Hence, since we have all the time in the world anyways, we
+    ;; update both and avoid branching and stuff.
+    .proc nmi_update_scores
+        ;; The 'y' register will contain the right high byte for the PPU
+        ;; address. This is needed because scores are to be displayed on both
+        ;; the title and game screens.
+        lda PPU::zp_control
+        and #$02
+        tax
+        ldy hi_ppu_address, x
+
+        ;; Now we just put the numbers. The 'x' index has to go "backwards", and
+        ;; taking into account that both players live on the same buffer. The
+        ;; tile ID is basically the integer value + $10, which is the position
+        ;; of the '0' character on our tile set.
+
+        bit PPU::m_status
+        sty PPU::m_address
+        lda #$62
+        sta PPU::m_address
+
+        clc
+        ldx #(PLAYERS_BUFF_SIZE - 2)
+    @player1_loop:
+        lda Score::m_players, x
+        adc #$10
+        sta PPU::m_data
+
+        dex
+        dex
+        cpx #$FE
+        bne @player1_loop
+
+        ;; And the same for the second player.
+
+        bit PPU::m_status
+        sty PPU::m_address
+        lda #$78
+        sta PPU::m_address
+
+        clc
+        ldx #(PLAYERS_BUFF_SIZE - 1)
+    @player2_loop:
+        lda Score::m_players, x
+        adc #$10
+        sta PPU::m_data
+
+        dex
+        dex
+        cpx #$FF
+        bne @player2_loop
+
+        ;; Disable the 'score' flag.
+        lda Globals::zp_extra_flags
+        and #$3F
+        sta Globals::zp_extra_flags
 
         rts
+
+    hi_ppu_address:
+        .byte $20, $00, $28, $00
     .endproc
 .endscope