colorized

README.md

@@ -21,6 +21,9 @@ in the original.
 
 - PAL frame loop synced by polling the raster beam (no interrupts), one
   state update per frame — title, play and game over are `updvec` states.
+- The background is raster-split at the horizon: sky above, grass below.
+  The road is a grey wedge of inverse-space characters between painted
+  white edge lines, with trees along both shoulders.
 - The player is hardware sprite 0; up to seven rabbits live on sprites
   1–7. Rabbits follow the road's perspective: a linear y ramp and a t²
   horizontal fan-out, both precomputed into tables at assembly time

common.asm

@@ -46,47 +46,126 @@ pt_loop:
     bne pt_loop
     rts
 
-; ---- the road: two diagonals from the horizon apex down to
+; ---- set scrlo/hi + collo/hi to the start of char row X ----
-; the screen corners, plus a tree on the left shoulder ----
+row_ptr:
-draw_road:
+    lda mul40lo,x
-    ldx #0
-dr_loop:
-    txa
-    clc
-    adc #6               ; road runs from char row 6 to row 24
-    tay
-    lda mul40lo,y
     sta scrlo
-    lda mul40hi,y
+    sta collo
+    lda mul40hi,x
     clc
     adc #>SCREEN
     sta scrhi
+    clc
+    adc #$d4             ; COLRAM - SCREEN high byte distance
+    sta colhi
+    rts
+
+; ---- the road: grey surface between two painted edge lines,
+; from the horizon apex down to the screen corners, then the
+; trees along both shoulders ----
+draw_road:
+    ldx #0
+dr_loop:
     stx drtmp
+    txa
+    clc
+    adc #6               ; road runs from char row 6 to row 24
+    tax
+    jsr row_ptr
     lda #19              ; left edge: one column left per row
     sec
     sbc drtmp
     tay
+    sty drleft
     lda #$4e             ; '/' diagonal
     sta (scrlo),y
+    lda #COL_EDGE
+    sta (collo),y
     lda #20              ; right edge: one column right per row
     clc
     adc drtmp
     tay
     lda #$4d             ; '\' diagonal
     sta (scrlo),y
+    lda #COL_EDGE
+    sta (collo),y
+    dey                  ; fill the surface between the edges
+dr_fill:
+    cpy drleft
+    beq dr_rowdone
+    lda #$a0             ; inverse space: solid block
+    sta (scrlo),y
+    lda #COL_ROAD
+    sta (collo),y
+    dey
+    jmp dr_fill
+dr_rowdone:
+    ldx drtmp
     inx
     cpx #19
     bne dr_loop
-    ; tree on the left shoulder
+; falls through: the roadside trees
-    lda #$51             ; ball
+draw_trees:
-    sta SCREEN+10*40+3
+    lda #0
-    sta SCREEN+11*40+2
+    sta ttidx
-    sta SCREEN+11*40+3
+dt_loop:
-    sta SCREEN+11*40+4
+    ldx ttidx
-    lda #$5d             ; trunk
+    lda tree_tbl,x
-    sta SCREEN+12*40+3
+    sta trow
+    lda tree_tbl+1,x
+    sta tcol
+    jsr draw_tree
+    inc ttidx
+    inc ttidx
+    lda ttidx
+    cmp #NTREES*2
+    bne dt_loop
     rts
 
+; ---- one tree: crown of balls on trow, top ball above,
+; trunk below (trow/tcol = middle row, left column) ----
+draw_tree:
+    ldx trow
+    dex
+    jsr row_ptr
+    ldy tcol
+    iny
+    jsr tree_ball
+    ldx trow
+    jsr row_ptr
+    ldy tcol
+    jsr tree_ball
+    iny
+    jsr tree_ball
+    iny
+    jsr tree_ball
+    ldx trow
+    inx
+    jsr row_ptr
+    ldy tcol
+    iny
+    lda #$5d             ; trunk
+    sta (scrlo),y
+    lda #BROWN
+    sta (collo),y
+    rts
+
+tree_ball:
+    lda #$51             ; foliage ball
+    sta (scrlo),y
+    lda #LGREEN
+    sta (collo),y
+    rts
+
+NTREES = 6
+tree_tbl:                ; middle row, left column - far trees sit
+    !byte  9,  4         ;   higher and closer to the road
+    !byte 14,  6
+    !byte 19,  3
+    !byte  8, 31
+    !byte 12, 34
+    !byte 17, 36
+
 ; ---- input ----
 
 ; read joystick port 2 merged with the a/d keys,
@@ -488,6 +567,10 @@ rowidx:    !byte 0
 bitcnt:    !byte 0
 curbits:   !byte 0
 drtmp:     !byte 0       ; draw_road internals
+drleft:    !byte 0
+ttidx:     !byte 0       ; draw_trees internals
+trow:      !byte 0
+tcol:      !byte 0
 rslot:     !byte 0       ; rab_pos internals
 rt:        !byte 0
 rlane:     !byte 0

defs.asm

@@ -28,8 +28,25 @@ SPR_COL  = $d027         ; sprite 0 color, +1 = sprite 1, ...
 ; ---- colors ----
 BLACK   = 0
 WHITE   = 1
+RED     = 2
+CYAN    = 3
+GREEN   = 5
+BLUE    = 6
+YELLOW  = 7
+ORANGE  = 8
+BROWN   = 9
+DGREY   = 11
+MGREY   = 12
+LGREEN  = 13
+LBLUE   = 14
 LGREY   = 15
 
+; ---- scene palette ----
+COL_SKY   = LBLUE        ; background above the horizon
+COL_GRASS = GREEN        ; background below it
+COL_ROAD  = MGREY        ; road surface (inverse-space fill)
+COL_EDGE  = WHITE        ; painted road edge lines
+
 ; ---- joystick port 2 bits (after read_joy, active high) ----
 JOY_LEFT  = 4
 JOY_RIGHT = 8
@@ -46,6 +63,7 @@ T_EXP     = 192          ; ... and where the sprite gets double-sized
 REP_HOLD  = 12           ; frames before a held direction auto-repeats
 REP_PERIOD = 6           ; frames between auto-repeat steps
 RAS_SYNC  = 251          ; raster line polled for the frame sync
+RAS_SPLIT = 97           ; horizon line: sky/grass background split
 
 ; ---- zero page pointers (same slots as the c64-demo) ----
 txtlo  = $f5             ; text pointer for the print routines (2 bytes)

main.asm

@@ -37,19 +37,21 @@
 start:
     sei                  ; no KERNAL IRQ - raster polling must not jitter
 
-    ; LCD look: black bezel border, pale screen, black artwork
+    ; sunny scene: black frame, sky above the horizon split
     lda #BLACK
     sta BORDER
-    lda #LGREY
+    lda #COL_SKY
     sta BG
 
-    ; sprites: all black, hires, in front of the characters
+    ; sprites: red scooter, white rabbits, hires, in front
+    lda #RED
+    sta SPR_COL
     ldx #7
 sprcol:
-    lda #BLACK
+    lda #WHITE
     sta SPR_COL,x
     dex
-    bpl sprcol
+    bne sprcol
     lda #0
     sta SPR_EN
     sta SPR_MC
@@ -72,9 +74,17 @@ sprcol:
 ; ============================================================
 main:
     jsr wait_frame
+    lda #COL_SKY         ; repaint the sky while the beam is off screen
+    sta BG
     inc framectr
     jsr rand8            ; stir the RNG once per frame
-    jsr call_update
+    jsr call_update      ; finishes long before the horizon line
+wait_grass:
+    lda RASTER           ; split the background at the horizon:
+    cmp #RAS_SPLIT       ;   sky above, grass below
+    bne wait_grass
+    lda #COL_GRASS
+    sta BG
     jmp main
 
 call_update:

over.asm

@@ -26,18 +26,27 @@ oi_row:
     lda mul40hi,y
     adc #>SCREEN
     sta scrhi
+    sta colhi            ; color RAM pointer for the same cells
+    lda scrlo
+    sta collo
+    lda colhi
+    clc
+    adc #$d4
+    sta colhi
     ldy #BOXW-1
 oi_col:
     jsr box_char
     sta (scrlo),y
+    lda #WHITE
+    sta (collo),y
     dey
     bpl oi_col
     inx
     cpx #5
     bne oi_row
 
-    +prtext BOXROW+1, 15, BLACK, txt_over, 9
+    +prtext BOXROW+1, 15, WHITE, txt_over, 9
-    +prtext BOXROW+2, 15, BLACK, txt_score, 5
+    +prtext BOXROW+2, 15, WHITE, txt_score, 5
 
     ; final score digits next to the label
     lda sc_d0
@@ -49,6 +58,10 @@ oi_col:
     lda sc_d2
     ora #48
     sta SCREEN+(BOXROW+2)*40+23
+    lda #YELLOW
+    sta COLRAM+(BOXROW+2)*40+21
+    sta COLRAM+(BOXROW+2)*40+22
+    sta COLRAM+(BOXROW+2)*40+23
 
     +setupd over_update
     rts
@@ -100,10 +113,10 @@ over_update:
     lda framectr
     and #32
     bne ou_hide
-    +prtext BOXROW+3, 14, BLACK, txt_retry, 12
+    +prtext BOXROW+3, 14, YELLOW, txt_retry, 12
     jmp ou_start
 ou_hide:
-    +prtext BOXROW+3, 14, BLACK, txt_blank, 12
+    +prtext BOXROW+3, 14, YELLOW, txt_blank, 12
 ou_start:
     jsr start_edge
     beq ou_done

play.asm

@@ -35,6 +35,17 @@ pi_clr:
     lda #2               ; start in the middle lane
     sta player_lane
 
+    ; sprite colors back to red scooter + white rabbits
+    ; (the title borrows sprites 1-4 as red scooters)
+    ldx #7
+pi_col:
+    lda #WHITE
+    sta SPR_COL,x
+    dex
+    bne pi_col
+    lda #RED
+    sta SPR_COL
+
     ; player sprite: scooter, fixed row, rabbits come per frame
     lda #SPRP_SCOOT
     sta SPRPTR
@@ -266,6 +277,8 @@ add_miss:
     ldy miss             ; Y: the rabbit loop still needs X
     lda #24              ; 'x'
     sta SCREEN+34,y      ; marks land on columns 35-37
+    lda #RED
+    sta COLRAM+34,y
     lda #12
     sta flash
     rts

title.asm

@@ -8,11 +8,17 @@ title_init:
     jsr clear_screen
     jsr draw_road
 
-    +prbig 1, 8, BLACK, txt_rabbit, 6
+    +prbig 1, 8, RED, txt_rabbit, 6
-    +prtext 6, 16, BLACK, txt_scooter, 7
+    +prtext 6, 16, WHITE, txt_scooter, 7
-    +prtext 17, 4, BLACK, txt_info, 31
+    +prtext 17, 4, WHITE, txt_info, 31
 
-    ; one parked scooter per lane on sprites 0-4
+    ; one parked scooter per lane on sprites 0-4, all in red
+    ldx #4
+ti_col:
+    lda #RED
+    sta SPR_COL,x
+    dex
+    bne ti_col
     ldx #4
 ti_scoot:
     txa
@@ -80,10 +86,10 @@ tu_pos:
     lda framectr
     and #32
     bne tu_hide
-    +prtext 15, 10, BLACK, txt_press, 19
+    +prtext 15, 10, YELLOW, txt_press, 19
     jmp tu_start
 tu_hide:
-    +prtext 15, 10, BLACK, txt_blank, 19
+    +prtext 15, 10, YELLOW, txt_blank, 19
 tu_start:
     jsr start_edge
     beq tu_done