WIP sky scroller

loader/samples/minexample/minexample.s

@@ -43,10 +43,6 @@ copy_start:
     sei
     lda #$35
     sta $01
-    lda #>(code_end-CODE_START_ADDR)
-    sta $ff
-    lda #<(code_end-CODE_START_ADDR)
-    sta $fe
 
     lda #<CODE_START_ADDR
     sta $fc
@@ -58,26 +54,26 @@ copy_start:
     lda #>code_start
     sta $fb
 
-@copy_loop:
     ldy #0
+    ldx #>(code_end-CODE_START_ADDR)
+    beq :+++
+:
     lda ($fa), y
     sta ($fc), y
-    inc $fc
-    bne :+
-    inc $fd
-:
-    inc $fa
-    bne :+
+    iny
+    bne :-
     inc $fb
+    inc $fd
+    dex
+    bne :-
+    beq :+
 :
-    lda $fe
-    bne :+
-    dec $ff
+    lda ($fa), y
+    sta ($fc), y
+    iny
 :
-    dec $fe
-    lda $fe
-    ora $ff
-    bne @copy_loop
+    cpy #<(code_end-CODE_START_ADDR)
+    bne :--
 
     lda #$36
     sta $01
@@ -86,7 +82,7 @@ copy_start:
     sei
     lda #$35
     sta $01
-    jmp CODE_START_ADDR
+    jmp part_9
 
     .res loadraw - *
 .incbin "../../build/loader-c64.prg", 2
@@ -137,16 +133,7 @@ code_start:
 
     ldx #<badguy
     ldy #>badguy
-    jsr loadraw
-
-    lda #0
-    sta ZX0_src
-    lda #$80
-    sta ZX0_src+1
-    lda #0
-    sta ZX0_dst
-    lda #$20
-    jsr zx02
+    jsr load_8000_zx02_2000
 
     lda #127
     sta $dc0d
@@ -189,16 +176,8 @@ code_start:
     sei
     ldx #<introname
     ldy #>introname
-    jsr loadraw
-
-    lda #0
-    sta ZX0_src
-    lda #$80
-    sta ZX0_src+1
-    lda #0
-    sta ZX0_dst
     lda #$10
-    jsr zx02
+    jsr load_8000_zx02
 
     ldx #<sidname
     ldy #>sidname
@@ -232,14 +211,8 @@ code_start:
     lda #1
     sta timer_mode
 
-    lda #0
-    sta ZX0_src
-    lda #$80
-    sta ZX0_src+1
-    lda #0
-    sta ZX0_dst
     lda #$20
-    jsr zx02
+    jsr zx02_8000
 
 :
     lda timer_reached
@@ -285,15 +258,7 @@ code_start:
 
     ldx #<towerbeamname
     ldy #>towerbeamname
-    jsr loadraw
-    lda #0
-    sta ZX0_src
-    lda #$80
-    sta ZX0_src+1
-    lda #0
-    sta ZX0_dst
-    lda #$20
-    jsr zx02
+    jsr load_8000_zx02_2000
 
 :
     lda timer_reached
@@ -356,15 +321,7 @@ code_start:
 
     ldx #<fieldname
     ldy #>fieldname
-    jsr loadraw
-    lda #0
-    sta ZX0_src
-    lda #$80
-    sta ZX0_src+1
-    lda #0
-    sta ZX0_dst
-    lda #$20
-    jsr zx02
+    jsr load_8000_zx02_2000
 
 :
     lda timer_reached
@@ -441,15 +398,7 @@ code_start:
 
     ldx #<fallingstarname
     ldy #>fallingstarname
-    jsr loadraw
-    lda #0
-    sta ZX0_src
-    lda #$80
-    sta ZX0_src+1
-    lda #0
-    sta ZX0_dst
-    lda #$20
-    jsr zx02
+    jsr load_8000_zx02_2000
 
 :
     lda timer_reached
@@ -492,15 +441,7 @@ code_start:
 
     ldx #<lilianame
     ldy #>lilianame
-    jsr loadraw
-    lda #0
-    sta ZX0_src
-    lda #$80
-    sta ZX0_src+1
-    lda #0
-    sta ZX0_dst
-    lda #$20
-    jsr zx02
+    jsr load_8000_zx02_2000
 
 :
     lda timer_reached
@@ -547,15 +488,7 @@ code_start:
 
     ldx #<liliaheroname
     ldy #>liliaheroname
-    jsr loadraw
-    lda #0
-    sta ZX0_src
-    lda #$80
-    sta ZX0_src+1
-    lda #0
-    sta ZX0_dst
-    lda #$20
-    jsr zx02
+    jsr load_8000_zx02_2000
 
 :
     lda timer_reached
@@ -571,9 +504,110 @@ code_start:
     lda timer_reached
     beq :-
 
+part_9:
     jsr init_bmp
+
+    ldx #<skyscrname
+    ldy #>skyscrname
+    lda #$70
+    jsr load_8000_zx02
+    ldx #<skyscrmapname
+    ldy #>skyscrmapname
+    jsr loadraw
+    ldx #0
+    ldy #$90
+    jsr LZ_init_decomp
+
+    ; $0c00-$0fff buffer 0 tilemap
+    ; $2000-$3fff buffer 0 bitmap
+    ; $4000-$5fff buffer 1 bitmap
+    ; $6000-$63ff buffer 1 tilemap
+    ; $6400-$67ff next buffer CRAM
+    ; $7000-$77ff tileset bitmap
+    ; $7800-$78ff tileset tile colors
+    ; $7900-$79ff tileset CRAM colors
+    ; $9000-      compressed tilemap
+
+    lda #$38
+    sta $d018
+    lda #<((17+4)*40+$c08)
+    sta text_ptr
+    lda #>((17+4)*40+$c08)
+    sta text_ptr+1
+    ldx #16
+:
+    lda #0
+    lda text_ptr
+    sec
+    sbc #40
+    sta text_ptr
+    sta scr_ptr
+    sta cram_ptr
+    sta bmp_ptr
+    lda text_ptr+1
+    sbc #0
+    sta text_ptr+1
+    sta scr_ptr+1
+    ; carry is always set here
+    adc #$d8-$0c-1
+    sta cram_ptr+1
+    adc #<(($20>>3)-$d8)
+    asl bmp_ptr
+    rol a
+    asl bmp_ptr
+    rol a
+    asl bmp_ptr
+    rol a
+    sta bmp_ptr+1
+    stx temp+1
+    jsr drawrow
+    ldx temp+1
+    dex
+    bpl :-
+
+:
+    stx $d020
+    inx
+    jmp :-
     jmp *
 
+drawrow:
+    ldy #0
+charloop:
+    sty temp
+    lda #$70>>3
+    sta bmp_addr+1
+    jsr LZ_get_byte
+    tax
+    asl a
+    rol bmp_addr+1
+    asl a
+    rol bmp_addr+1
+    asl a
+    rol bmp_addr+1
+    sta bmp_addr
+    ldy #0
+    .repeat 8, I
+        lda (bmp_addr),y
+        sta (bmp_ptr),y
+        iny
+    .endrepeat
+    clc
+    lda bmp_ptr
+    adc #8
+    sta bmp_ptr
+    bne :+
+    inc bmp_ptr+1
+:
+    ldy temp
+    lda $7800,x
+    sta (scr_ptr),y
+    lda $7900,x
+    sta (cram_ptr),y
+    iny
+    cpy #24
+    bne charloop
+    rts
 
 intro:
     lda #0
@@ -1116,6 +1150,8 @@ fieldname: .byte "field", 0
 fallingstarname: .byte "fallstar", 0
 lilianame: .byte "lilia", 0
 liliaheroname: .byte "lilhero", 0
+skyscrname: .byte "skyscr", 0
+skyscrmapname: .byte "skyscrmap", 0
 
 
 darmtower_txt:
@@ -1256,6 +1292,24 @@ run_nufli_bmp:
 .include "zx02.asm"
 .include "thcmod_lz.asm"
 
+zx02_8000:
+    pha
+    jmp :+
+
+load_8000_zx02_2000:
+    lda #$20
+load_8000_zx02:
+    pha
+    jsr loadraw
+:
+    lda #0
+    sta ZX0_src
+    sta ZX0_dst
+    lda #$80
+    sta ZX0_src+1
+    pla
+    jmp zx02
+
 story_writ:
 .res 11, ' '
 .byte "story written by"