8bitworkshop/presets/vcs/ecs/kernel2.ecs

//#resource "vcs-ca65.h"

import "vcslib.ecs"
import "sprites.ecs"

system Kernel2Sprite
    locals 13
    on preframe do with [KernelSection]
---
; TODOO: can store KLINES in memory?
.define KLINES {{<lines}}
.define KPAD 32
; set height to zero in case no sprites
    lda #0
    sta {{$8}}
    sta {{$9}}
---
    on preframe do join 
    	[SpriteSlot] with
    	[Sprite] limit 2
---
; set player object flags
    lda {{<plyrflags}}
    sta NUSIZ0,y
    sta REFP0,y
; calculate screen height - ypos
    lda KLINES
    clc
    adc KPAD
    sec
    sbc {{<ypos}}
    sta {{$11}}
; calculate bitmap pointer
    stx {{$12}}		; save X (Sprite index)
    lda {{<bitmap}}     ; deref bitmap
    tax
    lda {{<Bitmap:bitmapdata}},x
    sec
    sbc {{$11}}
    sta {{$0}},y	; Y = sprite slot index
    lda {{>Bitmap:bitmapdata}},x
    sbc #0
    sta {{$2}},y
; get bitmap height
    lda {{<Bitmap:height}},x
    sta {{$8}},y
; calculate colormap pointer
    ldx {{$12}}		; restore X
    lda {{<colormap}}	; deref colormap
    tax
    lda {{<Colormap:colormapdata}},x
    sec
    sbc {{$11}}
    sta {{$4}},y
    lda {{>Colormap:colormapdata}},x
    sbc #0
    sta {{$6}},y
; save ypos
    ldx {{$12}}		; restore X
    lda {{<ypos}}
    sta {{$10}},y
---
    on preframe do once
---
; shuffle pointers into (MSB, LSB) byte order
; L0 L1 H0 H1 -> L0 H0 L1 H1
    lda {{$1}}
    ldy {{$2}}
    sty {{$1}}
    sta {{$2}}
    lda {{$5}}
    ldy {{$6}}
    sty {{$5}}
    sta {{$6}}
---
    on preframe do if [KernelSection,BGColor]
---
    lda {{<bgcolor}}
    sta COLUBK
---
    on preframe do if [Missile,HasYpos]
---
    lda KLINES
    sec
    sbc {{<ypos}}
    sta {{$12}}
---
    on kernel do with [KernelSection]
---
    ldy #0
    sty VDELP0
    iny
    sty VDELP1
---
    on kernel do critical with [KernelSection] 
---    
    ldy {{<lines}}
@LVScan:
    {{!scanline 0}}
    dey		; next scanline
    {{!scanline 1}}
    dey		; next scanline
    bne @LVScan	; repeat until out of lines
---
    on scanline do once
---
; draw player 0
    lda {{$8}} ; height
    dcp {{$10}} ; ypos
    bcs @DoDraw1
    lda #0
    .byte $2C
@DoDraw1:
    lda ({{$0}}),y
;    .if {{#0}} = 0 ; TODO: configurable?
    sta WSYNC
;    .endif
    sta GRP0
    lda ({{$4}}),y
    sta COLUP0
; draw player 1
    lda {{$9}} ; height
    dcp {{$11}} ; ypos
    bcs @DoDraw2
    lda #0
    .byte $2C
@DoDraw2:
    lda ({{$2}}),y
    sta GRP1
    lda ({{$6}}),y
    sta COLUP1
---
    on kernel do once
---
    lda #0
    sta GRP0
    sta GRP1
    sta GRP0
    sta GRP1
---
    on scanline do if [Missile,HasYpos]
---
    cpy {{$12}}
    php
    pla
    sta ENAM0
---
end

///

demo Main

    using FrameLoop, Kernel2Sprite
    using Joystick, MoveJoyX, MoveJoyY
    using SetXPos, SetHorizPos
    using SpriteShuffler, SpriteHider

    entity Kernel [KernelSection, BGColor]
        const lines = 192
        const bgcolor = 0xa2
    end
    
    entity Bitmap1 [Bitmap]
        const bitmapdata = [1, 1, 3, 7, 15, 31, 63, 127, 0]
        const height = 8
    end
    
    entity Bitmap2 [Bitmap]
        const bitmapdata = [$18,$3e,$ff,$ff,$ff,$ff,$3e,$18, 0]
        const height = 8
    end
    
    entity Colormap1 [Colormap]
        const colormapdata = [2, 4, 6, 8, 10, 12, 14, 14, 14]
    end
    
    entity Sprite0 [Sprite,HasBitmap,HasColormap,HasXpos,HasYpos,Player]
        init xpos = 50
        init ypos = 150
        init bitmap = #Bitmap2
        init colormap = #Colormap1
        const plyrflags = 0
    end
    
    entity Sprite1 [Sprite,HasBitmap,HasColormap,HasXpos,HasYpos,Player]
        init xpos = 100
        init ypos = 60
        init bitmap = #Bitmap1
        init colormap = #Colormap1
        const plyrflags = 3
    end

    entity Sprite2 [Sprite,HasBitmap,HasColormap,HasXpos,HasYpos,Player]
        init xpos = 80
        init ypos = 90
        init bitmap = #Bitmap2
        init colormap = #Colormap1
        const plyrflags = 2
    end

    entity Sprite3 [Sprite,HasBitmap,HasColormap,HasXpos,HasYpos,Player]
        init xpos = 40
        init ypos = 150
        init bitmap = #Bitmap1
        init colormap = #Colormap1
        const plyrflags = 0
    end
    /*
    entity [Missile,HasXpos,HasYpos]
        init xpos = 70
        init ypos = 70
    end
    */
    entity Slot0 [SpriteSlot]
    	init sprite = #Sprite0
    end
    entity Slot1 [SpriteSlot]
    	init sprite = #Sprite1
    end
    entity Slot2 [SpriteSlot]
    	init sprite = #Sprite2
    end
    entity Slot3 [SpriteSlot]
    	init sprite = #Sprite3
    end

end demo