//#resource "vcs-ca65.h"

import "vcslib.ecs"

component Bitmap48
  bitmap0: array of 0..0xff
  bitmap1: array of 0..0xff
  bitmap2: array of 0..0xff
  bitmap3: array of 0..0xff
  bitmap4: array of 0..0xff
  bitmap5: array of 0..0xff
  height: 0..255
end

system Kernel48Pixel
  locals 2
  on kernelsetup do if [Bitmap48] ---
        lda {{<height}}
        sta {{$0}}	; scanline counter
        lda #$22
        sta COLUP0	; show how players alternate
        lda #$12
        sta COLUP1	; by having different colors
        lda #3
        sta NUSIZ0
        sta NUSIZ1	; both players have 3 copies
        sta WSYNC
        SLEEPH 34
        sta RESP0	; position 1st player
        sta RESP1	; ...and 2nd player
        lda #$10
        sta HMP1	; 1 pixel to the left
        sta WSYNC
        sta HMOVE	; apply HMOVE
        SLEEPH 24	; sleep 24 cycles
        sta HMCLR	; clear HMOVE registers
        lda #1
        sta VDELP0	; we need the VDEL registers
        sta VDELP1	; so we can do our 4-store trick
---
/* already exists on StaticKernel
  on kernelsetup do if [BGColor] ---
    lda {{<bgcolor}}
    sta COLUBK
---
*/
  on kernelsetup do if [PFColor] ---
    lda {{<pfcolor}}
    sta COLUP0
    sta COLUP1
---
  on kerneldraw do if [Bitmap48] ---
  	txa
        pha
@Loop:
	ldy {{$0}}	; counts backwards
        sta WSYNC	; sync to next scanline
        lda {{data bitmap0}},y	; load B0 (1st sprite byte)
        sta GRP0	; B0 -> [GRP0]
        lda {{data bitmap1}},y	; load B1 -> A
        sta GRP1	; B1 -> [GRP1], B0 -> GRP0
        lda {{data bitmap2}},y	; load B2 -> A
        sta GRP0	; B2 -> [GRP0], B1 -> GRP1
        lda {{data bitmap5}},y	; load B5 -> A
        sta {{$1}}	; B5 -> temp
        ldx {{data bitmap4}},y	; load B4 -> X
        lda {{data bitmap3}},y	; load B3 -> A
        ldy {{$1}}	; load B5 -> Y
        sta GRP1	; B3 -> [GRP1]; B2 -> GRP0
        stx GRP0	; B4 -> [GRP0]; B3 -> GRP1
        sty GRP1	; B5 -> [GRP1]; B4 -> GRP0
        sta GRP0	; ?? -> [GRP0]; B5 -> GRP1
        dec {{$0}}	; go to next line
	bpl @Loop	; repeat until < 0
        pla
        tax
---
end

demo Main

    //using FrameLoop, StaticKernel, Kernel48Pixel
    using FrameLoop, Kernel48Pixel, StaticKernel
    
    // TODO

    entity [KernelSection, BGColor]
      const lines = 10
      const bgcolor = $a0
    end

    entity [KernelSection, BGColor]
      const lines = 10
      const bgcolor = $a2
    end

    entity [KernelSection, BGColor, PFColor, Bitmap48]
        const lines = 2
        const bgcolor = 0xa4
        const pfcolor = 0xfc
        decode vcs_bitmap48 ---
x.............................................xx
xx.........................................xxx.x
xxxx....................................xxx....x
xx..xxxx..............................xx.......x
xx......xx...........................x.........x
xx...x....x............xx............x.........x
xx...x....x...........x..x.........xx..........x
xx...x..x..x....x......xx.....x...x............x
xx...xxxx...x...xxx...x..x..xxx..x.............x
xx...x..x..x......x....xx...x.....x............x
xx...x....x...........x..x.........xx..........x
xx......xx.............xx............x.........x
xx..xxxx..............................xx.......x
xxxx....................................xxxxxxxx
................................................
---
    end

    entity [KernelSection, BGColor]
      const lines = 10
      const bgcolor = $a2
    end

    entity [KernelSection, BGColor]
      const lines = 10
      const bgcolor = $a0
    end

end