tweaks to the cx16 sprite example

This commit is contained in:
Irmen de Jong 2023-08-31 22:31:04 +02:00
parent 2d528c26ae
commit 83d4592526

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@ -3,37 +3,39 @@
%option no_sysinit %option no_sysinit
main { main {
const ubyte SPRITE_BANK = 0 ; we choose arbitrary unused vram location for sprite data: $12000
const uword SPRITE_ADDR = $2000 const ubyte SPRITE_DATA_BANK = 1
const uword SPRITE_DATA_ADDR = $2000
sub start() { sub start() {
void diskio.vload_raw("dragonsprite.bin", SPRITE_BANK, SPRITE_ADDR) void diskio.vload_raw("dragonsprite.bin", SPRITE_DATA_BANK, SPRITE_DATA_ADDR)
void diskio.vload_raw("dragonsprite.pal", 1, $fa00 + sprites.PALETTE_OFFSET) ; load directly into vera color palette void diskio.vload_raw("dragonsprite.pal", 1, $fa00 + sprites.PALETTE_OFFSET*2) ; load directly into vera color palette
sprites.init(1, SPRITE_ADDR) ; top half of dragon sprites.init(1, SPRITE_DATA_BANK, SPRITE_DATA_ADDR) ; top half of dragon
sprites.init(2, SPRITE_ADDR + 64*64/2) ; bottom half of dragon sprites.init(2, SPRITE_DATA_BANK, SPRITE_DATA_ADDR + 64*64/2) ; bottom half of dragon
word xpos = -64 word xpos = -64
word ypos = 100 word ypos = 100
ubyte tt = 0 ubyte tt = 0
bool flipped bool flippedx
repeat { repeat {
if flipped if flippedx
xpos -= 2 xpos -= 2
else else
xpos += 2 xpos += 2
if xpos >= 640 or xpos <= -64 if xpos >= 640 or xpos <= -64
flipped = not flipped flippedx = not flippedx
ypos = (240-64 as word) + math.sin8(tt) ypos = (240-64 as word) + math.sin8(tt)
tt++ tt++
sys.waitvsync() sys.waitvsync()
sprites.pos(1, xpos, ypos) sprites.pos(1, xpos, ypos)
sprites.pos(2, xpos, ypos+64) sprites.pos(2, xpos, ypos+64)
sprites.flipx(1, flipped) sprites.flipx(1, flippedx)
sprites.flipx(2, flipped) sprites.flipx(2, flippedx)
} }
} }
} }
@ -46,31 +48,39 @@ sprites {
; … ; …
; Sprite 127: $1FFF8 - $1FFFF ; Sprite 127: $1FFF8 - $1FFFF
const uword VERA_SPRITEREGS = $fc00 ; $1fc00 const uword VERA_SPRITEREGS = $fc00 ; $1fc00
const ubyte PALETTE_OFFSET = 32 ; in bytes, so 16 color entries const ubyte PALETTE_OFFSET = 16 ; color palette indices 16-31
uword sprite_regs uword @zp sprite_reg
sub init(ubyte sprite_num, uword data_addr) { sub init(ubyte sprite_num, ubyte data_bank, uword data_addr) {
hide(sprite_num)
cx16.VERA_DC_VIDEO |= %01000000 ; enable sprites globally cx16.VERA_DC_VIDEO |= %01000000 ; enable sprites globally
uword address = data_addr >> 5 data_addr >>= 5
sprite_regs = VERA_SPRITEREGS + sprite_num*$0008 data_addr |= (data_bank as uword)<<11
cx16.vpoke(1, sprite_regs, lsb(address)) ; address 12:5 sprite_reg = VERA_SPRITEREGS + sprite_num*$0008
cx16.vpoke(1, sprite_regs+1, %00000000 | msb(address)) ; 4 bpp + address 16:13 cx16.vpoke(1, sprite_reg, lsb(data_addr)) ; address 12:5
cx16.vpoke(1, sprite_regs+6, %00001100) ; sprite flags: enable sprite, z depth %11 = before both layers cx16.vpoke(1, sprite_reg+1, %00000000 | msb(data_addr)) ; 4 bpp + address 16:13
cx16.vpoke(1, sprite_regs+7, %11110000 | PALETTE_OFFSET>>5) ; 64x64 pixels, palette offset cx16.vpoke(1, sprite_reg+6, %00001100) ; z depth %11 = in front of both layers, no flips
pos(sprite_num, 100, 100) cx16.vpoke(1, sprite_reg+7, %11110000 | PALETTE_OFFSET>>4) ; 64x64 pixels, palette offset
}
sub hide(ubyte sprite_num) {
pos(sprite_num, -64, -64)
} }
sub flipx(ubyte sprite_num, bool flipped) { sub flipx(ubyte sprite_num, bool flipped) {
uword sprite_reg = VERA_SPRITEREGS + sprite_num*$0008 + 6 cx16.vpoke_mask(1, VERA_SPRITEREGS + 6 + sprite_num*$0008, %11111110, flipped)
cx16.vpoke(1, sprite_reg, cx16.vpeek(1, sprite_reg) & %11111110 | flipped) }
sub flipy(ubyte sprite_num, bool flipped) {
cx16.vpoke_mask(1, VERA_SPRITEREGS + 6 + sprite_num*$0008, %11111101, flipped<<1)
} }
sub pos(ubyte sprite_num, word x, word y) { sub pos(ubyte sprite_num, word x, word y) {
sprite_regs = VERA_SPRITEREGS + sprite_num*$0008 sprite_reg = VERA_SPRITEREGS + 2 + sprite_num*$0008
cx16.vpoke(1, sprite_regs+2, lsb(x)) cx16.vpoke(1, sprite_reg, lsb(x))
cx16.vpoke(1, sprite_regs+3, msb(x)) cx16.vpoke(1, sprite_reg+1, msb(x))
cx16.vpoke(1, sprite_regs+4, lsb(y)) cx16.vpoke(1, sprite_reg+2, lsb(y))
cx16.vpoke(1, sprite_regs+5, msb(y)) cx16.vpoke(1, sprite_reg+3, msb(y))
} }
} }