prog8/examples/cx16/bobs.p8
2023-08-31 16:56:52 +02:00

331 lines
9.0 KiB
Lua

%import palette
%import conv
%import textio
%import math
; "unlimited sprites / bobs" demo effect.
; Note that everything is prog8, no inline assembly used/required.
; Note2: these aren't actual sprites, it's a bitmap backbuffer display trick.
main {
sub start() {
void cx16.screen_mode(3, false)
txt.print("\n\n how many sprites does\n the commander x16 have?\n")
sys.wait(120)
txt.print("\n\n the manual says: '128'.\n")
sys.wait(80)
txt.print("\n\n but that's just a manual...\n")
sys.wait(80)
txt.print("\n\n let's find out for ourselves,\n shall we?")
sys.wait(180)
; enable bitmap mode 320x240, 1 bpp, only layer 1
cx16.VERA_DC_VIDEO = (cx16.VERA_DC_VIDEO & %11001111) | %00100000
cx16.VERA_DC_HSCALE = 64
cx16.VERA_DC_VSCALE = 64
cx16.VERA_L1_CONFIG = %00000100
cx16.VERA_L1_MAPBASE = 0
cx16.VERA_L1_TILEBASE = 0
; limit display heigth to 200 pixels to have enough vram for 14 backbuffers
const ubyte vstart = 20
const ubyte vheight = 200
cx16.VERA_CTRL = %00000010
cx16.VERA_DC_VSTART = vstart
cx16.VERA_DC_VSTOP = vstart + vheight - 1
init_buffers()
palette.set_color(0, $000)
palette.set_color(1, $af8)
sys.set_rasterirq(&irq, 340) ; time it so that the page flip at the end occurs near the bottom of the screen to avoid tearing
repeat {
; don't exit
}
}
const ubyte num_backbuffers = 12 ; there is vram space for 14 backbuffers. reduce to make tighter "loops"
uword num_bobs = 0
ubyte backbuffer = num_backbuffers-1
ubyte blitbuffer = 0
uword anim1 = $0432
uword anim2 = $f123
uword anim3 = $e321
uword anim4 = $7500
sub irq() {
; palette.set_color(0, $f00) ; debug rastertime
; draw 2 bobs per frame to speed up bob count
ubyte vmembase = blitbuffer*4 ; 2048 * 4 per backbuffer
blit(vmembase)
blitbuffer++
if blitbuffer==num_backbuffers
blitbuffer=0
vmembase = blitbuffer*4 ; 2048 * 4 per backbuffer
blit(vmembase)
blitbuffer++
if blitbuffer==num_backbuffers
blitbuffer=0
backbuffer++
if backbuffer==num_backbuffers {
backbuffer=0
num_bobs+=2
}
vmembase = backbuffer*4 ; 2048 * 4 per backbuffer
draw_number(vmembase, num_bobs)
cx16.VERA_L1_TILEBASE = vmembase << 2 ; flip to next backbuffer
; palette.set_color(0, $000)
}
sub init_buffers() {
; erase all vram
cx16.VERA_CTRL = 0
cx16.VERA_ADDR_L = 0
cx16.VERA_ADDR_M = 0
cx16.VERA_ADDR_H = %00010000 ; auto incr 1
repeat $ffff
cx16.VERA_DATA0 = 0
repeat $f960
cx16.VERA_DATA0 = 0
}
sub blit(ubyte vmembase) {
ubyte bank = vmembase>=32
uword vmem = vmembase * 2048 ; mkword(vmembase,0) * 8
uword blit_x = (math.cos8u(msb(anim1)) as uword) + math.sin8u(msb(anim2))/6
ubyte blit_y = math.sin8u(msb(anim3))/2 + math.cos8u(msb(anim4))/5
vmem += blit_x/8 + (blit_y as uword) * 40
bitshift(lsb(blit_x) & 7)
; left column of the (shifted) "sprite" (bob)
cx16.VERA_CTRL = 0
cx16.VERA_ADDR_L = lsb(vmem)
cx16.VERA_ADDR_M = msb(vmem)
cx16.VERA_ADDR_H = bank | %10110000 ; increment 40 for read (next line)
cx16.VERA_CTRL = 1
cx16.VERA_ADDR_L = lsb(vmem)
cx16.VERA_ADDR_M = msb(vmem)
cx16.VERA_ADDR_H = bank | %10110000 ; increment 40 for read (next line)
ubyte ix
for ix in 0 to len(shifted_sprite)-1 step 3
cx16.VERA_DATA1 = cx16.VERA_DATA0 & shifted_mask[ix] | shifted_sprite[ix]
; middle column of the (shifted) "sprite" (bob)
vmem++
cx16.VERA_CTRL = 0
cx16.VERA_ADDR_L = lsb(vmem)
cx16.VERA_ADDR_M = msb(vmem)
cx16.VERA_CTRL = 1
cx16.VERA_ADDR_L = lsb(vmem)
cx16.VERA_ADDR_M = msb(vmem)
for ix in 1 to len(shifted_sprite)-1 step 3
cx16.VERA_DATA1 = cx16.VERA_DATA0 & shifted_mask[ix] | shifted_sprite[ix]
; right column of the (shifted) "sprite" (bob)
vmem++
cx16.VERA_CTRL = 0
cx16.VERA_ADDR_L = lsb(vmem)
cx16.VERA_ADDR_M = msb(vmem)
cx16.VERA_CTRL = 1
cx16.VERA_ADDR_L = lsb(vmem)
cx16.VERA_ADDR_M = msb(vmem)
for ix in 2 to len(shifted_sprite)-1 step 3
cx16.VERA_DATA1 = cx16.VERA_DATA0 & shifted_mask[ix] | shifted_sprite[ix]
anim1 += 117
anim2 += 90
anim3 += 122
anim4 += 145
}
sub bitshift(ubyte shift) {
ubyte yix
ubyte yy
for yy in 0 to 15 {
uword @zp sprw = sprite[yy]
uword @zp maskw = mask[yy]
ubyte @zp sprite_3 = 0
ubyte @zp mask_3 = 255
repeat shift {
sprw >>= 1
ror(sprite_3)
sys.set_carry()
ror(maskw)
ror(mask_3)
}
shifted_sprite[yix] = msb(sprw)
shifted_mask[yix] = msb(maskw)
yix++
shifted_sprite[yix] = lsb(sprw)
shifted_mask[yix] = lsb(maskw)
yix++
shifted_sprite[yix] = sprite_3
shifted_mask[yix] = mask_3
yix++
}
}
sub draw_number(ubyte vmembase, uword number) {
uword vmem = vmembase * 2048 ; mkword(vmembase,0) * 8
ubyte bank = vmembase>=32
vmem += 35
conv.str_uw0(number)
uword pixelsptr = &numberpixels + (conv.string_out[1] & 15)*7
ubyte pix
cx16.VERA_CTRL = 0
cx16.VERA_ADDR_L = lsb(vmem)
cx16.VERA_ADDR_M = msb(vmem)
cx16.VERA_ADDR_H = bank | %10110000 ; increment 40 for read (next line)
for pix in 0 to 6
cx16.VERA_DATA0 = pixelsptr[pix]
vmem++
cx16.VERA_ADDR_L = lsb(vmem)
cx16.VERA_ADDR_M = msb(vmem)
pixelsptr = &numberpixels + (conv.string_out[2] & 15)*7
for pix in 0 to 6
cx16.VERA_DATA0 = pixelsptr[pix]
vmem++
cx16.VERA_ADDR_L = lsb(vmem)
cx16.VERA_ADDR_M = msb(vmem)
pixelsptr = &numberpixels + (conv.string_out[3] & 15)*7
for pix in 0 to 6
cx16.VERA_DATA0 = pixelsptr[pix]
vmem++
cx16.VERA_ADDR_L = lsb(vmem)
cx16.VERA_ADDR_M = msb(vmem)
pixelsptr = &numberpixels + (conv.string_out[4] & 15)*7
for pix in 0 to 6
cx16.VERA_DATA0 = pixelsptr[pix]
}
ubyte[10*7] numberpixels = [
%00111000,
%01000100,
%10000100,
%10000100,
%10000100,
%01111000,
%00000000,
%00010000,
%00110000,
%01010000,
%00010000,
%00010000,
%01111100,
%00000000,
%01111000,
%10000100,
%00011000,
%00110000,
%01100000,
%11111100,
%00000000,
%01111000,
%00000100,
%00111000,
%00000100,
%00000100,
%11111000,
%00000000,
%00010100,
%00100100,
%01000100,
%11111100,
%00000100,
%00000100,
%00000000,
%11111000,
%10000000,
%11111000,
%00000100,
%00000100,
%11111000,
%00000000,
%01111000,
%10000000,
%11111000,
%10000100,
%10000100,
%01111000,
%00000000,
%11111100,
%00001000,
%00010000,
%00010000,
%00010000,
%00010000,
%00000000,
%01111000,
%10000100,
%01111000,
%10000100,
%10000100,
%01111000,
%00000000,
%01111000,
%10000100,
%01111100,
%00000100,
%10000100,
%01111000,
%00000000
]
uword[16] sprite = [
%0000001111000000,
%0001111111111000,
%0011111110101100,
%0111111011010010,
%0111111010100010,
%0111110100001010,
%1111101000100001,
%1111010000000001,
%1111000100100001,
%1110100000000001,
%0110001000000010,
%0101000000000010,
%0100000000000010,
%0010100000000100,
%0001110000111000,
%0000001111000000
]
uword[16] mask = [
%1111110000111111,
%1110000000000111,
%1100000000000011,
%1000000000000001,
%1000000000000001,
%1000000000000001,
%0000000000000000,
%0000000000000000,
%0000000000000000,
%0000000000000000,
%1000000000000001,
%1000000000000001,
%1000000000000001,
%1100000000000011,
%1110000000000111,
%1111110000111111
]
ubyte[16*3] shifted_sprite
ubyte[16*3] shifted_mask
}