mirror of
https://github.com/irmen/prog8.git
synced 2024-11-30 08:52:30 +00:00
92 lines
2.8 KiB
Lua
92 lines
2.8 KiB
Lua
%import syslib
|
|
%import graphics
|
|
%import math
|
|
|
|
; Note: this program is compatible with C64 and CX16.
|
|
|
|
main {
|
|
|
|
; vertices
|
|
word[] xcoor = [ -100, -100, -100, -100, 100, 100, 100, 100 ]
|
|
word[] ycoor = [ -100, -100, 100, 100, -100, -100, 100, 100 ]
|
|
word[] zcoor = [ -100, 100, -100, 100, -100, 100, -100, 100 ]
|
|
|
|
; storage for rotated coordinates
|
|
word[len(xcoor)] rotatedx
|
|
word[len(ycoor)] rotatedy
|
|
word[len(zcoor)] rotatedz
|
|
|
|
; edges
|
|
ubyte[] edgesFrom = [ 0, 2, 6, 4, 1, 3, 7, 5, 0, 2, 6, 4]
|
|
ubyte[] edgesTo = [ 2, 6, 4, 0, 3, 7, 5, 1, 1, 3, 7, 5]
|
|
|
|
|
|
sub start() {
|
|
uword anglex
|
|
uword angley
|
|
uword anglez
|
|
|
|
graphics.enable_bitmap_mode()
|
|
|
|
|
|
repeat {
|
|
rotate_vertices(msb(anglex), msb(angley), msb(anglez))
|
|
graphics.clear_screen(1, 0)
|
|
draw_lines()
|
|
anglex-=500
|
|
angley+=217
|
|
anglez+=452
|
|
|
|
sys.waitvsync()
|
|
sys.waitvsync()
|
|
}
|
|
}
|
|
|
|
sub rotate_vertices(ubyte ax, ubyte ay, ubyte az) {
|
|
; rotate around origin (0,0,0)
|
|
|
|
; set up the 3d rotation matrix values
|
|
word wcosa = math.cos8(ax)
|
|
word wsina = math.sin8(ax)
|
|
word wcosb = math.cos8(ay)
|
|
word wsinb = math.sin8(ay)
|
|
word wcosc = math.cos8(az)
|
|
word wsinc = math.sin8(az)
|
|
|
|
word wcosa_sinb = wcosa*wsinb / 128
|
|
word wsina_sinb = wsina*wsinb / 128
|
|
|
|
word Axx = wcosa*wcosb / 128
|
|
word Axy = (wcosa_sinb*wsinc - wsina*wcosc) / 128
|
|
word Axz = (wcosa_sinb*wcosc + wsina*wsinc) / 128
|
|
word Ayx = wsina*wcosb / 128
|
|
word Ayy = (wsina_sinb*wsinc + wcosa*wcosc) / 128
|
|
word Ayz = (wsina_sinb*wcosc - wcosa*wsinc) / 128
|
|
word Azx = -wsinb
|
|
word Azy = wcosb*wsinc / 128
|
|
word Azz = wcosb*wcosc / 128
|
|
|
|
ubyte @zp i
|
|
for i in 0 to len(xcoor)-1 {
|
|
; don't normalize by dividing by 128, instead keep some precision for perspective calc later
|
|
rotatedx[i] = (Axx*xcoor[i] + Axy*ycoor[i] + Axz*zcoor[i])
|
|
rotatedy[i] = (Ayx*xcoor[i] + Ayy*ycoor[i] + Ayz*zcoor[i])
|
|
rotatedz[i] = (Azx*xcoor[i] + Azy*ycoor[i] + Azz*zcoor[i])
|
|
}
|
|
}
|
|
|
|
sub draw_lines() {
|
|
ubyte @zp i
|
|
for i in len(edgesFrom) -1 downto 0 {
|
|
ubyte @zp vFrom = edgesFrom[i]
|
|
ubyte @zp vTo = edgesTo[i]
|
|
word @zp persp1 = 256 + rotatedz[vFrom]/256
|
|
word @zp persp2 = 256 + rotatedz[vTo]/256
|
|
graphics.line(rotatedx[vFrom] / persp1 + graphics.WIDTH/2 as uword,
|
|
rotatedy[vFrom] / persp1 + graphics.HEIGHT/2 as ubyte,
|
|
rotatedx[vTo] / persp2 + graphics.WIDTH/2 as uword,
|
|
rotatedy[vTo] / persp2 + graphics.HEIGHT/2 as ubyte)
|
|
}
|
|
}
|
|
}
|