mirror of
https://github.com/irmen/prog8.git
synced 2024-08-18 23:29:32 +00:00
101 lines
2.9 KiB
Lua
101 lines
2.9 KiB
Lua
%target cx16
|
|
%import cx16textio
|
|
|
|
main {
|
|
|
|
const uword screen_width = 80
|
|
const uword screen_height = 60
|
|
|
|
; vertices
|
|
word[] xcoor = [ -40, -40, -40, -40, 40, 40, 40, 40 ]
|
|
word[] ycoor = [ -40, -40, 40, 40, -40, -40, 40, 40 ]
|
|
word[] zcoor = [ -40, 40, -40, 40, -40, 40, -40, 40 ]
|
|
|
|
; storage for rotated coordinates
|
|
word[len(xcoor)] rotatedx
|
|
word[len(ycoor)] rotatedy
|
|
word[len(zcoor)] rotatedz
|
|
|
|
sub start() {
|
|
|
|
uword anglex
|
|
uword angley
|
|
uword anglez
|
|
ubyte timer_jiffies
|
|
|
|
repeat {
|
|
rotate_vertices(msb(anglex), msb(angley), msb(anglez))
|
|
txt.clear_screenchars(' ')
|
|
draw_edges()
|
|
anglex+=500
|
|
angley+=215
|
|
anglez+=453
|
|
}
|
|
}
|
|
|
|
sub rotate_vertices(ubyte ax, ubyte ay, ubyte az) {
|
|
; rotate around origin (0,0,0)
|
|
|
|
; set up the 3d rotation matrix values
|
|
word wcosa = cos8(ax)
|
|
word wsina = sin8(ax)
|
|
word wcosb = cos8(ay)
|
|
word wsinb = sin8(ay)
|
|
word wcosc = cos8(az)
|
|
word wsinc = 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_edges() {
|
|
|
|
; plot the points of the 3d cube
|
|
; first the points on the back, then the points on the front (painter algorithm)
|
|
|
|
ubyte @zp i
|
|
word @zp rz
|
|
word @zp persp
|
|
byte sx
|
|
byte sy
|
|
|
|
for i in 0 to len(xcoor)-1 {
|
|
rz = rotatedz[i]
|
|
if rz >= 10 {
|
|
persp = 500 + rz/64
|
|
sx = rotatedx[i] / persp as byte + screen_width/2
|
|
sy = rotatedy[i] / persp as byte + screen_height/2
|
|
txt.setcc(sx as ubyte, sy as ubyte, 46, 7)
|
|
}
|
|
}
|
|
|
|
for i in 0 to len(xcoor)-1 {
|
|
rz = rotatedz[i]
|
|
if rz < 10 {
|
|
persp = 500 + rz/64
|
|
sx = rotatedx[i] / persp as byte + screen_width/2
|
|
sy = rotatedy[i] / persp as byte + screen_height/2
|
|
txt.setcc(sx as ubyte, sy as ubyte, 81, 7)
|
|
}
|
|
}
|
|
}
|
|
}
|