Cycling 74 » Topic: [lua] what am i doing wrong?

[lua] what am i doing wrong?

joshua goldberg — Mon, 17 Sep 2007 01:10:18 +0000

hi there. working on my first attempt at writing lua code, and also
i’m an amazingly crappy procedural programmer. any help on what i’m
experiencing would be lovely. special bonus if the question is
answered by one of my students (ROB)!

i’m getting a “lua pcall error attempt to call a string value” error
when my jit.gl.lua object tries to read its file. where’s my error?
(oh, and a line number reference for error messages would be AWESOME,
please wes)

here’s the max patch

—

#P window setfont “Sans Serif” 9.;
#P window linecount 1;
#P message 272 351 30 196617 read;
#P newex 254 424 197 196617 jit.gl.lua bork @file
josh.planesprinkle.lua;
#P newex 254 381 63 196617 jit.qt.movie;
#P message 134 50 34 196617 reset;
#P newex 134 74 188 196617 jit.gl.handle bork @inherit_transform 1;
#P message 375 135 70 196617 fullscreen $1;
#P toggle 375 115 15 0;
#P newex 375 92 38 196617 sel 27;
#P newex 375 70 40 196617 key;
#P number 91 41 35 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P user jit.fpsgui 31 178 60 196617 0;
#P newex 34 269 416 196617 t b b b b b b b b b b b b b b b b b b b;
#P newex 34 245 40 196617 r stuff;
#P toggle 31 47 15 0;
#P newex 128 127 40 196617 s stuff;
#P newex 31 153 201 196617 jit.gl.render bork @erase_color 0. 0. 0. 1.;
#P newex 31 98 58 196617 t b b erase;
#P newex 31 73 57 196617 qmetro 33;
#P newex 375 156 207 196617 jit.window bork @floating 1 @depthbuffer 1;
#P connect 18 0 16 0;
#P fasten 7 9 17 0 237 394;
#P connect 16 0 17 0;
#P connect 7 10 16 0;
#P connect 13 0 0 0;
#P connect 12 0 13 0;
#P connect 11 0 12 0;
#P connect 10 0 11 0;
#P connect 15 0 14 0;
#P connect 2 1 4 0;
#P connect 9 0 1 1;
#P connect 6 0 7 0;
#P connect 3 0 8 0;
#P connect 2 2 3 0;
#P connect 2 0 3 0;
#P connect 14 0 3 0;
#P connect 1 0 2 0;
#P connect 5 0 1 0;
#P window clipboard copycount 19;

and here’s josh.planesprinkle.lua

—

render_context = this.drawto

current = 1
vcount = 32

vplanes = {}

function resetplane(i)
vplanes[i].color = {1., 1., 1., 1.}
rand1 = (math.random() – .5) * 3.
rand2 = (math.random() – .5) * 3.
rand3 = (math.random() – .5) * 3.
vplanes[i].position = {rand1, rand2, rand3}
vplanes[i].scale = {.2, .2, 1.}
end

function setup()

for i=1, vcount do
vplanes[i] = jit.new(“jit.gl.videoplane”, render_context)
vplanes[i].automatic = 0
vplanes[i].blend_enable = 1
vplanes[i].depth_enable = 0
vplanes[i].blend_mode = {6, 1}
resetplane(i)
end
end

function draw(theplane)
vplanes[theplane]:draw()
end

function jit_matrix(name)
current = current + 1
if (current > vcount) then
current = 1
end
resetplane(current)
vplanes.[current]:jit_matrix(name)

end

function bang()
for i=1, vcount do
draw(i)
end
end

Re: [lua] what am i doing wrong?

Wesley Smith — Mon, 17 Sep 2007 01:24:15 +0000

Line 39:
vplanes.[current]:jit_matrix(name)

you have a period before the []. Indeed I don’t have syntax error
line reporting. I’ll add that for the next release. Right now I only
have runtime error line reporting.

wes

Re: [lua] what am i doing wrong?

joshua goldberg — Mon, 17 Sep 2007 02:03:22 +0000

ok, awesome. next error, happens every render cycle:

lua pcall error [string "render_context = this.drawto..."]:30:
attempt to index field ‘?’ (a nil value)

where’s this coming from?

(thanks again thanks again)

Re: [lua] what am i doing wrong?

Wesley Smith — Mon, 17 Sep 2007 02:12:47 +0000

apparently on line 30:

vplanes[theplane]:draw()

theplane is not valid key to the vplanes table which is what “attempt
to index field ‘?’ (a nil value)” means. Looks like you need to call
setup() somewhere before drawing starts.

wes

Re: [lua] what am i doing wrong?

Rob Ramirez — Mon, 17 Sep 2007 02:52:39 +0000

hey josh.
you better make good on that special bonus…

#P window setfont “Sans Serif” 9.;
#P window linecount 1;
#P newex 338 362 55 196617 delay 500;
#P newex 338 340 48 196617 loadbang;
#P newex 254 393 64 196617 prepend call;
#P newex 254 448 32 196617 print;
#P user jit.pwindow 167 405 82 62 0 1 0 0 1 0;
#P message 323 395 53 196617 call setup;
#P message 272 336 30 196617 read;
#P newex 254 424 263 196617 jit.gl.lua bork @file josh.planesprinkle.lua @autowatch 1;
#P newex 254 366 63 196617 jit.qt.movie;
#P message 134 50 34 196617 reset;
#P newex 134 74 188 196617 jit.gl.handle bork @inherit_transform 1;
#P message 375 135 70 196617 fullscreen $1;
#P toggle 375 115 15 0;
#P newex 375 92 38 196617 sel 27;
#P newex 375 70 40 196617 key;
#P number 91 41 35 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P user jit.fpsgui 31 178 60 196617 0;
#P newex 34 269 416 196617 t b b b b b b b b b b b b b b b b b b b;
#P newex 34 245 40 196617 r stuff;
#P toggle 31 47 15 0;
#P newex 128 127 40 196617 s stuff;
#P newex 31 153 201 196617 jit.gl.render bork @erase_color 0. 0. 0. 1.;
#P newex 31 98 58 196617 t b b erase;
#P newex 31 73 57 196617 qmetro 33;
#P newex 375 156 207 196617 jit.window bork @floating 1 @depthbuffer 1;
#P connect 13 0 0 0;
#P connect 12 0 13 0;
#P connect 11 0 12 0;
#P connect 10 0 11 0;
#P connect 23 0 24 0;
#P connect 24 0 19 0;
#P connect 17 0 21 0;
#P fasten 7 9 17 0 237 394;
#P connect 19 0 17 0;
#P connect 22 0 17 0;
#P connect 16 0 20 0;
#P connect 16 0 22 0;
#P connect 7 10 16 0;
#P connect 18 0 16 0;
#P connect 15 0 14 0;
#P connect 2 1 4 0;
#P connect 9 0 1 1;
#P connect 6 0 7 0;
#P connect 3 0 8 0;
#P connect 14 0 3 0;
#P connect 2 0 3 0;
#P connect 2 2 3 0;
#P connect 1 0 2 0;
#P connect 5 0 1 0;
#P window clipboard copycount 25;

———————————-

render_context = this.drawto

current = 0
vcount = 32

vplanes = {}

function setup()
for i=1, vcount do
vplanes[i] = jit.new(“jit.gl.videoplane”, render_context)
vplanes[i].automatic = 0
vplanes[i].blend_enable = 1
vplanes[i].depth_enable = 0
vplanes[i].blend_mode = {6, 1}
resetplane(i)
end
end

function jit_matrix(name)
current = current + 1
if (current > vcount) then
current = 1
end
resetplane(current)
vplanes[current]:jit_matrix(name)
end

function draw()
for i=1, vcount do
vplanes[i]:draw()
end
end