Lua Programming Help Thread

on lua for windows, it doesnt report an error, but nothing pops up on the screen.

Code:

---

background = Image.load("Cursor/background.png")
mouse = Image.load("Cursor/mouse1.png")
blood = Image.load("Cursor/blood.png")
enemy = Image.load("Cursor/enemy1.png")

mousex = 100
mousey = 172

while true do
screen:clear()
end


pad = Controls.read()

screen:blit(0, 0, background, false)
screen:blit(mousex, mousey, mouse)

if pad:up() then
mousey = mousey - 5
end

if pad:down() then
mousey = mousey + 5
end

if pad:left() then
mousex = mousex - 5
end

if pad:right() then
mousex = mousex + 5
end

if pad:r() then
if mousex == 135 and mousey == 151 then
screen:blit(135, 151, blood)
end

screen.waitVblankStart()
screen.flip()
end

---

montrob: try this:

Code:

---

background = Image.load("Cursor/background.png")
mouse = Image.load("Cursor/mouse1.png")
blood = Image.load("Cursor/blood.png")
enemy = Image.load("Cursor/enemy1.png")

mousex = 100
mousey = 172


while true do

screen:clear()

pad = Controls.read()

screen:blit(0, 0, background, false)
screen:blit(mousex, mousey, mouse)

if pad:up() then
mousey = mousey - 5
end

if pad:down() then
mousey = mousey + 5
end

if pad:left() then
mousex = mousex - 5
end

if pad:right() then
mousex = mousex + 5
end

if pad:r() and mousex > 130 and mousex < 140 then
if mousey > 146 and mousey < 156 then
screen:blit(135, 151, blood)
end
end

screen.waitVblankStart()
screen.flip()
end

---

(at the very end of the code)

or just take out screen:clear() it just is constantly clearing the screen

For my new game, WildSniper , i am going to have bullets shooting from the enemies guns. I need to know how to detect a collision when they moving bullet hits my aimer that is moving.

Zitat:

---

Zitat von montrob

For my new game, WildSniper , i am going to have bullets shooting from the enemies guns. I need to know how to detect a collision when they moving bullet hits my aimer that is moving.

---

well if you have ur aimer x and y like theis:

Code:

---

aimerx = 100
amiery=  130

---

and u have the bullets x and y like this:

Code:

---

enemyBulletx = 30
enemyBullety = 50

---

this u just do this:

Code:

---

if enemyBulletx > aimerrx - 5 and enemyBulletx < aimerx + 5 then
if enemyBullety > aimerry - 5 and enemyBullety < aimery + 5 then
-- the rest of ur code

---

this means that if the bullet comes within 5 pixels of the aimer, then it will do what u want it to do.

hope i helped!! good luck! :D

EDIT- 600th post!! w00t!!!!!!! :D :D :D :D

Does anyone know how to check what the last number is in a table? For example, if I have LUA automatically make a table like this:

Code:

---

folders=System.listDirectory()

---

is there a way LUA can find the number of the last entry in that table, for example, folders[4] ? Thanks to anyone who can answer my question.

Had a look on google, and I found this :)

Code:

---

We can find the size of a table using the standard
table library function table.getn() (i.e. get
number of elements)

table.getn(t)

---

So you would want folders.getn(t), and then I presume t will hold the number of entries.

Source: http://lua-users.org/wiki/TablesTutorial

Zitat:

---

Zitat von Psilocybeing

Had a look on google, and I found this :)

Code:

---

We can find the size of a table using the standard
table library function table.getn() (i.e. get
number of elements)

table.getn(t)

---

So you would want folders.getn(t), and then I presume t will hold the number of entrys.

Source: http://lua-users.org/wiki/TablesTutorial

---

Thank you very much! I checked the wiki and but never saw that part of it. Thanks again, Psilocybeing, now custom characters will be easy to implement in my game by just placing in the folder. :icon_smil

One other question. Is there a way that I can quote a variable? Like say I wanted to concatenate a variable, but it needed quotes around it to work. For example:

Code:

---

folders=System.listDirectory()

screen:blit(0,0,"images/"..folders[1].name.."/pic.png")

---

doesn't work because the folder names don't have quotes around them.

Because the table is created by LUA, I can't manually add quotes around each entry, so is there a way I could do this when blitting to the screen? Thanks again.