rotateImage ?

[Julu Julu]

Hi.

I found this function here.

Code: Select all

function rotateImage(theImage) 
   newImage = Image.createEmpty(theImage:height(), theImage:width()) 
   for x = 1, theImage:width() do 
      for y = 1, theImage:height() do 
         newImage:blit(y, x, theImage, x, y, 1, 1) 
      end 
   end 
   return newImage 
end -- rotateImage

I do not understand this function.
The picture turns always 90 degrees.
How can I turn the picture differently?

For example 50 degrees.

[Zenurb]

Hi.

I found this function here.

Code: Select all

function rotateImage(theImage) 
   newImage = Image.createEmpty(theImage:height(), theImage:width()) 
   for x = 1, theImage:width() do 
      for y = 1, theImage:height() do 
         newImage:blit(y, x, theImage, x, y, 1, 1) 
      end 
   end 
   return newImage 
end -- rotateImage

I do not understand this function.
The picture turns always 90 degrees.
How can I turn the picture differently?

For example 50 degrees.

You can use sin/cos functions to work out the position of each new pixel.

[Julu Julu]

Where I must set sin/cos ?

Code: Select all

function rotateImage(theImage) 
   newImage = Image.createEmpty(theImage:height(), theImage:width()) 
   for x = 1, theImage:width() do 
      for y = 1, theImage:height() do 



         newImage:blit(   here -> ??? cos , here -> ??? sin   x, theImage, x, y, 1, 1) 
      end 
   end 
   return newImage 
end -- rotateImage

[Zenurb]

sin and cos are mathematic functions which describe a wave pattern, sine and cosine. cosine is at a 90 degree angle to sine.

here is some code for making something move in a circle (i don't know lua very well)

Code: Select all

x = 130
y = 130
aimage = Image.createEmpty(100, 100)
aimage:print("lol")
while(true)
  screen.clear()
  a = a + 1
  x = x + (sin(a) * 10)
  y = y + (cos(a) * 10)
  screen:blit(x, y, aimage, 0, 0, 100, 100)
end

I think that works but probably not =)

the basic maths will work if you can fix it, to move something in a circle.

the radians value (a) goes from 0 to pi/2+pi (i think) pi=3.14152..etc and you can just divide the highest radian value by 360 then times by the angle you want to find the new position of a singular pixel.

[Julu Julu]

Thanks :)