OpenEuphoria

integer frame1 = 1 
integer frame2 = 2 
sequence ani = {frame1,frame2} 
atom link_up_buffer 
 
	if key(KEY_UP) then 
		for i = 1 to 2 do 
			blit(link_up_buffer[i],screen,0,0,floor((640 - bitmap_w(link_up_buffer[i]))/2), 
				floor((480 - bitmap_h(link_up_buffer[i]))/2), bitmap_w(link_up_buffer[i]), 
					bitmap_h(link_up_buffer[i])) 
		end for 
	end if 

2. Re: Subscript an atom Attempt Error

• Posted by LarryMiller Jan 16, 2012
• 1535 views

link_up_buffer is declared as an atom. But in several cases you are attempting to subscript it with link_up_buffer[i]. This is not legal in Euphoria. This syntax is only valid with sequences. Also, in the code nothing is ever assigned to this variable. I am not sure what you are trying to do but this cannot possibly work.

atom g_palette 
link_up_buffer = load_bitmap("linkup.bmp",g_palette) 

4. Re: Subscript an atom Attempt Error

• Posted by ssallen Jan 16, 2012
• 1490 views

Ok, so I am guessing that you have a single bitmap with multiple images drawn into a grid. However, load_bitmap is not going to split those for you, its only going to load the entire image. You will need to programatically determine or specify where each frame begins and ends. A valid approach to your problem:

 
atom image 
integer cframe 
sequence framedata 
 
framedata = { 
              {0, 0, 100, 100},  -- frame 1 upper left and lower right (x1, y1, x2, y2) 
              {100, 0, 200, 100}  -- frame 2 upper left and lower right (x1, y1, x2, y2)            
            } 
cframe = 1 
 
image = load_bitmap("mybitmap.bmp", 0) 
 
if key(KEY_UP) then  
       if cframe = 1 then 
          cframe = 2 
       else 
          cframe = 1 
       end if 
end if  
 
blit(image,screen,0,0,framedata[cframe][1], framedata[cframe][2],framedata[cframe][3], framedata[cframe][4])  
 
 

Framedata is going to contain the coordinates of each frame on the bitmap. The example I used above will be a filmstrip pattern with two images side by side on the same y-plane:

----------- 
*IM1* *IM2* 
***** ***** 
***** ***** 
----------- 

This code really isn't usable without some pacing mechanisms but hopefully you can at least see where you are going wrong.

Edit: Here is a small EuAllegro demo I was playing with a couple years back. It illustrates a very simple game fairly well. It is written in Eu 3.2 but the code should still be fairly handy. http://www.mediafire.com/download.php?6mjk96nr5v2yyda

 
atom image 
integer cframe 
sequence framedata 
 
framedata = { 
              {0, 0, 100, 100},  -- frame 1 upper left and lower right (x1, y1, x2, y2) 
              {100, 0, 200, 100}  -- frame 2 upper left and lower right (x1, y1, x2, y2)            
            } 
cframe = 1 
 
image = load_bitmap("mybitmap.bmp", 0) 
 
if key(KEY_UP) then  
       if cframe = 1 then 
          cframe = 2 
       else 
          cframe = 1 
       end if 
end if  
 
blit(image,screen,0,0,framedata[cframe][1], framedata[cframe][2],framedata[cframe][3], framedata[cframe][4])  
 
 

----------- 
*IM1* *IM2* 
***** ***** 
***** ***** 
-----------