Sorry for asking questions about C, but I'm trying to convert a code to Verge. But what in the hell are:

byte *z
byte *p=buffer-line[0]
*(p+offset)=c
offset = j-319-(p)%320+(p)*320

What is this '*' before z and p? And the '-' is for what? I have problems with the '%' character in the code too... Thanks for any help.

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Okies, first of all the * symbol means that you're declaring a pointer. A pointer is a special type of variable that, instead of holding an actual value, holds the address of a place in memory where a value is stored. Performing mathematical operations on pointers (subtraction, addition) causes them to move to the respective place in memory. For instance, a pointer that is at 2 in the memory that has 3 added to it will now 'point' to 5 in memory. This is especially useful for reading information that you know is going to be sequentially placed in memory, i.e. arrays.

The % operator is called the modulo (modulus?). It returns the 'remainder' after division. For instance, the modulo of 7 and 3 is 1, since 1 is the remainder of the division operation.

Im not so sure about the last one (<) coupled with -but the < symbol alone is called a comparison operator; it returns 0 if the number on the right is larger or 1 if the number on the left is larger or vice versa depending on which one you use. Other comparison operators are == and !=.

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-- Lunarbeam @

Thanks for the help, it was exactly what I wanted to know. Now I want to know if there is a way to use them in Verge. The '%' I know I can use directly, but the others... Thanks anyway...

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It's not possible to give you the exact VC code without seeing the struct definition for buffer. What you would need to do goes something like this:

1. Decide on a format for the buffer struct. In order to handle a dynamically created struct in Verge, you'd need to use malloc to allocate a chunk of memory, and pretend that chunk is actually a structure...for example, you could decide that bytes 0 through 319 represent line[0] array, bytes 320 through 639 represent line[1], etc, plus byte positions for whatever other members of the struct exist.

2. Malloc a chunk of memory for a given buffer, like this:
local int buffer;
buffer = malloc(SIZE_OF_BUFFER_STRUCT);

3. Stick this code wherever it's supposed to go:
local int z, p, offset;
p = byte[buffer+LINE0_OFFSET];
byte[p+offset] = c
offset = j-319-(byte[p] % 320)+(byte[p]*320);

4. Fill in whatever supporting code it needs (like the declarations and uses of the c and z)

There's a fair chance that you didn't understand that, since you apparently don't know how to use pointers in C...if that's the case, I'd suggest getting a good programming book or online tutorial and reading up on them =) When you understand pointers, come back and read about the byte, word and quad quasifunctions in Verge, and see if you can make the transition from there. Good luck.

--Feyr

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