[C++] Len, Mid$ And Asc: String / Text Commands

[Clyde]

Im trying to develop my skills with a bitmap printer, in Blitz / Freebasic you'd use the following:

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text_message="hello there how's the weather"
....
for index=1 to len(text_message); length of the message text.
frame=(asc(mid(text_message,index,1)))-32 ;splits message into appropriate letter.
draw_image( x, 120, frame)
x=x+fontwidth
next


I'd love to know how to go about using those commands - ( i dont want the code for an entire bitmap routine as i'll work on that part ), just the equivalents: some more example are, left$ / right$, upper / ucase ), or similar if they dont exist in C++.

Hugest of thanks,
Clyde.

[Jim]

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#include <string.h>
...
char text[]="Three cheers for Clyde";
unsigned int len = strlen(text);//22

As I put in my other post, you need to add

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using namespace std;

after the last of your includes to access the functions.

Since in this case in C++ a string is just an array of letters, you don't need Mid$(text, posn, 1), you just use
text[posn], remembering that posn starts at 0, ie text[0] is T, text[6] is c.

You don't need Asc(), letters are just char, which is just a number.

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char text_message[]="hello there how's the weather";
...
for (int index=0; index < strlen(text_message); index++) //length of the message text.
{
char frame=text_message[index]-32; //splits message into appropriate letter.
draw_image(x, 120, frame);
x+=fontwidth;
}


Jim

[Clyde]

this is strange when I add using namespace std;  it keeps telling me that a namespace of that name doesnt exist.

[Jim]

If everything's working OK without it, then don't worry.  At the moment the C++ code you're writing looks like C, that is, you're using zero of the C++ language features.  When we move more in the C++ direction it'll become more useful.

Jim

[Clyde]

for ( int a=0; a<strlen(text); a+=1 )
char asc_letter=text[a]-32;
//

the above doesnt give me asc order / the correct letters to be drawn.
HELLO = MJRRU

i've tried -37, which displays H, but on the next increment of loop a, the letter isnt an E but D.

btw for the none returning function to work, i need to have in the call char *text

[Jim]

Something else must be wrong, since the code above is correct.

Have you tried printing your alphabet to check everything's in the right place?

for (int a=32; a < 127; a++)
 draw_graphic(a-32);

Jim

[hellfire]

In create_anim_images you're missing the last character of each line.
Your loops should look something like this:

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for (y=0; y<frame_h*height; y+=height )
{
for (x=0; x<frame_w*wwidth; x+=wwidth )
{