[MSX-C] Q&A official thread

If you had asked Google you would already have the answer.
- Fusion-C 1.2 : https://github.com/ericb59/Fusion-C-v1.2
- Fusion-C 1.3 : https://github.com/ericb59/FUSION-C-1.3 (stable?)
- Fusion-C 2.0 : Incoming...

Hi All,

New project. I solved my linked list issue and went to a new challenge. I made a little program that reads a screen 8 file and vpokes it straight in to cram, starting at 0, all the way to EOF. I skip the header, start location and size of the file. That way I get the image but the colours are not what I see with MifUI when I create a file.

Second challenge: I can also decrease the image size by taking every second byte and skipping every second line. But whatever way I try, it doesn't work. At some point I even got my input image at two location with one vpoke. Does anyone have a smart way to do something like this? In ascii C, not assembly please.

Another question: is there an example or description of the layout of other screenmodes and there .sc files? I happen to find a site that described the layout of the screen 8 file. I also have some code that can translate RGB to screen 12 (YJK) but I don't understand how I can use that when vpoking it in to VRAM.

code below works but doesn't really display a correct image.

#include 
#include 


#define TRUE	1		/* constants for BOOL */
#define FALSE	0



FILE *ptr;
char buf;
unsigned teller, tel2, size;
NAT maxX;
NAT maxY;
BOOL skip = FALSE;

VOID disscr();
VOID enascr();

VOID wait()
{
	char toets='\0';
	while (toets == '\0' )
		{
			if ( kbhit()) {
				toets=chget();
			}

		}
}

VOID main() {
   
    TINY ylin,it,ix, yt;
    NAT Fc=2;
    tel2=0;
    

    it = 1; 
    yt = 0;
    ix= ylin =0;
    ginit();
    screen((TINY)8);
    setbuf(stdout, NULL);
    maxX = gtxmax();
    maxY = gtymax();
    teller = 0;
    if ( (ptr = fopen("flower.sc8","rb")) == NULL ) {
        screen((TINY)0);
        puts("Couldn't open file");
        exit(0);
    }
    /* skip header*/
    fread(&buf,1,1,ptr);
    /* skip location in memory*/
    fread(&size,2,1,ptr);
    /* read size*/
    fread(&size,2,1,ptr);
    /* go */
    for (teller=0;teller <= size;++teller) {
            fread(&buf,1,1,ptr);
            tel2++;
            if ( it < Fc) 
            { 
            if (skip == FALSE ) vpoke ((NAT)((ylin*maxX)+ix),(TINY)buf);
                ++ix;
                ++it;
            } else {
                it=1;
            }
            if (tel2 == (int)(maxX/Fc)) 
                {
                    yt++;
                    if ( yt == Fc ) {
                        yt=1;
                        if (skip) { 
                            skip = FALSE;
                        } else { 
                            skip = TRUE;
                        }
                        ylin++;
                    }
                    ix=0;
                    tel2=0;
                    it=1;
                }
        }   
    wait();
    screen((TINY)0);
    exit(0);
}

Detailed description of screen modes can be found in the V9938 Programmers Guide (for MSX 1 and 2 modes).
.SCx format description can be found on the MSX-BASIC file formats wiki page.
It's just a dump of the VRAM so depending of the screen mode a .SCx file can contain bitmap information, screen layout, pattern shape/color, sprite or palette.

If you want to code in C to create MSX application, you should use a newer library like Fusion-C or MSXgl.

And what about MSXgl?