1024x768?

[kolontsov]

Hi, thank you for pigfx, it works well, but it doesn't look very good when scaled.. Is implementing 1024x768 difficult because it's bare metal? What is the main obstacle?

[chregu82]

I just gave this a test. It would be easy to include 1024x768 mode. Graphics are quite slow though and the text is quite small.

[chregu82]

Without having tested anything, I would try the follwing:

• Add the resolution in gfx.c to the enum DISPLAY_MODE_DEFINITION, e.g. replace element 7 with {800,600,8}.
• Send esc[=7h to the Pi

[willtco]

Thanks, I had found initialize_framebuffer in pigfx.c and altered that to 800x600 which seems to work fine - is that reasonable?

[chregu82]

That's probably fine.

[willtco]

I've added a simple 3 byte command that allows me to select any 1 of 16 resolutions from 320x240 to 1920x1080 - I use the card purely for graphics so all the escape sequences have been replaced with short binary packets. - My screen res routine is below, once tested fully (along with now using a PS/2 kbd) I hope to offer it up for others.

/*Function to allow Z80 to change screen mode by sending 3 bytes only. Added Sept 14 2021.
Command string: 0xff,0xe3,0x40+mode (where mode is 0-f only). */

int state_set_screen_resolution( char ch, scn_state *state ) //function E3
{
static unsigned char mode;
lineparms[parm]=ch & 0x0f; //;low 4 bits contain mode data
mode=lineparms[0];

switch (mode)
{
case 0x01:
	initialize_framebuffer(400,300,8);
	break;
case 0x02:
	initialize_framebuffer(320,240,8);
	break;
case 0x03:
	initialize_framebuffer(640,480,8);
	break;
case 0x04:
	initialize_framebuffer(800,600,8);
	break;
case 0x05:
	initialize_framebuffer(1024,768,8);
	break;
case 0x06:
	initialize_framebuffer(1280,800,8);
	break;
case 0x07:
	initialize_framebuffer(1600,900,8);
	break;
case 0x08:
	initialize_framebuffer(1920,1080,8);
	break;
}

state->cmd_params_size = 0;
state->next = state_fun_normaltext;

return 1;
}