Function tablet_lightpen

src/inputdevice.cpp:2794–2880

}

void tablet_lightpen(int tx, int ty, int tmaxx, int tmaxy, int touch, int buttonmask, bool touchmode, int devid, int lpnum)
{
	int monid = 0;
	struct vidbuf_description *vidinfo = &adisplays[monid].gfxvidinfo;
	struct amigadisplay *ad = &adisplays[monid];
	int dw, dh, ax, ay, aw, ah;
	float fx, fy;
	float xmult, ymult;
	float fdx, fdy, fmx, fmy;
	int x, y;

	if (ad->picasso_on)
		goto end;

	if (vidinfo->outbuffer == NULL)
		goto end;

	if (touch < 0)
		goto end;

	fx = (float)tx;
	fy = (float)ty;

	desktop_coords (0, &dw, &dh, &ax, &ay, &aw, &ah);

	if (tmaxx < 0 || tmaxy < 0) {
		tmaxx = dw;
		tmaxy = dh;
	} else if (tmaxx == 0 || tmaxy == 0) {
		tmaxx = aw;
		tmaxy = ah;
	}

	if (!touchmode) {
		dw = aw;
		dh = ah;
		ax = 0;
		ay = 0;
	}

	xmult = (float)tmaxx / dw;
	ymult = (float)tmaxy / dh;

	fx = fx / xmult;
	fy = fy / ymult;

	fx -= ax;
	fy -= ay;

	getgfxoffset(0, &fdx, &fdy, &fmx, &fmy);

	x = (int)(fx * fmx);
	y = (int)(fy * fmy);
	x -= (int)(fdx * fmx) - 1;
	y -= (int)(fdy * fmy) - 2;

	if (x < 0 || y < 0 || x >= aw || y >= ah)
		goto end;