Clean scale HUD Messages

[Nash]

EDIT 21 Feb 2017: This whole thread is irrelevant due to ZScriptification of menus. Goodbye shitty ACS menus

I'm trying to emulate what ZDoom is doing with the menu text because I'm really sick of HUDMessages with dirty pixels on the screen. Took a look inside ZDoom and did some Shift Ctrl F but I don't really understand how it's done in ZDoom. Can anyone explain it to me? Is it even possible with HUDMessage or is the drawing code such that you are forever doomed with dirty pixels.

[Gez]

Here's what ZDoom does to compute clean factors:

---

Code: Select all

// Tries to guess the physical dimensions of the screen based on the
// screen's pixel dimensions. Can return:
// 0: 4:3
// 1: 16:9
// 2: 16:10
// 3: 17:10
// 4: 5:4
int CheckRatio (int width, int height, int *trueratio)
{
	int fakeratio = -1;
	int ratio;

	if ((vid_aspect >= 1) && (vid_aspect <= 5))
	{
		// [SP] User wants to force aspect ratio; let them.
		fakeratio = int(vid_aspect);
		if (fakeratio == 3)
		{
			fakeratio = 0;
		}
		else if (fakeratio == 5)
		{
			fakeratio = 3;
		}
	}
	if (vid_nowidescreen)
	{
		if (!vid_tft)
		{
			fakeratio = 0;
		}
		else
		{
			fakeratio = (height * 5/4 == width) ? 4 : 0;
		}
	}
	// If the size is approximately 16:9, consider it so.
	if (abs (height * 16/9 - width) < 10)
	{
		ratio = 1;
	}
	// Consider 17:10 as well.
	else if (abs (height * 17/10 - width) < 10)
	{
		ratio = 3;
	}
	// 16:10 has more variance in the pixel dimensions. Grr.
	else if (abs (height * 16/10 - width) < 60)
	{
		// 320x200 and 640x400 are always 4:3, not 16:10
		if ((width == 320 && height == 200) || (width == 640 && height == 400))
		{
			ratio = 0;
		}
		else
		{
			ratio = 2;
		}
	}
	// Unless vid_tft is set, 1280x1024 is 4:3, not 5:4.
	else if (height * 5/4 == width && vid_tft)
	{
		ratio = 4;
	}
	// Assume anything else is 4:3. (Which is probably wrong these days...)
	else
	{
		ratio = 0;
	}

	if (trueratio != NULL)
	{
		*trueratio = ratio;
	}
	return (fakeratio >= 0) ? fakeratio : ratio;
}

Code: Select all

void V_CalcCleanFacs (int designwidth, int designheight, int realwidth, int realheight, int *cleanx, int *cleany, int *_cx1, int *_cx2)
{
	int ratio;
	int cwidth;
	int cheight;
	int cx1, cy1, cx2, cy2;

	ratio = CheckRatio(realwidth, realheight);
	if (ratio & 4)
	{
		cwidth = realwidth;
		cheight = realheight * BaseRatioSizes[ratio][3] / 48;
	}
	else
	{
		cwidth = realwidth * BaseRatioSizes[ratio][3] / 48;
		cheight = realheight;
	}
	// Use whichever pair of cwidth/cheight or width/height that produces less difference
	// between CleanXfac and CleanYfac.
	cx1 = MAX(cwidth / designwidth, 1);
	cy1 = MAX(cheight / designheight, 1);
	cx2 = MAX(realwidth / designwidth, 1);
	cy2 = MAX(realheight / designheight, 1);
	if (abs(cx1 - cy1) <= abs(cx2 - cy2))
	{ // e.g. 640x360 looks better with this.
		*cleanx = cx1;
		*cleany = cy1;
	}
	else
	{ // e.g. 720x480 looks better with this.
		*cleanx = cx2;
		*cleany = cy2;
	}

	if (*cleanx > 1 && *cleany > 1 && *cleanx != *cleany)
	{
		if (*cleanx < *cleany)
			*cleany = *cleanx;
		else
			*cleanx = *cleany;
	}
	if (_cx1 != NULL)	*_cx1 = cx1;
	if (_cx2 != NULL)	*_cx2 = cx2;
}

So if we simplify, we have:
* real screen dimensions
* letterboxed or pillarboxed screen dimensions (if appropriate, depending on aspect ratio)
* virtual screen dimensions (the low-res stuff we want to scale up)

What it's doing is looking at the height and width ratio, and taking the smaller factor of the two. There's some fudging around because of the variety of aspect ratios, but that's it.

[Nash]

Thanks... that's a start. What are the inputs cleanx/y and _cx1/2 supposed to be?

[Gez]

They aren't input. They are output. Notice that they are pointers: this function will set them. The only times the function references them, it is to set them to a value, never to read their value.

What you want is cleanx and cleany. They're the factors you are looking for.

[Nash]

In an ACS context, can I just move those pointers down to become variable declarations? Still struggling with understanding pointers (but that's for another thread)...

[phantombeta]

Still struggling with understanding pointers (but that's for another thread)...

Even if you did, you'd have to change them to something else because ACS/ACC doesn't have pointers. (GDCC does though, which is cool :))

[Gez]

In an ACS context, you'd have to make them global variables, since presumably you'll want to use them outside of that function. Also you can just ignore the _cx vars and delete the two lines that reference them.

[Nash]

I've "converted" the stuff to ACS, and I >think< it's working but I don't know if the numbers reported are correct. It seems to look okay mostly at high resolutions, but at lower and more uncommon resolutions, the pixels are still dirty (not matching what ZDoom is doing with the clean menu scaling). Halp?