display_windows.cpp

/**************************************************************

   display_windows.cpp - Display manager for Windows

   ---------------------------------------------------------

   Switchres   Modeline generation engine for emulation

   License     GPL-2.0+
   Copyright   2010-2021 Chris Kennedy, Antonio Giner,
                         Alexandre Wodarczyk, Gil Delescluse

 **************************************************************/

#include <stdio.h>
#include "display_windows.h"
#include "log.h"

typedef struct ENUM_INFO
{
	int index;
	HMONITOR h_monitor;
} ENUM_INFO;

//============================================================
//  windows_display::windows_display
//============================================================

windows_display::windows_display(display_settings *ds)
{
	// Get display settings
	m_ds = *ds;
}

//============================================================
//  windows_display::~windows_display
//============================================================

windows_display::~windows_display()
{
	// Restore previous settings
	if (!m_ds.keep_changes) ChangeDisplaySettingsExA(m_device_name, NULL, NULL, 0, 0);
}

//============================================================
//  windows_display::init
//============================================================

int CALLBACK monitor_by_index(HMONITOR h_monitor, HDC, LPRECT, LPARAM data)
{
	ENUM_INFO *mon_info = (ENUM_INFO*) data;
	if (--mon_info->index < 0)
	{
		mon_info->h_monitor = h_monitor;
		return false;
	}
	return true;
}

bool windows_display::init(void*)
{
	char display[32] = {};

	// If monitor is passed by index, find the matching device
	if (strlen(m_ds.screen) == 1)
	{
		int monitor_index = m_ds.screen[0] - '0';
		if (monitor_index < 0 || monitor_index > 9)
		{
			log_error("Switchres: bad monitor index %d\n", monitor_index);
			return false;
		}

		ENUM_INFO mon_info;
		mon_info.index = monitor_index;
		mon_info.h_monitor = NULL;

		EnumDisplayMonitors(NULL, NULL, monitor_by_index, (LPARAM)&mon_info);
		if (mon_info.h_monitor != NULL)
		{
			MONITORINFOEXA info = {};
			info.cbSize = sizeof(info);
			GetMonitorInfoA(mon_info.h_monitor, &info);
			snprintf(display, sizeof(display) -1, "%s", info.szDevice);
			log_info("display %s\n", display);
		}
		else
		{
			log_error("Swichres: couldn't find handle for monitor index %d\n", monitor_index);
			return false;
		}
	}
	else
		strncpy(display, m_ds.screen, sizeof(display)-1);

	// Find the display by device name, or "auto" for primary display
	DISPLAY_DEVICEA lpDisplayDevice[DISPLAY_MAX];
	int idev = 0;
	int found = -1;

	while (idev < DISPLAY_MAX)
	{
		memset(&lpDisplayDevice[idev], 0, sizeof(DISPLAY_DEVICEA));
		lpDisplayDevice[idev].cb = sizeof(DISPLAY_DEVICEA);

		if (EnumDisplayDevicesA(NULL, idev, &lpDisplayDevice[idev], 0) == FALSE)
			break;

		if ((!strcmp(display, "auto") && (lpDisplayDevice[idev].StateFlags & DISPLAY_DEVICE_PRIMARY_DEVICE))
			|| !strcmp(display, lpDisplayDevice[idev].DeviceName))
			found = idev;

		idev++;
	}
	if (found != -1)
	{
		strncpy(m_device_name, lpDisplayDevice[found].DeviceName, sizeof(m_device_name) -1);
		strncpy(m_device_id, lpDisplayDevice[found].DeviceID, sizeof(m_device_id) -1);
		log_verbose("Switchres: %s: %s (%s)\n", m_device_name, lpDisplayDevice[found].DeviceString, m_device_id);

		char *pch;
		int i;
		for (i = 0; i < idev; i++)
		{
			pch = strstr(lpDisplayDevice[i].DeviceString, lpDisplayDevice[found].DeviceString);
			if (pch)
			{
				found = i;
				break;
			}
		}

		char *chsrc, *chdst;
		chdst = m_device_key;

		for (chsrc = lpDisplayDevice[i].DeviceKey + 18; *chsrc != 0; chsrc++)
			*chdst++ = *chsrc;

		*chdst = 0;
	}
	else
	{
		log_verbose("Switchres: Failed obtaining default video registry key\n");
		return false;
	}

	log_verbose("Switchres: Device key: %s\n", m_device_key);

	// Initialize custom video
	int method = CUSTOM_VIDEO_TIMING_AUTO;
	if(!strcmp(m_ds.api, "powerstrip")) method = CUSTOM_VIDEO_TIMING_POWERSTRIP;
	strcpy(m_ds.vs.device_reg_key, m_device_key);

	// Create custom video backend
	set_factory(new custom_video);
	set_custom_video(factory()->make(m_device_name, m_device_id, method, &m_ds.vs));
	if (video()) video()->init();

	// Build our display's mode list
	video_modes.clear();
	backup_modes.clear();
	get_desktop_mode();
	get_available_video_modes();
	if (!strcmp(m_ds.monitor, "lcd")) auto_specs();
	filter_modes();

	return true;
}

//============================================================
//  windows_display::set_mode
//============================================================

bool windows_display::set_mode(modeline *mode)
{
	if (mode && set_desktop_mode(mode, (m_ds.keep_changes? CDS_UPDATEREGISTRY : CDS_FULLSCREEN) | CDS_RESET))
	{
		set_current_mode(mode);
		return true;
	}

	return false;
}

//============================================================
//  windows_display::get_desktop_mode
//============================================================

bool windows_display::get_desktop_mode()
{
	memset(&m_devmode, 0, sizeof(DEVMODEA));
	m_devmode.dmSize = sizeof(DEVMODEA);

	if (EnumDisplaySettingsExA(!strcmp(m_device_name, "auto")?NULL:m_device_name, ENUM_CURRENT_SETTINGS, &m_devmode, 0))
	{
		desktop_mode.width = m_devmode.dmDisplayOrientation == DMDO_DEFAULT || m_devmode.dmDisplayOrientation == DMDO_180? m_devmode.dmPelsWidth:m_devmode.dmPelsHeight;
		desktop_mode.height = m_devmode.dmDisplayOrientation == DMDO_DEFAULT || m_devmode.dmDisplayOrientation == DMDO_180? m_devmode.dmPelsHeight:m_devmode.dmPelsWidth;
		desktop_mode.refresh = m_devmode.dmDisplayFrequency;
		desktop_mode.interlace = (m_devmode.dmDisplayFlags & DM_INTERLACED)?1:0;
		return true;
	}
	return false;
}

//============================================================
//  windows_display::set_desktop_mode
//============================================================

bool windows_display::set_desktop_mode(modeline *mode, int flags)
{
	if (mode)
	{
		DEVMODEA lpDevMode;
		memset(&lpDevMode, 0, sizeof(DEVMODEA));
		lpDevMode.dmSize = sizeof(DEVMODEA);
		lpDevMode.dmPelsWidth = mode->type & MODE_ROTATED? mode->height : mode->width;
		lpDevMode.dmPelsHeight = mode->type & MODE_ROTATED? mode->width : mode->height;
		lpDevMode.dmDisplayFrequency = (int)mode->refresh;
		lpDevMode.dmDisplayFlags = mode->interlace? DM_INTERLACED : 0;
		lpDevMode.dmFields = DM_PELSWIDTH | DM_PELSHEIGHT | DM_DISPLAYFREQUENCY | DM_DISPLAYFLAGS;

		log_info("set_desktop_mode: %s (%dx%d@%d) flags(%x)\n", m_device_name, (int)lpDevMode.dmPelsWidth, (int)lpDevMode.dmPelsHeight, (int)lpDevMode.dmDisplayFrequency, (int)lpDevMode.dmDisplayFlags);

		int result = ChangeDisplaySettingsExA(m_device_name, &lpDevMode, NULL, flags, 0);
		if (result == DISP_CHANGE_SUCCESSFUL)
			return true;

		log_error("ChangeDisplaySettingsExA error(%x)\n", (int)result);
	}
	return false;
}

//============================================================
//  windows_display::restore_desktop_mode
//============================================================

bool windows_display::restore_desktop_mode()
{
	if (ChangeDisplaySettingsExA(m_device_name, &m_devmode, NULL, 0, 0) == DISP_CHANGE_SUCCESSFUL)
		return true;

	return false;
}

//============================================================
//  windows_display::get_available_video_modes
//============================================================

int windows_display::get_available_video_modes()
{
	int iModeNum = 0, j = 0, k = 0;
	DEVMODEA lpDevMode;

	memset(&lpDevMode, 0, sizeof(DEVMODEA));
	lpDevMode.dmSize = sizeof(DEVMODEA);

	log_verbose("Switchres: Searching for custom video modes...\n");

	while (EnumDisplaySettingsExA(m_device_name, iModeNum, &lpDevMode, m_ds.lock_unsupported_modes?0:EDS_RAWMODE) != 0)
	{
		if (lpDevMode.dmBitsPerPel == 32 && lpDevMode.dmDisplayFixedOutput == DMDFO_DEFAULT)
		{
			modeline m;
			memset(&m, 0, sizeof(struct modeline));
			m.interlace = (lpDevMode.dmDisplayFlags & DM_INTERLACED)?1:0;
			m.width = lpDevMode.dmDisplayOrientation == DMDO_DEFAULT || lpDevMode.dmDisplayOrientation == DMDO_180? lpDevMode.dmPelsWidth:lpDevMode.dmPelsHeight;
			m.height = lpDevMode.dmDisplayOrientation == DMDO_DEFAULT || lpDevMode.dmDisplayOrientation == DMDO_180? lpDevMode.dmPelsHeight:lpDevMode.dmPelsWidth;
			m.refresh = lpDevMode.dmDisplayFrequency;
			m.hactive = m.width;
			m.vactive = m.height;
			m.vfreq = m.refresh;
			m.type |= lpDevMode.dmDisplayOrientation == DMDO_90 || lpDevMode.dmDisplayOrientation == DMDO_270? MODE_ROTATED : MODE_OK;

			for (auto &mode : video_modes) if (mode.width == m.width && mode.height == m.height && mode.refresh == m.refresh && m.interlace == mode.interlace) goto found;

			if (m.width == desktop_mode.width && m.height == desktop_mode.height && m.refresh == desktop_mode.refresh && m.interlace == desktop_mode.interlace)
			{
				m.type |= MODE_DESKTOP;
				if (m.type & MODE_ROTATED) set_desktop_is_rotated(true);
				if (current_mode() == nullptr)
				set_current_mode(&m);
			}

			log_verbose("Switchres: [%3d] %4dx%4d @%3d%s%s %s: ", k, m.width, m.height, m.refresh, m.interlace?"i":"p", m.type & MODE_DESKTOP?"*":"",  m.type & MODE_ROTATED?"rot":"");

			if (video() && video()->get_timing(&m))
			{
				j++;
				log_mode(&m);
			}
			else
			{
				m.type |= CUSTOM_VIDEO_TIMING_SYSTEM;
				log_verbose("system mode\n");
			}

			// Save our desktop mode now that we queried detailed timings
			if (m.type & MODE_DESKTOP) desktop_mode = m;

			video_modes.push_back(m);
			backup_modes.push_back(m);
			k++;
		}
		found:
		iModeNum++;
	}
	k--;
	log_verbose("Switchres: Found %d custom of %d active video modes\n", j, k);
	return k;
}