/* 
 * Copyright (c) 2002 Light Weight Java Game Library Project
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are 
 * met:
 * 
 * * Redistributions of source code must retain the above copyright 
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * * Neither the name of 'Light Weight Java Game Library' nor the names of 
 *   its contributors may be used to endorse or promote products derived 
 *   from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
/**
 * $Id$
 *
 * Win32 specific library for display handdling.
 *
 * @author cix_foo <cix_foo@users.sourceforge.net>
 * @version $Revision$
 */

#include "Window.h"
#include "org_lwjgl_Display.h"

#define WINDOWCLASSNAME "LWJGLWINDOW"

jobjectArray GetAvailableDisplayModesEx(JNIEnv * env);
jobjectArray GetAvailableDisplayModes(JNIEnv * env);
bool modeSet = false; // Whether we've done a display mode change
WORD* originalGamma = new WORD[256 * 3]; // Original gamma settings
WORD* currentGamma = new WORD[256 * 3]; // Current gamma settings
DEVMODE devmode; // Now we'll remember this value for the future


/*
 * Class:     org_lwjgl_Display
 * Method:    nGetAvailableDisplayModes
 * Signature: ()[Lorg/lwjgl/DisplayMode;
 */
JNIEXPORT jobjectArray JNICALL Java_org_lwjgl_Display_nGetAvailableDisplayModes
  (JNIEnv * env, jclass clazz)
{
	jobjectArray result = GetAvailableDisplayModesEx(env);
	if (result == NULL) {
#ifdef _DEBUG
		printf("Extended display mode selection failed, using fallback\n");
#endif
		result = GetAvailableDisplayModes(env);
	}
	return result;
}

/**
 * Choose displaymodes using extended codepath (multiple displaydevices)
 */
jobjectArray GetAvailableDisplayModesEx(JNIEnv * env) {
	typedef BOOL (WINAPI * EnumDisplayDevicesAPROC)(IN LPCSTR lpDevice, IN DWORD iDevNum, OUT PDISPLAY_DEVICEA lpDisplayDevice, IN DWORD dwFlags);
	typedef BOOL (WINAPI * EnumDisplaySettingsExAPROC)(IN LPCSTR lpszDeviceName, IN DWORD iModeNum, OUT LPDEVMODEA lpDevMode, IN DWORD dwFlags);
	EnumDisplayDevicesAPROC EnumDisplayDevicesA;
	EnumDisplaySettingsExAPROC EnumDisplaySettingsExA;

	HMODULE lib_handle = LoadLibrary("user32.dll");
	if (lib_handle == NULL) {
#ifdef _DEBUG
		printf("Could not load user32.dll\n");
#endif
		return NULL;
	}
	EnumDisplayDevicesA = (EnumDisplayDevicesAPROC)GetProcAddress(lib_handle, "EnumDisplayDevicesA");
	if (EnumDisplayDevicesA == NULL)
		return NULL;
	EnumDisplaySettingsExA = (EnumDisplaySettingsExAPROC)GetProcAddress(lib_handle, "EnumDisplaySettingsExA");
	if (EnumDisplaySettingsExA == NULL)
		return NULL;

	int i = 0, j = 0, n = 0;
	int AvailableModes = 0;

	DISPLAY_DEVICE DisplayDevice;
	DEVMODE DevMode;

	ZeroMemory(&DevMode, sizeof(DEVMODE));
	ZeroMemory(&DisplayDevice, sizeof(DISPLAY_DEVICE));

	DevMode.dmSize = sizeof(DEVMODE);
	DisplayDevice.cb = sizeof(DISPLAY_DEVICE);
  
  //enumerate all displays, and all of their displaymodes
	while(EnumDisplayDevicesA(NULL, i++, &DisplayDevice, 0) != 0) {
#ifdef _DEBUG
	  printf("Querying %s device\n", DisplayDevice.DeviceString);
#endif
		j = 0;
		while(EnumDisplaySettingsExA(DisplayDevice.DeviceName, j++, &DevMode, 0) != 0) {
#ifdef _DEBUG
			printf("Checking setting #%d\n", j);
#endif
			if (DevMode.dmBitsPerPel > 8) {
				AvailableModes++;
			}
		}
	}

#ifdef _DEBUG
	printf("Found %d displaymodes\n", AvailableModes);
#endif
  
	// now that we have the count create the classes, and add 'em all - we'll remove dups in Java
	// Allocate an array of DisplayModes big enough
	jclass displayModeClass = env->FindClass("org/lwjgl/DisplayMode");

	jobjectArray ret = env->NewObjectArray(AvailableModes, displayModeClass, NULL);
	jmethodID displayModeConstructor = env->GetMethodID(displayModeClass, "<init>", "(IIII)V");
  
	i = 0, n = 0;
	while(EnumDisplayDevicesA(NULL, i++, &DisplayDevice, 0) != 0) {
		j = 0;
		while(EnumDisplaySettingsExA(DisplayDevice.DeviceName, j++, &DevMode, 0) != 0) {
			// Filter out indexed modes
			if (DevMode.dmBitsPerPel > 8) {
				jobject displayMode;
				displayMode = env->NewObject(displayModeClass, displayModeConstructor, 
											 DevMode.dmPelsWidth, DevMode.dmPelsHeight,
											 DevMode.dmBitsPerPel, DevMode.dmDisplayFrequency);

				env->SetObjectArrayElement(ret, n++, displayMode);
			}
		}
	}
	FreeLibrary(lib_handle);
	return ret;
}

/**
 * Choose displaymodes using standard codepath (single displaydevice)
 */
jobjectArray GetAvailableDisplayModes(JNIEnv * env) {
	int i = 0, j = 0, n = 0;
	int AvailableModes = 0;

	DEVMODE DevMode;

	ZeroMemory(&DevMode, sizeof(DEVMODE));

	DevMode.dmSize = sizeof(DEVMODE);
  
	//enumerate all displaymodes
	while(EnumDisplaySettings(NULL, j++, &DevMode) != 0) {
		if (DevMode.dmBitsPerPel > 8) {
			AvailableModes++;
		}
	}
		
#ifdef _DEBUG
	printf("Found %d displaymodes\n", AvailableModes);
#endif
  
	// now that we have the count create the classes, and add 'em all - we'll remove dups in Java
	// Allocate an array of DisplayModes big enough
	jclass displayModeClass = env->FindClass("org/lwjgl/DisplayMode");

	jobjectArray ret = env->NewObjectArray(AvailableModes, displayModeClass, NULL);
	jmethodID displayModeConstructor = env->GetMethodID(displayModeClass, "<init>", "(IIII)V");  
  
	i = 0, j = 0, n = 0;
	while(EnumDisplaySettings(NULL, j++, &DevMode) != 0) {
		// Filter out indexed modes
		if (DevMode.dmBitsPerPel > 8) {
			jobject displayMode;
			displayMode = env->NewObject(displayModeClass, displayModeConstructor,
			                              DevMode.dmPelsWidth, DevMode.dmPelsHeight,
						                  DevMode.dmBitsPerPel, DevMode.dmDisplayFrequency);
			env->SetObjectArrayElement(ret, n++, displayMode);
		}
	}
	return ret;
}


/*
 * Class:     org_lwjgl_Display
 * Method:    getPlatform
 * Signature: ()I
 */
JNIEXPORT jint JNICALL Java_org_lwjgl_Display_getPlatform
  (JNIEnv * env, jclass clazz)
{
	return org_lwjgl_Display_PLATFORM_WGL;
}

/*
 * Class:     org_lwjgl_Display
 * Method:    setDisplayMode
 * Signature: (Lorg/lwjgl/DisplayMode;)V
 */
JNIEXPORT void JNICALL Java_org_lwjgl_Display_setDisplayMode
  (JNIEnv * env, jclass clazz, jobject mode)
{

	jclass cls_displayMode = env->FindClass("org/lwjgl/DisplayMode");
	jfieldID fid_width = env->GetFieldID(cls_displayMode, "width", "I");
	jfieldID fid_height = env->GetFieldID(cls_displayMode, "height", "I");
	jfieldID fid_bpp = env->GetFieldID(cls_displayMode, "bpp", "I");
	jfieldID fid_freq = env->GetFieldID(cls_displayMode, "freq", "I");

	int width = env->GetIntField(mode, fid_width);
	int height = env->GetIntField(mode, fid_height);
	int bpp = env->GetIntField(mode, fid_bpp);
	int freq = env->GetIntField(mode, fid_freq);

	devmode.dmSize = sizeof(DEVMODE);
	devmode.dmBitsPerPel = bpp;
	devmode.dmPelsWidth = width;
	devmode.dmPelsHeight = height;
	devmode.dmDisplayFlags = 0;
	devmode.dmDisplayFrequency = freq;
	devmode.dmFields = DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT | DM_DISPLAYFLAGS;
	if (freq != 0)
		devmode.dmFields |= DM_DISPLAYFREQUENCY;


	LONG cdsret = ChangeDisplaySettings(&devmode, CDS_FULLSCREEN);

	if (cdsret != DISP_CHANGE_SUCCESSFUL) {
		// Failed: so let's check to see if it's a wierd dual screen display
#ifdef _DEBUG
		printf("Failed to set display mode... assuming dual monitors\n");
#endif
		devmode.dmPelsWidth = width * 2;
		cdsret = ChangeDisplaySettings(&devmode, CDS_FULLSCREEN);

		if (cdsret != DISP_CHANGE_SUCCESSFUL) {
#ifdef _DEBUG
			printf("Failed to set display mode using dual monitors\n");
#endif
			throwException(env, "Failed to set display mode.");
			return;
		}
	}

	// The change was successful but might not be the exact change we were expecting.
	// Now we'll construct a new DisplayMode instance and stash it back in the Display
	// class's mode instance variable.

	// Get the screen
	HDC screenDC = GetDC(NULL);
	// Get the device caps
	width = GetDeviceCaps(screenDC, HORZRES);
	height = GetDeviceCaps(screenDC, VERTRES);
	bpp = GetDeviceCaps(screenDC, COLORRES);
	freq = GetDeviceCaps(screenDC, VREFRESH);
	if (freq <= 1)
		freq = 0; // Unknown
	ReleaseDC(NULL, screenDC);

	jmethodID ctor = env->GetMethodID(cls_displayMode, "<init>", "(IIII)V");
	jobject newMode = env->NewObject(cls_displayMode, ctor, width, height, bpp, freq);
	jfieldID fid_initialMode = env->GetStaticFieldID(clazz, "mode", "Lorg/lwjgl/DisplayMode;");
	env->SetStaticObjectField(clazz, fid_initialMode, newMode);
	env->DeleteLocalRef(newMode);

	modeSet = true;
}

/*
 * Class:     org_lwjgl_Display
 * Method:    resetDisplayMode
 * Signature: ()V
 */
JNIEXPORT void JNICALL Java_org_lwjgl_Display_resetDisplayMode
  (JNIEnv * env, jclass clazz)
{

	// Return device gamma to normal
	HDC screenDC = GetDC(NULL);
	try {
		if (!SetDeviceGammaRamp(screenDC, originalGamma)) {
	#ifdef _DEBUG
			printf("Could not reset device gamma\n");
	#endif
		}
	} catch (...) {
		printf("Exception occurred in SetDeviceGammaRamp\n");
	}	
	ReleaseDC(NULL, screenDC);	

	if (modeSet) {
		modeSet = false;
		// Under Win32, all we have to do is:
		ChangeDisplaySettings(NULL, 0);

		// And we'll call init() again to put the correct mode back in Display
		Java_org_lwjgl_Display_init(env, clazz);
	}
}

/*
 * Temporarily reset display settings. This is called when the window is minimized.
 */
void tempResetDisplayMode() {
	// Return device gamma to normal
	HDC screenDC = GetDC(NULL);
	try {
		if (!SetDeviceGammaRamp(screenDC, originalGamma)) {
	#ifdef _DEBUG
			printf("Could not reset device gamma\n");
	#endif
		}
	} catch (...) {
		printf("Exception occurred in SetDeviceGammaRamp\n");
	}	
	ReleaseDC(NULL, screenDC);	

	if (modeSet) {
#ifdef _DEBUG
		printf("Attempting to temporarily reset the display mode\n");
#endif
		modeSet = false;
		// Under Win32, all we have to do is:
		ChangeDisplaySettings(NULL, 0);
	}
}

/*
 * Put display settings back to what they were when the window is maximized.
 */
void tempRestoreDisplayMode() {
	// Restore gamma
	HDC screenDC = GetDC(NULL);
	try { 
		if (!SetDeviceGammaRamp(screenDC, currentGamma)) {
	#ifdef _DEBUG
			printf("Could not restore device gamma\n");
	#endif
		}
	} catch (...) {
		printf("Exception occurred in SetDeviceGammaRamp\n");
	}	
	ReleaseDC(NULL, screenDC);

	if (!modeSet) {

#ifdef _DEBUG
		printf("Attempting to restore the display mode\n");
#endif
		modeSet = true;
		LONG cdsret = ChangeDisplaySettings(&devmode, CDS_FULLSCREEN);

#ifdef _DEBUG
		if (cdsret != DISP_CHANGE_SUCCESSFUL) {
			printf("Failed to restore display mode\n");
		}
#endif
	}
}


/*
 * Class:     org_lwjgl_Display
 * Method:    getGammaRampLength
 * Signature: ()I
 */
JNIEXPORT jint JNICALL Java_org_lwjgl_Display_getGammaRampLength
  (JNIEnv *env, jclass clazz)
{
	return 256;
}

/*
 * Class:     org_lwjgl_Display
 * Method:    setGammaRamp
 * Signature: (I)Z
 */
JNIEXPORT jboolean JNICALL Java_org_lwjgl_Display_setGammaRamp
  (JNIEnv * env, jclass clazz, jobject gammaRampBuffer)
{
	const float *gammaRamp = (const float *)env->GetDirectBufferAddress(gammaRampBuffer);
	// Turn array of floats into array of RGB WORDs

	for (int i = 0; i < 256; i ++) {
		float scaledRampEntry = gammaRamp[i]*0xffff;
		WORD rampEntry = (WORD)scaledRampEntry;
		currentGamma[i] = rampEntry;
		currentGamma[i + 256] = rampEntry;
		currentGamma[i + 512] = rampEntry;
	}
	jboolean ret;
	HDC screenDC = GetDC(NULL);
	try {
		if (SetDeviceGammaRamp(screenDC, currentGamma) == FALSE) {
	#ifdef _DEBUG
			printf("Failed to set device gamma\n");
	#endif
			ret = JNI_FALSE;
		} else {
			ret = JNI_TRUE;
		}
	} catch (...) {
		printf("Exception occurred in SetDeviceGammaRamp\n");
		ret = JNI_FALSE;
	}
	ReleaseDC(NULL, screenDC);

	return ret;
}


/*
 * Class:     org_lwjgl_Display
 * Method:    init
 * Signature: ()V
 */
JNIEXPORT void JNICALL Java_org_lwjgl_Display_init
  (JNIEnv * env, jclass clazz)
{
	// Determine the current screen resolution
	// Get the screen
	HDC screenDC = GetDC(NULL);
	if (!screenDC) {
		printf("Couldn't get screen DC!\n");
		return;
	}
	// Get the device caps
	int width = GetDeviceCaps(screenDC, HORZRES);
	int height = GetDeviceCaps(screenDC, VERTRES);
	int bpp = GetDeviceCaps(screenDC, COLORRES);
	int freq = GetDeviceCaps(screenDC, VREFRESH);
	if (freq <= 1)
		freq = 0; // Unknown

	jclass jclass_DisplayMode = env->FindClass("org/lwjgl/DisplayMode");
	jmethodID ctor = env->GetMethodID(jclass_DisplayMode, "<init>", "(IIII)V");
	jobject newMode = env->NewObject(jclass_DisplayMode, ctor, width, height, bpp, freq);
	jfieldID fid_initialMode = env->GetStaticFieldID(clazz, "mode", "Lorg/lwjgl/DisplayMode;");
	env->SetStaticObjectField(clazz, fid_initialMode, newMode);
	env->DeleteLocalRef(newMode);

	// Get the default gamma ramp
	try {
		if (GetDeviceGammaRamp(screenDC, originalGamma) == FALSE) {
	#ifdef _DEBUG
			printf("Failed to get initial device gamma\n");
	#endif
		}
	} catch (...) {
		printf("Exception occurred in GetDeviceGammaRamp\n");
	}

	ReleaseDC(NULL, screenDC);
}