/*
 * Copyright (c) 2002-2008 LWJGL 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 'LWJGL' 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: org_lwjgl_opengl_LinuxContextImplementation.c 3203 2009-04-24 20:35:33Z elias_naur $
 *
 * @author elias_naur <elias_naur@users.sourceforge.net>
 * @version $Revision: 3203 $
 */

#include <jni.h>
#include <X11/X.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include "org_lwjgl_opengl_LinuxContextImplementation.h"
#include "extgl_glx.h"
#include "context.h"
#include "common_tools.h"

typedef struct {
	GLXExtensions extension_flags;
	GLXContext context;
} X11Context;

static bool checkContext(JNIEnv *env, Display *display, GLXContext context) {
	if (context == NULL) {
		throwException(env, "Could not create GLX context");
		return false;
	}
	/*
	 * Ditched the requirement that contexts have to be direct. It was
	 * never true that all accelerated contexts are direct, but it
	 * was a reasonable test until the appearance of Xgl and AIGLX.
	 * Now the test is at best useless, and at worst wrong,
	 * in case the current X server accelerates indirect rendering.
	 */
/*	jboolean allow_software_acceleration = getBooleanProperty(env, "org.lwjgl.opengl.Display.allowSoftwareOpenGL");
	if (!allow_software_acceleration && lwjgl_glXIsDirect(display, context) == False) {
		lwjgl_glXDestroyContext(display, context);
		throwException(env, "Could not create a direct GLX context");
		return false;
	}*/
	return true;
}

static void createContextGLX13(JNIEnv *env, X11PeerInfo *peer_info, X11Context *context_info, jobject attribs, GLXContext shared_context) {
	GLXFBConfig *config = getFBConfigFromPeerInfo(env, peer_info);
	if (config == NULL)
		return;
	GLXContext context;
	if (attribs) {
		const int *attrib_list = (const int *)(*env)->GetDirectBufferAddress(env, attribs);
		context = lwjgl_glXCreateContextAttribsARB(peer_info->display, *config, shared_context, True, attrib_list);
	} else {
		int render_type;
		if (lwjgl_glXGetFBConfigAttrib(peer_info->display, *config, GLX_RENDER_TYPE, &render_type) != 0) {
			throwException(env, "Could not get GLX_RENDER_TYPE attribute");
			return;
		}
		int context_render_type = (render_type & GLX_RGBA_FLOAT_BIT) != 0 ? GLX_RGBA_FLOAT_TYPE : GLX_RGBA_TYPE;
		context = lwjgl_glXCreateNewContext(peer_info->display, *config, context_render_type, shared_context, True);
	}
	XFree(config);
	if (!checkContext(env, peer_info->display, context))
		return;
	context_info->context = context;
}

static void createContextGLX(JNIEnv *env, X11PeerInfo *peer_info, X11Context *context_info, GLXContext shared_context) {
	XVisualInfo *vis_info = getVisualInfoFromPeerInfo(env, peer_info);
	if (vis_info == NULL)
		return;
	GLXContext context = lwjgl_glXCreateContext(peer_info->display, vis_info, shared_context, True);
	XFree(vis_info);
	if (!checkContext(env, peer_info->display, context))
		return;
	context_info->context = context;
}

JNIEXPORT void JNICALL Java_org_lwjgl_opengl_LinuxContextImplementation_nSetSwapInterval
  (JNIEnv *env, jclass clazz, jobject context_handle, jint value)
{
	X11Context *context_info = (*env)->GetDirectBufferAddress(env, context_handle);
	if (context_info->extension_flags.GLX_SGI_swap_control) {
		lwjgl_glXSwapIntervalSGI(value);
	}
}

JNIEXPORT jobject JNICALL Java_org_lwjgl_opengl_LinuxContextImplementation_nCreate
  (JNIEnv *env , jclass clazz, jobject peer_handle, jobject attribs, jobject shared_context_handle) {
	jobject context_handle = newJavaManagedByteBuffer(env, sizeof(X11Context));
	if (context_handle == NULL) {
		throwException(env, "Could not allocate handle buffer");
		return NULL;
	}
	X11PeerInfo *peer_info = (*env)->GetDirectBufferAddress(env, peer_handle);
	X11Context *context_info = (*env)->GetDirectBufferAddress(env, context_handle);
	GLXExtensions extension_flags;
	if (!extgl_InitGLX(peer_info->display, peer_info->screen, &extension_flags)) {
		throwException(env, "Could not initialize GLX");
		return NULL;
	}
	GLXContext shared_context = NULL;
	if (shared_context_handle != NULL) {
		X11Context *shared_context_info = (*env)->GetDirectBufferAddress(env, shared_context_handle);
		shared_context = shared_context_info->context;
	}
	if (peer_info->glx13) {
		createContextGLX13(env, peer_info, context_info, extension_flags.GLX_ARB_create_context ? attribs : NULL, shared_context);
	} else {
		createContextGLX(env, peer_info, context_info, shared_context);
	}
	context_info->extension_flags = extension_flags;
	return context_handle;
}

JNIEXPORT void JNICALL Java_org_lwjgl_opengl_LinuxContextImplementation_nDestroy
  (JNIEnv *env, jclass clazz, jobject peer_handle, jobject context_handle) {
	X11PeerInfo *peer_info = (*env)->GetDirectBufferAddress(env, peer_handle);
	X11Context *context_info = (*env)->GetDirectBufferAddress(env, context_handle);
	lwjgl_glXDestroyContext(peer_info->display, context_info->context);
}

JNIEXPORT void JNICALL Java_org_lwjgl_opengl_LinuxContextImplementation_nReleaseCurrentContext
  (JNIEnv *env , jclass clazz, jobject peer_info_handle) {
	X11PeerInfo *peer_info = (*env)->GetDirectBufferAddress(env, peer_info_handle);
	Bool result;
	if (peer_info->glx13) {
		result = lwjgl_glXMakeContextCurrent(peer_info->display, None, None, NULL);
	} else {
		result = lwjgl_glXMakeCurrent(peer_info->display, None, NULL);
	}
	if (!result)
		throwException(env, "Could not release current context");
}

JNIEXPORT void JNICALL Java_org_lwjgl_opengl_LinuxContextImplementation_nMakeCurrent
  (JNIEnv *env, jclass clazz, jobject peer_info_handle, jobject context_handle) {
	X11PeerInfo *peer_info = (*env)->GetDirectBufferAddress(env, peer_info_handle);
	X11Context *context_info = (*env)->GetDirectBufferAddress(env, context_handle);
	Bool result;
	if (peer_info->glx13) {
		result = lwjgl_glXMakeContextCurrent(peer_info->display, peer_info->drawable, peer_info->drawable, context_info->context);
	} else {
		result = lwjgl_glXMakeCurrent(peer_info->display, peer_info->drawable, context_info->context);
	}
	if (!result)
		throwException(env, "Could not make context current");
}

JNIEXPORT jboolean JNICALL Java_org_lwjgl_opengl_LinuxContextImplementation_nIsCurrent
  (JNIEnv *env, jclass clazz, jobject context_handle) {
	X11Context *context_info = (*env)->GetDirectBufferAddress(env, context_handle);
	return context_info->context == lwjgl_glXGetCurrentContext();
}

JNIEXPORT void JNICALL Java_org_lwjgl_opengl_LinuxContextImplementation_nSwapBuffers
  (JNIEnv *env, jclass clazz, jobject peer_info_handle) {
	X11PeerInfo *peer_info = (*env)->GetDirectBufferAddress(env, peer_info_handle);
	lwjgl_glXSwapBuffers(peer_info->display, peer_info->drawable);
}