lwjgl/src/native/linux/org_lwjgl_opengl_Pbuffer.cpp

/* 
 * Copyright (c) 2002-2004 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, 
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 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * $Id$
 *
 * Linux Pbuffer.
 *
 * @author elias_naur <elias_naur@users.sourceforge.net>
 * @version $Revision$
 */

#include <stdlib.h>
#include "org_lwjgl_opengl_Pbuffer.h"
#include "extgl.h"
#include "Window.h"
#include "common_tools.h"

typedef struct _PbufferInfo {
	GLXPbuffer buffer;
	GLXContext context;
	bool use_display_context;
} PbufferInfo;

JNIEXPORT jboolean JNICALL Java_org_lwjgl_opengl_Pbuffer_nIsBufferLost
  (JNIEnv *env, jclass clazz, jint handle)
{
	// The buffer is never lost, because of the GLX_PRESERVED_CONTENTS flag
	return JNI_FALSE;
}

JNIEXPORT jint JNICALL Java_org_lwjgl_opengl_Pbuffer_getPbufferCaps
  (JNIEnv *env, jclass clazz)
{
	// Only support the GLX 1.3 Pbuffers and ignore the GLX_SGIX_pbuffer extension
	return extgl_Extensions.GLX13 ? org_lwjgl_opengl_Pbuffer_PBUFFER_SUPPORTED : 0;
}

static void destroyPbuffer(PbufferInfo *buffer_info) {
	GLXPbuffer buffer = buffer_info->buffer;
	GLXContext context = buffer_info->context;
	glXDestroyPbuffer(getDisplay(), buffer);
	if (!buffer_info->use_display_context)
		glXDestroyContext(getDisplay(), context);
	free(buffer_info);
	decDisplay();
}

static bool checkPbufferCaps(JNIEnv *env, GLXFBConfig config, int width, int height) {
	int max;
	int result = glXGetFBConfigAttrib(getDisplay(), config, GLX_MAX_PBUFFER_WIDTH, &max);
	if (result != Success) {
		throwException(env, "Could not get GLX_MAX_PBUFFER_WIDTH from configuration");
		return false;
	}
	if (max < width) {
		throwException(env, "Width too large");
		return false;
	}
	result = glXGetFBConfigAttrib(getDisplay(), config, GLX_MAX_PBUFFER_HEIGHT, &max);
	if (result != Success) {
		throwException(env, "Could not get GLX_MAX_PBUFFER_WIDTH from configuration");
		return false;
	}
	if (max < height) {
		throwException(env, "Height too large");
		return false;
	}
	return true;
}

static bool createPbufferUsingUniqueContext(JNIEnv *env, PbufferInfo *pbuffer_info, jobject pixel_format, int width, int height, const int *buffer_attribs) {
	GLXFBConfig *configs = chooseVisualGLX13(env, pixel_format, false, GLX_PBUFFER_BIT, false);
	if (configs == NULL) {
		throwException(env, "No matching pixel format");
		return false;
	}
	if (!checkPbufferCaps(env, configs[0], width, height)) {
		XFree(configs);
		return false;
	}
	GLXContext context = glXCreateNewContext(getDisplay(), configs[0], GLX_RGBA_TYPE, getCurrentContext(), True);
	if (context == NULL) {
		XFree(configs);
		throwException(env, "Could not create a GLX context");
		return false;
	}
	jboolean allow_software_acceleration = getBooleanProperty(env, "org.lwjgl.opengl.Window.allowSoftwareOpenGL");
	if (!allow_software_acceleration && glXIsDirect(getDisplay(), context) == False) {
		glXDestroyContext(getDisplay(), context);
		XFree(configs);
		throwException(env, "Could not create a direct GLX context");
		return false;
	}
	GLXPbuffer buffer = glXCreatePbuffer(getDisplay(), configs[0], buffer_attribs);
	XFree(configs);
	pbuffer_info->context = context;
	pbuffer_info->buffer = buffer;
	return true;
}

static bool createPbufferUsingDisplayContext(JNIEnv *env, PbufferInfo *buffer_info, int width, int height, const int *buffer_attribs) {
	if (!checkPbufferCaps(env, getCurrentGLXFBConfig(), width, height)) {
		return false;
	}
	int drawable_type;
	if (glXGetFBConfigAttrib(getDisplay(), getCurrentGLXFBConfig(), GLX_DRAWABLE_TYPE, &drawable_type) != Success) {
		throwException(env, "Could not get GLX_DRAWABLE_TYPE attribute from Display context");
		return false;
	}
	if (drawable_type & GLX_PBUFFER_BIT == 0) {
		throwException(env, "Display context does not support Pbuffers");
		return false;
	}
	GLXPbuffer buffer = glXCreatePbuffer(getDisplay(), getCurrentGLXFBConfig(), buffer_attribs);
	buffer_info->buffer = buffer;
	buffer_info->context = getCurrentGLXContext();
	return true;
}

JNIEXPORT jint JNICALL Java_org_lwjgl_opengl_Pbuffer_nCreate(JNIEnv *env, jclass clazz, jboolean use_display_context, jint width, jint height, jobject pixel_format, jobject pixelFormatCaps, jobject pBufferAttribs)
{
	Display *disp = incDisplay(env);
	if (disp == NULL) {
		return -1;
	}
	int current_screen = XDefaultScreen(disp);
	if (!extgl_InitGLX(env, disp, current_screen)) {
		decDisplay();
		throwException(env, "Could not init GLX");
		return -1;
	}

	const int buffer_attribs[] = {GLX_PBUFFER_WIDTH, width,
				      GLX_PBUFFER_HEIGHT, height,
				      GLX_PRESERVED_CONTENTS, True,
				      GLX_LARGEST_PBUFFER, False,
					  None, None};

	PbufferInfo *buffer_info = (PbufferInfo *)malloc(sizeof(PbufferInfo));
	buffer_info->use_display_context = use_display_context;
	bool result;
	if (use_display_context) {
		result = createPbufferUsingDisplayContext(env, buffer_info, width, height, buffer_attribs);
	} else {
		result = createPbufferUsingUniqueContext(env, buffer_info, pixel_format, width, height, buffer_attribs);
	}
	if (!result)
		return -1;
	if (!checkXError(env)) {
		destroyPbuffer(buffer_info);
		return -1;
	}
	return (jint)buffer_info;
}

JNIEXPORT void JNICALL Java_org_lwjgl_opengl_Pbuffer_nMakeCurrent
  (JNIEnv *env, jclass clazz, jint handle)
{
	PbufferInfo *buffer_info = (PbufferInfo *)handle;
	GLXPbuffer buffer = buffer_info->buffer;
	GLXContext context = buffer_info->context;
	if (glXMakeContextCurrent(getDisplay(), buffer, buffer, context) == False) {
		throwException(env, "Could not make pbuffer context current");
	}
}

/*
 * Class:     org_lwjgl_opengl_Pbuffer
 * Method:    nDestroyGL
 * Signature: (I)V
 */
JNIEXPORT void JNICALL Java_org_lwjgl_opengl_Pbuffer_nDestroy
  (JNIEnv *env, jclass clazz, jint handle)
{
	PbufferInfo *buffer_info = (PbufferInfo *)handle;
	destroyPbuffer(buffer_info);
}

JNIEXPORT void JNICALL Java_org_lwjgl_opengl_Pbuffer_nSetAttrib
  (JNIEnv *env, jclass clazz, jint handle, jint attrib, jint value)
{
	throwException(env, "The render-to-texture extension is not supported.");
}

JNIEXPORT void JNICALL Java_org_lwjgl_opengl_Pbuffer_nBindTexImage
  (JNIEnv *env, jclass clazz, jint handle, jint buffer)
{
	throwException(env, "The render-to-texture extension is not supported.");
}

JNIEXPORT void JNICALL Java_org_lwjgl_opengl_Pbuffer_nReleaseTexImage
  (JNIEnv *env, jclass clazz, jint handle, jint buffer)
{
	throwException(env, "The render-to-texture extension is not supported.");
}