/* Copyright (C) 2003 Cedric Cellier, Dominique Lavault This program is free software; you can redistribute
it and/or modify it under the terms of the GNU General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later version. This program is
distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; if not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#ifndef OPENGL_H
#define OPENGL_H
/*
#ifdef _WINDOWS
#include
#include
#include
#include
#else
#ifdef __APPLE_CC__
#include
#include
#include
#else
#include
#include
#include
#endif
#endif
*/
#ifndef GLAPIENTRY
#ifdef _WIN32
#define GLAPIENTRY __stdcall /* just in case */
#else
#define GLAPIENTRY
#endif
#endif
/* Borrowed from http://www.west.net/~brittain/3dsmax2.htm#OpenGL * * This is an explication of how
the KTX (Kinetix) extension works. * ******************************************************************
The OpenGL extension described below, if present, will be used by MAX to implement dual planes under
OpenGL. As with all OpenGL extensions under Windows NT, the functions are imported into MAX by calling
wglGetProcAddress, and the functions themselves are implemented with the __stdcall calling convention.
The presence of this extension is indicated by the keyword "GL_KTX_buffer_region" being present in the
string returned by glGetString(GL_EXTENSIONS). In an optimal implementation of this extension, the buffer
regions are stored in video RAM so that buffer data transfers do not have to cross the system bus. Note
that no data in the backing buffers is ever interpreted by MAX - it is just returned to the active image
and/or Z buffers later to restore a partially rendered scene without having to actually perform any
rendering. Thus, the buffered data should be kept in the native display card format without any
translation. GLuint glNewBufferRegion(GLenum type) This function creates a new buffer region and returns
a handle to it. The type parameter can be one of GL_KTX_FRONT_REGION, GL_KTX_BACK_REGION, GL_KTX_Z_REGION
or GL_KTX_STENCIL_REGION. These symbols are defined in the MAX gfx.h header file, but they are simply
mapped to 0 through 3 in the order given above. Note that the storage of this region data is
implementation specific and the pixel data is not available to the client. void
glDeleteBufferRegion(GLuint region) This function deletes a buffer region and any
associated buffer data. void glReadBufferRegion(GLuint region, GLint x, GLint y,
GLsizei width, GLsizei height) This function reads buffer data into a region specified
by the given region handle. The type of data read depends on the type of the region handle being used.
All coordinates are window-based (with the origin at the lower-left, as is common with OpenGL)
and attempts to read areas that are clipped by the window bounds fail silently. In MAX, x and y
are always 0. void glDrawBufferRegion(GLuint region, GLint x, GLint y, Glsizei width, GLsizei height,
GLint xDest, GLint yDest) This copies a rectangular region of data back to a display buffer.
In other words, it moves previously saved data from the specified region back to its originating buffer.
The type of data drawn depends on the type of the region handle being used. The rectangle specified
by x, y, width, and height will always lie completely within the rectangle specified by previous calls
to glReadBufferRegion. This rectangle is to be placed back into the display buffer at the location
specified by xDest and yDest. Attempts to draw sub-regions outside the area of the last buffer region
read will fail (silently). In MAX, xDest and yDest are always equal to x and y, respectively.)
GLuint glBufferRegionEnabled(void) This routine returns 1 (TRUE) if MAX should use the buffer region
extension, and 0 (FALSE) if MAX shouldn't. This call is here so that if a single display driver
supports a family of display cards with varying functionality and onboard memory, the extension
can be implemented yet only used if a given display card could benefit from its use.
In particular, if a given display card does not have enough memory to efficiently support the buffer
region extension, then this call should return FALSE. (Even for cards with lots of memory, whether
or not to enable the extension could be left up to the end-user through a configuration option
available through a manufacturer's addition to the Windows tabbed Display Properties dialog.
Then, those users who like to have as much video memory available for textures as possible could
disable the option, or other users who work with large scene databases but not lots of textures
could explicitly enable the extension.) Notes: Buffer region data is stored per window. Any
context associated with the window can access the buffer regions for that window. Buffer regions
are cleaned up on deletion of the window. MAX uses the buffer region calls to squirrel away
complete copies of each viewport?s image and Z buffers. Then, when a rectangular region of the
screen must be updated because "foreground" objects have moved, that subregion is moved from
"storage" back to the image and Z buffers used for scene display. MAX then renders the objects
that have moved to complete the update of the viewport display. */
#ifndef GL_KTX_FRONT_REGION
#define GL_KTX_FRONT_REGION 0
#endif
#ifndef GL_KTX_BACK_REGION
#define GL_KTX_BACK_REGION 1
#endif
#ifndef GL_KTX_Z_REGION
#define GL_KTX_Z_REGION 2
#endif
#ifndef GL_KTX_STENCIL_REGION
#define GL_KTX_STENCIL_REGION 3
#endif
typedef GLuint (GLAPIENTRY * PFNGLNEWBUFFERREGIONPROC) (GLenum type);
typedef void (GLAPIENTRY * PFNGLDELETEBUFFERREGIONPROC) (GLuint region);
typedef void (GLAPIENTRY * PFNGLREADBUFFERREGIONPROC)
(GLuint region, GLint x, GLint y, GLsizei width, GLsizei height);
typedef void (GLAPIENTRY * PFNGLDRAWBUFFERREGIONPROC)
(GLuint region, GLint x, GLint y, GLsizei width, GLsizei height, GLint xDest, GLint yDest);
typedef GLuint (GLAPIENTRY * PFNGLBUFFERREGIONENABLEDPROC) (void);
#endif
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