qzdoom/src/gl/stereo3d/gl_quadstereo.cpp
Christoph Oelckers 8b6e09ca09 - changed the license of the OpenGL renderer to LGPL v3.
This was done to clean up the license and to ensure that any commercial fork of the engine has to obey the far stricter requirements concerning source distribution. The old license was compatible with GPLv2 whereas combining GPLv2 and LGPLv3 force a license upgrade to GPLv3. The license of code that originates from ZDoomGL has not been changed.
2016-09-14 20:01:13 +02:00

116 lines
4 KiB
C++

//
//---------------------------------------------------------------------------
//
// Copyright(C) 2015 Christopher Bruns
// All rights reserved.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this program. If not, see http://www.gnu.org/licenses/
//
//--------------------------------------------------------------------------
//
/*
** gl_quadstereo.cpp
** Quad-buffered OpenGL stereoscopic 3D mode for GZDoom
**
*/
#include "gl_quadstereo.h"
#include "gl/renderer/gl_renderer.h"
#include "gl/renderer/gl_renderbuffers.h"
namespace s3d {
QuadStereo::QuadStereo(double ipdMeters)
: leftEye(ipdMeters), rightEye(ipdMeters)
{
// Check whether quad-buffered stereo is supported in the current context
// We are assuming the OpenGL context is already current at this point,
// i.e. this constructor is called "just in time".
// First initialize to mono-ish initial state
bQuadStereoSupported = leftEye.bQuadStereoSupported = rightEye.bQuadStereoSupported = false;
eye_ptrs.Push(&leftEye); // We ALWAYS want to show at least this one view...
// We will possibly advance to true stereo mode in the Setup() method...
}
// Sometimes the stereo render context is not ready immediately at start up
/* private */
void QuadStereo::checkInitialRenderContextState()
{
// Keep trying until we see at least one good OpenGL context to render to
static bool bDecentContextWasFound = false;
if (!bDecentContextWasFound) {
// I'm using a "random" OpenGL call (glGetFramebufferAttachmentParameteriv)
// that appears to correlate with whether the context is ready
GLint attachmentType = GL_NONE;
glGetFramebufferAttachmentParameteriv(GL_DRAW_FRAMEBUFFER, GL_FRONT_LEFT, GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE, &attachmentType);
if (attachmentType != GL_NONE) // Finally, a useful OpenGL context
{
// This block will be executed exactly ONCE during a game run
bDecentContextWasFound = true; // now we can stop checking every frame...
// Now check whether this context supports hardware stereo
GLboolean supportsStereo, supportsBuffered;
glGetBooleanv(GL_STEREO, &supportsStereo);
glGetBooleanv(GL_DOUBLEBUFFER, &supportsBuffered);
bQuadStereoSupported = supportsStereo && supportsBuffered;
leftEye.bQuadStereoSupported = bQuadStereoSupported;
rightEye.bQuadStereoSupported = bQuadStereoSupported;
if (bQuadStereoSupported)
eye_ptrs.Push(&rightEye); // Use the other eye too, if we can do stereo
}
}
}
void QuadStereo::Present() const
{
if (bQuadStereoSupported)
{
GLRenderer->mBuffers->BindOutputFB();
glDrawBuffer(GL_BACK_LEFT);
GLRenderer->ClearBorders();
GLRenderer->mBuffers->BindEyeTexture(0, 0);
GLRenderer->DrawPresentTexture(GLRenderer->mOutputLetterbox, true);
glDrawBuffer(GL_BACK_RIGHT);
GLRenderer->ClearBorders();
GLRenderer->mBuffers->BindEyeTexture(1, 0);
GLRenderer->DrawPresentTexture(GLRenderer->mOutputLetterbox, true);
glDrawBuffer(GL_BACK);
}
else
{
GLRenderer->mBuffers->BindOutputFB();
GLRenderer->ClearBorders();
GLRenderer->mBuffers->BindEyeTexture(0, 0);
GLRenderer->DrawPresentTexture(GLRenderer->mOutputLetterbox, true);
}
}
void QuadStereo::SetUp() const
{
Stereo3DMode::SetUp();
// Maybe advance to true stereo mode (ONCE), after the stereo context is finally ready
const_cast<QuadStereo*>(this)->checkInitialRenderContextState();
}
/* static */
const QuadStereo& QuadStereo::getInstance(float ipd)
{
static QuadStereo instance(ipd);
return instance;
}
} /* namespace s3d */