//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
void GLRenderToVertexBuffer::update(SceneManager* sceneMgr)
{
checkGLError(true, false, "start of GLRenderToVertexBuffer::update");
size_t bufSize = mVertexData->vertexDeclaration->getVertexSize(0) * mMaxVertexCount;
if (mVertexBuffers[0].isNull() || mVertexBuffers[0]->getSizeInBytes() != bufSize)
{
//Buffers don't match. Need to reallocate.
mResetRequested = true;
}
//Single pass only for now
Ogre::Pass* r2vbPass = mMaterial->getBestTechnique()->getPass(0);
//Set pass before binding buffers to activate the GPU programs
sceneMgr->_setPass(r2vbPass);
checkGLError(true, false);
bindVerticesOutput(r2vbPass);
RenderOperation renderOp;
size_t targetBufferIndex;
if (mResetRequested || mResetsEveryUpdate)
{
//Use source data to render to first buffer
mSourceRenderable->getRenderOperation(renderOp);
targetBufferIndex = 0;
}
else
{
//Use current front buffer to render to back buffer
this->getRenderOperation(renderOp);
targetBufferIndex = 1 - mFrontBufferIndex;
}
if (mVertexBuffers[targetBufferIndex].isNull() ||
mVertexBuffers[targetBufferIndex]->getSizeInBytes() != bufSize)
{
reallocateBuffer(targetBufferIndex);
}
GLHardwareVertexBuffer* vertexBuffer = static_cast<GLHardwareVertexBuffer*>(mVertexBuffers[targetBufferIndex].getPointer());
GLuint bufferId = vertexBuffer->getGLBufferId();
//Bind the target buffer
glBindBufferOffsetNV(GL_TRANSFORM_FEEDBACK_BUFFER_NV, 0, bufferId, 0);
glBeginTransformFeedbackNV(getR2VBPrimitiveType(mOperationType));
glEnable(GL_RASTERIZER_DISCARD_NV); // disable rasterization
glBeginQuery(GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN_NV, mPrimitivesDrawnQuery);
RenderSystem* targetRenderSystem = Root::getSingleton().getRenderSystem();
//Draw the object
targetRenderSystem->_setWorldMatrix(Matrix4::IDENTITY);
targetRenderSystem->_setViewMatrix(Matrix4::IDENTITY);
targetRenderSystem->_setProjectionMatrix(Matrix4::IDENTITY);
if (r2vbPass->hasVertexProgram())
{
targetRenderSystem->bindGpuProgramParameters(GPT_VERTEX_PROGRAM,
r2vbPass->getVertexProgramParameters(), GPV_ALL);
}
if (r2vbPass->hasGeometryProgram())
{
targetRenderSystem->bindGpuProgramParameters(GPT_GEOMETRY_PROGRAM,
r2vbPass->getGeometryProgramParameters(), GPV_ALL);
}
targetRenderSystem->_render(renderOp);
//Finish the query
glEndQuery(GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN_NV);
glDisable(GL_RASTERIZER_DISCARD_NV);
glEndTransformFeedbackNV();
//read back query results
GLuint primitivesWritten;
glGetQueryObjectuiv(mPrimitivesDrawnQuery, GL_QUERY_RESULT, &primitivesWritten);
mVertexData->vertexCount = primitivesWritten * getVertexCountPerPrimitive(mOperationType);
checkGLError(true, true, "GLRenderToVertexBuffer::update");
//Switch the vertex binding if neccesary
if (targetBufferIndex != mFrontBufferIndex)
{
mVertexData->vertexBufferBinding->unsetAllBindings();
mVertexData->vertexBufferBinding->setBinding(0, mVertexBuffers[targetBufferIndex]);
mFrontBufferIndex = targetBufferIndex;
}
glDisable(GL_RASTERIZER_DISCARD_NV); // enable rasterization
//Clear the reset flag
mResetRequested = false;
}
JNIEXPORT void JNICALL Java_org_lwjgl_opengl_NVTransformFeedback_glBindBufferOffsetNV(JNIEnv *__env, jclass clazz, jint target, jint index, jint buffer, jlong offset) {
glBindBufferOffsetNVPROC glBindBufferOffsetNV = (glBindBufferOffsetNVPROC)tlsGetFunction(2148);
UNUSED_PARAM(clazz)
glBindBufferOffsetNV(target, index, buffer, (intptr_t)offset);
}
