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vtkOpenGLHAVSVolumeMapper.cxx
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vtkOpenGLHAVSVolumeMapper.cxx
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/*=========================================================================
Program: Visualization Toolkit
Module: vtkOpenGLHAVSVolumeMapper.cxx
Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
All rights reserved.
See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the above copyright notice for more information.
=========================================================================*/
/* Copyright 2005, 2006 by University of Utah. */
#include "vtkOpenGLHAVSVolumeMapper.h"
#include "vtkCamera.h"
#include "vtkColorTransferFunction.h"
#include "vtkgl.h"
#include "vtkInformation.h"
#include "vtkObjectFactory.h"
#include "vtkOpenGL.h"
#include "vtkOpenGLExtensionManager.h"
#include "vtkPiecewiseFunction.h"
#include "vtkRenderer.h"
#include "vtkRenderWindow.h"
#include "vtkTimerLog.h"
#include "vtkTransform.h"
#include "vtkUnstructuredGrid.h"
#include "vtkUnstructuredGridPartialPreIntegration.h"
#include "vtkVolumeProperty.h"
#include "vtkOpenGLRenderWindow.h"
#include "vtkHAVSVolumeMapper_kbufferVP.h"
#include "vtkHAVSVolumeMapper_k2BeginFP.h"
#include "vtkHAVSVolumeMapper_k2FP.h"
#include "vtkHAVSVolumeMapper_k2EndFP.h"
#include "vtkHAVSVolumeMapper_k6BeginFP.h"
#include "vtkHAVSVolumeMapper_k6FP.h"
#include "vtkHAVSVolumeMapper_k6EndFP.h"
vtkStandardNewMacro(vtkOpenGLHAVSVolumeMapper);
//----------------------------------------------------------------------------
// return the correct type of UnstructuredGridVolumeMapper
vtkOpenGLHAVSVolumeMapper::vtkOpenGLHAVSVolumeMapper()
{
this->VBOVertexName = 0;
this->VBOTexCoordName = 0;
this->VBOVertexIndexName = 0;
this->PsiTableTexture = 0;
this->FramebufferObjectSize = 0;
this->OrderedTriangles = 0;
this->RenderWindow=0;
}
//----------------------------------------------------------------------------
// return the correct type of UnstructuredGridVolumeMapper
vtkOpenGLHAVSVolumeMapper::~vtkOpenGLHAVSVolumeMapper()
{
if (!this->GPUDataStructures)
{
if(this->OrderedTriangles!=0)
{
delete [] this->OrderedTriangles;
}
}
}
//----------------------------------------------------------------------------
void vtkOpenGLHAVSVolumeMapper::CheckOpenGLError(const char * str)
{
int err = glGetError(); (void)str;
if ( err != GL_NO_ERROR && this->GetDebug() )
{
vtkDebugMacro( << "OpenGL Error: " << str );
}
}
//----------------------------------------------------------------------------
void vtkOpenGLHAVSVolumeMapper::ReleaseGraphicsResources(vtkWindow *renWin)
{
if (this->Initialized)
{
static_cast<vtkRenderWindow *>(renWin)->MakeCurrent();
this->DeleteShaders();
glDisable( vtkgl::VERTEX_PROGRAM_ARB );
glDisable( vtkgl::FRAGMENT_PROGRAM_ARB );
glDeleteTextures(1, reinterpret_cast<GLuint *>(&this->TransferFunctionTexture));
int numBuffers = (this->KBufferState == VTK_KBUFFER_SIZE_2)? 2 : 4;
for (int i = 0; i < numBuffers; i++)
{
glDeleteTextures(1,reinterpret_cast<GLuint *>(&this->FramebufferTextures[i]));
}
vtkgl::DeleteFramebuffersEXT(1,reinterpret_cast<GLuint *>(&this->FramebufferObject));
this->Initialized = false;
if (this->GPUDataStructures)
{
vtkgl::DeleteBuffers(1, reinterpret_cast<GLuint *>(&this->VBOVertexName));
vtkgl::DeleteBuffers(1, reinterpret_cast<GLuint *>(&this->VBOTexCoordName));
vtkgl::DeleteBuffers(1,reinterpret_cast<GLuint *>(&this->VBOVertexIndexName));
vtkgl::BindBuffer(vtkgl::ARRAY_BUFFER, 0);
vtkgl::BindBuffer(vtkgl::ELEMENT_ARRAY_BUFFER, 0);
}
}
this->Superclass::ReleaseGraphicsResources(renWin);
}
//----------------------------------------------------------------------------
void vtkOpenGLHAVSVolumeMapper::Initialize(vtkRenderer *ren,
vtkVolume *vol)
{
// Check for the required extensions only.
if (!this->SupportedByHardware(ren))
{
this->InitializationError = vtkHAVSVolumeMapper::UNSUPPORTED_EXTENSIONS;
return;
}
vtkOpenGLExtensionManager *extensions=
static_cast<vtkOpenGLRenderWindow *>(ren->GetRenderWindow())
->GetExtensionManager();
// Load required extensions
// supports_GL_1_3=1 as checked by this->SupportedByHardware()
// OpenGL 1.3 is required by GL_ARB_draw_buffers, GL_ARB_fragment_program
// and GL_ARB_vertex_program.
// CLAMP_TO_EGDE is core feature of OpenGL 1.2 and
// multitexture is core feature of OpenGL 1.3.
extensions->LoadExtension("GL_VERSION_1_3"); // multitexture
// supports_draw_buffers as checked by this->SupportedByHardware()
int supports_GL_2_0=extensions->ExtensionSupported( "GL_VERSION_2_0" );
if(supports_GL_2_0)
{
extensions->LoadExtension("GL_VERSION_2_0");
}
else
{
extensions->LoadCorePromotedExtension( "GL_ARB_draw_buffers" );
}
// supports_fragment_program && supports_vertex_program as checked
// by this->SupportedByHardware()
extensions->LoadExtension( "GL_ARB_fragment_program" );
extensions->LoadExtension( "GL_ARB_vertex_program" );
// supports_GL_EXT_framebuffer_object==1 as checked
// by this->SupportedByHardware()
extensions->LoadExtension("GL_EXT_framebuffer_object");
// GL_ARB_texture_float or GL_ATI_texture_float introduce new tokens but
// no new function: don't need to call LoadExtension.
// Optional extension.
int supports_GL_1_5=extensions->ExtensionSupported( "GL_VERSION_1_5" );
int supports_vertex_buffer_object;
if(supports_GL_1_5)
{
supports_vertex_buffer_object=1;
}
else
{
supports_vertex_buffer_object =
extensions->ExtensionSupported( "GL_ARB_vertex_buffer_object" );
}
if(supports_vertex_buffer_object)
{
if(supports_GL_1_5)
{
extensions->LoadExtension("GL_VERSION_1_5");
}
else
{
extensions->LoadCorePromotedExtension( "GL_ARB_vertex_buffer_object" );
}
}
if (!supports_vertex_buffer_object)
{
this->SetGPUDataStructures(false);
}
this->UpdateProgress(0.0);
// Initialize triangles and VBOs or Vertex Arrays
this->InitializePrimitives(vol);
this->UpdateProgress(0.4);
// Initialize scalars and VBOs
this->InitializeScalars();
this->UpdateProgress(0.5);
// Initialize Level-of-Detail data structures
this->InitializeLevelOfDetail();
this->UpdateProgress(0.7);
// Initialize Lookup tables
this->InitializeLookupTables(vol);
this->UpdateProgress(0.8);
// Initialize vertex and scalar storage
this->InitializeGPUDataStructures();
this->UpdateProgress(0.9);
// Initialize shaders
this->InitializeShaders();
// Initialize FBOs
this->InitializeFramebufferObject();
this->UpdateProgress(1.0);
this->Initialized = 1;
}
//----------------------------------------------------------------------------
// Change GPU data structures state
void vtkOpenGLHAVSVolumeMapper::SetGPUDataStructures(bool gpu)
{
if(this->GPUDataStructures!=gpu)
{
if(!this->GPUDataStructures)
{
if(this->OrderedTriangles!=0)
{
delete [] this->OrderedTriangles;
this->OrderedTriangles=0;
}
}
this->GPUDataStructures = gpu;
if (this->Initialized)
{
this->InitializeGPUDataStructures();
}
}
}
//----------------------------------------------------------------------------
// Store data structures on GPU if possible
void vtkOpenGLHAVSVolumeMapper::InitializeGPUDataStructures()
{
if (this->GPUDataStructures)
{
if (VBOVertexName)
{
vtkgl::DeleteBuffers(1, reinterpret_cast<GLuint *>(&this->VBOVertexName));
}
if (VBOVertexIndexName)
{
vtkgl::DeleteBuffers(1,reinterpret_cast<GLuint *>(&this->VBOVertexIndexName));
}
if (VBOTexCoordName)
{
vtkgl::DeleteBuffers(1, reinterpret_cast<GLuint *>(&this->VBOTexCoordName));
}
// Build vertex array
vtkgl::GenBuffers(1, reinterpret_cast<GLuint *>(&this->VBOVertexName));
vtkgl::BindBuffer(vtkgl::ARRAY_BUFFER, this->VBOVertexName);
vtkgl::BufferData(vtkgl::ARRAY_BUFFER,
this->NumberOfVertices*3*sizeof(float),
this->Vertices, vtkgl::STATIC_DRAW);
// Build dynamic vertex index array
vtkgl::GenBuffers(1, reinterpret_cast<GLuint *>(&this->VBOVertexIndexName));
vtkgl::BindBuffer(vtkgl::ELEMENT_ARRAY_BUFFER,
this->VBOVertexIndexName);
vtkgl::BufferData(vtkgl::ELEMENT_ARRAY_BUFFER,
this->NumberOfTriangles*3*sizeof(GLuint), 0,
vtkgl::STREAM_DRAW);
vtkgl::BindBuffer(vtkgl::ARRAY_BUFFER, 0);
vtkgl::BindBuffer(vtkgl::ELEMENT_ARRAY_BUFFER, 0);
this->CheckOpenGLError("Initializing VBOs");
// Build tex coord array
vtkgl::GenBuffers(1, reinterpret_cast<GLuint *>(&this->VBOTexCoordName));
vtkgl::BindBuffer(vtkgl::ARRAY_BUFFER, this->VBOTexCoordName);
vtkgl::BufferData(vtkgl::ARRAY_BUFFER,
this->NumberOfScalars*sizeof(float),
this->Scalars, vtkgl::STATIC_DRAW);
vtkgl::BindBuffer(vtkgl::ARRAY_BUFFER, 0);
}
else
{
if (this->OrderedTriangles)
{
delete [] this->OrderedTriangles;
}
this->OrderedTriangles = new unsigned int[this->NumberOfTriangles*3];
}
}
//----------------------------------------------------------------------------
// Vertex and Fragment shaders
void vtkOpenGLHAVSVolumeMapper::InitializeShaders()
{
// Create vertex shader
glEnable( vtkgl::VERTEX_PROGRAM_ARB );
vtkgl::GenProgramsARB(1, reinterpret_cast<GLuint *>(&this->VertexProgram));
vtkgl::BindProgramARB(vtkgl::VERTEX_PROGRAM_ARB, this->VertexProgram);
vtkgl::ProgramStringARB(vtkgl::VERTEX_PROGRAM_ARB,
vtkgl::PROGRAM_FORMAT_ASCII_ARB,
static_cast<GLsizei>(strlen(vtkHAVSVolumeMapper_kbufferVP)),
vtkHAVSVolumeMapper_kbufferVP);
// Create fragment shaders
glEnable( vtkgl::FRAGMENT_PROGRAM_ARB );
if (this->KBufferSize == VTK_KBUFFER_SIZE_2)
{
vtkgl::GenProgramsARB(1,
reinterpret_cast<GLuint *>(&this->FragmentProgramBegin));
vtkgl::BindProgramARB(vtkgl::FRAGMENT_PROGRAM_ARB,
this->FragmentProgramBegin);
vtkgl::ProgramStringARB(vtkgl::FRAGMENT_PROGRAM_ARB,
vtkgl::PROGRAM_FORMAT_ASCII_ARB,
static_cast<GLsizei>(strlen(vtkHAVSVolumeMapper_k2BeginFP)),
vtkHAVSVolumeMapper_k2BeginFP);
vtkgl::GenProgramsARB(1, reinterpret_cast<GLuint *>(&this->FragmentProgram));
vtkgl::BindProgramARB(vtkgl::FRAGMENT_PROGRAM_ARB, this->FragmentProgram);
vtkgl::ProgramStringARB(vtkgl::FRAGMENT_PROGRAM_ARB,
vtkgl::PROGRAM_FORMAT_ASCII_ARB,
static_cast<GLsizei>(strlen(vtkHAVSVolumeMapper_k2FP)),
vtkHAVSVolumeMapper_k2FP);
vtkgl::GenProgramsARB(1, reinterpret_cast<GLuint *>(&this->FragmentProgramEnd));
vtkgl::BindProgramARB(vtkgl::FRAGMENT_PROGRAM_ARB,
this->FragmentProgramEnd);
vtkgl::ProgramStringARB(vtkgl::FRAGMENT_PROGRAM_ARB,
vtkgl::PROGRAM_FORMAT_ASCII_ARB,
static_cast<GLsizei>(strlen(vtkHAVSVolumeMapper_k2EndFP)),
vtkHAVSVolumeMapper_k2EndFP);
}
else
{
vtkgl::GenProgramsARB(1,
reinterpret_cast<GLuint *>(&this->FragmentProgramBegin));
vtkgl::BindProgramARB(vtkgl::FRAGMENT_PROGRAM_ARB,
this->FragmentProgramBegin);
vtkgl::ProgramStringARB(vtkgl::FRAGMENT_PROGRAM_ARB,
vtkgl::PROGRAM_FORMAT_ASCII_ARB,
static_cast<GLsizei>(strlen(vtkHAVSVolumeMapper_k6BeginFP)),
vtkHAVSVolumeMapper_k6BeginFP);
vtkgl::GenProgramsARB(1, reinterpret_cast<GLuint *>(&this->FragmentProgram));
vtkgl::BindProgramARB(vtkgl::FRAGMENT_PROGRAM_ARB, this->FragmentProgram);
vtkgl::ProgramStringARB(vtkgl::FRAGMENT_PROGRAM_ARB,
vtkgl::PROGRAM_FORMAT_ASCII_ARB,
static_cast<GLsizei>(strlen(vtkHAVSVolumeMapper_k6FP)),
vtkHAVSVolumeMapper_k6FP);
vtkgl::GenProgramsARB(1, reinterpret_cast<GLuint *>(&this->FragmentProgramEnd));
vtkgl::BindProgramARB(vtkgl::FRAGMENT_PROGRAM_ARB,
this->FragmentProgramEnd);
vtkgl::ProgramStringARB(vtkgl::FRAGMENT_PROGRAM_ARB,
vtkgl::PROGRAM_FORMAT_ASCII_ARB,
static_cast<GLsizei>(strlen(vtkHAVSVolumeMapper_k6EndFP)),
vtkHAVSVolumeMapper_k6EndFP);
}
// Disable shaders
vtkgl::BindProgramARB(vtkgl::VERTEX_PROGRAM_ARB, 0);
vtkgl::BindProgramARB(vtkgl::FRAGMENT_PROGRAM_ARB, 0);
glDisable( vtkgl::VERTEX_PROGRAM_ARB );
glDisable( vtkgl::FRAGMENT_PROGRAM_ARB );
}
//----------------------------------------------------------------------------
void vtkOpenGLHAVSVolumeMapper::DeleteShaders()
{
vtkgl::DeleteProgramsARB(1, reinterpret_cast<GLuint *>(&this->VertexProgram));
vtkgl::DeleteProgramsARB(1,
reinterpret_cast<GLuint *>(&this->FragmentProgramBegin));
vtkgl::DeleteProgramsARB(1, reinterpret_cast<GLuint *>(&this->FragmentProgram));
vtkgl::DeleteProgramsARB(1,
reinterpret_cast<GLuint *>(&this->FragmentProgramEnd));
}
//----------------------------------------------------------------------------
// Build the lookup tables used for partial pre-integration
void vtkOpenGLHAVSVolumeMapper::InitializeLookupTables(vtkVolume *vol)
{
this->Superclass::InitializeLookupTables(vol);
// Create a 1D texture for transfer function look up
glGenTextures(1, reinterpret_cast<GLuint *>(&this->TransferFunctionTexture));
glBindTexture(GL_TEXTURE_1D, this->TransferFunctionTexture);
glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_S, vtkgl::CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexImage1D(GL_TEXTURE_1D, 0, GL_RGBA8, this->TransferFunctionSize,0,
GL_RGBA,GL_FLOAT, this->TransferFunction);
if (!this->PsiTableTexture)
{
vtkUnstructuredGridPartialPreIntegration *ppi =
vtkUnstructuredGridPartialPreIntegration::New();
ppi->BuildPsiTable();
int tableSize = 0;
float *psiTable = ppi->GetPsiTable(tableSize);
// Create a 2D texture for the PSI lookup table
glGenTextures(1, reinterpret_cast<GLuint *>(&this->PsiTableTexture));
glBindTexture(GL_TEXTURE_2D, this->PsiTableTexture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, vtkgl::CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, vtkgl::CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE8, tableSize, tableSize,
0, GL_LUMINANCE, GL_FLOAT, psiTable);
ppi->Delete();
}
}
//----------------------------------------------------------------------------
// Initialize FBO and attach color and depth textures.
void vtkOpenGLHAVSVolumeMapper::InitializeFramebufferObject()
{
GLint maxRB;
glGetIntegerv(vtkgl::MAX_RENDERBUFFER_SIZE_EXT, &maxRB);
int texSize = (maxRB > 1024)? 1024 : maxRB;
int numBuffers = (this->KBufferState == VTK_KBUFFER_SIZE_2)? 2 : 4;
if (!this->Initialized)
{
// Create FBO
vtkgl::GenFramebuffersEXT(1,
reinterpret_cast<GLuint *>(&this->FramebufferObject));
this->CheckOpenGLError("creating FBO");
}
else
{
glDeleteTextures(numBuffers,
reinterpret_cast<GLuint *>(this->FramebufferTextures));
vtkgl::DeleteRenderbuffersEXT(1,
reinterpret_cast<GLuint *>(&this->DepthTexture));
}
numBuffers = (this->KBufferSize == VTK_KBUFFER_SIZE_2)? 2 : 4;
// Create FBO textures
glGenTextures(numBuffers, reinterpret_cast<GLuint *>(this->FramebufferTextures));
for (int i = 0; i < numBuffers; i++)
{
glBindTexture(GL_TEXTURE_2D, this->FramebufferTextures[i]);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexImage2D(GL_TEXTURE_2D, 0, vtkgl::RGBA32F_ARB, texSize, texSize, 0,
GL_RGBA, GL_FLOAT, 0);
}
this->CheckOpenGLError("creating fbo textures");
// Bind framebuffer object
GLint savedFrameBuffer;
glGetIntegerv(vtkgl::FRAMEBUFFER_BINDING_EXT,&savedFrameBuffer);
vtkgl::BindFramebufferEXT(vtkgl::FRAMEBUFFER_EXT, this->FramebufferObject);
this->CheckOpenGLError("binding FBO");
// Generate depth buffer texture for framebuffer
vtkgl::GenRenderbuffersEXT(1, reinterpret_cast<GLuint *>(&this->DepthTexture));
// Attach texture to framebuffer color buffer
vtkgl::FramebufferTexture2DEXT( vtkgl::FRAMEBUFFER_EXT,
vtkgl::COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D,
this->FramebufferTextures[0], 0 );
vtkgl::FramebufferTexture2DEXT( vtkgl::FRAMEBUFFER_EXT,
vtkgl::COLOR_ATTACHMENT1_EXT, GL_TEXTURE_2D,
this->FramebufferTextures[1], 0 );
if (numBuffers == 4)
{
vtkgl::FramebufferTexture2DEXT( vtkgl::FRAMEBUFFER_EXT,
vtkgl::COLOR_ATTACHMENT2_EXT,
GL_TEXTURE_2D,
this->FramebufferTextures[2], 0 );
vtkgl::FramebufferTexture2DEXT( vtkgl::FRAMEBUFFER_EXT,
vtkgl::COLOR_ATTACHMENT3_EXT,
GL_TEXTURE_2D,
this->FramebufferTextures[3], 0 );
}
// Attach depth texture to framebuffer
vtkgl::BindRenderbufferEXT(vtkgl::RENDERBUFFER_EXT, this->DepthTexture);
vtkgl::RenderbufferStorageEXT(vtkgl::RENDERBUFFER_EXT,
vtkgl::DEPTH_COMPONENT24,
texSize, texSize);
vtkgl::FramebufferRenderbufferEXT(vtkgl::FRAMEBUFFER_EXT,
vtkgl::DEPTH_ATTACHMENT_EXT,
vtkgl::RENDERBUFFER_EXT,
this->DepthTexture);
this->CheckOpenGLError("attach textures to FBO");
// Validate FBO after attaching textures
if (vtkgl::CheckFramebufferStatusEXT(vtkgl::FRAMEBUFFER_EXT) !=
vtkgl::FRAMEBUFFER_COMPLETE_EXT && this->GetDebug())
{
vtkDebugMacro( << "FBO incomplete" );
}
// Disable FBO rendering
vtkgl::BindFramebufferEXT(vtkgl::FRAMEBUFFER_EXT,savedFrameBuffer);
this->FramebufferObjectSize = texSize;
this->KBufferState = this->KBufferSize;
}
//----------------------------------------------------------------------------
void vtkOpenGLHAVSVolumeMapper::Render(vtkRenderer *ren,
vtkVolume *vol)
{
ren->GetRenderWindow()->MakeCurrent();
this->RenderWindow=ren->GetRenderWindow();
if (!this->Initialized)
{
this->InitializationError =
vtkHAVSVolumeMapper::NO_INIT_ERROR;
this->Initialize(ren, vol);
if (this->CheckInitializationError())
{
return;
}
}
if (ren->GetRenderWindow()->CheckAbortStatus())
{
return;
}
// Check to see if we need to update the lookup table
if ((this->ColorTransferFunctionMTime <
vol->GetProperty()->GetRGBTransferFunction()->GetMTime())
||(this->AlphaTransferFunctionMTime <
vol->GetProperty()->GetScalarOpacity()->GetMTime())
||(this->UnitDistance != vol->GetProperty()->GetScalarOpacityUnitDistance()))
{
this->InitializeLookupTables(vol);
this->ColorTransferFunctionMTime.Modified();
this->AlphaTransferFunctionMTime.Modified();
}
if (ren->GetRenderWindow()->CheckAbortStatus())
{
return;
}
// Check to see if we need to update the scalars
if ((this->ScalarsMTime < this->MTime)
|| (this->ScalarsMTime < this->GetInput()->GetMTime())
|| (this->LastVolume != vol))
{
this->InitializationError =
vtkHAVSVolumeMapper::NO_INIT_ERROR;
this->InitializeScalars();
this->InitializeGPUDataStructures();
if (this->CheckInitializationError())
return;
this->ScalarsMTime.Modified();
}
if (ren->GetRenderWindow()->CheckAbortStatus())
{
return;
}
// Check to see if we need to update the geometry
if ((this->UnstructuredGridMTime < this->GetInput()->GetMTime())
|| (this->UnstructuredGridMTime < this->MTime))
{
this->InitializationError =
vtkHAVSVolumeMapper::NO_INIT_ERROR;
this->InitializePrimitives(vol);
this->InitializeLevelOfDetail();
this->InitializeGPUDataStructures();
if (this->CheckInitializationError())
return;
this->UnstructuredGridMTime.Modified();
}
if (ren->GetRenderWindow()->CheckAbortStatus())
{
return;
}
this->Timer->StartTimer();
this->RenderHAVS(ren);
this->LastVolume = vol;
this->Timer->StopTimer();
this->TimeToDraw = static_cast<float>(this->Timer->GetElapsedTime());
// Update level-of-detail
this->UpdateLevelOfDetail(TimeToDraw);
}
//----------------------------------------------------------------------------
// The OpenGL rendering
void vtkOpenGLHAVSVolumeMapper::RenderHAVS(vtkRenderer *ren)
{
glPushAttrib(GL_ENABLE_BIT |
GL_CURRENT_BIT |
GL_COLOR_BUFFER_BIT |
GL_STENCIL_BUFFER_BIT |
GL_DEPTH_BUFFER_BIT |
GL_POLYGON_BIT |
GL_TEXTURE_BIT |
GL_LIGHTING_BIT |
GL_TRANSFORM_BIT |
GL_VIEWPORT_BIT);
// Setup OpenGL state
glShadeModel(GL_SMOOTH);
glDisable(GL_DEPTH_TEST);
glDisable(GL_CULL_FACE);
glDisable(GL_LIGHTING);
glDisable(GL_NORMALIZE);
glDisable(GL_BLEND);
glDisable(GL_SCISSOR_TEST);
glDisable(GL_STENCIL_TEST);
int screenWidth, screenHeight;
ren->GetTiledSize(&screenWidth, &screenHeight);
// Keep shaders up to date
if (this->KBufferSize != this->KBufferState)
{
this->DeleteShaders();
this->InitializeShaders();
// Keep FBO up to date
this->InitializeFramebufferObject();
}
int vpWidth = screenWidth;
int vpHeight = screenHeight;
if (screenWidth > this->FramebufferObjectSize)
{
vpWidth = this->FramebufferObjectSize;
}
if (screenHeight > this->FramebufferObjectSize)
{
vpHeight = this->FramebufferObjectSize;
}
// Bind geometry arrays
if (this->GPUDataStructures)
{
glEnableClientState(GL_VERTEX_ARRAY);
vtkgl::BindBuffer(vtkgl::ARRAY_BUFFER, this->VBOVertexName);
glVertexPointer(3, GL_FLOAT, 0, static_cast<char *>(NULL));
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
vtkgl::BindBuffer(vtkgl::ARRAY_BUFFER, this->VBOTexCoordName);
glTexCoordPointer(1, GL_FLOAT, 0, static_cast<char *>(NULL));
vtkgl::BindBuffer(vtkgl::ELEMENT_ARRAY_BUFFER, this->VBOVertexIndexName);
}
else
{
glEnableClientState(GL_VERTEX_ARRAY);
glVertexPointer(3, GL_FLOAT, 0, this->Vertices);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glTexCoordPointer(1, GL_FLOAT, 0, this->Scalars);
}
if (ren->GetRenderWindow()->CheckAbortStatus())
{
return;
}
// Object-space sorting
double *e = ren->GetActiveCamera()->GetPosition();
float eye[3];
eye[0] = e[0];
eye[1] = e[1];
eye[2] = e[2];
if (this->GPUDataStructures)
{
this->OrderedTriangles =
static_cast<unsigned int *>(vtkgl::MapBuffer(vtkgl::ELEMENT_ARRAY_BUFFER,
vtkgl::WRITE_ONLY));
}
this->PartialVisibilitySort(eye);
if (this->GPUDataStructures)
{
vtkgl::UnmapBuffer(vtkgl::ELEMENT_ARRAY_BUFFER);
}
this->UpdateProgress(0.4);
if (ren->GetRenderWindow()->CheckAbortStatus())
{
return;
}
// Get depth range from OpenGL state for correct z
GLfloat depthRange[2];
glGetFloatv(GL_DEPTH_RANGE, depthRange);
// Get the current z-buffer
float *zbuffer =
ren->GetRenderWindow()->GetZbufferData(0,0,screenWidth-1,screenHeight-1);
// Enable FBO Rendering
GLint savedFrameBuffer;
glGetIntegerv(vtkgl::FRAMEBUFFER_BINDING_EXT,&savedFrameBuffer);
vtkgl::BindFramebufferEXT(vtkgl::FRAMEBUFFER_EXT, this->FramebufferObject);
// Setup z-buffer
this->SetupFBOZBuffer(vpWidth, vpHeight, depthRange[0], depthRange[1],
zbuffer);
delete [] zbuffer;
// Setup multiple render targets
this->SetupFBOMRT();
// Draw Initialization pass
this->DrawFBOInit(vpWidth, vpHeight, depthRange[0], depthRange[1]);
// Draw Geometry pass
this->DrawFBOGeometry();
this->UpdateProgress(0.9);
// Draw Flushing pass
this->DrawFBOFlush(vpWidth, vpHeight, depthRange[0], depthRange[1]);
// Disable FBO rendering
vtkgl::BindFramebufferEXT(vtkgl::FRAMEBUFFER_EXT, savedFrameBuffer);
glPopAttrib();
// Blend Result into framebuffer
this->DrawBlend(vpWidth, vpHeight, depthRange[0], depthRange[1]);
this->UpdateProgress(1.0);
}
//----------------------------------------------------------------------------
// Draw the current z-buffer into the FBO z-buffer for correct compositing
// with existing geometry or widgets.
void vtkOpenGLHAVSVolumeMapper::SetupFBOZBuffer(int screenWidth,
int screenHeight,
float depthNear,
float depthFar,
float *zbuffer)
{
// Setup view for z-buffer copy
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();
glOrtho(0.0, static_cast<GLdouble>(screenWidth), 0.0,
static_cast<GLdouble>(screenHeight),
static_cast<GLdouble>(depthNear), static_cast<GLdouble>(depthFar));
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
// Enable FBO z-buffer
glEnable(GL_DEPTH_TEST);
glClearDepth(depthFar);
glClear(GL_DEPTH_BUFFER_BIT);
glDepthFunc(GL_LESS);
glDrawBuffer(vtkgl::DEPTH_ATTACHMENT_EXT);
glRasterPos2i(0,0);
glPixelStorei(GL_PACK_ALIGNMENT, 1);
glDrawPixels(screenWidth, screenHeight, GL_DEPTH_COMPONENT, GL_FLOAT,
zbuffer);
glFlush();
// Make z-buffer Read only
glDepthMask(GL_FALSE);
// Reset view state after z-buffer copy
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glMatrixMode(GL_MODELVIEW);
glPopMatrix();
}
//----------------------------------------------------------------------------
// Setup reading and writing into multiple textures from an FBO
void vtkOpenGLHAVSVolumeMapper::SetupFBOMRT()
{
int numBuffers = (this->KBufferSize == VTK_KBUFFER_SIZE_2)? 2 : 4;
GLenum buffers[4] = {vtkgl::COLOR_ATTACHMENT0_EXT,
vtkgl::COLOR_ATTACHMENT1_EXT,
vtkgl::COLOR_ATTACHMENT2_EXT,
vtkgl::COLOR_ATTACHMENT3_EXT};
vtkgl::DrawBuffers(numBuffers, buffers);
this->CheckOpenGLError("setup MRTs");
// Bind textures for reading
glEnable(GL_TEXTURE_2D);
vtkgl::ActiveTexture(vtkgl::TEXTURE0);
glBindTexture(GL_TEXTURE_2D, this->FramebufferTextures[0]);
vtkgl::ActiveTexture(vtkgl::TEXTURE1);
glBindTexture(GL_TEXTURE_2D, this->FramebufferTextures[1]);
if (numBuffers == 2)
{
// Bind lookup tables
glEnable(GL_TEXTURE_2D);
vtkgl::ActiveTexture(vtkgl::TEXTURE2);
glBindTexture(GL_TEXTURE_2D, this->PsiTableTexture);
glEnable(GL_TEXTURE_1D);
vtkgl::ActiveTexture(vtkgl::TEXTURE3);
glBindTexture(GL_TEXTURE_1D,this->TransferFunctionTexture);
}
else
{
// Bind lookup tables
vtkgl::ActiveTexture(vtkgl::TEXTURE2);
glBindTexture(GL_TEXTURE_2D, this->FramebufferTextures[2]);
vtkgl::ActiveTexture(vtkgl::TEXTURE3);
glBindTexture(GL_TEXTURE_2D, this->FramebufferTextures[3]);
glEnable(GL_TEXTURE_2D);
vtkgl::ActiveTexture(vtkgl::TEXTURE4);
glBindTexture(GL_TEXTURE_2D, this->PsiTableTexture);
glEnable(GL_TEXTURE_1D);
vtkgl::ActiveTexture(vtkgl::TEXTURE5);
glBindTexture(GL_TEXTURE_1D,this->TransferFunctionTexture);
}
this->CheckOpenGLError("setup FBO reading");
}
//----------------------------------------------------------------------------
// Draw a screen-aligned plane with the init fragment shader enabled. The
// init fragment shader clears the framebuffer to 0 and the k-buffers to -1.
void vtkOpenGLHAVSVolumeMapper::DrawFBOInit(int screenWidth, int screenHeight,
float depthNear, float depthFar)
{
// Bind initializing fragment shader
glEnable(vtkgl::FRAGMENT_PROGRAM_ARB);
vtkgl::BindProgramARB(vtkgl::FRAGMENT_PROGRAM_ARB,
this->FragmentProgramBegin);
// Setup ortho view
glViewport(0,0,screenWidth,screenHeight);
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();
glOrtho(0.0, static_cast<GLdouble>(screenWidth), 0.0,
static_cast<GLdouble>(screenHeight),
static_cast<GLdouble>(depthNear), static_cast<GLdouble>(depthFar));
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
// Draw a quad to initialize the k-buffer
glBegin(GL_QUADS);
glVertex3f(0.0, 0.0, 0.0);
glVertex3f(static_cast<float>(screenWidth), 0.0, 0.0);
glVertex3f(static_cast<float>(screenWidth),
static_cast<float>(screenHeight), 0.0);
glVertex3f(0.0, static_cast<float>(screenHeight), 0.0);
glEnd();
vtkgl::BindProgramARB(vtkgl::FRAGMENT_PROGRAM_ARB, 0);
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glMatrixMode(GL_MODELVIEW);
glPopMatrix();
}
//----------------------------------------------------------------------------
// Draw the geometry using the k-buffer to sort and composite into the
// framebuffer.
void vtkOpenGLHAVSVolumeMapper::DrawFBOGeometry()
{
// Bind shaders
glEnable(vtkgl::VERTEX_PROGRAM_ARB);
vtkgl::BindProgramARB(vtkgl::VERTEX_PROGRAM_ARB, this->VertexProgram);
vtkgl::BindProgramARB(vtkgl::FRAGMENT_PROGRAM_ARB, this->FragmentProgram);
float scale = this->MaxEdgeLength;
if (this->LevelOfDetail || !this->PartiallyRemoveNonConvexities)
{
scale = this->LevelOfDetailMaxEdgeLength;
}
float params[4] = {1.0/this->FramebufferObjectSize,
1.0/this->FramebufferObjectSize,
scale, 0.0};
vtkgl::ProgramLocalParameter4fvARB(vtkgl::FRAGMENT_PROGRAM_ARB, 0, params);
// Draw geometry
if (this->GPUDataStructures)
{
glDrawElements(GL_TRIANGLES, this->LevelOfDetailTriangleCount*3,
GL_UNSIGNED_INT, static_cast<char *>(NULL));
}
else
{
glDrawElements(GL_TRIANGLES, this->LevelOfDetailTriangleCount*3,
GL_UNSIGNED_INT, this->OrderedTriangles);
}
vtkgl::BindProgramARB(vtkgl::FRAGMENT_PROGRAM_ARB, 0);
vtkgl::BindProgramARB(vtkgl::VERTEX_PROGRAM_ARB, 0);
glDisable( vtkgl::VERTEX_PROGRAM_ARB);
}
//----------------------------------------------------------------------------
// Draw a k-1 screen-aligned planes to flush the valid entries from the
// k-buffer.
void vtkOpenGLHAVSVolumeMapper::DrawFBOFlush(int screenWidth,
int screenHeight,
float depthNear, float depthFar)
{
float scale = this->MaxEdgeLength;
if (this->LevelOfDetail || !this->PartiallyRemoveNonConvexities)
{
scale = this->LevelOfDetailMaxEdgeLength;
}
float params[4] = {1.0/this->FramebufferObjectSize,
1.0/this->FramebufferObjectSize,
scale, 0.0};
// Bind fragment shader
vtkgl::BindProgramARB(vtkgl::FRAGMENT_PROGRAM_ARB, this->FragmentProgramEnd);
vtkgl::ProgramLocalParameter4fvARB(vtkgl::FRAGMENT_PROGRAM_ARB, 0, params);
// Setup ortho view
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();
glOrtho(0.0, static_cast<GLdouble>(screenWidth), 0.0,
static_cast<GLdouble>(screenHeight),
static_cast<GLdouble>(depthNear), static_cast<GLdouble>(depthFar));
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
// Draw k-1 quads to flush k-buffer
int flushCount = (this->KBufferSize == VTK_KBUFFER_SIZE_2)? 1 : 5;
for (int i = 0; i < flushCount; i++)
{
glBegin(GL_QUADS);
glVertex3f(0.0, 0.0, 0.0);
glVertex3f(0.0, static_cast<float>(screenHeight), 0.0);
glVertex3f(static_cast<float>(screenWidth),
static_cast<float>(screenHeight), 0.0);
glVertex3f(static_cast<float>(screenWidth), 0.0, 0.0);
glEnd();
}
// Disable shader
vtkgl::BindProgramARB(vtkgl::FRAGMENT_PROGRAM_ARB, 0);
glDisable( vtkgl::FRAGMENT_PROGRAM_ARB );
// Reset view
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glMatrixMode(GL_MODELVIEW);
glPopMatrix();
// Disable Textures
if (this->KBufferSize == VTK_KBUFFER_SIZE_2)
{
vtkgl::ActiveTexture(vtkgl::TEXTURE2);
glDisable(GL_TEXTURE_2D);
vtkgl::ActiveTexture(vtkgl::TEXTURE3);
glDisable(GL_TEXTURE_1D);
}
else
{
vtkgl::ActiveTexture(vtkgl::TEXTURE4);
glDisable(GL_TEXTURE_2D);
vtkgl::ActiveTexture(vtkgl::TEXTURE5);
glDisable(GL_TEXTURE_1D);
}