304 lines
9.4 KiB
C++
304 lines
9.4 KiB
C++
/*
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* This program source code file is part of KiCad, a free EDA CAD application.
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*
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* Copyright (C) 2013-2016 CERN
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* @author Maciej Suminski <maciej.suminski@cern.ch>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, you may find one here:
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* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
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* or you may search the http://www.gnu.org website for the version 2 license,
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* or you may write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
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*/
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/**
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* @file opengl_compositor.cpp
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* @brief Class that handles multitarget rendering (i.e. to different textures/surfaces) and
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* later compositing into a single image (OpenGL flavour).
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*/
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#include <gal/opengl/opengl_compositor.h>
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#include <gal/opengl/utils.h>
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#include <stdexcept>
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#include <cassert>
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using namespace KIGFX;
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OPENGL_COMPOSITOR::OPENGL_COMPOSITOR() :
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m_initialized( false ), m_curBuffer( 0 ),
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m_mainFbo( 0 ), m_depthBuffer( 0 ), m_curFbo( DIRECT_RENDERING )
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{
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}
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OPENGL_COMPOSITOR::~OPENGL_COMPOSITOR()
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{
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if( m_initialized )
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clean();
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}
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void OPENGL_COMPOSITOR::Initialize()
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{
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if( m_initialized )
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return;
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// We need framebuffer objects for drawing the screen contents
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// Generate framebuffer and a depth buffer
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glGenFramebuffersEXT( 1, &m_mainFbo );
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checkGlError( "generating framebuffer" );
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bindFb( m_mainFbo );
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// Allocate memory for the depth buffer
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// Attach the depth buffer to the framebuffer
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glGenRenderbuffersEXT( 1, &m_depthBuffer );
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checkGlError( "generating renderbuffer" );
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glBindRenderbufferEXT( GL_RENDERBUFFER_EXT, m_depthBuffer );
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checkGlError( "binding renderbuffer" );
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glRenderbufferStorageEXT( GL_RENDERBUFFER_EXT, GL_DEPTH24_STENCIL8, m_width, m_height );
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checkGlError( "creating renderbuffer storage" );
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glFramebufferRenderbufferEXT( GL_FRAMEBUFFER_EXT, GL_DEPTH_STENCIL_ATTACHMENT,
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GL_RENDERBUFFER_EXT, m_depthBuffer );
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checkGlError( "attaching renderbuffer" );
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// Unbind the framebuffer, so by default all the rendering goes directly to the display
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bindFb( DIRECT_RENDERING );
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m_initialized = true;
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}
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void OPENGL_COMPOSITOR::Resize( unsigned int aWidth, unsigned int aHeight )
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{
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if( m_initialized )
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clean();
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m_width = aWidth;
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m_height = aHeight;
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}
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unsigned int OPENGL_COMPOSITOR::CreateBuffer()
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{
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assert( m_initialized );
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int maxBuffers, maxTextureSize;
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// Get the maximum number of buffers
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glGetIntegerv( GL_MAX_COLOR_ATTACHMENTS, (GLint*) &maxBuffers );
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if( (int) usedBuffers() >= maxBuffers )
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{
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throw std::runtime_error( "Cannot create more framebuffers. OpenGL rendering "
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"backend requires at least 3 framebuffers. You may try to update/change "
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"your graphic drivers." );
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}
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glGetIntegerv( GL_MAX_TEXTURE_SIZE, (GLint*) &maxTextureSize );
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if( maxTextureSize < (int) m_width || maxTextureSize < (int) m_height )
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{
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throw std::runtime_error( "Requested texture size is not supported. "
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"Could not create a buffer." );
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}
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// GL_COLOR_ATTACHMENTn are consecutive integers
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GLuint attachmentPoint = GL_COLOR_ATTACHMENT0 + usedBuffers();
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GLuint textureTarget;
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// Generate the texture for the pixel storage
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glGenTextures( 1, &textureTarget );
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checkGlError( "generating framebuffer texture target" );
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glBindTexture( GL_TEXTURE_2D, textureTarget );
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checkGlError( "binding framebuffer texture target" );
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// Set texture parameters
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glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
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glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA8, m_width, m_height, 0, GL_RGBA,
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GL_UNSIGNED_BYTE, NULL );
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checkGlError( "creating framebuffer texture" );
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glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
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glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
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// Bind the texture to the specific attachment point, clear and rebind the screen
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bindFb( m_mainFbo );
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glFramebufferTexture2DEXT( GL_FRAMEBUFFER_EXT, attachmentPoint,
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GL_TEXTURE_2D, textureTarget, 0 );
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// Check the status, exit if the framebuffer can't be created
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GLenum status = glCheckFramebufferStatusEXT( GL_FRAMEBUFFER_EXT );
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if( status != GL_FRAMEBUFFER_COMPLETE_EXT )
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{
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switch( status )
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{
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case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT:
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throw std::runtime_error( "Cannot create the framebuffer." );
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break;
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case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT_EXT:
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throw std::runtime_error( "The framebuffer attachment points are incomplete." );
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break;
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case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT:
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throw std::runtime_error( "The framebuffer does not have at least one "
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"image attached to it." );
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break;
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case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT:
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throw std::runtime_error( "The framebuffer read buffer is incomplete." );
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break;
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case GL_FRAMEBUFFER_UNSUPPORTED_EXT:
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throw std::runtime_error( "The combination of internal formats of the attached "
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"images violates an implementation-dependent set of restrictions." );
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break;
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case GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE_EXT:
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throw std::runtime_error( "GL_RENDERBUFFER_SAMPLES is not the same for "
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"all attached renderbuffers" );
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break;
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case GL_FRAMEBUFFER_INCOMPLETE_LAYER_TARGETS_EXT:
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throw std::runtime_error( "Framebuffer incomplete layer targets errors." );
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break;
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default:
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throw std::runtime_error( "Cannot create the framebuffer." );
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break;
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}
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return 0;
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}
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ClearBuffer();
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// Return to direct rendering (we were asked only to create a buffer, not switch to one)
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bindFb( DIRECT_RENDERING );
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// Store the new buffer
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OPENGL_BUFFER buffer = { textureTarget, attachmentPoint };
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m_buffers.push_back( buffer );
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return usedBuffers();
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}
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void OPENGL_COMPOSITOR::SetBuffer( unsigned int aBufferHandle )
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{
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assert( m_initialized );
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assert( aBufferHandle <= usedBuffers() );
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// Either unbind the FBO for direct rendering, or bind the one with target textures
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bindFb( aBufferHandle == DIRECT_RENDERING ? DIRECT_RENDERING : m_mainFbo );
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// Switch the target texture
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if( m_curFbo != DIRECT_RENDERING )
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{
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m_curBuffer = aBufferHandle - 1;
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glDrawBuffer( m_buffers[m_curBuffer].attachmentPoint );
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checkGlError( "setting draw buffer" );
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}
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}
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void OPENGL_COMPOSITOR::ClearBuffer()
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{
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assert( m_initialized );
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glClearColor( 0.0f, 0.0f, 0.0f, 0.0f );
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glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT );
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}
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void OPENGL_COMPOSITOR::DrawBuffer( unsigned int aBufferHandle )
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{
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assert( m_initialized );
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assert( aBufferHandle != 0 && aBufferHandle <= usedBuffers() );
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// Switch to the main framebuffer and blit the scene
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bindFb( DIRECT_RENDERING );
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// Depth test has to be disabled to make transparency working
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glDisable( GL_DEPTH_TEST );
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glBlendFunc( GL_ONE, GL_ONE_MINUS_SRC_ALPHA );
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// Enable texturing and bind the main texture
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glEnable( GL_TEXTURE_2D );
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glBindTexture( GL_TEXTURE_2D, m_buffers[aBufferHandle - 1].textureTarget );
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// Draw a full screen quad with the texture
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glMatrixMode( GL_MODELVIEW );
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glPushMatrix();
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glLoadIdentity();
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glMatrixMode( GL_PROJECTION );
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glPushMatrix();
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glLoadIdentity();
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glBegin( GL_TRIANGLES );
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glTexCoord2f( 0.0f, 1.0f );
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glVertex2f( -1.0f, -1.0f );
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glTexCoord2f( 1.0f, 1.0f );
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glVertex2f( 1.0f, -1.0f );
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glTexCoord2f( 1.0f, 0.0f );
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glVertex2f( 1.0f, 1.0f );
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glTexCoord2f( 0.0f, 1.0f );
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glVertex2f( -1.0f, -1.0f );
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glTexCoord2f( 1.0f, 0.0f );
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glVertex2f( 1.0f, 1.0f );
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glTexCoord2f( 0.0f, 0.0f );
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glVertex2f( -1.0f, 1.0f );
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glEnd();
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glPopMatrix();
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glMatrixMode( GL_MODELVIEW );
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glPopMatrix();
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}
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void OPENGL_COMPOSITOR::bindFb( unsigned int aFb ) {
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// Currently there are only 2 valid FBOs
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assert( aFb == DIRECT_RENDERING || aFb == m_mainFbo );
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if( m_curFbo != aFb )
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{
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glBindFramebufferEXT( GL_FRAMEBUFFER, aFb );
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checkGlError( "switching framebuffer" );
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m_curFbo = aFb;
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}
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}
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void OPENGL_COMPOSITOR::clean()
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{
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assert( m_initialized );
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bindFb( DIRECT_RENDERING );
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for( OPENGL_BUFFERS::const_iterator it = m_buffers.begin(); it != m_buffers.end(); ++it )
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{
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glDeleteTextures( 1, &it->textureTarget );
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}
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m_buffers.clear();
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glDeleteFramebuffersEXT( 1, &m_mainFbo );
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glDeleteRenderbuffersEXT( 1, &m_depthBuffer );
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m_initialized = false;
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}
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