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Diffstat (limited to 'common/gal/opengl/opengl_compositor.cpp')
| -rw-r--r-- | common/gal/opengl/opengl_compositor.cpp | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/common/gal/opengl/opengl_compositor.cpp b/common/gal/opengl/opengl_compositor.cpp new file mode 100644 index 0000000..9f35d9e --- /dev/null +++ b/common/gal/opengl/opengl_compositor.cpp @@ -0,0 +1,291 @@ +/* + * This program source code file is part of KiCad, a free EDA CAD application. + * + * Copyright (C) 2013-2015 CERN + * @author Maciej Suminski <maciej.suminski@cern.ch> + * + * 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, you may find one here: + * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html + * or you may search the http://www.gnu.org website for the version 2 license, + * or you may write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA + */ + +/** + * @file opengl_compositor.cpp + * @brief Class that handles multitarget rendering (i.e. to different textures/surfaces) and + * later compositing into a single image (OpenGL flavour). + */ + +#include <gal/opengl/opengl_compositor.h> + +#include <stdexcept> +#include <cassert> + +using namespace KIGFX; + +OPENGL_COMPOSITOR::OPENGL_COMPOSITOR() : + m_initialized( false ), m_current( 0 ), m_currentFbo( DIRECT_RENDERING ) +{ + // Avoid not initialized members: + m_framebuffer = 0; + m_depthBuffer = 0; +} + + +OPENGL_COMPOSITOR::~OPENGL_COMPOSITOR() +{ + if( m_initialized ) + clean(); +} + + +void OPENGL_COMPOSITOR::Initialize() +{ + if( m_initialized ) + return; + + // We need framebuffer objects for drawing the screen contents + // Generate framebuffer and a depth buffer + glGenFramebuffersEXT( 1, &m_framebuffer ); + glBindFramebufferEXT( GL_FRAMEBUFFER, m_framebuffer ); + m_currentFbo = m_framebuffer; + + // Allocate memory for the depth buffer + // Attach the depth buffer to the framebuffer + glGenRenderbuffersEXT( 1, &m_depthBuffer ); + glBindRenderbufferEXT( GL_RENDERBUFFER_EXT, m_depthBuffer ); + + // Use here a size of 24 bits for the depth buffer, 8 bits for the stencil buffer + // this is required later for anti-aliasing + glRenderbufferStorageEXT( GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT16, m_width, m_height ); + glFramebufferRenderbufferEXT( GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT, + GL_RENDERBUFFER_EXT, m_depthBuffer ); + + // Unbind the framebuffer, so by default all the rendering goes directly to the display + glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, DIRECT_RENDERING ); + m_currentFbo = DIRECT_RENDERING; + + m_initialized = true; +} + + +void OPENGL_COMPOSITOR::Resize( unsigned int aWidth, unsigned int aHeight ) +{ + if( m_initialized ) + clean(); + + m_width = aWidth; + m_height = aHeight; +} + + +unsigned int OPENGL_COMPOSITOR::CreateBuffer() +{ + assert( m_initialized ); + + unsigned int maxBuffers; + + // Get the maximum number of buffers + glGetIntegerv( GL_MAX_COLOR_ATTACHMENTS, (GLint*) &maxBuffers ); + + if( usedBuffers() >= maxBuffers ) + { + throw std::runtime_error("Cannot create more framebuffers. OpenGL rendering " + "backend requires at least 3 framebuffers. You may try to update/change " + "your graphic drivers."); + } + + // GL_COLOR_ATTACHMENTn are consecutive integers + GLuint attachmentPoint = GL_COLOR_ATTACHMENT0 + usedBuffers(); + GLuint textureTarget; + + // Generate the texture for the pixel storage + glGenTextures( 1, &textureTarget ); + glBindTexture( GL_TEXTURE_2D, textureTarget ); + + // Set texture parameters + glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE ); + glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA8, m_width, m_height, 0, GL_RGBA, + GL_UNSIGNED_BYTE, NULL ); + glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST ); + glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST ); + + // Bind the texture to the specific attachment point, clear and rebind the screen + glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, m_framebuffer ); + m_currentFbo = m_framebuffer; + glFramebufferTexture2DEXT( GL_FRAMEBUFFER_EXT, attachmentPoint, + GL_TEXTURE_2D, textureTarget, 0 ); + + // Check the status, exit if the framebuffer can't be created + GLenum status = glCheckFramebufferStatusEXT( GL_FRAMEBUFFER_EXT ); + + if( status != GL_FRAMEBUFFER_COMPLETE_EXT ) + { + switch( status ) + { + case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT: + throw std::runtime_error( "Cannot create the framebuffer." ); + break; + + case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT_EXT: + throw std::runtime_error( "The framebuffer attachment points are incomplete." ); + break; + + case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT: + throw std::runtime_error( "The framebuffer does not have at least one " + "image attached to it." ); + break; + + case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT: + throw std::runtime_error( "The framebuffer read buffer is incomplete." ); + break; + + case GL_FRAMEBUFFER_UNSUPPORTED_EXT: + throw std::runtime_error( "The combination of internal formats of the attached " + "images violates an implementation-dependent set of restrictions." ); + break; + + case GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE_EXT: + throw std::runtime_error( "GL_RENDERBUFFER_SAMPLES is not the same for " + "all attached renderbuffers" ); + break; + + case GL_FRAMEBUFFER_INCOMPLETE_LAYER_TARGETS_EXT: + throw std::runtime_error( "Framebuffer incomplete layer targets errors." ); + break; + + default: + throw std::runtime_error( "Cannot create the framebuffer." ); + break; + } + + return 0; + } + + ClearBuffer(); + + // Return to direct rendering (we were asked only to create a buffer, not switch to one) + glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, DIRECT_RENDERING ); + m_currentFbo = DIRECT_RENDERING; + + // Store the new buffer + OPENGL_BUFFER buffer = { textureTarget, attachmentPoint }; + m_buffers.push_back( buffer ); + + return usedBuffers(); +} + + +void OPENGL_COMPOSITOR::SetBuffer( unsigned int aBufferHandle ) +{ + if( aBufferHandle > usedBuffers() ) + return; + + // Change the rendering destination to the selected attachment point + if( aBufferHandle == DIRECT_RENDERING ) + { + m_currentFbo = DIRECT_RENDERING; + } + else if( m_currentFbo != m_framebuffer ) + { + glBindFramebufferEXT( GL_FRAMEBUFFER_EXT, m_framebuffer ); + m_currentFbo = m_framebuffer; + } + + if( m_currentFbo != DIRECT_RENDERING ) + { + m_current = aBufferHandle - 1; + glDrawBuffer( m_buffers[m_current].attachmentPoint ); + } +} + + +void OPENGL_COMPOSITOR::ClearBuffer() +{ + assert( m_initialized ); + + glClearColor( 0.0f, 0.0f, 0.0f, 0.0f ); + glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); +} + + +void OPENGL_COMPOSITOR::DrawBuffer( unsigned int aBufferHandle ) +{ + assert( m_initialized ); + assert( aBufferHandle != 0 && aBufferHandle <= usedBuffers() ); + + // Switch to the main framebuffer and blit the scene + glBindFramebufferEXT( GL_FRAMEBUFFER, DIRECT_RENDERING ); + m_currentFbo = DIRECT_RENDERING; + + // Depth test has to be disabled to make transparency working + glDisable( GL_DEPTH_TEST ); + glBlendFunc( GL_ONE, GL_ONE_MINUS_SRC_ALPHA ); + + // Enable texturing and bind the main texture + glEnable( GL_TEXTURE_2D ); + glBindTexture( GL_TEXTURE_2D, m_buffers[aBufferHandle - 1].textureTarget ); + + // Draw a full screen quad with the texture + glMatrixMode( GL_MODELVIEW ); + glPushMatrix(); + glLoadIdentity(); + glMatrixMode( GL_PROJECTION ); + glPushMatrix(); + glLoadIdentity(); + + glBegin( GL_TRIANGLES ); + glTexCoord2f( 0.0f, 1.0f ); + glVertex2f( -1.0f, -1.0f ); + glTexCoord2f( 1.0f, 1.0f ); + glVertex2f( 1.0f, -1.0f ); + glTexCoord2f( 1.0f, 0.0f ); + glVertex2f( 1.0f, 1.0f ); + + glTexCoord2f( 0.0f, 1.0f ); + glVertex2f( -1.0f, -1.0f ); + glTexCoord2f( 1.0f, 0.0f ); + glVertex2f( 1.0f, 1.0f ); + glTexCoord2f( 0.0f, 0.0f ); + glVertex2f( -1.0f, 1.0f ); + glEnd(); + + glPopMatrix(); + glMatrixMode( GL_MODELVIEW ); + glPopMatrix(); +} + + +void OPENGL_COMPOSITOR::clean() +{ + assert( m_initialized ); + + glBindFramebufferEXT( GL_FRAMEBUFFER, DIRECT_RENDERING ); + m_currentFbo = DIRECT_RENDERING; + + OPENGL_BUFFERS::const_iterator it; + + for( it = m_buffers.begin(); it != m_buffers.end(); ++it ) + { + glDeleteTextures( 1, &it->textureTarget ); + } + + m_buffers.clear(); + + glDeleteFramebuffersEXT( 1, &m_framebuffer ); + glDeleteRenderbuffersEXT( 1, &m_depthBuffer ); + + m_initialized = false; +} |