Framebuffer Struct Reference

#include <framebuffer.h>

Public Member Functions
GLuint	create (const int width, const int height)
	creation du framebuffer More...
void	release ()
	destruction. More...
int	width () const
	renvoie la largeur du framebuffer. More...
int	height () const
	renvoie la hauteur du framebuffer. More...
void	bind (const GLuint program, const bool store_color, const bool store_depth, const bool store_position, const bool store_texcoord, const bool store_normal, const bool store_material)
	selection du framebuffer, stocker les sorties du fragment shader. les textures sont initialisees avec les valeurs par defaut definies par clear_color(), clear_depth(), etc. More...
void	unbind (const int width, const int height)
	desactive le framebuffer, selection du framebuffer par defaut associe a la fenetre. More...
void	unbind_textures ()
	nettoyage, desactive les textures utilisees par les autres shaders, cf use_color_texture(), etc. More...
configuration des valeurs par defaut.
void	clear_color (const Color &value)
	couleur par defaut. More...
void	clear_depth (const float value)
	profondeur par defaut. More...
void	clear_position (const Point &value)
	position par defaut. More...
void	clear_texcoord (const vec2 &value)
	texcoord par defaut. More...
void	clear_normal (const Vector &value)
	normale par defaut. More...
void	clear_material (const unsigned value)
	indice de matiere par defaut. More...
utilisation des textures resultats par un shader.
meme utilisation que program_use_texture().
void	use_color_texture (const GLuint program, const char *uniform, const int unit, const GLuint sampler=0)
void	use_depth_texture (const GLuint program, const char *uniform, const int unit, const GLuint sampler=0)
void	use_position_texture (const GLuint program, const char *uniform, const int unit, const GLuint sampler=0)
void	use_texcoord_texture (const GLuint program, const char *uniform, const int unit, const GLuint sampler=0)
void	use_normal_texture (const GLuint program, const char *uniform, const int unit, const GLuint sampler=0)
void	use_material_texture (const GLuint program, const char *uniform, const int unit, const GLuint sampler=0)
visualisation des textures.
copie la texture dans le rectangle (X0, Y0) x (X1, Y1) du framebuffer actuellement selectionne sur GL_DRAW_FRAMEBUFFER, utilise glBlitFramebuffer().
void	blit_depth (const int dstX0, const int dstY0, const int dstX1, const int dstY1)
void	blit_color (const int dstX0, const int dstY0, const int dstX1, const int dstY1)
void	blit_position (const int dstX0, const int dstY0, const int dstX1, const int dstY1)
void	blit_texcoord (const int dstX0, const int dstY0, const int dstX1, const int dstY1)
void	blit_normal (const int dstX0, const int dstY0, const int dstX1, const int dstY1)

Protected Member Functions
bool	status ()

Protected Attributes
std::vector< GLenum >	m_draw_buffers
std::vector< GLuint >	m_color_textures
std::vector< std::array< unsigned, 4 > >	m_clear_colors
std::vector< int >	m_color_units
float	m_clear_depth
int	m_depth_unit
GLuint	m_depth_texture
GLuint	m_fbo
int	m_width
int	m_height

Detailed Description

stockage des sorties d'un fragment shader. exemple complet d'utilisation dans tuto_shadows.cpp

Framebuffer framebuffer;
GLuint program1;
GLuint program2;
 
init( ) : 
    program1= read_program( "..." );
    program2= read_program( "..." );
    
    framebuffer.create(1024, 1024);
    framebuffer.clear_color( White() );
    framebuffer.clear_depth( 1 );
    
render( ) :
    // etape 1 : dessiner des objets dans le framebuffer, avec un shader qui stocke une ou plusieurs valeurs par pixel
        glUseProgram( program1 );
        framebuffer.bind( program1, store_color, store_depth, store_position, store_texcoord, store_normal, store_material );
        
    // draw
        { ... }
    
    // etape 2 : retour au framebuffer de la fenetre
        framebuffer.unbind( window_width(), window_height() );
    
    // etape 3 : utiliser les valeurs stockees dans le framebuffer, comme des textures... avec un autre shader...
        glUseProgram( program2 );
        framebuffer.use_color_texture( program2, "sampler2D declare dans le shader", unit );
        
    // draw
        { ... }
        
    // etape 4 : nettoyage !!
        framebuffer.unbind_textures();

Definition at line 52 of file framebuffer.h.

Member Function Documentation

create()

GLuint Framebuffer::create	(	const int	width,
		const int	height
	)

creation du framebuffer

Definition at line 13 of file framebuffer.cpp.

{
    glGenFramebuffers(1, &m_fbo);
    
    // etat par defaut
    m_draw_buffers= std::vector<GLenum>(8, GL_NONE);
    m_color_textures= std::vector<GLuint>(8, 0);
    m_depth_texture= 0;
    
    m_clear_colors= std::vector< std::array<unsigned, 4> >(8);
    m_clear_depth= 1;
    
    m_color_units= std::vector<int>(8, -1);
    m_depth_unit= -1;
    
    m_width= width;
    m_height= height;
    return m_fbo;
}

release()

void Framebuffer::release

(

)

destruction.

Definition at line 33 of file framebuffer.cpp.

{
    glDeleteTextures(8, m_color_textures.data());
    glDeleteTextures(1, &m_depth_texture);
    glDeleteFramebuffers(1, &m_fbo);
}

width()

int Framebuffer::width

(

)

const

renvoie la largeur du framebuffer.

Definition at line 40 of file framebuffer.cpp.

{
    return m_width;
}

height()

int Framebuffer::height

(

)

const

renvoie la hauteur du framebuffer.

Definition at line 45 of file framebuffer.cpp.

{
    return m_height;
}

clear_color()

void Framebuffer::clear_color

(

const Color &

value

)

couleur par defaut.

Definition at line 315 of file framebuffer.cpp.

{
    if(m_fbo == 0)
        printf("[error] uninitialized framebuffer...\n");
    
    float values[4]= { value.r, value.g, value.b, value.a };
    memcpy(&m_clear_colors[0], values, sizeof(values));
}

clear_depth()

void Framebuffer::clear_depth

(

const float

value

)

profondeur par defaut.

Definition at line 307 of file framebuffer.cpp.

{
    if(m_fbo == 0)
        printf("[error] uninitialized framebuffer...\n");
    
    m_clear_depth= value;
}

clear_position()

void Framebuffer::clear_position

(

const Point &

value

)

position par defaut.

Definition at line 324 of file framebuffer.cpp.

{
    if(m_fbo == 0)
        printf("[error] uninitialized framebuffer...\n");
    
    float values[4]= { value.x, value.y, value.z, 0 };
    memcpy(&m_clear_colors[1], values, sizeof(values));
}

clear_texcoord()

void Framebuffer::clear_texcoord

(

const vec2 &

value

)

texcoord par defaut.

Definition at line 333 of file framebuffer.cpp.

{
    if(m_fbo == 0)
        printf("[error] uninitialized framebuffer...\n");
    
    float values[4]= { value.x, value.y, 0, 0 };
    memcpy(&m_clear_colors[2], values, sizeof(values));
}

clear_normal()

void Framebuffer::clear_normal

(

const Vector &

value

)

normale par defaut.

Definition at line 342 of file framebuffer.cpp.

{
    if(m_fbo == 0)
        printf("[error] uninitialized framebuffer...\n");
    
    float values[4]= { value.x, value.y, value.z, 0 };
    memcpy(&m_clear_colors[3], values, sizeof(values));
}

clear_material()

void Framebuffer::clear_material

(

const unsigned

value

)

indice de matiere par defaut.

Definition at line 351 of file framebuffer.cpp.

{
    if(m_fbo == 0)
        printf("[error] uninitialized framebuffer...\n");
    
    unsigned values[4]= { value, 0, 0, 0 };
    memcpy(&m_clear_colors[4], values, sizeof(values));
}

bind()

void Framebuffer::bind	(	const GLuint	program,
		const bool	store_color,
		const bool	store_depth,
		const bool	store_position,
		const bool	store_texcoord,
		const bool	store_normal,
		const bool	store_material
	)

selection du framebuffer, stocker les sorties du fragment shader. les textures sont initialisees avec les valeurs par defaut definies par clear_color(), clear_depth(), etc.

Definition at line 51 of file framebuffer.cpp.

{
    if(m_fbo == 0)
        create(m_width, m_height);
    
    // desactive les textures associees au framebuffer, si necessaire (ie l'application ne l'a pas fait... mais non ca n'arrive jamais)
    // todo ou generer une erreur ?
    unbind_textures();
    
    // selectionne le framebuffer
    assert(m_fbo > 0);
    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, m_fbo);
 
    // verifier que le fragment shader declare chaque sortie... 
    // openGL 4.3 / glGetProgramInterface() et glGetProgramResoucre()
    // uniquement en mode debug...
#ifndef GK_RELEASE
    if(program > 0)
    {
        // recuperer le nom du shader... si possible
        char label[2048]= { 0 };
        #ifdef GL_VERSION_4_3
        {
            char tmp[1024];
            glGetObjectLabel(GL_PROGRAM, program, sizeof(tmp), nullptr, tmp);
            sprintf(label, "program( %u '%s' )", program, tmp);
        }
        #else
            sprintf(label, "program( %u )", program); 
        #endif
        
    #if 0
        // verifie que le program est selectionne
        GLuint current;
        glGetIntegerv(GL_CURRENT_PROGRAM, (GLint *) &current);
        if(current != program)
            printf("[oops] %s: not active... undefined draw !!\n", label); 
    #endif
        
    #ifdef GL_VERSION_4_3
        // lister les sorties du fragment shader
        // fonctionnalite openGL 4.3, n'existe pas sur mac...
        GLint outputs= 0;
        glGetProgramInterfaceiv(program, GL_PROGRAM_OUTPUT, GL_ACTIVE_RESOURCES, &outputs);
        
        char name[1024];
        for(int i= 0; i < outputs; i++)
        {
            int location= -1;
            GLenum props[]= { GL_LOCATION };
            glGetProgramResourceiv(program, GL_PROGRAM_OUTPUT, i, 1, props, 1, nullptr, &location);
            glGetProgramResourceName(program, GL_PROGRAM_OUTPUT, i, sizeof(name), nullptr, name);
            
            if(location == 0)   // sortie color
            {
                if(!color)
                    printf("[oops] color output '%s' in %s not stored...\n", name, label);
            }
            else if(location == 1)  // sortie position
            {
                if(!position)
                    printf("[oops] position output '%s' in %s not stored...\n", name, label);
            }
            else if(location == 2)  // sortie texcoord
            {
                if(!texcoord)
                    printf("[oops] texcoord output '%s' in %s not stored...\n", name, label);
            }
            else if(location == 3)  // sortie normal
            {
                if(!normal)
                    printf("[oops] normal output '%s' in %s not stored...\n", name, label);
            }
            else if(location == 4)  // sortie material_id
            {
                if(!material_id)
                    printf("[oops] material output '%s' in %s not stored...\n", name, label);
            }
        }
    #endif
    }
#endif
    
    // configuration du framebuffer, et creation des textures, si necessaire
    if(depth)
    {
        if(m_depth_texture == 0)
            m_depth_texture= make_depth_texture(0, m_width, m_height);
        
        assert(m_depth_texture > 0);
        glFramebufferTexture(GL_DRAW_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, m_depth_texture, /* mipmap */ 0);
    }
    else
    {
        glFramebufferTexture(GL_DRAW_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, 0, /* mipmap */ 0);
    }
    
    //
    bool draw_buffers= false;
    if(color)
    {
        if(m_color_textures[0] == 0)
            m_color_textures[0]= make_vec4_texture(0, m_width, m_height);
        
        assert(m_color_textures[0] > 0);
        if(m_draw_buffers[0] == GL_NONE)
        {
            glFramebufferTexture(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, m_color_textures[0], /* mipmap */ 0);
            m_draw_buffers[0]= GL_COLOR_ATTACHMENT0;
            draw_buffers= true;
        }
    }
    else
    {
        glFramebufferTexture(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, 0, /* mipmap */ 0);
        m_draw_buffers[0]= GL_NONE;
        draw_buffers= true;
    }
    
    if(position)
    {
        if(m_color_textures[1] == 0)
            m_color_textures[1]= make_vec3_texture(0, m_width, m_height);
        
        assert(m_color_textures[1] > 0);
        if(m_draw_buffers[1] == GL_NONE)
        {
            glFramebufferTexture(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, m_color_textures[1], /* mipmap */ 0);
            m_draw_buffers[1]= GL_COLOR_ATTACHMENT1;
            draw_buffers= true;
        }
    }
    else
    {
        glFramebufferTexture(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, 0, /* mipmap */ 0);
        m_draw_buffers[1]= GL_NONE;
        draw_buffers= true;
    }
    
    if(texcoord)
    {
        if(m_color_textures[2] == 0)
            m_color_textures[2]= make_vec2_texture(0, m_width, m_height);
        
        assert(m_color_textures[2] > 0);
        if(m_draw_buffers[2] == GL_NONE)
        {
            glFramebufferTexture(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT2, m_color_textures[2], /* mipmap */ 0);        
            m_draw_buffers[2]= GL_COLOR_ATTACHMENT2;
            draw_buffers= true;
        }
    }
    else
    {
        glFramebufferTexture(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT2, 0, /* mipmap */ 0);
        m_draw_buffers[2]= GL_NONE;
        draw_buffers= true;
    }
    
    if(normal)
    {
        if(m_color_textures[3] == 0)
            m_color_textures[3]= make_vec3_texture(0, m_width, m_height);
        
        assert(m_color_textures[3] > 0);
        if(m_draw_buffers[3] == GL_NONE)
        {
            glFramebufferTexture(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT3, m_color_textures[3], /* mipmap */ 0);
            m_draw_buffers[3]= GL_COLOR_ATTACHMENT3;
            draw_buffers= true;
        }
    }
    else
    {
        glFramebufferTexture(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT3, 0, /* mipmap */ 0);
        m_draw_buffers[3]= GL_NONE;
        draw_buffers= true;
    }
    
    if(material_id)
    {
        if(m_color_textures[4] == 0)
            m_color_textures[4]= make_uint_texture(0, m_width, m_height);
        
        assert(m_color_textures[4] > 0);
        if(m_draw_buffers[4] == GL_NONE)
        {
            glFramebufferTexture(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT4, m_color_textures[4], /* mipmap */ 0);
            m_draw_buffers[4]= GL_COLOR_ATTACHMENT4;
            draw_buffers= true;
        }
    }
    else
    {
        glFramebufferTexture(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT4, 0, /* mipmap */ 0);
        m_draw_buffers[4]= GL_NONE;
        draw_buffers= true;
    }
    
    if(draw_buffers)
        glDrawBuffers(8, m_draw_buffers.data());
    
    // verifie la configuration du framebuffer
    if(!status())
        return;
    
    // prepare le rendu dans le framebuffer
    glViewport(0, 0, m_width, m_height);
    
    // pas joli, mais plus simple que declarer n variables du bon type...
    if(depth)
        glClearBufferfv(GL_DEPTH, 0, &m_clear_depth);
    if(color)
        glClearBufferfv(GL_COLOR, 0, (const GLfloat *) &m_clear_colors[0]);
    if(position)
        glClearBufferfv(GL_COLOR, 1, (const GLfloat *) &m_clear_colors[1]);
    if(texcoord)
        glClearBufferfv(GL_COLOR, 2, (const GLfloat *) &m_clear_colors[2]);
    if(normal)
        glClearBufferfv(GL_COLOR, 3, (const GLfloat *) &m_clear_colors[3]);
    if(material_id)
        glClearBufferuiv(GL_COLOR, 4, (const GLuint *) &m_clear_colors[4]);
}

unbind()

void Framebuffer::unbind	(	const int	width,
		const int	height
	)

desactive le framebuffer, selection du framebuffer par defaut associe a la fenetre.

Definition at line 276 of file framebuffer.cpp.

{
    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
    glViewport(0, 0, width, height);
}

unbind_textures()

void Framebuffer::unbind_textures

(

)

nettoyage, desactive les textures utilisees par les autres shaders, cf use_color_texture(), etc.

Definition at line 283 of file framebuffer.cpp.

{
    // desactive les textures associees au framebuffer, si necessaire
    // le pipeline ne peut pas lire et modifier les textures en meme temps.
    for(int i= 0; i < 8; i++)
        if(m_color_units[i] != -1)
        {
            glActiveTexture(GL_TEXTURE0 + m_color_units[i]);
            glBindTexture(GL_TEXTURE_2D, 0);
            
            m_color_units[i]= -1;
        }
    
    if(m_depth_unit != -1)
    {
        glActiveTexture(GL_TEXTURE0 + m_depth_unit);
        glBindTexture(GL_TEXTURE_2D, 0);
        
        m_depth_unit= -1;
    }
}

---

The documentation for this struct was generated from the following files:

• src/gKit/framebuffer.h
• src/gKit/framebuffer.cpp