StorageImage Class Reference

Inheritance diagram for StorageImage:

Public Member Functions
int	init ()
	a deriver pour creer les objets openGL. More...
int	quit ()
	a deriver pour detruire les objets openGL. More...
int	update (const float time, const float delta)
	a deriver et redefinir pour animer les objets en fonction du temps. More...
int	render ()
	a deriver pour afficher les objets. More...
Public Member Functions inherited from AppTime
	AppTime (const int width, const int height, const int major=3, const int minor=3, const int samples=0)
	constructeur, dimensions de la fenetre et version d'openGL. More...
Public Member Functions inherited from App
	App (const int width, const int height, const int major=3, const int minor=3, const int samples=0)
	constructeur, dimensions de la fenetre et version d'openGL. More...
int	run ()
	execution de l'application. More...

Protected Attributes
Mesh	m_mesh
Orbiter	m_camera
GLuint	m_program
GLuint	m_program_display
GLuint	m_texture
Protected Attributes inherited from AppTime
std::chrono::high_resolution_clock::time_point	m_cpu_start
std::chrono::high_resolution_clock::time_point	m_cpu_stop
GLuint	m_time_query [MAX_FRAMES]
GLint64	m_frame_time
int	m_frame
Text	m_console
Protected Attributes inherited from App
Window	m_window
Context	m_context
bool	sync

Additional Inherited Members
Protected Member Functions inherited from AppTime
virtual int	prerender ()
virtual int	postrender ()
Protected Member Functions inherited from App
void	vsync_off ()

Detailed Description

Definition at line 19 of file tuto_storage_texture.cpp.

Member Function Documentation

init()

int StorageImage::init ( )

inlinevirtual

a deriver pour creer les objets openGL.

Implements AppTime.

Definition at line 25 of file tuto_storage_texture.cpp.

    {
        m_mesh= read_mesh("data/bigguy.obj");
        
        Point pmin, pmax;
        m_mesh.bounds(pmin, pmax);
        m_camera.lookat(pmin, pmax);
        
        // cree la texture, 1 canal, entiers 32bits non signes
        glGenTextures(1, &m_texture);
        glBindTexture(GL_TEXTURE_2D, m_texture);
        glTexImage2D(GL_TEXTURE_2D, 0,
            GL_R32UI, window_width(), window_height(), 0,
            GL_RED_INTEGER, GL_UNSIGNED_INT, nullptr);  // GL_RED_INTEGER, sinon normalisation implicite...
        
        // pas la peine de construire les mipmaps / pas possible pour une texture int / uint
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 0);
        
        // 
        m_program= read_program("tutos/tuto_storage_texture.glsl");
        program_print_errors(m_program);
        
        m_program_display= read_program("tutos/storage_texture_display.glsl");
        program_print_errors(m_program_display);
        
        // etat openGL par defaut
        glClearColor(0.2f, 0.2f, 0.2f, 1.f);        // couleur par defaut de la fenetre
        
        glClearDepth(1.f);                          // profondeur par defaut
        glDepthFunc(GL_LESS);                       // ztest, conserver l'intersection la plus proche de la m_camera
        glEnable(GL_DEPTH_TEST);                    // activer le ztest
 
        return 0;   // ras, pas d'erreur
    }

quit()

int StorageImage::quit ( )

inlinevirtual

a deriver pour detruire les objets openGL.

Implements AppTime.

Definition at line 61 of file tuto_storage_texture.cpp.

    {
        m_mesh.release();
        release_program(m_program);
        glDeleteTextures(1, &m_texture);
        return 0;
    }

update()

int StorageImage::update ( const float  time, const float  delta  )

inlinevirtual

a deriver et redefinir pour animer les objets en fonction du temps.

Reimplemented from AppTime.

Definition at line 69 of file tuto_storage_texture.cpp.

    {
 
        return 0;
    }

render()

int StorageImage::render ( )

inlinevirtual

a deriver pour afficher les objets.

Implements AppTime.

Definition at line 76 of file tuto_storage_texture.cpp.

    {
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
        // effacer la texture image / compteur, le shader ajoute 1 a chaque fragment dessine...
        GLuint zero= 0;
        glClearTexImage(m_texture, 0, GL_RED_INTEGER, GL_UNSIGNED_INT, &zero);
        
        // recupere les mouvements de la souris
        int mx, my;
        unsigned int mb= SDL_GetRelativeMouseState(&mx, &my);
        int mousex, mousey;
        SDL_GetMouseState(&mousex, &mousey);
 
        // deplace la m_camera
        if(mb & SDL_BUTTON(1))
            m_camera.rotation(mx, my);      // tourne autour de l'objet
        else if(mb & SDL_BUTTON(3))
            m_camera.translation((float) mx / (float) window_width(), (float) my / (float) window_height()); // deplace le point de rotation
        else if(mb & SDL_BUTTON(2))
            m_camera.move(mx);           // approche / eloigne l'objet
 
        SDL_MouseWheelEvent wheel= wheel_event();
        if(wheel.y != 0)
        {
            clear_wheel_event();
            m_camera.move(8.f * wheel.y);  // approche / eloigne l'objet
        }
 
        if(key_state('r'))
        {
            clear_key_state('r');
            reload_program(m_program, "tutos/tuto_storage_texture.glsl");
            program_print_errors(m_program);
            
            reload_program(m_program_display, "tutos/storage_texture_display.glsl");
            program_print_errors(m_program_display);            
        }
        
        
        // passe 1 : compter le nombre de fragments par pixel
        glUseProgram(m_program);
        
        Transform model= RotationY(global_time() / 60);
        Transform view= m_camera.view();
        Transform projection= m_camera.projection(window_width(), window_height(), 45);
        Transform mv= view * model;
        Transform mvp= projection * mv;
        
        program_uniform(m_program, "mvpMatrix", mvp);
        
        // selectionne la texture sur l'unite image 0, operations atomiques / lecture + ecriture
        glBindImageTexture(0, m_texture, 0, GL_TRUE, 0, GL_READ_WRITE, GL_R32UI);
        program_uniform(m_program, "image", 0);
        
        // indiquer quels attributs de sommets du mesh sont necessaires a l'execution du shader.
        // le shader n'utilise que position. les autres de servent a rien.
        m_mesh.draw(m_program, /* use position */ true, /* use texcoord */ false, /* use normal */ false, /* use color */ false, /* material */ false );
        
        if(key_state(' ') == 0)
        {
            // passe 2 : afficher le compteur
            glUseProgram(m_program_display);
 
            // attendre que les resultats de la passe 1 soit disponible
            glMemoryBarrier(GL_SHADER_IMAGE_ACCESS_BARRIER_BIT);
            
            // RE-selectionne la texture sur l'unite image 0 / LECTURE SEULE
            glBindImageTexture(0, m_texture, 0, GL_TRUE, 0, GL_READ_ONLY, GL_R32UI);
            program_uniform(m_program_display, "image", 0);
            
            glDrawArrays(GL_TRIANGLES, 0, 3);
        }
        
        return 1;
    }

---

The documentation for this class was generated from the following file:

• tutos/tuto_storage_texture.cpp