program.cpp

 
#include <fstream>
#include <sstream>
#include <string>
#include <vector>
#include <algorithm>
 
#include <climits>
 
#include "program.h"
 
 
// charge un fichier texte.
static
std::string read( const char *filename )
{
    std::stringbuf source;
    std::ifstream in(filename);
    if(in.good() == false)
        printf("[error] loading program '%s'...\n", filename);
    else
        printf("loading program '%s'...\n", filename);
 
    in.get(source, 0);        // lire tout le fichier, le caractere '\0' ne peut pas se trouver dans le source de shader
    return source.str();
}
 
// insere les definitions apres la ligne contenant #version
static
std::string prepare_source( std::string file, const std::string& definitions )
{
    if(file.empty())
        return std::string();
 
    // un peu de gymnastique, #version doit rester sur la premiere ligne, meme si on insere des #define dans le source
    std::string source;
 
    // recupere la ligne #version
    std::string version;
    size_t b= file.find("#version");
    if(b != std::string::npos)
    {
        size_t e = file.find( '\n', b );
        if(e != std::string::npos)
        {
            version= file.substr(0, e +1);
            file.erase(0, e +1);
 
            if(file.find("#version") != std::string::npos)
            {
                printf("[error] found several #version directives. failed.\n");
                return std::string();
            }
        }
    }
    else
    {
        printf("[error] no #version directive found. failed.\n");
        return std::string();
    }
 
    // reconstruit le source complet
    if(definitions.empty() == false)
    {
        source.append(version);                         // insere la version
        source.append(definitions).append("\n");        // insere les definitions
        source.append(file);                            // insere le source
    }
    else
    {
        source.append(version);                         // re-insere la version (supprimee de file)
        source.assign(file);                            // insere le source
    }
 
    return source;
}
 
 
static 
const char *shader_string( const GLenum type )
{
    switch (type)
    {
        case GL_VERTEX_SHADER: return "vertex shader";
        case GL_FRAGMENT_SHADER: return "fragment shader";
        case GL_GEOMETRY_SHADER: return "geometry shader";
    #ifdef GL_VERSION_4_0
        case GL_TESS_CONTROL_SHADER: return "control shader";
        case GL_TESS_EVALUATION_SHADER: return "evaluation shader";
    #endif
    #ifdef GL_VERSION_4_3
        case GL_COMPUTE_SHADER: return "compute shader";
    #endif
        default: return "shader";
    }
}
 
static 
const char *shader_keys[] = 
{
    "VERTEX_SHADER",
    "FRAGMENT_SHADER",
    "GEOMETRY_SHADER",
    "TESSELATION_CONTROL",
    "EVALUATION_CONTROL",
    "COMPUTE_SHADER"
};
const int shader_keys_max= 6;
 
static
GLenum shader_types[] =
{
    GL_VERTEX_SHADER,
    GL_FRAGMENT_SHADER,
    GL_GEOMETRY_SHADER,
#ifdef GL_VERSION_4_0
    GL_TESS_CONTROL_SHADER,
    GL_TESS_EVALUATION_SHADER,
#else
    0, 
    0,
#endif
#ifdef GL_VERSION_4_3
    GL_COMPUTE_SHADER
#else
    0
#endif
};
 
static
GLuint compile_shader( const GLuint program, const GLenum shader_type, const std::string& source )
{
    if(source.size() == 0 || shader_type == 0)
        return 0;
 
    GLuint shader= glCreateShader(shader_type);
    glAttachShader(program, shader);
 
    const char *sources= source.c_str();
    glShaderSource(shader, 1, &sources, NULL);
    glCompileShader(shader);
 
    GLint status;
    glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
    return (status == GL_TRUE) ? shader : 0;
}
 
 
int reload_program( const GLuint program, const char *filename, const char *definitions )
{
    if(program == 0)
        return -1;
 
    // supprime les shaders attaches au program
    int shaders_max= 0;
    glGetProgramiv(program, GL_ATTACHED_SHADERS, &shaders_max);
    if(shaders_max > 0)
    {
        std::vector<GLuint> shaders(shaders_max, 0);
        glGetAttachedShaders(program, shaders_max, NULL, &shaders.front());
        for (int i = 0; i < shaders_max; i++)
        {
            glDetachShader(program, shaders[i]);
            glDeleteShader(shaders[i]);
        }
    }
 
#ifdef GL_VERSION_4_3
    glObjectLabel(GL_PROGRAM, program, -1, filename);
#endif
 
    // prepare les sources
    std::string common_source= read(filename);
    for(int i = 0; i < shader_keys_max; i++)
    {
        if(common_source.find(shader_keys[i]) != std::string::npos)
        {
            // cree et compile les shaders detectes dans le source
            std::string source= prepare_source(common_source, std::string(definitions).append("#define ").append(shader_keys[i]).append("\n"));
            GLuint shader= compile_shader(program, shader_types[i], source);
            //~ printf("  %s...\n", shader_string(shader_types[i]));
            if(shader == 0)
                printf("[error] compiling %s...\n%s\n", shader_string(shader_types[i]), definitions);
        }
    }
    
    // linke les shaders
    glLinkProgram(program);
 
    // verifie les erreurs
    GLint status;
    glGetProgramiv(program, GL_LINK_STATUS, &status);
    if(status == GL_FALSE)
    {
        printf("[error] linking program %u '%s'...\n", program, filename);
        return -1;
    }
 
    // pour etre coherent avec les autres fonctions de creation, active l'objet gl qui vient d'etre cree.
    glUseProgram(program);
    return 0;
}
 
GLuint read_program( const char *filename, const char *definitions )
{
    GLuint program= glCreateProgram();
    reload_program(program, filename, definitions);
    return program;
}
 
int release_program( const GLuint program )
{
    if(program == 0)
        return -1;
 
    // recupere les shaders
    int shaders_max= 0;
    glGetProgramiv(program, GL_ATTACHED_SHADERS, &shaders_max);
 
    if(shaders_max > 0)
    {
        std::vector<GLuint> shaders(shaders_max, 0);
        glGetAttachedShaders(program, shaders_max, NULL, &shaders.front());
        for(int i= 0; i < shaders_max; i++)
        {
            glDetachShader(program, shaders[i]);
            glDeleteShader(shaders[i]);
        }
    }
 
    glDeleteProgram(program);
    return 0;
}
 
 
bool program_ready( const GLuint program )
{
    if(program == 0)
        return false;
    
    GLint status= GL_FALSE;
    glGetProgramiv(program, GL_LINK_STATUS, &status);
    
#ifndef GK_RELEASE
    #ifdef GL_VERSION_4_3
        char label[1024];
        glGetObjectLabel(GL_PROGRAM, program, sizeof(label), nullptr, label);
        
        if(status == GL_FALSE)  // n'affiche le messsage qu'en cas d'erreur...
            printf("program %u '%s' %s...\n", program, label, (status == GL_TRUE) ? "ready" : "not ready");
    #else
        printf("program %u %s...\n", program, (status == GL_TRUE) ? "ready" : "not ready");
    #endif
#endif
    
    return (status == GL_TRUE);
}
 
bool program_errors( const GLuint program )
{
    if(program == 0)
        return true;
    
    GLint status;
    glGetProgramiv(program, GL_LINK_STATUS, &status);
    
#ifndef GK_RELEASE
    #ifdef GL_VERSION_4_3
        char label[1024];
        glGetObjectLabel(GL_PROGRAM, program, sizeof(label), nullptr, label);
        
        if(status == GL_FALSE)  // n'affiche le messsage qu'en cas d'erreur...
            printf("program %u '%s' %s...\n", program, label, (status == GL_TRUE) ? "ready" : "not ready");
    #else
        printf("program %u %s...\n", program, (status == GL_TRUE) ? "ready" : "not ready");
    #endif
#endif
    
    return (status == GL_FALSE);
}
 
 
// formatage des erreurs de compilation des shaders
 
static
void print_line( std::string& errors, const char *source, const int begin_id, const int line_id )
{
    int line= 0;
    char last= '\n';
    for(unsigned int i= 0; source[i] != 0; i++)
    {
        if(line > line_id)
            break;
 
        if(last == '\n')
        {
            line++;
            if(line >= begin_id && line <= line_id)
            {
                errors.append("  ");
                errors.push_back('0' + (line / 1000) % 10);
                errors.push_back('0' + (line / 100) % 10);
                errors.push_back('0' + (line / 10) % 10);
                errors.push_back('0' + (line / 1) % 10);
                errors.append("  ");
            }
        }
 
        if(line >= begin_id && line <= line_id)
        {
            if(source[i] == '\t')
                errors.append("    ");
            else
                errors.push_back(source[i]);
        }
        last= source[i];
    }
}
 
static
int print_errors( std::string& errors, const char *log, const char *source )
{
    printf("[error log]\n%s\n", log);
 
    int first_error= INT_MAX;
    int last_string= -1;
    int last_line= -1;
    for(int i= 0; log[i] != 0; i++)
    {
        // recupere la ligne assiciee a l'erreur
        int string_id= 0, line_id= 0, position= 0;
        if(sscanf(&log[i], "%d ( %d ) : %n", &string_id, &line_id, &position) == 2        // nvidia syntax
        || sscanf(&log[i], "%d : %d (%*d) : %n", &string_id, &line_id, &position) == 2  // mesa syntax
        || sscanf(&log[i], "ERROR : %d : %d : %n", &string_id, &line_id, &position) == 2  // ati syntax
        || sscanf(&log[i], "WARNING : %d : %d : %n", &string_id, &line_id, &position) == 2)  // ati syntax
        {
            if(string_id != last_string || line_id != last_line)
            {
                // conserve la premiere erreur
                first_error= std::min(first_error, line_id);
 
                // extrait la ligne du source...
                errors.append("\n");
                print_line(errors, source, last_line +1, line_id);
                errors.append("\n");
            }
        }
        // et affiche l'erreur associee...
        for(i+= position; log[i] != 0; i++)
        {
            errors.push_back(log[i]);
            if(log[i] == '\n')
                break;
        }
 
        last_string= string_id;
        last_line= line_id;
    }
    errors.append("\n");
    print_line(errors, source, last_line +1, 1000);
    errors.append("\n");
 
    return first_error;
}
 
int program_format_errors( const GLuint program, std::string& errors )
{
    errors.clear();
 
    if(program == 0)
    {
        errors.append("[error] no program...\n");
        return -1;
    }
 
    GLint status;
    glGetProgramiv(program, GL_LINK_STATUS, &status);
    if(status == GL_TRUE)
        return 0;
 
    int first_error= INT_MAX;
    // recupere les shaders
    int shaders_max= 0;
    glGetProgramiv(program, GL_ATTACHED_SHADERS, &shaders_max);
    if(shaders_max == 0)
    {
        errors.append("[error] no shaders...\n");
        return 0;
    }
 
    std::vector<GLuint> shaders(shaders_max, 0);
    glGetAttachedShaders(program, shaders_max, NULL, &shaders.front());
    for(int i= 0; i < shaders_max; i++)
    {
        GLint value;
        glGetShaderiv(shaders[i], GL_COMPILE_STATUS, &value);
        if(value == GL_FALSE)
        {
            // recupere les erreurs de compilation des shaders
            glGetShaderiv(shaders[i], GL_INFO_LOG_LENGTH, &value);
            std::vector<char>log(value+1, 0);
            glGetShaderInfoLog(shaders[i], (GLsizei) log.size(), NULL, &log.front());
 
            // recupere le source
            glGetShaderiv(shaders[i], GL_SHADER_SOURCE_LENGTH, &value);
            std::vector<char> source(value+1, 0);
            glGetShaderSource(shaders[i], (GLsizei) source.size(), NULL, &source.front());
 
            glGetShaderiv(shaders[i], GL_SHADER_TYPE, &value);
            errors.append("[error] compiling ").append(shader_string(value)).append("...\n");
            
            // formatte les erreurs
            int last_error= print_errors(errors, &log.front(), &source.front());
            first_error= std::min(first_error, last_error);
        }
    }
 
    // recupere les erreurs de link du program
    {
        GLint value= 0;
        glGetProgramiv(program, GL_INFO_LOG_LENGTH, &value);
 
        std::vector<char>log(value+1, 0);
        glGetProgramInfoLog(program, (GLsizei) log.size(), NULL, &log.front());
 
        errors.append("[error] linking program...\n").append(log.begin(), log.end());
    }
 
    return first_error;
}
 
int program_print_errors( const GLuint program )
{
    std::string errors;
    int code= program_format_errors(program, errors);
    if(errors.size() > 0)
        printf("%s\n", errors.c_str());
    return code;
}