#include "pch.h"
#include "shader.hpp"

bool Shader::create(std::string vertex, std::string fragment)
{
    GLint status;
    static char infolog[4096];
    int infolen;
    const GLchar* source;
    
    auto vs = glCreateShader(GL_VERTEX_SHADER);
    if (!vs)
    {
        return false;
    }
    source = vertex.c_str();
    glShaderSource(vs, 1, &source, nullptr);
    glCompileShader(vs);
    glGetShaderiv(vs, GL_COMPILE_STATUS, &status);
    glGetShaderInfoLog(vs, sizeof(infolog), &infolen, infolog);
    if (infolen > 0)
        printf("VERTEX SHADER:\n%s", infolog);
    if (status == 0)
    {
        glDeleteShader(vs);
        return false;
    }
    
    auto fs = glCreateShader(GL_FRAGMENT_SHADER);
    if (!fs)
    {
        glDeleteShader(vs);
        return false;
    }
    source = fragment.c_str();
    glShaderSource(fs, 1, &source, nullptr);
    glCompileShader(fs);
    glGetShaderiv(fs, GL_COMPILE_STATUS, &status);
    glGetShaderInfoLog(fs, sizeof(infolog), &infolen, infolog);
    if (infolen > 0)
        printf("FRAGMENT SHADER:\n%s", infolog);
    if (status == 0)
    {
        glDeleteShader(vs);
        glDeleteShader(fs);
        return false;
    }
    
    auto ps = glCreateProgram();
    if (!ps)
    {
        glDeleteShader(vs);
        glDeleteShader(fs);
        return false;
    }
    glAttachShader(ps, vs);
    glAttachShader(ps, fs);
    glDeleteShader(vs);
    glDeleteShader(fs);
    
    glBindAttribLocation(ps, 0, "pos");
    glBindAttribLocation(ps, 1, "uvs");
    
    glLinkProgram(ps);
    glGetProgramiv(ps, GL_LINK_STATUS, &status);
    glGetProgramInfoLog(ps, sizeof(infolog), &infolen, infolog);
    if (infolen > 0)
        printf("LINK SHADER:\n%s", infolog);
    if (status == 0)
    {
        glDeleteProgram(ps);
        return false;
    }
    
    prog = ps;
    
    return true;
}
void Shader::use()
{
    glUseProgram(prog);
}
void Shader::u_vec4(const char* name, const glm::vec4& v)
{
    auto loc = glGetUniformLocation(prog, name);
    glUniform4fv(loc, 1, glm::value_ptr(v));
}
void Shader::u_mat4(const char* name, const glm::mat4& m)
{
    auto loc = glGetUniformLocation(prog, name);
    glUniformMatrix4fv(loc, 1, GL_FALSE, glm::value_ptr(m));
}
void Shader::u_int(const char* name, int i)
{
    auto loc = glGetUniformLocation(prog, name);
    glUniform1i(loc, i);
}