#include <stdio.h>
#include <stdlib.h>

#include "shader.h"

GLuint compile_shader(GLenum type, const char *src) {
    GLuint shader = glCreateShader(type);
    glShaderSource(shader, 1, &src, NULL);
    glCompileShader(shader);

    GLint ok;
    glGetShaderiv(shader, GL_COMPILE_STATUS, &ok);
    if (!ok) {
        char log[512];
        glGetShaderInfoLog(shader, sizeof(log), NULL, log);
        fprintf(stderr, "shader compile error: %s\n", log);
        exit(1);
    }

    return shader;
}

GLuint create_program(const char *vs_src, const char *fs_src) {
    GLuint vs = compile_shader(GL_VERTEX_SHADER, vs_src);
    GLuint fs = compile_shader(GL_FRAGMENT_SHADER, fs_src);

    GLuint prog = glCreateProgram();
    glAttachShader(prog, vs);
    glAttachShader(prog, fs);
    glLinkProgram(prog);

    GLint ok;
    glGetProgramiv(prog, GL_LINK_STATUS, &ok);
    if (!ok) {
        char log[512];
        glGetProgramInfoLog(prog, sizeof(log), NULL, log);
        fprintf(stderr, "program link error: %s\n", log);
        exit(1);
    }

    glDeleteShader(vs);
    glDeleteShader(fs);

    return prog;
}