pretty-automata/src/shader-helper.cpp

#include "shader-helper.h"
#include <cstdlib>
#include <iostream>
#include <span>

GLuint loadShader(std::string_view name, std::span<const std::byte> source, GLenum shader_type) {
  GLuint shaderId = glCreateShader(shader_type);
  GLint result = GL_FALSE;
  int infoLogLength;

  auto data = reinterpret_cast<const char*>(source.data());
  auto size = static_cast<GLint>(source.size());

  glShaderSource(shaderId, 1, &data, &size);
  glCompileShader(shaderId);
  glGetShaderiv(shaderId, GL_COMPILE_STATUS, &result);
  glGetShaderiv(shaderId, GL_INFO_LOG_LENGTH, &infoLogLength);
  if (infoLogLength > 0) {
    std::cout << "errors in shader " << name << std::endl;
    std::vector<char> VertexShaderErrorMessage(infoLogLength + 1);
    glGetShaderInfoLog(shaderId, infoLogLength, nullptr,
                       &VertexShaderErrorMessage[0]);
    std::cout <<  &VertexShaderErrorMessage[0] << std::endl;
    std::cout << "=====" << std::endl;
      std::cout << std::string_view(data, size) << std::endl;
    exit(-1);
  }
  return shaderId;
}

GLuint loadProgram(std::string_view name, const std::vector<GLuint> &shaders) {
  GLuint programId = glCreateProgram();
  for (const auto &item : shaders) {
    glAttachShader(programId, item);
  }
  glLinkProgram(programId);

  GLint result = GL_FALSE;
  int infoLogLength;

  glGetProgramiv(programId, GL_LINK_STATUS, &result);
  glGetProgramiv(programId, GL_INFO_LOG_LENGTH, &infoLogLength);
  if (infoLogLength > 0) {
    std::cout << "errors in program " << name << std::endl;
    std::vector<char> ProgramErrorMessage(infoLogLength + 1);
    glGetProgramInfoLog(programId, infoLogLength, nullptr,
                        &ProgramErrorMessage[0]);
    std::cout << &ProgramErrorMessage[0] << std::endl;
  }
  return programId;
}