Files
fall-fever/src/shader.cpp

147 lines
4.5 KiB
C++

#include "shader.h"
#include "util/Log.h"
#include <fmt/format.h>
#include <fstream>
#include <glm/gtc/type_ptr.hpp>
Shader::Shader(std::string_view name, std::filesystem::path const &directory)
: program(glCreateProgram())
{
std::filesystem::path vertex_shader_path = directory / name;
vertex_shader_path.concat(".vert");
std::filesystem::path frag_shader_path = directory / name;
frag_shader_path.concat(".frag");
std::string vertex_shader_source = parse(vertex_shader_path);
std::string fragment_shader_source = parse(frag_shader_path);
GLuint vertex_shader = compile(vertex_shader_source, GL_VERTEX_SHADER);
GLuint fragment_shader = compile(fragment_shader_source, GL_FRAGMENT_SHADER);
glAttachShader(program, vertex_shader);
glAttachShader(program, fragment_shader);
glLinkProgram(program);
GLint linked = 0;
glGetProgramiv(program, GL_LINK_STATUS, &linked);
if (linked == 0) {
Log::logger().warn(R"(Failed to link Shader "{}")", name);
}
#ifdef NDEBUG
glDetachShader(program, vertex_shader);
glDetachShader(program, fragment_shader);
glDeleteShader(vertex_shader);
glDeleteShader(fragment_shader);
#endif
Log::logger().trace(R"(Loaded Shader "{}")", name);
}
Shader::~Shader()
{
glDeleteProgram(program);
}
void Shader::bind() const
{
glUseProgram(program);
}
void Shader::unbind()
{
glUseProgram(0);
}
auto Shader::parse(const std::filesystem::path &path) -> std::string
{
std::fstream file;
file.open(path, std::ios::in);
if (!file.is_open()) {
Log::logger().critical(R"(Shader "{}" not found!)", path.string());
std::terminate();
}
return {(std::istreambuf_iterator<char>(file)), (std::istreambuf_iterator<char>())};
}
auto Shader::compile(std::string_view source, GLenum type) -> GLuint
{
GLuint program = glCreateShader(type);
auto const *src = source.data();
glShaderSource(program, 1, &src, nullptr);
glCompileShader(program);
int result{};
glGetShaderiv(program, GL_COMPILE_STATUS, &result);
if (result != GL_TRUE) {
int length{};
glGetShaderiv(program, GL_INFO_LOG_LENGTH, &length);
std::string message;
message.reserve(static_cast<unsigned>(length));
glGetShaderInfoLog(program, length, &length, message.data());
Log::logger().error("Shader compilation failed: {}", message);
return 0;
}
return program;
}
auto Shader::retrieveUniformLocation(std::string_view uniform_name) const -> GLint
{
if (uniform_location_cache.find(uniform_name.data()) != uniform_location_cache.end()) {
return uniform_location_cache[uniform_name.data()];
}
GLint location = glGetUniformLocation(program, uniform_name.data());
if (location != -1) {
uniform_location_cache[uniform_name.data()] = location;
} else {
Log::logger().warn(R"(Uniform "{}" not found.)", uniform_name);
}
return location;
}
template <typename T>
void Shader::set_uniform(std::string_view name, T value) const
{
GLint location = retrieveUniformLocation(name);
if constexpr (std::is_same_v<T, bool> || std::is_same_v<T, int>) {
glUniform1i(location, (int)value);
} else if constexpr (std::is_same_v<T, unsigned>) {
glUniform1ui(location, value);
} else if constexpr (std::is_same_v<T, float>) {
glUniform1f(location, value);
} else if constexpr (std::is_same_v<T, glm::vec2>) {
glUniform2f(location, value.x, value.y); //NOLINT(cppcoreguidelines-pro-type-union-access)
} else if constexpr (std::is_same_v<T, glm::vec3>) {
glUniform3f(location, value.x, value.y, value.z); //NOLINT(cppcoreguidelines-pro-type-union-access)
} else if constexpr (std::is_same_v<T, glm::mat3>) {
glUniformMatrix3fv(location, 1, GL_FALSE, glm::value_ptr(value));
} else if constexpr (std::is_same_v<T, glm::mat4>) {
glUniformMatrix4fv(location, 1, GL_FALSE, glm::value_ptr(value));
}
}
template void Shader::set_uniform(std::string_view, bool) const;
template void Shader::set_uniform(std::string_view, int) const;
template void Shader::set_uniform(std::string_view, unsigned) const;
template void Shader::set_uniform(std::string_view, float) const;
template void Shader::set_uniform(std::string_view, glm::vec2) const;
template void Shader::set_uniform(std::string_view, glm::vec3) const;
template void Shader::set_uniform(std::string_view, glm::mat3) const;
template void Shader::set_uniform(std::string_view, glm::mat4) const;