Files
Cinecraft/src/Shader.cpp
2026-04-13 00:51:32 +02:00

79 lines
2.2 KiB
C++

#include <fstream>
#include <iostream>
#include "Shader.hpp"
Shader::Shader(const char* vertexShaderFileName, const char* fragmentShaderFileName) {
shaderId = createShader(vertexShaderFileName, fragmentShaderFileName);
}
Shader::~Shader() {
glDeleteProgram(shaderId);
}
void Shader::bind() {
glUseProgram(shaderId);
}
void Shader::unbind() {
glUseProgram(0);
}
GLuint Shader::compile(std::string shaderSource, GLenum shaderType) {
GLuint id = glCreateShader(shaderType);
const char* src = shaderSource.c_str();
glShaderSource(id, 1, &src, nullptr);
glCompileShader(id);
int result;
glGetShaderiv(id, GL_COMPILE_STATUS, &result);
if (result == GL_FALSE) {
int length = 0;
glGetShaderiv(id, GL_INFO_LOG_LENGTH, &length);
char* message = new char[length];
glGetShaderInfoLog(id, length, &length, message);
std::cout << "Shader Compilation Error" << message << std::endl;
delete[] message;
return 0;
}
return id;
}
std::string Shader::parse(const char* filename) {
FILE* file;
file = fopen(filename, "rb");
if (file == nullptr) {
std::cout << "File " << filename << " not found" << std::endl;
}
std::string contents;
fseek(file, 0, SEEK_END);
size_t filesize = ftell(file);
rewind(file);
contents.resize(filesize);
fread(&contents[0], 1, filesize, file);
fclose(file);
return contents;
}
GLuint Shader::createShader(const char* vertexShaderFileName, const char* fragmentShaderFileName) {
std::string vertexShaderSource = parse(vertexShaderFileName);
std::string fragmentShaderSource = parse(fragmentShaderFileName);
GLuint program = glCreateProgram();
GLuint vert = compile(vertexShaderSource, GL_VERTEX_SHADER);
GLuint frag = compile(fragmentShaderSource, GL_FRAGMENT_SHADER);
glAttachShader(program, vert);
glAttachShader(program, frag);
glLinkProgram(program);
// ATTENTION: use only for release
// NOTE: if you do not detach and delete the program from the gpu, it's easier to debug if errors happen with the shaders
// glDetachShader(program, vert);
// glDetachShader(program, frag);
// glDeleteShader(vert);
// glDeleteShader(frag);
return program;
}