Shader.cpp

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/*
   Copyright 2022 Rishi Challa
 
   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at
 
       http://www.apache.org/licenses/LICENSE-2.0
 
   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/
 
#ifdef KALE_OPENGL
 
#include "Shader.hpp"
 
#include <fstream>
#include <sstream>
#include <string>
#include <stdexcept>
#include <memory>
 
#include <glad/glad.h>
 
using namespace Kale;
using namespace Kale::OpenGL;
 
unsigned int Shader::createShader(unsigned int type, const char* filePath) {
    using namespace std::string_literals;
 
    unsigned int shader = glCreateShader(type);
 
    // Read in the file source
    std::string src;
    {
        std::ifstream file(filePath);
        std::ostringstream stream;
        stream << file.rdbuf();
        src = stream.str();
    }
 
    // Pass the file source to opengl
    const char* cStrSrc = src.c_str();
    int strLen = static_cast<int>(src.size());
    glShaderSource(shader, 1, &cStrSrc, &strLen);
 
    // compile the shader and deal with errors
    glCompileShader(shader);
    int successful;
    glGetShaderiv(shader, GL_COMPILE_STATUS, &successful);
 
    // deal with errors
    if (!successful) {
        int logLen = 0;
        glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &logLen);
        std::unique_ptr<char*> infoLog = std::make_unique<char*>(new char[logLen]);
        glGetShaderInfoLog(shader, logLen, nullptr, *infoLog.get());
        std::string strInfoLog(*infoLog.get(), logLen);
        glDeleteShader(shader);
        throw std::runtime_error("Unable to compile shader ("s + filePath + ") - \n" + strInfoLog);
    }
 
    return shader;
}
 
Shader::Shader(const char* vertShaderFile, const char* fragShaderFile) {
 
    // Create the shaders
    unsigned int vertexShader = createShader(GL_VERTEX_SHADER, vertShaderFile);
    unsigned int fragmentShader = createShader(GL_FRAGMENT_SHADER, fragShaderFile);
 
    // Create the program and link it with the shaders
    program = glCreateProgram();
    glAttachShader(program, vertexShader);
    glAttachShader(program, fragmentShader);
    glLinkProgram(program);
 
    // Check if linking was successful
    int success;
    glGetProgramiv(program, GL_LINK_STATUS, &success);
 
    // Deal with errors
    if (!success) {
        int logLen;
        glGetProgramiv(program, GL_INFO_LOG_LENGTH, &logLen);
        std::unique_ptr<char*> infoLog = std::make_unique<char*>(new char[logLen]);
        glGetProgramInfoLog(program, logLen, nullptr, *infoLog.get());
        std::string strInfoLog(*infoLog.get(), logLen);
 
        glDeleteProgram(program);
        glDeleteShader(vertexShader);
        glDeleteShader(fragmentShader);
        throw std::runtime_error("Unable to link shaders to program - " + strInfoLog);
    }
 
    glDeleteShader(vertexShader);
    glDeleteShader(fragmentShader);
    glUseProgram(program);
}
 
Shader::~Shader() {
    glDeleteProgram(program);
}
 
void Shader::useProgram() const {
    glUseProgram(program);
}
 
int Shader::getAttributeLocation(const char* name) const {
    return glGetAttribLocation(program, name);
}
 
int Shader::getUniformLocation(const char* name) const {
    return glGetUniformLocation(program, name);
}
 
void Shader::uniform(unsigned int location, const Vector2f& value) const {
    useProgram();
    glUniform2f(location, value.x, value.y);
}
 
void Shader::uniform(unsigned int location, const Vector3f& value) const {
    useProgram();
    glUniform3f(location, value.x, value.y, value.z);
}
 
void Shader::uniform(unsigned int location, const Vector4f& value) const {
    useProgram();
    glUniform4f(location, value.x, value.y, value.z, value.w);
}
 
void Shader::uniform(unsigned int location, const Matrix2f& value) const {
    useProgram();
    glUniformMatrix2fv(location, 1, GL_FALSE, value.data.data());
}
 
void Shader::uniform(unsigned int location, const Matrix3f& value) const {
    useProgram();
    glUniformMatrix3fv(location, 1, GL_FALSE, value.data.data());
}
 
void Shader::uniform(unsigned int location, const Matrix4f& value) const {
    useProgram();
    glUniformMatrix4fv(location, 1, GL_FALSE, value.data.data());
}
 
void Shader::uniform(unsigned int location, const Transform& value) const {
    useProgram();
    glUniformMatrix3fv(location, 1, GL_FALSE, value.data.data());
}
 
void Shader::uniform(unsigned int location, float value) const {
    useProgram();
    glUniform1f(location, value);
}
 
void Shader::uniform(unsigned int location, int value) const {
    useProgram();
    glUniform1i(location, value);
}
 
void Shader::uniform(unsigned int location, const std::vector<Vector2f>& value) const {
    useProgram();
    glUniform2fv(location, static_cast<GLsizei>(value.size()), reinterpret_cast<const float*>(value.data()));
}
 
void Shader::uniform(unsigned int location, const std::vector<Vector3f>& value) const {
    useProgram();
    glUniform3fv(location, static_cast<GLsizei>(value.size()), reinterpret_cast<const float*>(value.data()));
}
 
void Shader::uniform(unsigned int location, const std::vector<Vector4f>& value) const {
    useProgram();
    glUniform4fv(location, static_cast<GLsizei>(value.size()), reinterpret_cast<const float*>(value.data()));
}
 
void Shader::uniform(unsigned int location, const std::vector<Matrix2f>& value) const {
    useProgram();
    glUniformMatrix2fv(location, static_cast<GLsizei>(value.size()), GL_FALSE, value[0].data.data());
}
 
void Shader::uniform(unsigned int location, const std::vector<Matrix3f>& value) const {
    useProgram();
    glUniformMatrix3fv(location, static_cast<GLsizei>(value.size()), GL_FALSE, value[0].data.data());
}
 
void Shader::uniform(unsigned int location, const std::vector<Matrix4f>& value) const {
    useProgram();
    glUniformMatrix4fv(location, static_cast<GLsizei>(value.size()), GL_FALSE, value[0].data.data());
}
 
void Shader::uniform(unsigned int location, const std::vector<Transform>& value) const {
    useProgram();
    glUniformMatrix3fv(location, static_cast<GLsizei>(value.size()), GL_FALSE, value[0].data.data());
}
 
void Shader::uniform(unsigned int location, const std::vector<float>& value) const {
    useProgram();
    glUniform1fv(location, static_cast<GLsizei>(value.size()), value.data());
}
 
void Shader::uniform(unsigned int location, const Vector2f* ptr, size_t size) const {
    useProgram();
    glUniform2fv(location, static_cast<GLsizei>(size), reinterpret_cast<const float*>(ptr));
}
 
void Shader::uniform(unsigned int location, const Vector3f* ptr, size_t size) const {
    useProgram();
    glUniform3fv(location, static_cast<GLsizei>(size), reinterpret_cast<const float*>(ptr));
}
 
void Shader::uniform(unsigned int location, const Vector4f* ptr, size_t size) const {
    useProgram();
    glUniform4fv(location, static_cast<GLsizei>(size), reinterpret_cast<const float*>(ptr));
}
 
void Shader::uniform(unsigned int location, const Matrix2f* ptr, size_t size) const {
    useProgram();
    glUniformMatrix2fv(location, static_cast<GLsizei>(size), GL_FALSE, ptr->data.data());
}
 
void Shader::uniform(unsigned int location, const Matrix3f* ptr, size_t size) const {
    useProgram();
    glUniformMatrix3fv(location, static_cast<GLsizei>(size), GL_FALSE, ptr->data.data());
}
 
void Shader::uniform(unsigned int location, const Matrix4f* ptr, size_t size) const {
    useProgram();
    glUniformMatrix4fv(location, static_cast<GLsizei>(size), GL_FALSE, ptr->data.data());
}
 
void Shader::uniform(unsigned int location, const Transform* ptr, size_t size) const {
    useProgram();
    glUniformMatrix3fv(location, static_cast<GLsizei>(size), GL_FALSE, ptr->data.data());
}
 
void Shader::uniform(unsigned int location, const float* ptr, size_t size) const {
    useProgram();
    glUniform1fv(location, static_cast<GLsizei>(size), ptr);
}
 
#endif