GLSLProgram.h

//
//  GLSLProgram.h
//  avara3d
//
//  Created by Morgan Davis on 12/23/16.
//  Copyright © 2026 Morgan K Davis. All rights reserved.
//
//  Based largely on code from "OpenGL 4 Shading Language Cookbook" by David Wolff
//
 
#ifndef AVARA3D_RENDER_BACKEND_OPENGL_GLSLPROGRAM_H
#define AVARA3D_RENDER_BACKEND_OPENGL_GLSLPROGRAM_H
 
#include <map>
#include <memory>
#include <optional>
#include <string>
#include <unordered_map>
 
#include "a3d/Math.h"
#include "a3d/render/backend/ShaderType.h"
#include "a3d/render/backend/opengl/GLTypes.h"
 
namespace a3d {
 
class GLSLProgram {
 
public:
    // [Internal Lifecycle Functions]
 
    explicit GLSLProgram(const std::string& name);
 
    GLSLProgram(const GLSLProgram&)            = delete;
    GLSLProgram& operator=(const GLSLProgram&) = delete;
 
    GLSLProgram(GLSLProgram&&)            = delete;
    GLSLProgram& operator=(GLSLProgram&&) = delete;
 
    ~GLSLProgram();
 
    // [Internal Member Functions]
 
    bool               compile();
    bool               link();
    bool               validate();
    void               use();
    void               unuse();
 
    void               bindAttributeLocation(unsigned location, const char* name);
 
    void               setUniform(const char* name, float x, float y, float z);
    void               setUniform(const char* name, const math::vec2& v);
    void               setUniform(const char* name, const math::vec3& v);
    void               setUniform(const char* name, const math::vec4& v);
    void               setUniform(const char* name, const math::mat3& m);
    void               setUniform(const char* name, const math::mat4& m);
    void               setUniform(const char* name, bool val);
    void               setUniform(const char* name, int val);
    void               setUniform(const char* name, unsigned val);
    void               setUniform(const char* name, float val);
 
    // void               bindUniformBlock(const char* name, unsigned location);
    void               setUniformBlockBinding(const char* blockName, unsigned bindingPoint);
 
    void               bindTexture(const char*     name,
                                   const int&      target,
                                   const unsigned& slot,
                                   const unsigned& textureID,
                                   unsigned        index);
 
    unsigned           getAttributeLocation(const char* name) const;
 
    const std::string& name() const;
    gl::uint_t         glID();
    bool               isLinked() const;
 
private:
    // [Private Member Functions]
 
    std::optional<std::string>           shaderSource(const std::string& name, ShaderType type);
    void                                 prepare();
    bool                                 compile(const std::string& source, ShaderType type);
    int                                  getUniformLocation(const char* name);
    void                                 glID(unsigned glID);
    void                                 isLinked(bool isLinked);
 
    // [Private Member Variables]
 
    std::string                          _name;
    unsigned                             _glID;
    bool                                 _isLinked;
    std::optional<std::string>           _logString;
    std::string                          _vertexShaderSource;
    std::string                          _fragmentShaderSource;
    std::unordered_map<std::string, int> _uniformLocationCache;
};
 
} // namespace a3d
 
#endif // AVARA3D_RENDER_BACKEND_OPENGL_GLSLPROGRAM_H