- /*
- * Copyright (C) 2023 Christopher J. Howard
- *
- * This file is part of Antkeeper source code.
- *
- * Antkeeper source code is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * Antkeeper source code is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with Antkeeper source code. If not, see <http://www.gnu.org/licenses/>.
- */
-
- #include <engine/gl/shader-program.hpp>
- #include <engine/gl/shader-object.hpp>
- #include <engine/gl/opengl/gl-shader-variables.hpp>
- #include <glad/gl.h>
- #include <stdexcept>
- #include <string_view>
-
- namespace gl {
-
- shader_program::shader_program()
- {
- // Create an OpenGL shader program
- gl_program_id = glCreateProgram();
-
- // Handle OpenGL errors
- if (!gl_program_id)
- {
- throw std::runtime_error("Unable to create OpenGL shader program");
- }
- }
-
- shader_program::~shader_program()
- {
- // Detach all shader objects
- detach_all();
-
- // Delete the OpenGL shader program
- glDeleteProgram(gl_program_id);
- }
-
- void shader_program::attach(const shader_object& object)
- {
- if (attached_objects.find(&object) != attached_objects.end())
- {
- throw std::runtime_error("OpenGL shader object already attached to the shader program");
- }
- else
- {
- // Check that both the OpenGL shader program and OpenGL shader object are valid
- if (glIsProgram(gl_program_id) != GL_TRUE)
- {
- throw std::runtime_error("Invalid OpenGL shader program");
- }
- if (glIsShader(object.gl_shader_id) != GL_TRUE)
- {
- throw std::runtime_error("Invalid OpenGL shader object");
- }
-
- // Attach the OpenGL shader object to the OpenGL shader program
- glAttachShader(gl_program_id, object.gl_shader_id);
-
- // Add shader object to set of attached objects
- attached_objects.insert(&object);
- }
- }
-
- void shader_program::detach(const shader_object& object)
- {
- if (attached_objects.find(&object) == attached_objects.end())
- {
- throw std::runtime_error("Shader object is not attached to the shader program.");
- }
- else
- {
- // Check that both the OpenGL shader program and OpenGL shader object are valid
- if (glIsProgram(gl_program_id) != GL_TRUE)
- {
- throw std::runtime_error("Invalid OpenGL shader program");
- }
- if (glIsShader(object.gl_shader_id) != GL_TRUE)
- {
- throw std::runtime_error("Invalid OpenGL shader object");
- }
-
- // Detach the OpenGL shader object from the OpenGL shader program
- glDetachShader(gl_program_id, object.gl_shader_id);
-
- // Remove shader object from set of attached objects
- attached_objects.erase(&object);
- }
- }
-
- void shader_program::detach_all()
- {
- while (!attached_objects.empty())
- {
- detach(**attached_objects.begin());
- }
- }
-
- bool shader_program::link()
- {
- m_linked = false;
- info_log.clear();
- variable_map.clear();
-
- // Check that the OpenGL shader program is valid
- if (glIsProgram(gl_program_id) != GL_TRUE)
- {
- throw std::runtime_error("Invalid OpenGL shader program");
- }
-
- // Link OpenGL shader program
- glLinkProgram(gl_program_id);
-
- // Get OpenGL shader program linking status
- GLint gl_link_status;
- glGetProgramiv(gl_program_id, GL_LINK_STATUS, &gl_link_status);
- m_linked = (gl_link_status == GL_TRUE);
-
- // Populate info log string
- if (m_linked)
- {
- // Load shader variables
- load_variables();
- }
- else
- {
- // Get OpenGL shader program info log length
- GLint gl_info_log_length;
- glGetProgramiv(gl_program_id, GL_INFO_LOG_LENGTH, &gl_info_log_length);
-
- if (gl_info_log_length > 0)
- {
- // Resize string to accommodate OpenGL shader program info log
- info_log.resize(gl_info_log_length);
-
- // Read OpenGL shader program info log into string
- glGetProgramInfoLog(gl_program_id, gl_info_log_length, &gl_info_log_length, info_log.data());
-
- // Remove redundant null terminator from string
- info_log.pop_back();
- }
- }
-
- return m_linked;
- }
-
- void shader_program::load_variables()
- {
- variable_map.clear();
-
- // Get maximum uniform name length
- GLint max_uniform_name_length = 0;
- glGetProgramiv(gl_program_id, GL_ACTIVE_UNIFORM_MAX_LENGTH, &max_uniform_name_length);
-
- // Allocate uniform name buffer
- std::string uniform_name(static_cast<std::size_t>(max_uniform_name_length), '\0');
-
- // Get number of active uniforms in the shader
- GLint active_uniform_count = 0;
- glGetProgramiv(gl_program_id, GL_ACTIVE_UNIFORMS, &active_uniform_count);
-
- // Init texture unit index
- GLint texture_index = 0;
-
- // For each active uniform
- for (GLint uniform_index = 0; uniform_index < active_uniform_count; ++uniform_index)
- {
- // Get uniform info
- GLsizei uniform_name_length;
- GLint uniform_size;
- GLenum uniform_type;
- glGetActiveUniform(gl_program_id, static_cast<GLuint>(uniform_index), static_cast<GLsizei>(max_uniform_name_length), &uniform_name_length, &uniform_size, &uniform_type, uniform_name.data());
-
- // Get uniform location
- const GLint uniform_location = glGetUniformLocation(gl_program_id, uniform_name.c_str());
- if (uniform_location == -1)
- {
- throw std::runtime_error("Unable to get shader uniform location");
- }
-
- // Get length of variable name by stripping array notation from uniform name
- std::size_t uniform_base_name_length = static_cast<std::size_t>(uniform_name_length);
- if (std::size_t i = std::string_view(uniform_name.c_str(), uniform_name_length).find_first_of("["); i != std::string::npos)
- {
- uniform_base_name_length = i;
- }
-
- // Hash variable name to get variable key
- const hash::fnv1a32_t variable_key = hash::fnv1a32<char>({uniform_name.c_str(), uniform_base_name_length});
-
- // Get size of variable
- const std::size_t variable_size = static_cast<std::size_t>(uniform_size);
-
- // Construct shader variable
- std::unique_ptr<const gl::shader_variable> variable;
- switch (uniform_type)
- {
- case GL_BOOL:
- variable = std::make_unique<const gl_shader_bool>(variable_size, uniform_location);
- break;
- case GL_BOOL_VEC2:
- variable = std::make_unique<const gl_shader_bvec2>(variable_size, uniform_location);
- break;
- case GL_BOOL_VEC3:
- variable = std::make_unique<const gl_shader_bvec3>(variable_size, uniform_location);
- break;
- case GL_BOOL_VEC4:
- variable = std::make_unique<const gl_shader_bvec4>(variable_size, uniform_location);
- break;
-
- case GL_INT:
- variable = std::make_unique<const gl_shader_int>(variable_size, uniform_location);
- break;
- case GL_INT_VEC2:
- variable = std::make_unique<const gl_shader_ivec2>(variable_size, uniform_location);
- break;
- case GL_INT_VEC3:
- variable = std::make_unique<const gl_shader_ivec3>(variable_size, uniform_location);
- break;
- case GL_INT_VEC4:
- variable = std::make_unique<const gl_shader_ivec4>(variable_size, uniform_location);
- break;
-
- case GL_UNSIGNED_INT:
- variable = std::make_unique<const gl_shader_uint>(variable_size, uniform_location);
- break;
- case GL_UNSIGNED_INT_VEC2:
- variable = std::make_unique<const gl_shader_uvec2>(variable_size, uniform_location);
- break;
- case GL_UNSIGNED_INT_VEC3:
- variable = std::make_unique<const gl_shader_uvec3>(variable_size, uniform_location);
- break;
- case GL_UNSIGNED_INT_VEC4:
- variable = std::make_unique<const gl_shader_uvec4>(variable_size, uniform_location);
- break;
-
- case GL_FLOAT:
- variable = std::make_unique<const gl_shader_float>(variable_size, uniform_location);
- break;
- case GL_FLOAT_VEC2:
- variable = std::make_unique<const gl_shader_fvec2>(variable_size, uniform_location);
- break;
- case GL_FLOAT_VEC3:
- variable = std::make_unique<const gl_shader_fvec3>(variable_size, uniform_location);
- break;
- case GL_FLOAT_VEC4:
- variable = std::make_unique<const gl_shader_fvec4>(variable_size, uniform_location);
- break;
-
- case GL_FLOAT_MAT2:
- variable = std::make_unique<const gl_shader_fmat2>(variable_size, uniform_location);
- break;
- case GL_FLOAT_MAT3:
- variable = std::make_unique<const gl_shader_fmat3>(variable_size, uniform_location);
- break;
- case GL_FLOAT_MAT4:
- variable = std::make_unique<const gl_shader_fmat4>(variable_size, uniform_location);
- break;
-
- case GL_SAMPLER_1D:
- case GL_SAMPLER_1D_SHADOW:
- variable = std::make_unique<const gl_shader_texture_1d>(variable_size, uniform_location, texture_index);
- texture_index += uniform_size;
- break;
-
- case GL_SAMPLER_2D:
- case GL_SAMPLER_2D_SHADOW:
- variable = std::make_unique<const gl_shader_texture_2d>(variable_size, uniform_location, texture_index);
- texture_index += uniform_size;
- break;
-
- case GL_SAMPLER_3D:
- variable = std::make_unique<const gl_shader_texture_3d>(variable_size, uniform_location, texture_index);
- texture_index += uniform_size;
- break;
-
- case GL_SAMPLER_CUBE:
- variable = std::make_unique<const gl_shader_texture_cube>(variable_size, uniform_location, texture_index);
- texture_index += uniform_size;
- break;
-
- default:
- throw std::runtime_error("Unsupported to shader uniform type");
- break;
- }
-
- // Map variable to variable key
- variable_map.emplace(variable_key, std::move(variable));
- }
- }
-
- } // namespace gl
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